Respirable dust measured downwind during rock dust application.

Science.gov (United States)

Harris, M L; Organiscak, J; Klima, S; Perera, I E

2017-05-01

The Pittsburgh Mining Research Division of the U.S. National Institute for Occupational Safety and Health (NIOSH) conducted underground evaluations in an attempt to quantify respirable rock dust generation when using untreated rock dust and rock dust treated with an anticaking additive. Using personal dust monitors, these evaluations measured respirable rock dust levels arising from a flinger-type application of rock dust on rib and roof surfaces. Rock dust with a majority of the respirable component removed was also applied in NIOSH's Bruceton Experimental Mine using a bantam duster. The respirable dust measurements obtained downwind from both of these tests are presented and discussed. This testing did not measure miners' exposure to respirable coal mine dust under acceptable mining practices, but indicates the need for effective continuous administrative controls to be exercised when rock dusting to minimize the measured amount of rock dust in the sampling device.

Rock.XML - Towards a library of rock physics models

Science.gov (United States)

Jensen, Erling Hugo; Hauge, Ragnar; Ulvmoen, Marit; Johansen, Tor Arne; Drottning, Åsmund

2016-08-01

Rock physics modelling provides tools for correlating physical properties of rocks and their constituents to the geophysical observations we measure on a larger scale. Many different theoretical and empirical models exist, to cover the range of different types of rocks. However, upon reviewing these, we see that they are all built around a few main concepts. Based on this observation, we propose a format for digitally storing the specifications for rock physics models which we have named Rock.XML. It does not only contain data about the various constituents, but also the theories and how they are used to combine these building blocks to make a representative model for a particular rock. The format is based on the Extensible Markup Language XML, making it flexible enough to handle complex models as well as scalable towards extending it with new theories and models. This technology has great advantages as far as documenting and exchanging models in an unambiguous way between people and between software. Rock.XML can become a platform for creating a library of rock physics models; making them more accessible to everyone.

Measurements of thermal properties of rocks

International Nuclear Information System (INIS)

Kumada, Toshiaki

2001-02-01

The report concerns the measurement of thermal conductivity and specific heat of supplied sedimental rock B and Funyu rock. The method of measurement of these properties was done with the method which was developed at 1997 and improved much in its accuracy by the present author et al. The porosity of sedimental rock B is 0.55, which is deduced from the density of rock (the porosity deduced from the difference between dry and water filled conditions is 0.42) and the shape and size of pores in rock are much different. Its thermal conductivity is 0.238 W/mK in dry and 1.152 W/mK in water filled conditions respectively, while the thermal conductivity of bentonite is 0.238 W/mK in dry and 1.152 W/mK in water saturated conditions. The difference of thermal conductivity between dry and water saturated conditions is little difference in sedimental rock B and bentonite at same porosity. The porosity of Funyu rock is 0.26 and the shape and size of pores in the rock are uniform. Its thermal conductivity is 0.914 W/mK in dry and 1.405 W/mK in water saturated conditions, while the thermal conductivity of bentonite is 0.606 W/mK in dry and 1.591 W/mK in water saturated conditions respectively. The correlation estimating thermal conductivity of rocks was derived based on Fricke correlation by presuming rocks as a suspension. (author)

Effects of confinement on rock mass modulus: A synthetic rock mass modelling (SRM study

Directory of Open Access Journals (Sweden)

I. Vazaios

2018-06-01

Full Text Available The main objective of this paper is to examine the influence of the applied confining stress on the rock mass modulus of moderately jointed rocks (well interlocked undisturbed rock mass with blocks formed by three or less intersecting joints. A synthetic rock mass modelling (SRM approach is employed to determine the mechanical properties of the rock mass. In this approach, the intact body of rock is represented by the discrete element method (DEM-Voronoi grains with the ability of simulating the initiation and propagation of microcracks within the intact part of the model. The geometry of the pre-existing joints is generated by employing discrete fracture network (DFN modelling based on field joint data collected from the Brockville Tunnel using LiDAR scanning. The geometrical characteristics of the simulated joints at a representative sample size are first validated against the field data, and then used to measure the rock quality designation (RQD, joint spacing, areal fracture intensity (P21, and block volumes. These geometrical quantities are used to quantitatively determine a representative range of the geological strength index (GSI. The results show that estimating the GSI using the RQD tends to make a closer estimate of the degree of blockiness that leads to GSI values corresponding to those obtained from direct visual observations of the rock mass conditions in the field. The use of joint spacing and block volume in order to quantify the GSI value range for the studied rock mass suggests a lower range compared to that evaluated in situ. Based on numerical modelling results and laboratory data of rock testing reported in the literature, a semi-empirical equation is proposed that relates the rock mass modulus to confinement as a function of the areal fracture intensity and joint stiffness. Keywords: Synthetic rock mass modelling (SRM, Discrete fracture network (DFN, Rock mass modulus, Geological strength index (GSI, Confinement

Laboratory measurements of rock thermal properties

DEFF Research Database (Denmark)

Bording, Thue Sylvester; Balling, N.; Nielsen, S.B.

The thermal properties of rocks are key elements in understanding and modelling the temperature field of the subsurface. Thermal conductivity and thermal diffusivity can be measured in the laboratory if rock samples can be provided. We have introduced improvements to the divided bar and needle...... probe methods to be able to measure both thermal conductivity and thermal diffusivity. The improvements we implement include, for both methods, a combination of fast numerical finite element forward modelling and a Markov Chain Monte Carlo inversion scheme for estimating rock thermal parameters...

Final report of experiments with rock blocks interacting hydraulically with smectitic pellet fills

Energy Technology Data Exchange (ETDEWEB)

Pusch, Roland [Sweco Infrastructure AB, Stockholm (Sweden); Ramqvist, Gunnar [El-Tekno AB, Figeholm (Sweden); Hedin, Mikael [AaF, Stockholm (Sweden)

2010-11-15

The report describes the outcome of the work within the the project 'SU5 08.20 Impact of water inflow in deposition tunnels'. Project decision SKBdoc id 1178871 Version 3.0. Two activity plans have been used for the field work: AP TD SU50820-09-014 and AP TD SU50820-09-031. A problem in backfilling of KBS-3V tunnels with smectitic pellets surrounding highly compacted clay blocks is that water entering the fill have a very substantial effect on the manner in which water moves into or through a pellet-filled region in the period immediately following pellet placement. Channels will be formed that lead much water to the sloping front of the fill in the course of placing it. This can soften the fill and turn it into mud where the water is discharged as demonstrated by large-scale tests. The nature of such channels was investigated in the present study that comprised experiments with rock blocks equipped with nozzles for injecting water into contacting pellet fills at constant flow rates. The purpose was to identify the basic mechanisms in the first phase of hydration of pellet fills and to find out if there is a threshold flow rate for 'piping'. The question if channelling at breakthrough takes place along the contact with the confinement, as indicated by preceding tests with steel and plexiglass instead of rock, was in focus. While the mechanisms of water entering a fill from separate local spots in contacting rock are well understood, prediction of the entire wetting process of a larger pellet volume requires consideration of the interactive function of several inflow spots, representing single or networks of rock fractures. Experiments with pellet fills on a larger scale with simultaneous inflow from a number of fractures would provide further information on the wetting process. Such a test is outlined in the report.

Crustal contamination versus an enriched mantle source for intracontinental mafic rocks: Insights from early Paleozoic mafic rocks of the South China Block

Science.gov (United States)

Xu, Wenjing; Xu, Xisheng; Zeng, Gang

2017-08-01

Several recent studies have documented that the silicic rocks (SiO2 > 65 wt.%) comprising Silicic Large Igneous Provinces are derived from partial melting of the crust facilitated by underplating/intraplating of "hidden" large igneous province-scale basaltic magmas. The early Paleozoic intracontinental magmatic rocks in the South China Block (SCB) are dominantly granitoids, which cover a combined area of 22,000 km2. In contrast, exposures of mafic rocks total only 45 km2. These mafic rocks have extremely heterogeneous isotopic signatures that range from depleted to enriched (whole rock initial 87Sr/86Sr = 0.7041-0.7102; εNd(t) = - 8.4 to + 1.8; weighted mean zircon εHf(t) = - 7.4 to + 5.2), show low Ce/Pb and Nb/U ratios (0.59-13.1 and 3.5-20.9, respectively), and variable Th/La ratios (0.11-0.51). The high-MgO mafic rocks (MgO > 10 wt.%) tend to have lower εNd(t) values (- 4) and Sm/Nd ratios (> 0.255). The differences in geochemistry between the high-MgO and low-MgO mafic rocks indicate greater modification of the compositions of high-MgO mafic magmas by crustal material. In addition, generally good negative correlations between εNd(t) and initial 87Sr/86Sr ratios, MgO, and K2O, along with the presence of inherited zircons in some plutons, indicate that the geochemical and isotopic compositions of the mafic rocks reflect significant crustal contamination, rather than an enriched mantle source. The results show that high-MgO mafic rocks with fertile isotopic compositions may be indicative of crustal contamination in addition to an enriched mantle source, and it is more likely that the lithospheric mantle beneath the SCB during the early Paleozoic was moderately depleted than enriched by ancient subduction processes.

Geochronological studies by Rb/Sr method in rocks of the Jundiai block and surroundings. [Ampario group

Energy Technology Data Exchange (ETDEWEB)

Wernick, E [Faculdade de Filosofia Ciencias e Letras de Rio Claro; Oliveira, M A.F. de; Kawashita, K; Cordani, U G [Sao Paulo Univ. (Brazil). Inst. de Geociencias; Delhal, J [Musee Royal de l' Afrique Centrale, Belgica

1976-01-01

Field and petrological data, as well as radiometric results performed in granulitic, gneissic, migmatitic, and granitic rocks from the 'Jundiai tectonic block' (States of Sao Paulo and Minas Gerais), show for that region the existence of two superposed orogeneses. To the older, of transamazonian age whole rock Rb-Sr isochron 2,010 m.y. Rb/sup 87//Sr/sup 86/ initial = 0.702), belongs the Amparo Group, composed of gneisses, migmatites, and granulites, with intercalation of quartzites, schists and calc-silicate rocks. To the younger, of brazilian age whole rock Rb-Sr isochron 690 m.y. (Sr/sup 87//Sr/sup 86/ initial = 0.702), are related the feldspathization and migmatization of the Amparo Group, as well as the intrusion of granitic bodies. Possibly, also the metasediments around Jacarei belong to the brazilian cycle. This pattern of geologic evolution is similar to that observed for the Serra dos Orgaos region (States of Rio de Janeiro and Minas Gerais).

Investigation of intact rock geomechanical parameters' effects on commercial blocks' productivity within stone reserves: A case history of some quarries in Isfahan, Iran

Science.gov (United States)

Yarahmadi, Reza; Bagherpour, Raheb; Tabaei, Morteza; Sousa, Luis M. O.

2017-10-01

One of the common methods to determine commercial blocks productivity (CBP) in reserves of dimension stone is through the study of the discontinuities' network. However, this determination remains a difficult task due to geographical heterogeneity and lack of access to all reserves' formations. This study presents a new method based on various geomechanical tests performed on intact rocks that assessed the CBP of a dimension stones' rock mass. Assuming that a dimension stone's rock mass comprised a large block of an intact rock, due to tectonics, the geomechanical properties of this block had direct effects on the discontinuities created within it. Therefore, the geomechanical properties of the intact rock may be related to the CBP of a stone reserve. Based on this factor, this study explored the relationship among some geomechanical properties, including failure angle, uniaxial compressive strength, and modulus of elasticity, and CBP by using data acquired from 21 dimension stone quarries consisting of travertine, marble, and onyx groups. According to the results obtained from the analysis of the Isfahan province's Iranian quarries, failure angle was not highly related to the reserve's CBP. In marble quarries, CBP may decrease, if the compressive strength of an intact rock exceeds 60 MPa. Among the studied parameters, the saturated-to-dry ratio's modulus of elasticity had the greatest relationship to the CBP. Generally, the presented diagrams displayed that the correlation between geomechanical properties and the CBP were an appropriate guide in determining the potential cost-effectiveness of a accessing a particular rock reserve during the early exploration phase.

Measurement of diffusive properties of intact rock

Energy Technology Data Exchange (ETDEWEB)

Harvey, K B

1996-12-01

In the Postclosure Assessment of a Reference System for the Disposal of Canada`s Nuclear Fuel Waste (Goodwin et al. 1994) the disposal vault is assumed to be surrounded by a zone of intact rock, referred to as the `exclusion zone.` A sensitivity analysis of the relative effectiveness of the several engineered and natural barriers that contribute to the safety of the reference disposal system has shown that this zone of intact rock is the most effective of these barriers to the movement of radionuclides through the reference system. Peer review of the geosphere model used in the case study for the EIS (Environmental Impact Statement) of the Canadian Nuclear Fuel Waste Management Program has identified the need to quantify the properties of the intact rock surrounding the disposal vault that would control the transport of radionuclides by diffusion. The Postclosure Assessment also identified the need for appropriate values of the free water diffusion coefficient (D{sub o}) for {sup 129}1 and {sup 14}C. The measurement of rock resistivity allows the calculation of the Formation Factor for a rock This review describes the Formation Factor, diffusivity, permeability, and porosity, and how these properties might be measured or inferred for insitu rock under the conditions that apply to the intact rock surrounding a potential disposal vault. The importance of measuring the intrinsic diffusion coefficient (D{sup i}) of diffusing species under solution salinities simulating those of groundwaters is emphasised, and a method of measurement is described that is independent of the diffusing medium, and which would be appropriate for measurements made in chemically complex media such as groundwaters. (author). 95 refs., 4 tabs., 39 figs.

Measurement of diffusive properties of intact rock

International Nuclear Information System (INIS)

Harvey, K.B.

1996-12-01

In the Postclosure Assessment of a Reference System for the Disposal of Canada's Nuclear Fuel Waste (Goodwin et al. 1994) the disposal vault is assumed to be surrounded by a zone of intact rock, referred to as the 'exclusion zone.' A sensitivity analysis of the relative effectiveness of the several engineered and natural barriers that contribute to the safety of the reference disposal system has shown that this zone of intact rock is the most effective of these barriers to the movement of radionuclides through the reference system. Peer review of the geosphere model used in the case study for the EIS (Environmental Impact Statement) of the Canadian Nuclear Fuel Waste Management Program has identified the need to quantify the properties of the intact rock surrounding the disposal vault that would control the transport of radionuclides by diffusion. The Postclosure Assessment also identified the need for appropriate values of the free water diffusion coefficient (D o ) for 129 1 and 14 C. The measurement of rock resistivity allows the calculation of the Formation Factor for a rock This review describes the Formation Factor, diffusivity, permeability, and porosity, and how these properties might be measured or inferred for insitu rock under the conditions that apply to the intact rock surrounding a potential disposal vault. The importance of measuring the intrinsic diffusion coefficient (D i ) of diffusing species under solution salinities simulating those of groundwaters is emphasised, and a method of measurement is described that is independent of the diffusing medium, and which would be appropriate for measurements made in chemically complex media such as groundwaters. (author). 95 refs., 4 tabs., 39 figs

ONKALO rock mechanics model (RMM). Version 2.3

Energy Technology Data Exchange (ETDEWEB)

Haekkinen, T.; Merjama, S.; Moenkkoenen, H. [WSP Finland, Helsinki (Finland)

2014-07-15

The Rock Mechanics Model of the ONKALO rock volume includes the most important rock mechanics features and parameters at the Olkiluoto site. The main objective of the model is to be a tool to predict rock properties, rock quality and hence provide an estimate for the rock stability of the potential repository at Olkiluoto. The model includes a database of rock mechanics raw data and a block model in which the rock mechanics parameters are estimated through block volumes based on spatial rock mechanics raw data. In this version 2.3, special emphasis was placed on refining the estimation of the block model. The model was divided into rock mechanics domains which were used as constraints during the block model estimation. During the modelling process, a display profile and toolbar were developed for the GEOVIA Surpac software to improve visualisation and access to the rock mechanics data for the Olkiluoto area. (orig.)

Rock stress measurements in the Grimsel Underground Rock Laboratory and their geological interpretation

International Nuclear Information System (INIS)

Braeuer, V.; Heusermann, S.; Pahl, A.

1989-01-01

Rock stress is being studied as part of the Swiss-German cooperation between the National Cooperative for the Storage of Radioactive Waste (NAGRA), the Research Centre for Environmental Sciences (GSF), and the Federal Institute for Geosciences and Natural Resources (BGR) in the Grimsel Rock Laboratory in Switzerland. Several methods and various equipment for measuring rock stress have been developed and tested in an approximately 200-m borehole drilled from a gallery at a depth of 450 m. The measurements were made continually during overcoring; the data were recorded and processed in a computer located downhole or outside the borehole. The results of the overcoring tests and of frac tests indicate a principle horizontal stress of 25-40 MPa, directed mainly NW-SE. Detailed geological mapping shows relationships between stress and rock structure. A zone of nearly unfractured rock exhibits an increase in stress and a change in stress direction. (orig.)

ALS insertion device block measurement and inspection

International Nuclear Information System (INIS)

Marks, S.; Carrieri, J.; Cook, C.; Hassenzahl, W.V.; Hoyer, E.; Plate, D.

1991-05-01

The performance specifications for ALS insertion devices require detailed knowledge and strict control of the Nd-Fe-B permanent magnet blocks incorporated in these devices. This paper describes the measurement and inspection apparatus and the procedures designed to qualify and characterize these blocks. A detailed description of a new, automated Helmholtz coil facility for measurement of the three components of magnetic moment is included. Physical block inspection and magnetic moment measurement procedures are described. Together they provide a basis for qualifying blocks and for specifying placement of blocks within an insertion devices' magnetic structures. 1 ref., 4 figs

The rock mechanical stability of the VLJ repository

International Nuclear Information System (INIS)

Kuula, H.; Johansson, E.

1991-03-01

The aim of the study was to determine the rock mechanical stability around the VLJ repository based on the rock mechanical monitoring and rock mechanical modeling. Rock mechanical calculations were made in order to calculate the rock mass displacements and to analyze the stability around the VLJ repository The calculations were performed with three diiferent methods: continuum finite difference code FLAC, distinct element code UDEC and three dimensional distinct element code 3DEC. The first analyses were based on preliminary site investigations. The final modeling was based on investigations and rock mechanical monitoring done during the excavation. Some sensitive analyses were also performed. The modelled rock mass behaviour and the measured behaviour are generally close to each other. Both results show that the VLJ repository is rock mechanically stable. The modelled displacements and stresses were small enough to cause no instability around the rock caverns. The measured values do not indicate any discontinuous deformations like block movements or joint slip. The measured displacements in the extensometers during excavation indicates that the rock mass is even stiffer than anticipated

An isotopic study of granitoids in the Litchfield Block, Northern Territory

International Nuclear Information System (INIS)

Page, R.W.; Bower, M.J.; Guy, D.B.

1984-01-01

The Litchfield Block contains a variety of granitoids, gneissic rocks, and migmatites that are intrusive into metasediments of probable Early Proterozoic age at the western margin of the Pine Creek Inlier. Isotopic data, which include U-Pb measurements on cogenetic zircon and xenotime and Rb-Sr total-rock measurements on the least metamorphosed granodiorites, show that these rocks crystallised from mantle-derived melts between 1840 Ma and 1850 Ma ago. Radiogenic Pb was lost from zircon in the early Palaeozoic (about 435 Ma), but xenotime remained a closed system until recent time. Many granitoids in the Litchfield Block have a gneissic fabric imposed during greenschist to amphibolite-grade regional metamorphism. This disturbance allowed partial isotopic re-equilibration of Rb-Sr total-rock systems, at about 1770 +- 16 Ma. As this igneous and metamorphic evolution is mirrored in other parts of the Pine Creek Inlier, the Halls Creek Inlier, and many other orogenic belts in northern Australia, its recognition and isotopic definition in the Litchfield Block further emphasise the magnitude and chronological integrity of this early Proterozoic tectonic event

Rock Testing Handbook (Test Standards 1993)

Science.gov (United States)

1993-01-01

relatively inert granular angle of shear resistance-see angle of internal friction. mineral material, such as sand, gravel, slag , crushed stone, angle of...by bleeding. another species, blocking -wood blocks placed between the excavated sur- batch-in growing, quantity of grout mixed at one time. face of a...layer of revetment . lowering electrodes into the hole and measuring any of the failure (in rocks)-cxceeding the maximum strength of the. various

Geologic and petrophysic analysis of a travertine block as hydrocarbon reservoir analogue

International Nuclear Information System (INIS)

Basso, Mateus; Kuroda, Michelle Chaves; Vidal, Alexandre Campane

2017-01-01

Microbialitic limestones are gaining space in petroleum geology due to the existence of many reservoirs composed of these lithologies in the pre-salt producing fields. Travertine, calcareous tufa and stromatolites figure among the rocks proposed as analogous for the microbialitic rocks. This work conduces the study of geological, petrophysical and geophysical parameters of a travertine block measuring 1,60 x 1,60 x 2,70 m, weighing 21,2 tons and available in the Centro de Estudo do Petroleo (CEPETRO) at the Universidade Estadual de Campinas. The Italian block, named T-block, corresponds to the representative elementary volume of its original formation and allows the study in an intermediate scale between the hand sample and the outcrop scale. Permeability tests and gamma ray spectrometry measurements were conducted and the porosity was calculated by image analysis. Models were generated from the obtained data and then associated with descriptive geology of the block. A reduction in permeability, porosity and concentration of elements potassium (K), uranium (U) and thorium (Th) was recorded, following a gradient towards the top of the T-block accompanying the reduction in the degree of development of the rock fabric. (author)

Rock stress measurements. Preparatory stage of the equipment development project

International Nuclear Information System (INIS)

Mononen, S.; Hakala, M.; Mikkola, P.

2002-01-01

In recent years the rock stress measurement methods used in Finland have been overcoring and hydraulic fracturing. There have been mainly two companies involved in these measurements, namely Suomen Malmi Oy (Smoy) and SwedPower AB. Smoy has done measurements for mines and for rock engineering projects, whereas SwedPower AB has mainly been involved in nuclear waste disposal investigations and conducted hydraulic fracturing measurements in deep boreholes. Smoy together with its partners started in February 2001 a project named JTM, which was a preliminary stage for a future project, which aims to develop a device most suitable for rock stress measurements in Finland. The partners in the project were HUT Rock Engineering, Posiva Oy, Saanio and Riekkola Oy, Gridpoint Finland Oy and Geopros Oy. Tekes, the National Technology Agency, provided almost half of the project funding. In the management group of the project were Pekka Mikkola (chairman) and Tero Laurila from Smoy, Pekka Saerkkae and Sakari Mononen (full-time researcher) from HUT, Aimo Hautojaervi (Posiva Oy), Erik Johansson (Saanio and Riekkola Oy), Matti Hakala (Gridpoint Finland Oy) and Heikki Haemaelaeinen (Geopros Oy). The aim of the JTM-project was to find out the needs for the development of a device most suitable for rock stress measurements in Finnish mines and rock engineering projects. During the project work was done to find out the range of rock stress measurement devices available, to find out the needs for measurements, and to get acquainted to the measurements done in Scandinavia. Also a report of the most suitable methods for Finnish rock conditions was done based on literature and on interviews of rock stress experts. Based on all the information collected during the project a clear picture of the needs for rock stress measurements in Finland could be formed and a preliminary plan of a future project was done. The aim of the suggested project is to build a device based on hydraulic fracturing

High-voltage pulsed generator for dynamic fragmentation of rocks.

Science.gov (United States)

Kovalchuk, B M; Kharlov, A V; Vizir, V A; Kumpyak, V V; Zorin, V B; Kiselev, V N

2010-10-01

A portable high-voltage (HV) pulsed generator has been designed for rock fragmentation experiments. The generator can be used also for other technological applications. The installation consists of low voltage block, HV block, coaxial transmission line, fragmentation chamber, and control system block. Low voltage block of the generator, consisting of a primary capacitor bank (300 μF) and a thyristor switch, stores pulse energy and transfers it to the HV block. The primary capacitor bank stores energy of 600 J at the maximum charging voltage of 2 kV. HV block includes HV pulsed step up transformer, HV capacitive storage, and two electrode gas switch. The following technical parameters of the generator were achieved: output voltage up to 300 kV, voltage rise time of ∼50 ns, current amplitude of ∼6 kA with the 40 Ω active load, and ∼20 kA in a rock fragmentation regime (with discharge in a rock-water mixture). Typical operation regime is a burst of 1000 pulses with a frequency of 10 Hz. The operation process can be controlled within a wide range of parameters. The entire installation (generator, transmission line, treatment chamber, and measuring probes) is designed like a continuous Faraday's cage (complete shielding) to exclude external electromagnetic perturbations.

High-voltage pulsed generator for dynamic fragmentation of rocks

Science.gov (United States)

Kovalchuk, B. M.; Kharlov, A. V.; Vizir, V. A.; Kumpyak, V. V.; Zorin, V. B.; Kiselev, V. N.

2010-10-01

A portable high-voltage (HV) pulsed generator has been designed for rock fragmentation experiments. The generator can be used also for other technological applications. The installation consists of low voltage block, HV block, coaxial transmission line, fragmentation chamber, and control system block. Low voltage block of the generator, consisting of a primary capacitor bank (300 μF) and a thyristor switch, stores pulse energy and transfers it to the HV block. The primary capacitor bank stores energy of 600 J at the maximum charging voltage of 2 kV. HV block includes HV pulsed step up transformer, HV capacitive storage, and two electrode gas switch. The following technical parameters of the generator were achieved: output voltage up to 300 kV, voltage rise time of ˜50 ns, current amplitude of ˜6 kA with the 40 Ω active load, and ˜20 kA in a rock fragmentation regime (with discharge in a rock-water mixture). Typical operation regime is a burst of 1000 pulses with a frequency of 10 Hz. The operation process can be controlled within a wide range of parameters. The entire installation (generator, transmission line, treatment chamber, and measuring probes) is designed like a continuous Faraday's cage (complete shielding) to exclude external electromagnetic perturbations.

Deformation and velocity measurements at elevated temperature in a fractured 0.5 M block of tuff

International Nuclear Information System (INIS)

Blair, S.C.; Berge, P.A.

1996-01-01

This paper presents preliminary results of laboratory tests conducted on small block samples of Topopah Spring tuff, in support of the Yucca Mountain Site Characterization Project. The overall objective of these tests is to investigate the thermal-mechanical, thermal-hydrological, and thermal-chemical response of the rock to conditions similar to the near-field environment (NFE) of a potential nuclear waste repository. We present preliminary results of deformation and elastic wave velocity measurements on a 0.5-m-scale block of Topopah Spring tuff tested in uniaxial compression to 8.5 MPa and at temperatures to 85 degree C. The Young's modulus was found to be about 7 to 31 GPa for vertical measurements parallel to the stress direction across parts of the block containing no fractures or a few fractures, and 0.5 to 0.9 GPA for measurements across individual fractures, at ambient temperature and 8.5 MPa maximum stress. During stress cycles between 5 and 8.5 MPa, the deformation modulus values for the matrix with fractures were near 15-20 GPa at ambient temperature but dropped to about 10 GPa at 85 degree C. Compressional wave velocities were found to be about 3.6 to 4.7 km/s at ambient temperature and stress. After the stress was cycled, velocities dropped to values as low as 2.6 km/s in the south end of the block where vertical cracks developed. Heating the block to about 85 degree C raised velocities to as much as 5.6 km/s in the upper third of the block

Coupled deformation and fluid-flow behavior of a natural fracture in the CSM in situ test block

International Nuclear Information System (INIS)

Gertsch, L.S.

1989-01-01

The primary goal was the evaluation of an in situ block test as a data source for modeling the coupled flow and mechanical behavior of natural rock fractures. The experiments were conducted with the Colorado School of Mines in situ test block, an 8 m 3 (280 ft 3 ) gneiss cube which has been the focus of several previous studies. A single continuous fracture within the block was surrounded with instruments to measure stresses, deformations, and gas conductivity. The setup was subjected to combinations of normal and shear stress by pressurizing the block sides differentially with hydraulic flatjacks. The induced fracture deformation, as measured by two separate sensor systems, did not correlate closely with the fracture conductivity changes or with each other. The test fracture is more complicated physically than two parallel rock faces. Many joints which were not detected by mapping intersect the test fracture and strongly influence its behavior. These invisible joints create sub-blocks which react complexly to changes in applied load. The flow tests reflected the aggregate sub-block dislocations in the flow path. The deformation readings, however, were the movements of discrete points sparsely located among the sub-blocks. High-confidence extrapolation of block test results to large volumes, such as required for nuclear waste repository design, is not feasible currently. Present instrumentation does not sample rock mass behavior in situ at the proper scales. More basically, however, a fundamental gap exists between the nature of jointed rock and our conception of it. Therefore, the near-field rock mass must be discounted as an easily controllable barrier to groundwater flow, until radically different approaches to rock mass testing and modeling are developed

Salt Block II: description and results

International Nuclear Information System (INIS)

Hohlfelder, J.J.

1980-06-01

A description of and results from the Salt Block II experiment, which involved the heating of and measurement of water transport within a large sample of rock salt, are presented. These results include the measurement of water released into a heated borehole in the sample as well as measured temperatures within the salt. Measured temperatures are compared with the results of a mathematical model of the experiment

Proposal of rock mass behavior classification based on convergence measurement in shaft sinking through sedimentary soft rocks

International Nuclear Information System (INIS)

Tsusaka, Kimikazu

2010-01-01

Japan Atomic Energy Agency has been excavating deep shafts through sedimentary soft rocks in Horonobe, Hokkaido. From the viewpoint of the observational construction, site engineers need a practical guide to evaluate the field measurements conducted with shaft sinking. The author analyzed the relationship among initial deformation rate, observed deformation, the ratio of the modulus of elasticity of rock mass to the initial stress, and the magnitude of inelastic behavior of rock based on convergence measurements and investigation of rock mass properties on shaft walls. As a result, the rock mass behavior classification for shaft sinking which consists of three classes was proposed. (author)

Xenon NMR measurements of permeability and tortuosity in reservoir rocks.

Science.gov (United States)

Wang, Ruopeng; Pavlin, Tina; Rosen, Matthew Scott; Mair, Ross William; Cory, David G; Walsworth, Ronald Lee

2005-02-01

In this work we present measurements of permeability, effective porosity and tortuosity on a variety of rock samples using NMR/MRI of thermal and laser-polarized gas. Permeability and effective porosity are measured simultaneously using MRI to monitor the inflow of laser-polarized xenon into the rock core. Tortuosity is determined from measurements of the time-dependent diffusion coefficient using thermal xenon in sealed samples. The initial results from a limited number of rocks indicate inverse correlations between tortuosity and both effective porosity and permeability. Further studies to widen the number of types of rocks studied may eventually aid in explaining the poorly understood connection between permeability and tortuosity of rock cores.

Rock mass deformation properties of closely jointed basalt

International Nuclear Information System (INIS)

Kim, K.; Cramer, M.L.

1982-12-01

The deformational behavior of the Columbia River basalt is being investigated as part of a comprehensive site characterization program intended to determine the feasibility of constructing a nuclear waste repository in basalt at Hanford, Washington. Direct field measurements were conducted in a 2-m cube of basalt to obtain truly representative rock mass deformation properties. Load was applied to the test block in three orthogonal directions through the use of flat jacks in two perpendicular planes and a cable anchor system in the third. This configuration allowed the block to be placed in a simulated triaxial stress state at stress levels up to 12.5 MPa. The deformation at the center of the test block was monitored through the use of an optical measurement system developed for this project. The results indicate that the vertically oriented columnar joints have a significant influence on the deformation behavior of the basalt. The modulus in the direction parallel to the column axis was approx. 30 GPa, while the modulus value perpendicular to the columns was approx. 20 GPa. Laboratory measurements of intact specimens taken from this area yielded a value of 80 GPa with no indication of anisotropy. Hysteresis was observed in all loading cycles, but was distinctly more pronounced perpendicular to the column axis, indicative of significant joint displacement in this direction. The results of this test represent the first true rock mass modulus data obtained in closely jointed rock on a large scale. These measurement methods have eliminated many of the ambiguities associated with borehole jacking and surface measurement techniques

Measurement of rock properties at elevated pressures and temperatures

International Nuclear Information System (INIS)

Pincus, H.J.; Hoskins, E.R.

1985-01-01

The papers in this volume were presented at an ASTM symposium held on 20 June 1983 in conjunction with the 24th Annual Rock Mechanics Symposium at Texas A and M University, College Station, TX. The purpose of these papers is to present recent developments in the measurement of rock properties at elevated pressures and temperatures, and to examine and interpret the data produced by such measurement. The need for measuring rock properties at elevated pressures and temperatures has become increasingly important in recent years. Location and design of nuclear waste repositories, development of geothermal energy sites, and design and construction of deep excavations for civil, military, and mining engineering require significantly improved capabilities for measuring rock properties under conditions substantially different from those prevailing in most laboratory and in situ work. The development of high-pressure, high-temperature capabilities is also significant for the analysis of tectonic processes

Practical example of the infrastructure protection against rock fall

Science.gov (United States)

Jirásko, Daniel; Vaníček, Ivan

2017-09-01

The protection of transport infrastructures against rock falls represents for the Czech Republic one of the sensitive questions. Rock falls, similarly as other typical geo-hazards for the Czech Republic, as landslides and floods, can have negative impact on safety and security of these infrastructures. One practical example how to reduce risk of rock fall is described in the paper. Great care is devoted to the visual inspection enabling to indicate places with high potential to failure. With the help of numerical modelling the range of rock fall negative impact is estimated. Protection measures are dealing with two basic ways. The first one utilize the results of numerical modelling for the optimal design of protection measures and the second one is focused on the monitoring of the rock blocks with high potential of instability together with wire-less transfer of measured results. After quick evaluation, e.g. comparison with warning values, some protection measures, mostly connected with closure of the potential sector, can be recommended.

Thermal aspects of radioactive waste disposal in hard rock

International Nuclear Information System (INIS)

Beale, H.; Bourke, P.J.; Hodgkinson, D.P.

1980-01-01

Buried heat emitting radioactive waste will appreciably raise the temperature of the surrounding rock over distances of several hundred metres for many centuries. This paper describes continuing research at Harwell aimed at understanding how this heating affects the design of hard rock depositories for the waste. It also considers how water-borne leakage of radionuclides from a depository to the surface might be increased by thermal convection currents through the rock mass and by thermally induced changes in its permeability and porosity. A conceptual design for a three-dimensional depository with an array of vitrified waste blocks placed in vertical boreholes is described. The maximum permissible power outputs of individual blocks and the minimum permissible separations between blocks to limit the local and bulk average rock temperatures will be determined by heat transfer through the rock and are reviewed. Interim results of a field heating experiment to study transient heat transfer through granite are discussed subsequently. Field experiments are now being started to measure the fracture permeability and porosity over large distances in virgin granite and to investigate their variation on heating and cooling the rock. Theoretical estimates of the temperatures, thermal stresses and thermal convection currents around a depository are next presented. The implications for water-borne leakage are that the induced stresses could change the fracture permeability and porosity, and thermal convection could cause substantial water movement vertically towards the surface. Finally some conclusions from the work are presented. (author)

Characterization of Unstable Rock Slopes Through Passive Seismic Measurements

Science.gov (United States)

Kleinbrod, U.; Burjanek, J.; Fäh, D.

2014-12-01

Catastrophic rock slope failures have high social impact, causing significant damage to infrastructure and many casualties throughout the world each year. Both detection and characterization of rock instabilities are therefore of key importance. An analysis of ambient vibrations of unstable rock slopes might be a new alternative to the already existing methods, e.g. geotechnical displacement measurements. Systematic measurements have been performed recently in Switzerland to study the seismic response of potential rockslides concerning a broad class of slope failure mechanisms and material conditions. Small aperture seismic arrays were deployed at sites of interest for a short period of time (several hours) in order to record ambient vibrations. Each measurement setup included a reference station, which was installed on a stable part close to the instability. Recorded ground motion is highly directional in the unstable parts of the rock slope, and significantly amplified with respect to stable areas. These effects are strongest at certain frequencies, which were identified as eigenfrequencies of the unstable rock mass. In most cases the directions of maximum amplification are perpendicular to open cracks and in good agreement with the deformation directions obtained by geodetic measurements. Such unique signatures might improve our understanding of slope structure and stability. Thus we link observed vibration characteristics with available results of detailed geological characterization. This is supported by numerical modeling of seismic wave propagation in fractured media with complex topography.For example, a potential relation between eigenfrequencies and unstable rock mass volume is investigated.

Measurement of soil moisture using gypsum blocks

DEFF Research Database (Denmark)

Friis Dela, B.

the building. Consequently, measuring the moisture of the surrounding soil is of great importance for detecting the source of moisture in a building. Up till now, information has been needed to carry out individual calibrations for the different types of gypsum blocks available on the market and to account......For the past 50 years, gypsum blocks have been used to determine soil moisture content. This report describes a method for calibrating gypsum blocks for soil moisture measurements. Moisture conditions inside a building are strongly influenced by the moisture conditions in the soil surrounding...

On the K-Ar ages of the rocks of two kinds existed in the Kamuikotan metamorphic rocks located in the Horokanai district, Hokkaido

International Nuclear Information System (INIS)

Imaizumi, Masayuki; Ueda, Yoshio.

1981-01-01

In the Fransiscan metamorphic rocks known as the typical high-pressure type metamorphic belts, existence of the blocks of high grade metamorphic rocks of older age in the widely distributed low grade ones of younger age is commonly noticed. This feature has been explained as a phenomenon that the blocks had been tectonically mixed with the surroundings - so-called tectonic blocks - based on the absolute age determination of the component minerals. The Kamuikotan tectonic belt is a melange zone in which occur various kinds of metamorphic rocks of high-pressure and low-pressure types. The high-pressure Kamuikotan metamorphic rocks can be classified into two kinds based upon the modes of occurrence and mineral paragenesis. One is the low grade metamorphic rocks of greenschist and glaucophane schist and the other, the high grade metamorphic rocks of epidote glaucophane schist and epidote amphibolite. The high grade metamorphic rocks always occur as isolated blocks in the low grade metamorphics and associated serpentinite. The report discusses the age of muscovites separated from the two types of high-pressure Kamuikotan metamorphic rocks in the Horokanai district, central Hokkaido. The muscovites separated from the low grade metamorphics of the district give the age of 72 - 116 m.y., while those separated from the high grade metamorphics give the age of 132 - 145 m.y. These ages seem to agree with the idea that the blocks of high grade metamorphics (epidote glaucophane schist and epidote amphibolite) would be the ''tectonic blocks'' - namely the fragments tectonically mixed into the low grade metamorphics of younger age. (author)

Small-scale bentonite injection test on rock

International Nuclear Information System (INIS)

Pusch, R.

1978-03-01

When radiactive waste is disposed a sealing of the rock is very valuable since it reduces the rate of water percolation and diffusion. In an earlier report injection of bentonite gels by means of over-pressure and subsequent electrophoresis has been suggested. The present report describes a rock test series where bentonite injection was applied. For the test an approximately cubical block of about 1 m 3 was selected. The rock type was diorite with a fairly high frequency of quartz denses. The block was kept in a basin during the test in order to maintain the water saturation. Holes were bored in the block. A bentonite slurry with 1000 percent water content was injected. It was shown that the bentonite had a sealing effect but the depth of extrusion into rock joints was not large because of gelation. Electro-Kinetic injection of montmorillonite was found to be a more promising technique for rock lightening

Analysis of rock stress and rock stress measurements with application to Aespoe HRL

International Nuclear Information System (INIS)

Lundholm, Beatrice

2000-11-01

The process of choosing a site for a nuclear waste repository means that many aspects have to be taken into consideration. One of these is that the repository has to be mechanically stable for a long time. The mechanical stability of the rock is very difficult to determine. One of several factors, which determine the mechanical stability, is the virgin state of stress. The thesis project consists of two parts. In the first part the state of stress at Aespoe Hard Rock Laboratory had to be defined. This was done based on earlier rock stress measurements conducted during the years 1988 to 1997. Two different measurement techniques have been used, hydraulic fracturing and overcoring. During the overcoring two types of cells have been used, CSIRO HI-cell and a cell developed by the Swedish State Power Board (SSPB). In the second part of the project, investigation of the correlation between the stress and geological structures are made using numerical modelling tools such as FLAC, UDEC and 3DEC. The rock stress measurements using the hydraulic fracturing gave orientations of the horizontal stress that coincide with earlier hydraulic fracturing measurements conducted in Scandinavia. The magnitudes of rock stresses are slightly lower than the earlier reported stress magnitudes for the Scandinavian part of the earth crust. The rock stresses obtained from the overcoring resulted in higher stresses than what was predicted by the hydraulic fracturing measurements. However, the orientation of the maximum horizontal stresses coincides well between the two techniques. The orientation is also more or less constant with respect to increasing depth. The state of stress at Aespoe is defined by using the results from the hydraulic fracturing and the measurements conducted by SSPB-cell. The measurements from the SSPB-cell are used since these have a Poisson's ratio that corresponds well with the uniaxial tests of rock samples and since the measurements have been done at a distance from

Diffusivity and electrical resistivity measurements in rock matrix around fractures

International Nuclear Information System (INIS)

Kumpulainen, H.; Uusheimo, K.

1989-12-01

Microfracturing of rock matrix around permeable fractures was studied experimentally from drill core samples around major fractures. The methods used were diffusion measurements using a 36 Cl-tracer and electrical resistivity measurements. Rock samples were from the Romuvaara investigation site, the granite specimen around a partially filled carbonate fracture (KR4/333 m) and gneiss specimen around a slickenside fracture (KR1/645 m). A consistent difference of one to two orders of magnitude in the levels of the methods with regard to the effective diffusion coefficients for Cl - -ion was found, the electrical resistivity measurement giving higher values. On the basis of the diffusion measurements the diffusion porosities could be calculated but these remained one to two orders of magnitude lower than that expected for granitic rocks using the water saturation method. A possible reason for these differences could have been the low, in some cases 0.004 M NaC1-concentration in the diffusion experiments vs. the 1 M NaCl-concentration used in the electrical resistivity measurements. Due to the small number of specimens and cross sectional areas of only 2 cm 2 , rock inhomogeneity effects were significant making the interpretation of the results somewhat troublesome. Porosities on fracture surfaces seemed to be higher than in the deeper, more intact rock matrix

Large-Scale True Triaxial Apparatus for Geophysical Studies in Fractured Rock

KAUST Repository

Garcia, A. V.

2018-05-12

The study of fractured rock masses in the laboratory remains challenging because of the large specimen sizes and bulky loading systems that are required. This article presents the design, structural analysis, and operation of a compact and self-reacting true triaxial device for fractured rock. The frame subjects a 50 cm by 50 cm by 50 cm fractured rock specimen to a maximum stress of 3 MPa along three independent axes. Concurrent measurements include long-wavelength P-wave propagation, passive acoustic emission monitoring, deformations, and thermal measurements. The device can accommodate diverse research, from rock mass properties and geophysical fractured rock characterizations, to coupled hydro-chemo-thermo-mechanical processes, drilling, and grouting. Preliminary wave propagation data gathered under isotropic and anisotropic stress conditions for an assembly of 4,000 rock blocks demonstrate the system’s versatility and provide unprecedented information related to long-wavelength propagation in fractured rock under various stress anisotropies.

Large-Scale True Triaxial Apparatus for Geophysical Studies in Fractured Rock

KAUST Repository

Garcia, A. V.; Rached, R. M.; Santamarina, Carlos

2018-01-01

The study of fractured rock masses in the laboratory remains challenging because of the large specimen sizes and bulky loading systems that are required. This article presents the design, structural analysis, and operation of a compact and self-reacting true triaxial device for fractured rock. The frame subjects a 50 cm by 50 cm by 50 cm fractured rock specimen to a maximum stress of 3 MPa along three independent axes. Concurrent measurements include long-wavelength P-wave propagation, passive acoustic emission monitoring, deformations, and thermal measurements. The device can accommodate diverse research, from rock mass properties and geophysical fractured rock characterizations, to coupled hydro-chemo-thermo-mechanical processes, drilling, and grouting. Preliminary wave propagation data gathered under isotropic and anisotropic stress conditions for an assembly of 4,000 rock blocks demonstrate the system’s versatility and provide unprecedented information related to long-wavelength propagation in fractured rock under various stress anisotropies.

Acoustic emission measurements in petroleum-related rock mechanics

Energy Technology Data Exchange (ETDEWEB)

Unander, Tor Erling

2002-07-01

Acoustic emission activity in rock has usually been studied in crystalline rock, which reflects that rock mechanics has also mostly been occupied with such rocks in relations to seismology, mining and tunneling. On the other hand, petroleum-related rock mechanics focuses on the behaviour of sedimentary rock. Thus, this thesis presents a general study of acoustic emission activity in sedimentary rock, primarily in sandstone. Chalk, limestone and shale have also been tested, but to much less degree because the AE activity in these materials is low. To simplify the study, pore fluids have not been used. The advent of the personal computer and computerized measuring equipment have made possible new methods both for measuring and analysing acoustic emissions. Consequently, a majority of this work is devoted to the development and implementation of new analysis techniques. A broad range of topics are treated: (1) Quantification of the AE activity level, assuming that the event rate best represents the activity. An algorithm for estimating the event rate and a methodology for objectively describing special changes in the activity e.g., onset determination, are presented. (2) Analysis of AE waveform data. A new method for determining the source energy of an AE event is presented, and it is shown how seismic source theory can be used to analyze even intermediate quality data. Based on these techniques, it is shown that a major part of the measured AE activity originates from a region close to the sensor, not necessarily representing the entire sample. (3) An improved procedure for estimating source locations is presented. The main benefit is a procedure that better handles arrival time data with large errors. Statistical simulations are used to quantify the uncertainties in the locations. The analysis techniques are developed with the application to sedimentary rock in mind, and in two articles, the techniques are used in the study of such materials. The work in the first

A ball diameter-measuring instrument in a gauge block interferometer

NARCIS (Netherlands)

Kotte, G.J.W.L.; Haitjema, H.; Decker, J.E.; Brown, N.

1998-01-01

An instrument for the measurement of ball diameters in the 0.5-20 mm range in a gauge block interferometer is realized. The measurement principle is that the ball is positioned between an optical flat and a calibrated gauge block. The total length is measured in a gauge block relative to the optical

Anisotropy effect on strengths of metamorphic rocks

Directory of Open Access Journals (Sweden)

Ahmet Özbek

2018-02-01

Full Text Available This paper aims to study the effect of anisotropy on strengths of several metamorphic rocks of southern (Çine submassif of Menderes metamorphic massif in southwest Turkey. Four different metamorphic rocks including foliated phyllite, schist, gneiss and marble (calcschist were selected and examined. Discontinuity surveys were made along lines for each rock and evaluated with DIPS program. L-type Schmidt hammer was applied in the directions parallel and perpendicular to foliation during the field study. Several hand samples and rock blocks were collected during the field study for measurements of dry and saturated densities, dry and saturated unit weights and porosity, and for petrographic analysis and strength determination in laboratory. L- and N-type Schmidt hammers were applied in the directions perpendicular (anisotropy angle of 0° and parallel (anisotropy angle of 90° to the foliation on selected blocks of phyllite, schist, gneiss and marble (calcschist. The phyllite and schist have higher porosity and lower density values than the other rocks. However, coarse crystalline gneiss and marble (calcschist have higher rebound values and strengths, and they are classified as strong–very strong rocks. Generally, the rebound values in the direction perpendicular to the foliation are slightly higher than that in the direction parallel to foliation. Rebound values of N-type Schmidt hammer are higher than the L-type values except for phyllite. Sometimes, the rebound values of laboratory and field applications gave different results. This may result from variable local conditions such as minerals differentiation, discontinuities, water content, weathering degree and thickness of foliated structure.

Sr-Nd-Pb isotope systematics of the Permian volcanic rocks in the northern margin of the Alxa Block (the Shalazhashan Belt) and comparisons with the nearby regions: Implications for a Permian rift setting?

Science.gov (United States)

Shi, Guanzhong; Wang, Hua; Liu, Entao; Huang, Chuanyan; Zhao, Jianxin; Song, Guangzeng; Liang, Chao

2018-04-01

The petrogenesis of the Permian magmatic rocks in the Shalazhashan Belt is helpful for us to understand the tectonic evolution of the Central Asian Orogenic Belt (CAOB) in the northern margin of the Alxa Block. The Permian volcanic rocks in the Shalazhashan Belt include basalts, trachyandesites and trachydacites. Our study shows that two basalt samples have negative εNd(t) values (-5.4 to -1.5) and higher radiogenic Pb values, which are relevant to the ancient subcontinental lithospheric mantle. One basalt sample has positive εNd(t) value (+10) representing mafic juvenile crust and is derived from depleted asthenosphere. The trachyandesites are dated at 284 ± 3 Ma with εNd(t) = +2.7 to +8.0; ISr = 0.7052 to 0.7057, and they are generated by different degrees of mixing between mafic magmas and crustal melts. The trachydacites have high εNd(t) values and slightly higher ISr contents, suggesting the derivation from juvenile sources with crustal contamination. The isotopic comparisons of the Permian magmatic rocks of the Shalazhashan Belt, the Nuru-Langshan Belt (representing the northern margin of the Alxa Block), the Solonker Belt (Mandula area) and the northern margin of the North China Craton (Bayan Obo area) indicate that the radiogenic isotopic compositions have an increasingly evolved trend from the south (the northern margins of the Alxa Block and the North China Craton) to the north (the Shalazhashan Belt and the Solonker Belt). Three end-member components are involved to generate the Permian magmatic rocks: the ancient subcontinental lithospheric mantle, the mafic juvenile crust or newly underplated mafic rocks that were originated from depleted asthenosphere, and the ancient crust. The rocks correlative with the mafic juvenile crust or newly underplated mafic rocks are predominantly distributed along the Shalazhashan Belt and the Solonker Belt, and the rocks derived from ancient, enriched subcontinental lithospheric mantle are mainly distributed along

Cataclastic effects in rock salt laboratory and in situ measurements

International Nuclear Information System (INIS)

Gramberg, J.; Roest, J.P.A.

1984-01-01

The aim of the research is the determination of eventual cataclastic effects in environmental rock salt of a heated part of a vertical deep test bore hole, a model for HLW disposal. Known cataclastic systems from hard rock mining and rock salt mines will form the starting point for the explanation of convergence of underground cavity walls. In rock salt, however, different elements seem to prevail: crystal plasticity and micro-cataclasis. The environmental measurements at the deep bore hole have to be carried out from a distance. To this end the acoustic micro-seismic method will be a suitable one. The appropriate equipment for micro-seismic cross hole measurement is designed, constructed and tested in the laboratory as well as underground. Acoustic velocity data form a crucial point. A micro-seismic acoustic P-wave model, adapted to the process of structural changes, is developed. P-wave velocity measurements in rock salt cubes in the laboratory are described. An underground cross hole measurement in the wall of a gallery with semi-circular section is treated and analysed. A conclusion was that, in this case, no macro-cataclasis (systematic large fractures) will be involved in the process of gallery convergence, but that the mechanism proved to be a combination of crystal plasticity and micro-cataclasis. The same mechanism might be expected to be present in the environmental rock salt of the HLW-disposal deep bore hole. As a result this environmental rock salt might be expected to be impermeable. A plan for the application of the developed equipment during the heating test on the ECN-deep-bore-hole is shown. A theory on ''disking'' or ''rim cracks'' is presented in an annex

Improved characterization, monitoring and instability assessment of high rock faces by integrating TLS and GB-InSAR

Science.gov (United States)

Bianchetti, Matteo; Agliardi, Federico; Villa, Alberto; Battista Crosta, Giovanni; Rivolta, Carlo

2015-04-01

Rockfall risk analysis require quantifying rockfall onset susceptibility and magnitude scenarios at source areas, and the expected rockfall trajectories and related dynamic quantities. Analysis efforts usually focus on the rockfall runout component, whereas rock mass characterization and block size distribution quantification, monitoring and analysis of unstable rock volumes are usually performed using simplified approaches, due to technological and site-specific issues. Nevertheless, proper quantification of rock slope stability and rockfall magnitude scenarios is key when dealing with high rock walls, where widespread rockfall sources and high variability of release mechanisms and block volumes can result in excessive modelling uncertainties and poorly constrained mitigation measures. We explored the potential of integrating field, remote sensing, structural analysis and stability modelling techniques to improve hazard assessment at the Gallivaggio sanctuary site, a XVI century heritage located along the State Road 36 in the Spluga Valley (Italian Central Alps). The site is impended by a subvertical cliff up to 600 m high, made of granitic orthogneiss of the Truzzo granitic complex (Tambo Nappe, upper Pennidic domain). The rock mass is cut by NNW and NW-trending slope-scale structural lineaments and by 5-6 fracture sets with variable spatial distribution, spacing and persistence, which bound blocks up to tens of cubic meters and control the 3D slope morphology. The area is characterised by widespread rock slope instability from rockfalls to massive failures. Although a 180 m long embankment was built to protect the site from rockfalls, concerns remain about potential large unstable rock volumes or flyrocks projected by the widely observed impact fragmentation of stiff rock blocks. Thus, the authority in charge started a series of periodical GB-InSAR monitoring surveys using LiSALabTM technology (12 surveys in 2011-2014), which outlined the occurrence of unstable

Rock stress measurements using the LUT-Gauge overcoring method

International Nuclear Information System (INIS)

Leijon, B.

1988-04-01

With overcoring techniques, rock stresses are determined indirectly from measurements of the dimensional changes of a borehole, occurring when the rock volume surrounding the hole is isolated from the stresses in the host rock. This thesis describes the development and application of an overcoring technique. The key-component of the instrumentation that has been developed is a triaxial borehole strain cell, referred to as the LUT-Gauge. Laboratory tests were conducted to evaluate the performance of the instrumentation. Special emphasis was given to determining temperature sensitivity of the measuring system since this was identified as a potential source of measurement error. Results indicated good instrument reliability and that the measurement error due to temperature variations typically experienced under field conditions is ± 1 MPa or less. The technique was also evaluated by a series of field tests. Comparison of the results obtained by the different methods showed satisfactory agreement. Analysis of the comprehensive field data collected showed that the confidence that can be attached to an overcoring test is largely governed by the mechanical characteristics of the overcored specimen. Expressed as the standard deviation of the mean stress magnitude, the scatter obtained from repeated testing within a borehole section of about 10 m in length, is found to be ± 4 MPa or less. Rock engineering investigations typically refer to a scale of hundreds of metres or more. This study has demonstrated the existence of significant variations of the stress field on this scale. These variations thus impose difficulties in the application of stress data to the analysis of problems in rock engineering, since the pointwise results obtained from stress measurements cannot be extrapolated with good confidence. (30 refs.) (author)

Rock mechanics site descriptive model-theoretical approach. Preliminary site description Forsmark area - version 1.2

Energy Technology Data Exchange (ETDEWEB)

Fredriksson, Anders; Olofsson, Isabelle [Golder Associates AB, Uppsala (Sweden)

2005-12-15

The present report summarises the theoretical approach to estimate the mechanical properties of the rock mass in relation to the Preliminary Site Descriptive Modelling, version 1.2 Forsmark. The theoretical approach is based on a discrete fracture network (DFN) description of the fracture system in the rock mass and on the results of mechanical testing of intact rock and on rock fractures. To estimate the mechanical properties of the rock mass a load test on a rock block with fractures is simulated with the numerical code 3DEC. The location and size of the fractures are given by DFN-realisations. The rock block was loaded in plain strain condition. From the calculated relationship between stresses and deformations the mechanical properties of the rock mass were determined. The influence of the geometrical properties of the fracture system on the mechanical properties of the rock mass was analysed by loading 20 blocks based on different DFN-realisations. The material properties of the intact rock and the fractures were kept constant. The properties are set equal to the mean value of each measured material property. The influence of the variation of the properties of the intact rock and variation of the mechanical properties of the fractures are estimated by analysing numerical load tests on one specific block (one DFN-realisation) with combinations of properties for intact rock and fractures. Each parameter varies from its lowest values to its highest values while the rest of the parameters are held constant, equal to the mean value. The resulting distribution was expressed as a variation around the value determined with mean values on all parameters. To estimate the resulting distribution of the mechanical properties of the rock mass a Monte-Carlo simulation was performed by generating values from the two distributions independent of each other. The two values were added and the statistical properties of the resulting distribution were determined.

Rock mechanics site descriptive model-theoretical approach. Preliminary site description Forsmark area - version 1.2

International Nuclear Information System (INIS)

Fredriksson, Anders; Olofsson, Isabelle

2005-12-01

The present report summarises the theoretical approach to estimate the mechanical properties of the rock mass in relation to the Preliminary Site Descriptive Modelling, version 1.2 Forsmark. The theoretical approach is based on a discrete fracture network (DFN) description of the fracture system in the rock mass and on the results of mechanical testing of intact rock and on rock fractures. To estimate the mechanical properties of the rock mass a load test on a rock block with fractures is simulated with the numerical code 3DEC. The location and size of the fractures are given by DFN-realisations. The rock block was loaded in plain strain condition. From the calculated relationship between stresses and deformations the mechanical properties of the rock mass were determined. The influence of the geometrical properties of the fracture system on the mechanical properties of the rock mass was analysed by loading 20 blocks based on different DFN-realisations. The material properties of the intact rock and the fractures were kept constant. The properties are set equal to the mean value of each measured material property. The influence of the variation of the properties of the intact rock and variation of the mechanical properties of the fractures are estimated by analysing numerical load tests on one specific block (one DFN-realisation) with combinations of properties for intact rock and fractures. Each parameter varies from its lowest values to its highest values while the rest of the parameters are held constant, equal to the mean value. The resulting distribution was expressed as a variation around the value determined with mean values on all parameters. To estimate the resulting distribution of the mechanical properties of the rock mass a Monte-Carlo simulation was performed by generating values from the two distributions independent of each other. The two values were added and the statistical properties of the resulting distribution were determined

Attempt of groundwater dating using the drilled rock core. 1. Development of the rock sampling method for measurement of noble gases dissolved in interstitial water in rock

International Nuclear Information System (INIS)

Mahara, Yasunori

2002-01-01

Groundwater dating in low permeable rock is very difficult and impracticable, because we take a very long time to collect groundwater sample in a borehole and have to invest much fund in production of the in-situ groundwater sampler and in operation of it. If we can directly measure noble gases dissolved in interstitial groundwater in rock core, we have a big merit to estimate groundwater resident time easy. In this study, we designed and produced a high vacuum container to let dissolved noble gases diffuse until reaching in equilibrium, and we made a handling manual of the rock core into the container and a procedure to vacuum out air from the sealed container. We compared data sets of noble gas concentration obtained from rock cores and groundwater sample collected from boreholes in-situ. The measured rocks are pumice-tuff rock, mud rock and hornfels, which have their permeabilities of 10 -6 cm/s, 10 -9 cm/s and 10 -11 cm/s, respectively. Consequently, we evaluated the rock core method is better than the in-situ groundwater sampling method for low permeable rock. (author)

A heated large block test for high level nuclear waste management

International Nuclear Information System (INIS)

Lin, W.; Wilder, D.G.; Blink, J.A.; Blair, S.C.; Buscheck, T.A.; Glassley, W.E.; Lee, K.; Owens, M.W.; Roberts, J.J.

1995-01-01

The radioactive decay heat from high-level nuclear waste may, depending on the thermal load, create coupled thermal-mechanical-hydrological-chemical (TMHC) processes in the host rock of a repository. A heated large block test (LBT) is designed to understand some of the TNMC processes. A block of Topopah Spring tuff of about 3 x 3 x 4.5 m was isolated at Fran Ridge, Nevada Test Site. Small blocks of the rock adjacent to the large block were collected for laboratory testing of some individual thermal-mechanical, thermal-hydrological, and thermal-chemical processes. The large block will be heated by heaters within so that a dryout zone and a condensate zone will exist simultaneously. Guard heaters on the block sides will be used to minimize horizontal heat losses. A constant load of about 4 MPa will be applied to the top and sides of the large block. The sides will be sealed with moisture and thermal barriers. Temperature, moisture content, pore pressure, chemical composition, stress, displacement, electrical resistivity, acoustic emissions, and acoustic velocities will be measured throughout the block during the heating and cool-down phases. The results from the experiments on small blocks and the tests on the large block will provide a better understanding of some concepts of the coupled TMHC processes. The progress of the project is presented in this paper

Convergence measurements in a 300 m deep borehole in rock salt

International Nuclear Information System (INIS)

Heijdra, J.J.; Prij, J.

1992-05-01

An evaluation is presented of convergence measurements in a 300 m deep borehole in rock salt. The measured convergence is compared to the normalized convergence based on an analytical solution. Measurements endorse the assumptions on which the analytical solution has been based. With the aid of this analytical solution the ambient rock pressure at the locations of the measurements is determined. The derived pressures and the corresponding depth below the 750 m level are 20.3 MPa at -300 m, 15.4 MPa at -200 m and 13.3 MPa at -100 m. The measurements, normalized in order to account for the influence of the diameter and for the difference in depth, show good correspondence with former measurements on selected cavities in rock salt. (author). 6 refs.; 17 figs.; 3 tabs

Investigations of some rock stress measuring techniques and the stress field in Norway

Energy Technology Data Exchange (ETDEWEB)

Hanssen, Tor Harald

1998-12-31

Rock stresses are important to the safe construction and operation of all man-made structures in rock, whether In mining, civil or petroleum engineering. The crucial issue is their relative magnitude and orientation. This thesis develops equipment and methods for further rock stress assessment and reevaluates existing overcoring rock stress measurements, and relates this information to the present geological setting. Both laboratory work and field work are involved. In the field, rock stresses are measured by the overcoring and the hydraulic fracturing technique. An observation technique for assessing likely high stresses is developed. The field data refer to several hydropower projects and to some offshore hydrocarbon fields. The principal sections are: (1) Tectonic setting in the western Fennoscandia, (2) Triaxial rock stress measurements by overcoring using the NTH cell (a strain gauge cell developed at the Norwegian technical university in Trondheim and based on the CSIR cell of the South African Council for Scientific and Industrial Research), (3) Laboratory testing of the NTH cell, (4) Quality ranking of stresses measured by the NTH cell, (4) Recalculated rock stresses and implications to the regional stress field, (5) Hydraulic fracturing stress measurements. 113 refs., 98 figs., 62 tabs.

Investigations of some rock stress measuring techniques and the stress field in Norway

Energy Technology Data Exchange (ETDEWEB)

Hanssen, Tor Harald

1997-12-31

Rock stresses are important to the safe construction and operation of all man-made structures in rock, whether In mining, civil or petroleum engineering. The crucial issue is their relative magnitude and orientation. This thesis develops equipment and methods for further rock stress assessment and reevaluates existing overcoring rock stress measurements, and relates this information to the present geological setting. Both laboratory work and field work are involved. In the field, rock stresses are measured by the overcoring and the hydraulic fracturing technique. An observation technique for assessing likely high stresses is developed. The field data refer to several hydropower projects and to some offshore hydrocarbon fields. The principal sections are: (1) Tectonic setting in the western Fennoscandia, (2) Triaxial rock stress measurements by overcoring using the NTH cell (a strain gauge cell developed at the Norwegian technical university in Trondheim and based on the CSIR cell of the South African Council for Scientific and Industrial Research), (3) Laboratory testing of the NTH cell, (4) Quality ranking of stresses measured by the NTH cell, (4) Recalculated rock stresses and implications to the regional stress field, (5) Hydraulic fracturing stress measurements. 113 refs., 98 figs., 62 tabs.

Final Report: Geothermal dual acoustic tool for measurement of rock stress

Energy Technology Data Exchange (ETDEWEB)

Normann, Randy A. [Perma Works LLC, Pattonville, TX (United States)

2014-12-01

This paper outlines the technology need for a rock formation stress measurement in future EGS wells. This paper reports on the results of work undertaken under a Phase I, DOE/SBIR on the feasibility to build an acoustic well logging tool for measuring rock formation stress.

Final Report. Geothermal Dual Acoustic Tool for Measurement of Rock Stress

Energy Technology Data Exchange (ETDEWEB)

Normann, Randy A [Perma Works LLC, Pattonville, TX (United States)

2014-12-01

This paper outlines the technology need for a rock formation stress measurement in future EGS wells. This paper reports on the results of work undertaken under a Phase I, DOE/SBIR on the feasibility to build an acoustic well logging tool for measuring rock formation stress.

Comparison of laboratory, in situ, and rock mass measurements of the hydraulic conductivity of metamorphic rock at the Savannah River Plant near Aiken, South Carolina

International Nuclear Information System (INIS)

Marine, I.W.

1980-01-01

In situ testing of exploratory wells in metamorphic rock indicates that two types of fracturing occur in the rock mass. Rock containing small openings that permit only extremely slow movement of water is termed virtually impermeable rock. Rock containing openings of sufficient size to permit transmission of water at a significantly faster rate is termed hydraulically transmissive rock. Laboratory methods are unsuitable for measuring hydraulic conductivity in hydraulically transmissive rock; however, for the virtually impermeable rock, values comparable to the in situ tests are obtained. The hydraulic conductivity of the rock mass over a large region is calculated by using the hydraulic gradient, porosity, and regional velocity. This velocity is determined by dividing the inferred travel distance by the age of water which is determined by the helium content of the water. This rock mass hydraulic conductivity value is between the values measured for the two types of fractures, but is closer to the measured value for the virtually impermeable rock. This relationship is attributed to the control of the regional flow rate by the virtually impermeable rock where the discrete fractures do not form a continuous open connection through the entire rock mass. Thus, laboratory methods of measuring permeability in metamorphic rock are of value if they are properly applied

In-situ load-deformation characterization of the CSM/OCRD jointed test block

International Nuclear Information System (INIS)

Richardson, A.M.; Hustrulid, W.; Brown, S.; Ubbes, W.

1985-01-01

An extensive ambient-temperature test series has recently been completed on a block of Precambrian Gneiss at the Colorado School of Mines (CSM) Experimental Mine in Idaho Springs, Colorado. Block tests came into existence out of a desire to test a relatively large volume of rock and thereby minimize the scaling problems encountered when laboratory test results are used to obtain modeling parameters for full-size structures. A typical block test involves isolation of a large, approximately two-meter cube of rock by cutting slots on four sides and inserting flatjacks for loading. Much interest has recently centered around block tests as a promising method for in-situ characterization of rock-masses for licensing future commercial nuclear-waste repositories in crystalline rock. To date only a few block tests have been conducted

Engineering and Design: Characterization and Measurement of Discontinuities in Rock Slopes

National Research Council Canada - National Science Library

1983-01-01

This ETL provides guidance for characterizing and measuring rock discontinuities on natural slopes or slopes constructed in rock above reservoirs, darn abutments, or other types of constructed slopes...

Block Slides on Extremely Weak Tectonic Clay Seams in Openly Folded Tertiary Mud-Rocks at Auckland and the Rangitikei Valley, North Island, New Zealand

Science.gov (United States)

Prebble, Warwick M.; Williams, Ann L.

2016-06-01

Block slides have developed on extremely weak, thin clay seams of tectonic origin, parallel to bedding in gently dipping sandstones and mudstones of Tertiary age. Two areas of noted instability are investigated at Auckland and the Rangitikei valley. Dimensions range from 100 m across × 100 m long for short displacement block slides up to 4 km across × 3 km long for large landslide complexes in which block slides are a major component. Displacements of blocks range from incipient (cm) through short (30 m) to 2 or 3 km for large slides. Many of the Auckland slides are dormant but likely to move in a 2000 year return period earthquake or 100 year high intensity rain storm. At Rangitikei there are many active, younger slides. Sliding rates for active failures vary from a few cm/year to 50 m in 30 min. Host rocks are weak to very weak clayey sandstones and sandy mudstones. The seams are rich in smectite. They have polished and crushed walls, may have slickensides and some contain rounded rock fragments. Laboratory shear strength of the seams is 13 kPa cohesion and 13° friction, with a lower bound of 8° at zero cohesion. Strength is increased at the field scale by waviness, steps and splays. Continuity can be demonstrated over distances of hundreds of metres. Key investigation methods were mapping, shafts and trenches. Tectonic uplift, folding and faulting of the weak Tertiary strata and river down-cutting are perpetuating block slide development.

Results of monitoring at Olkiluoto in 2009. Rock mechanics

International Nuclear Information System (INIS)

Lahti, M.; Hakala, M.

2010-09-01

The rock mechanical monitoring at Olkiluoto concentrates on the assessment of potential tectonic movements and stability of the bedrock. The construction of ONKALO is not expected to induce large-scale movements of the rock blocks or affect the rate of isostatic uplift but the evaluation of any tectonic events is important for the safety assessment. The monitoring consists of seismic measurements, GPS measurements and precise levelling campaigns at Olkiluoto and vicinity and additionally extensometer and convergence measurements carried out in ONKALO. Posiva established a local seismic network of six stations on the island of Olkiluoto in 2002. The number of seismic stations has increased gradually being in 2009 altogether 14. The purpose of the microearthquake measurements at Olkiluoto is to improve understanding of the structure, behaviour and long term stability of the bedrock. The investigation area includes two target areas. The larger target area, called seismic semi-regional area, covers the Olkiluoto Island and its surroundings. The purpose is to monitor explosions and tectonic earthquakes in regional scale. The smaller target area is s called the seismic ONKALO block, which is a 2 km *2 km *2 km cube surrounding the ONKALO. All the expected excavation induced events assumingly occur within this volume. At the moment the seismic ONKALO block includes 10 seismic stations. An additional task of monitoring is related to safeguarding of the ONKALO. The seismic network has operated continuously in 2009 and during the year altogether 1256 events have been located in the Olkiluoto area. Most of them (1161) are explosions that occurred inside the seismic semi-regional area and especially inside the seismic ONKALO block (1135 events)

A methodology for interpretation of overcoring stress measurements in anisotropic rock

International Nuclear Information System (INIS)

Hakala, M.; Sjoeberg, J.

2006-11-01

The in situ state of stress is an important parameter for the design of a repository for final disposal of spent nuclear fuel. This report presents work conducted to improve the quality of overcoring stress measurements, focused on the interpretation of overcoring rock stress measurements when accounting for possible anisotropic behavior of the rock. The work comprised: (i) development/upgrading of a computer code for calculating stresses from overcoring strains for anisotropic materials and for a general overcoring probe configuration (up to six strain rosettes with six gauges each), (ii) development of a computer code for determining elastic constants for transversely isotropic rocks from biaxial testing, and (iii) analysis of case studies of selected overcoring measurements in both isotropic and anisotropic rocks from the Posiva and SKB sites in Finland and Sweden, respectively. The work was principally limited to transversely isotropic materials, although the stress calculation code is applicable also to orthotropic materials. The developed computer codes have been geared to work primarily with the Borre and CSIRO HI three-dimensional overcoring measurement probes. Application of the codes to selected case studies, showed that the developed tools were practical and useful for interpreting overcoring stress measurements conducted in anisotropic rock. A quantitative assessment of the effects of anisotropy may thus be obtained, which provides increased reliability in the stress data. Potential gaps in existing data and/or understanding can also be identified. (orig.)

Instruction manual for the use of CSIR triaxial rock stress measuring equipment

CSIR Research Space (South Africa)

Coetzer, SJ

1998-08-01

Full Text Available This is an updated version of CSIR Report no ME 1763 entitled "Instruction manual for the use for the CSIR triaxial rock stress measuring equipment" by F A Vreede. The manual contains a detailed description of CSIR Triaxial rock stress measuring...

Rock cliffs hazard analysis based on remote geostructural surveys: The Campione del Garda case study (Lake Garda, Northern Italy)

Science.gov (United States)

Ferrero, A. M.; Migliazza, M.; Roncella, R.; Segalini, A.

2011-02-01

The town of Campione del Garda (located on the west coast of Lake Garda) and its access road have been historically subject to rockfall phenomena with risk for public security in several areas of the coast. This paper presents a study devoted to the determination of risk for coastal cliffs and the design of mitigation measures. Our study was based on statistical rockfall analysis performed with a commercial code and on stability analysis of rock slopes based on the key block method. Hazard from block kinematics and rock-slope failure are coupled by applying the Rockfall Hazard Assessment Procedure (RHAP). Because of the huge dimensions of the slope, its morphology and the geostructural survey were particularly complicated and demanding. For these reasons, noncontact measurement methods, based on aerial photogrammetry by helicopter, were adopted. A special software program, developed by the authors, was applied for discontinuity identification and for their orientation measurements. The potentially of aerial photogrammetic survey in rock mechanic application and its improvement in the rock mass knowledge is analysed in the article.

Results of Monitoring at Olkiluoto in 2010. Rock Mechanics

Energy Technology Data Exchange (ETDEWEB)

Lahti, M [ed.; Siren, T

2011-12-15

The rock mechanical monitoring at Olkiluoto concentrates on the assessment of potential tectonic movements and stability of the bedrock. The construction of ONKALO is not expected to induce large-scale movements of the rock blocks or affect the rate of isostatic uplift but the evaluation of any tectonic events is important for the safety assessment. The monitoring consists of seismic measurements, GPS measurements and precise levelling campaigns at Olkiluoto and vicinity and extensometer and convergence measurements carried out in ONKALO. Posiva established a local seismic network of six stations on the island of Olkiluoto in 2002. After that the number of seismic stations has increased gradually. In 2010 the permanent seismic network consists of 15 seismic stations and 20 triaxial sensors. The purpose of the microearthquake measurements at Olkiluoto is to improve understanding of the structure, behaviour and long term stability of the bedrock. The investigation area includes two target areas. The larger target area, called seismic semiregional area, covers the Olkiluoto Island and its surroundings. The purpose is to monitor explosions and tectonic earthquakes in regional scale inside that area. The smaller target area is called the seismic ONKALO block, which is a 2 km *2 km *2 km cube surrounding the ONKALO. It is assumed that all the expected excavation induced events occur within this volume. At the moment the seismic ONKALO block includes ten seismic stations. An additional task of monitoring is related to safeguarding of the ONKALO. This report gives the results of microseismic monitoring during 2010.

Results of Monitoring at Olkiluoto in 2010. Rock Mechanics

International Nuclear Information System (INIS)

Lahti, M.; Siren, T.

2011-12-01

The rock mechanical monitoring at Olkiluoto concentrates on the assessment of potential tectonic movements and stability of the bedrock. The construction of ONKALO is not expected to induce large-scale movements of the rock blocks or affect the rate of isostatic uplift but the evaluation of any tectonic events is important for the safety assessment. The monitoring consists of seismic measurements, GPS measurements and precise levelling campaigns at Olkiluoto and vicinity and extensometer and convergence measurements carried out in ONKALO. Posiva established a local seismic network of six stations on the island of Olkiluoto in 2002. After that the number of seismic stations has increased gradually. In 2010 the permanent seismic network consists of 15 seismic stations and 20 triaxial sensors. The purpose of the microearthquake measurements at Olkiluoto is to improve understanding of the structure, behaviour and long term stability of the bedrock. The investigation area includes two target areas. The larger target area, called seismic semiregional area, covers the Olkiluoto Island and its surroundings. The purpose is to monitor explosions and tectonic earthquakes in regional scale inside that area. The smaller target area is called the seismic ONKALO block, which is a 2 km *2 km *2 km cube surrounding the ONKALO. It is assumed that all the expected excavation induced events occur within this volume. At the moment the seismic ONKALO block includes ten seismic stations. An additional task of monitoring is related to safeguarding of the ONKALO. This report gives the results of microseismic monitoring during 2010

Snow and ice blocking of tunnels

Energy Technology Data Exchange (ETDEWEB)

Lia, Leif

1998-12-31

Hydroelectric power development in cold regions causes much concern about operational reliability and dam safety. This thesis studies the temperature distribution in tunnels by means of air temperature measurements in six tunnel spillways and five diversion tunnels. The measurements lasted for two consecutive winters. The air through flow tunnel is used as it causes cooling of both rock and water. In open spillway tunnels, frost reaches the entire tunnel. In spillway tunnels with walls, the frost zones reach about 100 m from the downstream end. In mildly-inclined diversion tunnels, a frost free zone is located in the middle of the tunnel and snow and ice problems were only observed in the inlet and outlet. Severe aufeis is accumulation is observed in the frost zones. The heat transfer from rock to air, water and ice is calculated and used in a prediction model for the calculation of aufeis build-up together with local field observation data. The water penetration of snow plugs is also calculated, based on the heat balance. It takes 20 to 50 days for water to enter the blocked tunnel. The empirical values are 30 to 60 days, but only 1 day if the temperature of the snow pack is 0{sup o}C. Sensitivity analyses are carried out for temperature variations in rock, snow, water and ice. Systematic field observation shows that it is important for hydropower companies to know about the effects of snow and ice blocking in an area. A risk analysis of dam safety is presented for a real case. Finally, the thesis proposes solutions which can reduce the snow and ice problems. 79 refs., 63 figs., 11 tabs.

Simultaneous measurements of transport and poroelastic properties of rocks.

Science.gov (United States)

Hasanov, Azar K; Prasad, Manika; Batzle, Michael L

2017-12-01

A novel laboratory apparatus has been developed for simultaneous measurements of transport and poroelastic rock properties. These transport and poroelastic properties at reservoir pressure and temperature conditions are required inputs for various geoscience applications, such as reservoir simulation, basin modeling, or modeling of pore pressure generation. Traditionally, the transport and poroelastic properties are measured separately using, for example, the oscillating pore pressure method to measure hydraulic transport properties, static strain measurements for elastic properties, and pore volumometry for storage capacity. In addition to time, the separate set of measurements require either aliquot cores or subjecting the same core to multiple pressure tests. We modified the oscillating pore pressure method to build an experimental setup, capable of measuring permeability, storage capacity, and pseudo-bulk modulus of rocks simultaneously. We present here the test method, calibration measurements (capillary tube), and sample measurements (sandstone) of permeability and storage capacity at reservoir conditions. We establish that hydraulically measured storage capacities were overestimated by an order of magnitude when compared to elastically derived ones. Our concurrent measurement of elastic properties during the hydraulic experiment provides an independent constraint on storage capacity.

Interpretation of stress measurements around mining cavities in rock salt - a finite-element study

International Nuclear Information System (INIS)

Heusermann, S.

1986-01-01

Finite-element studies of stress measurements using the overcoring method and of large drift fields in rock salt show that the measurements are affected by local stress relaxation occurring near the test borehole and by general time-dependent stress redistribution in the marginal zones of adjacent drifts. Analysis of the overcoring method indicates that the following local effects have to be considered in the interpretation of the test results as opposed to measurements in elastic rock: The inelastic deformation behaviour of rock salt causes stress relaxation at the pilot borehole which can lead to an underestimation of the actual stress state in rock. During overcoring considerable inelastic deformations occur in rock salt which demand a modified interpretation of the measurements and as a result of stress relaxation at the borehole various tests conditions, such as overcoring diameter, pilot borehole diameter and time between drilling and overcoring, have an effect on the test results. (orig./PW)

Uniaxial backfill block compaction

International Nuclear Information System (INIS)

Koskinen, V.

2012-05-01

The main parts of the project were: to make a literature survey of the previous uniaxial compaction experiments; do uniaxial compaction tests in laboratory scale; and do industrial scale production tests. Object of the project was to sort out the different factors affecting the quality assurance chain of the backfill block uniaxial production and solve a material sticking to mould problem which appeared during manufacturing the blocks of bentonite and cruched rock mixture. The effect of mineralogical and chemical composition on the long term functionality of the backfill was excluded from the project. However, the used smectite-rich clays have been tested for mineralogical consistency. These tests were done in B and Tech OY according their SOPs. The objective of the Laboratory scale tests was to find right material- and compaction parameters for the industrial scale tests. Direct comparison between the laboratory scale tests and industrial scale tests is not possible because the mould geometry and compaction speed has a big influence for the compaction process. For this reason the selected material parameters were also affected by the previous compaction experiments. The industrial scale tests were done in summer of 2010 in southern Sweden. Blocks were done with uniaxial compaction. A 40 tons of the mixture of bentonite and crushed rock blocks and almost 50 tons of Friedland-clay blocks were compacted. (orig.)

The use of the durometer to measure rock hardness in geomorphology. Advantages and limitations.

Science.gov (United States)

Feal-Pérez, Alejandra; Blanco-Chao, Ramón; Valcarcel-Díaz, Marcos; Combes, Martín. A.

2010-05-01

The durometer is a hardness tester developed to measure hardness of metallic materials that has been recently introduced to measure rock hardness in weathering studies. Aoki & Matsukura (2007) highlight some advantages of the durometer compared with the Schmidt Rock Test Hammer: the smaller plunge allows measurements in small surfaces such as taffoni or rock carvings, the wider measurement range and the lower impact energy. This last makes it a non destructive method that can be used on relatively soft rocks. In this work the durometer Equotip (©) has been tested in different environments in the field and in the laboratory to explore its applicability and limitations. We applied the device on small rock samples of granite and limestone and a T-test showed that smaller sample size gave smaller hardness values (p values obtained inside and outside the grooves of the carvings using two different support rings, one flat and one concave. The flat ring was not able to reach the bottom of the groove, meanwhile the concave ring adjusts fairly well given its semi spherical section. A t-test confirmed the difference (p values obtained in the grooves using the flat ring and the higher and less scattered values obtained when the concave ring is used. As a very sensitive device, there are some problems in the use related with rock roughness and rock grain size. In weathered medium to coarse grained rocks, with very irregular surfaces, is not easy to get a good contact between the plunge and the rock surface. A poor contact caused by surface roughness causes the scattering and lowering of rebound values. On the contrary, in homogeneous fine grained rocks and in uniform rock surfaces the device gave very good results. The data obtained in glacial, nival and rock coastal environments showed the potential of the device in the identification of changes in rock hardness. We were able to asses the changes in the weathering degree of glacial striations and marked differences in the

Measurement of IgG-blocking antibodies: development and application of a radioimmunoassay

International Nuclear Information System (INIS)

Sobotka, A.K.; Valentine, M.D.; Ishizaka, K.; Lichtenstein, L.M.

1976-01-01

A radioimmunoassay for measuring blocking antibodies has been developed. We used the ragweed antigen E system to show that the same blocking antibodies (IgG) measured by inhibition of antigen-induced leukocyte histamine release were precipitated in the binding assay (r/sub s/ = 0.96 p less than 0.001), thus validating a widely applicable technique for measuring blocking antibodies. Binding of phospholipase-A (Phos-A), the major allergen in honey bee venom, was also shown to correlate significantly with inhibition of histamine release. Hymenoptera (insect) hypersensitivity was used as a model to demonstrate application of the binding assay. Sera obtained from patients undergoing whole body extract therapy contained negligible amounts of specific blocking antibodies. Significantly higher blocking antibody titers to both whole honey bee venom and Phos-A were measured in sera drawn from patients immunized with whole venom. The use of the binding radioimmunoassay should facilitate management of allergic disease processes in which blocking antibodies are thought to be protective

Results of using engineering and technological measures for rock burst prevention. [USSR

Energy Technology Data Exchange (ETDEWEB)

Kulikov, A P; Nechaev, A V; Khmara, O I

1980-01-01

The paper evaluates methods for rock burst forecasting and rock burst prevention used in the Donbass, Kuzbass, Karaganda and Pechora basins. Forecasting methods are based on measuring the initial velocity of gas flow from test boreholes and/or quantity ratio of drillings leaving a test borehole and monitoring seismoacoustic signals. Number of working faces at which each of the methods for rock burst forecasting is used is given. Methods for rock burst prevention are comparatively evaluated: explosive fracturing of rocks in seam roof or seam floor, fluid injection (water and surfactants), drilling destressing boreholes, cutting destressing slots using cutting machines or water jets, mining protective coal seams first for reducing rock burst hazard in protected coal seams, using narrow web coal cutter loaders, remote control of coal cutters at working faces with extremely high rock burst hazard, using mining schemes which reduce rock burst hazards (e.g. long pillar mining system). From 1976 to 1979 number of rock bursts in underground coal mines in the USSR decreased by 5 times in comparison to the period 1961 to 1965. (3 refs.) (In Russian)

Vibration measurement for evaluating the danger of rock-collapse; Rakuseki kikendo hantei no tame no shindo sokutei

Energy Technology Data Exchange (ETDEWEB)

Takeuchi, T; Harada, H [The Nippon Road Co. Ltd., Tokyo (Japan); Mitsuzuka, T [Chishitsu-Keisoku Co. Ltd., Tokyo (Japan)

1997-10-22

Discussions were given on feasibility of a method for investigating a problem of the danger of rock-collapse by applying vibration measurement. The measurement investigation was carried out at a mouth of a tunnel under construction on a highway where the danger of rock-collapse is being investigated according to a qualitative determination criterion. Sixty-four rocks have been evaluated of their danger, with the degree of the danger having been classified to ranks one to three. Vibration measurement was performed on five floating rocks out of the 64 rocks. Vibroscopes were installed on upper portion of the rocks to be investigated and on exposed rocks nearby. The measurement revealed that the vibration has nearly the same amplitude in both of the floating rocks and the settled rocks before and after an automobile has passed, but the floating rocks shake more strongly than the settled rocks while an automobile is passing. This trend appears more noticeably in rocks regarded unstable in the danger determining investigation, indicating presence of close relationship between wave amplitude excited by the automobile and adhesion of the floating rocks. As a result of the discussions, it was made clear that the maximum amplitude ratio and the spectral ratio among the vibration characteristics of the floating rocks can be used as effective determination criteria. 2 refs., 7 figs., 2 tabs.

Field evidence for control of quarrying by rock bridges in jointed bedrock

Science.gov (United States)

Hooyer, T. S.; Cohen, D. O.; Iverson, N. R.

2011-12-01

Quarrying is generally thought to be the most important mechanism by which glaciers erode bedrock. In quarrying models it is assumed that slow, subcritical, growth of pre-existing cracks rate-limits the process and occurs where there are large stress differences in the bed, such as near rock bumps where ice separates from the bed to form water-filled cavities. Owing to the direction of principal stresses in rocks associated with sliding and resultant cavity formation, models predict that quarrying will occur along cracks oriented perpendicular to the ice flow direction or parallel to zones of ice-bed contact. Preglacial cracks in rocks will tend to propagate mainly downward, and in sedimentary or some metamorphic rocks will merge with bedding planes, thereby helping to isolate rock blocks for dislodgement. In contrast to these model assumptions, new measurements of quarried surface orientations in the deglaciated forefield of nine glaciers in Switzerland and Canada indicate a strong correlation between orientations of pre-existing joints and quarried bedrock surfaces, independent of ice flow direction or ice-water contact lines. The strong correlation persists across all rock types, and rocks devoid of major joints lack quarried surfaces. We propose a new conceptual model of quarrying that idealizes the bedrock as a series of blocks separated by discontinuous preglacial joints containing intact rock bridges. Bridges concentrate stress differences caused by normal and shear forces acting at the rock surface. Failure of bridges is caused by slow subcritical crack growth enhanced by water pressure fluctuations. To lend credibility to this new model, we show field evidence of failed rock bridges in quarried surfaces and of rib marks on plumose structures that we interpret as arrest fracture fronts due to transient subglacial water-pressure fluctuations.

Role of large-scale permeability measurements in fractured rock and their application at Stripa

International Nuclear Information System (INIS)

Witherspoon, P.A.; Wilson, C.R.; Long, J.C.S.; DuBois, A.O.; Gale, J.E.; McPherson, M.

1979-10-01

Completion of the macropermeability experiment will provide: (i) a direct, in situ measurement of the permeability of 10 5 to 10 6 m 3 of rock; (ii) a potential method for confirming the analysis of a series of small scale permeability tests performed in surface and underground boreholes; (iii) a better understanding of the effect to open borehole zone length on pressure measurement; (iv) increased volume in fractured rock; (v) a basis for evaluating the ventilation technique for flow measurement in large scale testing of low permeability rocks

Estimating the Wet-Rock P-Wave Velocity from the Dry-Rock P-Wave Velocity for Pyroclastic Rocks

Science.gov (United States)

Kahraman, Sair; Fener, Mustafa; Kilic, Cumhur Ozcan

2017-07-01

Seismic methods are widely used for the geotechnical investigations in volcanic areas or for the determination of the engineering properties of pyroclastic rocks in laboratory. Therefore, developing a relation between the wet- and dry-rock P-wave velocities will be helpful for engineers when evaluating the formation characteristics of pyroclastic rocks. To investigate the predictability of the wet-rock P-wave velocity from the dry-rock P-wave velocity for pyroclastic rocks P-wave velocity measurements were conducted on 27 different pyroclastic rocks. In addition, dry-rock S-wave velocity measurements were conducted. The test results were modeled using Gassmann's and Wood's theories and it was seen that estimates for saturated P-wave velocity from the theories fit well measured data. For samples having values of less and greater than 20%, practical equations were derived for reliably estimating wet-rock P-wave velocity as function of dry-rock P-wave velocity.

Steady as a rock: Biogeomorphic influence of nurse rocks and slope processes on kūpaoa (Dubautia menziesii) shrubs in Haleakalā Crater (Maui, Hawai'i)

Science.gov (United States)

Pérez, Francisco L.

2017-10-01

This study examines biogeomorphic interactions between nurse rocks, slope processes, and 300 kūpaoa (Dubautia menziesii) shrubs in Haleakalā Crater (Maui, Hawai'i). Research objectives were to: assess the association of kūpaoa with substrates upslope and downslope of plants, and proximity to the closest rock uphill; contrast shrub/substrate relationships with site frequency of sediment types; measure surface soil shear-strength and compressibility on 50 paired locations near boulders; and investigate the aggregation characteristics and spatial patterns of kūpaoa in relation to rock and substrate variation. Data analyzed came from three 100-plant surveys at 3 sites: a plant census at 2720-2975 m altitude, and wandering-quarter transects (WQTs) across two areas (2610-2710 m); ground sediment cover was estimated along four phototransects on these sites. Data for the three 100-plant surveys included substrate type-outcrops, blocks, cobbles, pebbles, exposed soil, organic litter-upslope from each plant, and distance to the largest rock upslope. The two surveys examined along WQTs included substrate type found downslope from kūpaoa, plant height, plant diameters across and along the slope, and distance between successively censused plants. Most plants grew downslope of nurse rocks; > 74% were adjacent to blocks or outcrops, and > 17% near cobbles. Plants showed avoidance for finer substrates; only 5.3% and 2.7% grew on/near bare soils and pebbles, respectively. About 92% of kūpaoa were ≤ 10 cm downslope of rocks; > 89% grew ≤ 2 cm away, and 83% in direct contact with a rock. Some seedlings also grew on pukiawe (Leptecophylla tameiameiae) nurse plants. Several stable rock microsites protected plants from disturbance by slope processes causing debris shift. Site sediments were significantly finer than substrates near plants; shrubs grew preferentially adjacent to boulders > 20 cm wide, which were more common near plants than across sites. Soils downslope of 50

Apparatus for the measurement of radionuclide transport rates in rock cores

International Nuclear Information System (INIS)

Weed, H.C.; Koszykowski, R.F.; Dibley, L.L.; Murray, I.

1981-09-01

An apparatus and procedure for the study of radionuclide transport in intact rock cores are presented in this report. This equipment more closely simulates natural conditions of radionuclide transport than do crushed rock columns. The apparatus and the procedure from rock core preparation through data analysis are described. The retardation factors measured are the ratio of the transport rate of a non-retarded radionuclide, such as 3 H, to the transport rate of a retarded radionuclide. Sample results from a study of the transport of /sup 95m/Tc and 85 Sr in brine through a sandstone core are included

Geologic and petrophysic analysis of a travertine block as hydrocarbon reservoir analogue; Analise geologica e petrofisica de um bloco de travertino como analogo de reservatorio de hidrocarbonetos

Energy Technology Data Exchange (ETDEWEB)

Basso, Mateus; Kuroda, Michelle Chaves; Vidal, Alexandre Campane, E-mail: mbstraik@gmail.com, E-mail: ckuroda@ige.unicamp.br, E-mail: vidal@ige.unicamp.br [Universidade Estadual de Campinas (CEPETRO/UNICAMP), SP (Brazil). Centro de Estudos do Petroleo

2017-04-15

Microbialitic limestones are gaining space in petroleum geology due to the existence of many reservoirs composed of these lithologies in the pre-salt producing fields. Travertine, calcareous tufa and stromatolites figure among the rocks proposed as analogous for the microbialitic rocks. This work conduces the study of geological, petrophysical and geophysical parameters of a travertine block measuring 1,60 x 1,60 x 2,70 m, weighing 21,2 tons and available in the Centro de Estudo do Petroleo (CEPETRO) at the Universidade Estadual de Campinas. The Italian block, named T-block, corresponds to the representative elementary volume of its original formation and allows the study in an intermediate scale between the hand sample and the outcrop scale. Permeability tests and gamma ray spectrometry measurements were conducted and the porosity was calculated by image analysis. Models were generated from the obtained data and then associated with descriptive geology of the block. A reduction in permeability, porosity and concentration of elements potassium (K), uranium (U) and thorium (Th) was recorded, following a gradient towards the top of the T-block accompanying the reduction in the degree of development of the rock fabric. (author)

Effects of increased rock strata stresses on coal gettability

Energy Technology Data Exchange (ETDEWEB)

Sikora, W; Skoczynski, W [Politechnika Slaska, Gliwice (Poland). Instytut Mechanizacji Gornictwa

1988-01-01

Analyzes effects of rock strata pressure on a coal seam, its cracking and on energy consumption of coal cutting by shearer loaders and coal plows. Effects of mining depth on stresses in a coal seam rib side were analyzed using formulae developed by Budryk, Chudek and Borecki. Formulae used for selecting optimum yield strength of powered supports at working faces are reviewed. Four types of spontaneous separation of coal seam blocks caused by rock strata stresses are evaluated: layers parallel to the face with constant thickness, coal blocks with thickness decreasing in the direction of the floor or roof (blocks with a planar triangle cross-cut), blocks situated in the seam layer adjacent to the floor or roof. Causes of each type of coal seam separation are analyzed. 9 refs.

Numerical simulation and analysis for low-frequency rock physics measurements

Science.gov (United States)

Dong, Chunhui; Tang, Genyang; Wang, Shangxu; He, Yanxiao

2017-10-01

In recent years, several experimental methods have been introduced to measure the elastic parameters of rocks in the relatively low-frequency range, such as differential acoustic resonance spectroscopy (DARS) and stress-strain measurement. It is necessary to verify the validity and feasibility of the applied measurement method and to quantify the sources and levels of measurement error. Relying solely on the laboratory measurements, however, we cannot evaluate the complete wavefield variation in the apparatus. Numerical simulations of elastic wave propagation, on the other hand, are used to model the wavefield distribution and physical processes in the measurement systems, and to verify the measurement theory and analyze the measurement results. In this paper we provide a numerical simulation method to investigate the acoustic waveform response of the DARS system and the quasi-static responses of the stress-strain system, both of which use axisymmetric apparatus. We applied this method to parameterize the properties of the rock samples, the sample locations and the sensor (hydrophone and strain gauges) locations and simulate the measurement results, i.e. resonance frequencies and axial and radial strains on the sample surface, from the modeled wavefield following the physical experiments. Rock physical parameters were estimated by inversion or direct processing of these data, and showed a perfect match with the true values, thus verifying the validity of the experimental measurements. Error analysis was also conducted for the DARS system with 18 numerical samples, and the sources and levels of error are discussed. In particular, we propose an inversion method for estimating both density and compressibility of these samples. The modeled results also showed fairly good agreement with the real experiment results, justifying the effectiveness and feasibility of our modeling method.

Analyzer for measuring gas contained in the pore space of rocks

Science.gov (United States)

Kudasik, Mateusz; Skoczylas, Norbert

2017-10-01

In the present paper, the authors discussed the functioning of their own analyzer for measuring gas contained in the pore space of high strength rocks. A sample is placed inside a hermetic measuring chamber, and then undergoes impact milling as a result of colliding with the vibrating blade of a knife which is rotationally driven by a high-speed brushless electric motor. The measuring chamber is equipped with all the necessary sensors, i.e. gas, pressure, and temperature sensors. Trial tests involving the comminution of dolomite and anhydrite samples demonstrated that the constructed device is able to break up rocks into grains so fine that they are measured in single microns, and the sensors used in the construction ensure balancing of the released gas. The tests of the analyzer showed that the metrological concept behind it, together with the way it was built, make it fit for measurements of the content and composition of selected gases from the rock pore space. On the basis of the conducted tests of balancing the gases contained in the two samples, it was stated that the gas content of Sample no. 1 was (0.055  ±  0.002) cm3 g-1, and Sample no. 2 contained gas at atmospheric pressure, composed mostly of air.

Development of measurement system for gauge block interferometer

Science.gov (United States)

Chomkokard, S.; Jinuntuya, N.; Wongkokua, W.

2017-09-01

We developed a measurement system for collecting and analyzing the fringe pattern images from a gauge block interferometer. The system was based on Raspberry Pi which is an open source system with python programming and opencv image manipulation library. The images were recorded by the Raspberry Pi camera with five-megapixel capacity. The noise of images was suppressed for the best result in analyses. The low noise images were processed to find the edge of fringe patterns using the contour technique for the phase shift analyses. We tested our system with the phase shift patterns between a gauge block and a reference plate. The phase shift patterns were measured by a Twyman-Green type of interferometer using the He-Ne laser with the temperature controlled at 20.0 °C. The results of the measurement will be presented and discussed.

Migmatites and migmatite-like rocks of Olkiluoto

International Nuclear Information System (INIS)

Kaerki, A.

2015-02-01

Bedrock of the Olkiluoto Island in the western end of the Palaeoproterozoic Svecofennian Accretionary Arc Complex, SW Finland is composed of high-grade metamorphic pelites, arenites and intermediate, arc type metavolcanic rocks intruded by granodioritic to tonalitic plutonic rocks. Regional metamorphism culminated with voluminous migmatization in the temperature of 660 - 700 deg C and relatively low pressure of about 3.5 - 4 kbar. The end result of polyphase metamorphism and deformation is a metamorphic rock succession composed of diverse migmatite rocks, metatexites and diatexites. Metatexites are migmatites in which several, discrete components can be detected, and in which the paleosome with some pre-partial-melting textures is identifiable. Diatexites are more advanced migmatites in which the pre-migmatization structures are often totally destroyed and the rock is dominated by different neosome components meaning leucosome, melanosome or mesosome. Based on the migmatite structures the metatexites of Olkiluoto have been classified into six subgroups. Dike-structured metatexites are composed of well preserved paleosome intruded by one single set of narrow, subparallel leucosome dikes which cover ca. 5 - 10 % of the whole rock volume. Net-structure is composed of a network of narrow leucosome dikes which show a reticulated structure in a plane section and cover less than 30 % of the whole rock volume. Breccia-structure is composed of angular or rounded paleosome blocks surrounded by moderate amount of leucosome. Patch-structure is composed of irregular leucosome patches which intruded the well preserved paleosome and compose typically 20 - 70 % of the rock volume. Layer-structure is characterized by more or less regular leucosome dikes sub-parallel to the foliation of the well preserved paleosome. Vein-structured metatexites and also diatexites include a set of pipe-like, longish leucosome veins most probably generated by synchronous melting and deformation

Migmatites and migmatite-like rocks of Olkiluoto

Energy Technology Data Exchange (ETDEWEB)

Kaerki, A. [Kivitieto Oy, Oulu (Finland)

2015-02-15

Bedrock of the Olkiluoto Island in the western end of the Palaeoproterozoic Svecofennian Accretionary Arc Complex, SW Finland is composed of high-grade metamorphic pelites, arenites and intermediate, arc type metavolcanic rocks intruded by granodioritic to tonalitic plutonic rocks. Regional metamorphism culminated with voluminous migmatization in the temperature of 660 - 700 deg C and relatively low pressure of about 3.5 - 4 kbar. The end result of polyphase metamorphism and deformation is a metamorphic rock succession composed of diverse migmatite rocks, metatexites and diatexites. Metatexites are migmatites in which several, discrete components can be detected, and in which the paleosome with some pre-partial-melting textures is identifiable. Diatexites are more advanced migmatites in which the pre-migmatization structures are often totally destroyed and the rock is dominated by different neosome components meaning leucosome, melanosome or mesosome. Based on the migmatite structures the metatexites of Olkiluoto have been classified into six subgroups. Dike-structured metatexites are composed of well preserved paleosome intruded by one single set of narrow, subparallel leucosome dikes which cover ca. 5 - 10 % of the whole rock volume. Net-structure is composed of a network of narrow leucosome dikes which show a reticulated structure in a plane section and cover less than 30 % of the whole rock volume. Breccia-structure is composed of angular or rounded paleosome blocks surrounded by moderate amount of leucosome. Patch-structure is composed of irregular leucosome patches which intruded the well preserved paleosome and compose typically 20 - 70 % of the rock volume. Layer-structure is characterized by more or less regular leucosome dikes sub-parallel to the foliation of the well preserved paleosome. Vein-structured metatexites and also diatexites include a set of pipe-like, longish leucosome veins most probably generated by synchronous melting and deformation

The modelling and measurement of super-conducting rock joints

International Nuclear Information System (INIS)

Barton, N.; Makurat, A.; Vik, G.; Loset, F.

1985-01-01

Rock joints exhibiting exceptionally high conductivity have been responsible for severe inflows (10-50 m 3 /min.) and flooding in recent Norwegian tunneling projects. These events may be explained by channeling of flow in partially outwashed mineral fillings, associated with deep weathering in ancient basement rocks. There is also evidence to suggest extensional strain with consistent relationships to regional faulting patterns (Selmer-Olsen 1981). Hydraulic fractures making connection with joint systems that are sheared as a result of increased fluid pressure, has been deduced as the mechanism explaining unusually large fluid losses in the geothermal project in Cornwall, England (Pine and Batchelor, 1984). Such mechanisms also introduce uncertainty into water flood and MHF stimulation treatment of fractured oil and gas reservoirs, particularly when principal stress and joint orientations are poorly understood due to coring and stress measurement problems in weak, overstressed reservoir rocks. The possibility of permanent disposal of nuclear waste in crystalline rock, has also focussed attention on highly conductive (''super-conducting'') joints in nuclear waste programmes in Canada, the USA and in Europe. The bi-modal distributions of joint spacing, continuity, apertures and conductivities resulting from the discovery of super-conducting joints has important implications for the location of planned repositories, due to their dramatic impact on potential transport times. In the laboratory a class of super-conducting joints can be created by shear displacement that causes dilation when shearing non-planar features. Recent biaxial shear testing of rock joints recovered in jointed core has identified a strong coupling of conductivity and shear displacement. The theoretical predictions of constitutive relationships for coupled flow in rock joints (Barton et al. 1985) have been broadly verified

High frequency measurement of P- and S-wave velocities on crystalline rock massif surface - methodology of measurement

Science.gov (United States)

Vilhelm, Jan; Slavík, Lubomír

2014-05-01

For the purpose of non-destructive monitoring of rock properties in the underground excavation it is possible to perform repeated high-accuracy P- and S-wave velocity measurements. This contribution deals with preliminary results gained during the preparation of micro-seismic long-term monitoring system. The field velocity measurements were made by pulse-transmission technique directly on the rock outcrop (granite) in Bedrichov gallery (northern Bohemia). The gallery at the experimental site was excavated using TBM (Tunnel Boring Machine) and it is used for drinking water supply, which is conveyed in a pipe. The stable measuring system and its automatic operation lead to the use of piezoceramic transducers both as a seismic source and as a receiver. The length of measuring base at gallery wall was from 0.5 to 3 meters. Different transducer coupling possibilities were tested namely with regard of repeatability of velocity determination. The arrangement of measuring system on the surface of the rock massif causes better sensitivity of S-transducers for P-wave measurement compared with the P-transducers. Similarly P-transducers were found more suitable for S-wave velocity determination then P-transducers. The frequency dependent attenuation of fresh rock massif results in limited frequency content of registered seismic signals. It was found that at the distance between the seismic source and receiver from 0.5 m the frequency components above 40 kHz are significantly attenuated. Therefore for the excitation of seismic wave 100 kHz transducers are most suitable. The limited frequency range should be also taken into account for the shape of electric impulse used for exciting of piezoceramic transducer. The spike pulse generates broad-band seismic signal, short in the time domain. However its energy after low-pass filtration in the rock is significantly lower than the energy of seismic signal generated by square wave pulse. Acknowledgments: This work was partially

Polymetamorphic evolution of the granulite-facies Paleoproterozoic basement of the Kabul Block, Afghanistan

Science.gov (United States)

Collett, Stephen; Faryad, Shah Wali; Mosazai, Amir Mohammad

2015-08-01

The Kabul Block is an elongate crustal fragment which cuts across the Afghan Central Blocks, adjoining the Indian and Eurasian continents. Bounded by major strike slip faults and ophiolitic material thrust onto either side, the block contains a strongly metamorphosed basement consisting of some of the only quantifiably Proterozoic rocks south of the Herat-Panjshir Suture Zone. The basement rocks crop-out extensively in the vicinity of Kabul City and consist predominantly of migmatites, gneisses, schists and small amounts of higher-grade granulite-facies rocks. Granulite-facies assemblages were identified in felsic and mafic siliceous rocks as well as impure carbonates. Granulite-facies conditions are recorded by the presence of orthopyroxene overgrowing biotite in felsic rocks; by orthopyroxene overgrowing amphibole in mafic rocks and by the presence of olivine and clinohumite in the marbles. The granulite-facies assemblages are overprinted by a younger amphibolite-facies event that is characterized by the growth of garnet at the expense of the granulite-facies phases. Pressure-temperature (P-T) conditions for the granulite-facies event of around 850 °C and up to 7 kbar were calculated through conventional thermobarometry and phase equilibria modeling. The younger, amphibolite-facies event shows moderately higher pressures of up to 8.5 kbar at around 600 °C. This metamorphism likely corresponds to the dominant metamorphic event within the basement of the Kabul Block. The results of this work are combined with the litho-stratigraphic relations and recent geochronological dating to analyze envisaged Paleoproterozoic and Neoproterozoic metamorphic events in the Kabul Block.

New Techniques for Monitoring and Analyzing the Stability of Steep Cliffs against Rock Falls

OpenAIRE

Fujii, Yoshiaki; Maeda, S; Sugawara, T; Kodama, N; Miyashita, N

2016-01-01

Mechanisms of joint opening leading to the formation of unstable rock blocks, such as thermal deformation, water-mineral reaction, pore pressure, freeze-thaw cycle, intrusion of wood roots etc. have been more or less clarified; however, the triggering mechanisms of rock falls remain to be elucidated. The problems which prevent the understanding of the mechanisms are (1) difficulty in installation of sensors to very unstable rock blocks, (2) thermoelastic deformation of sensors and attachments...

Multifractal magnetic susceptibility distribution models of hydrothermally altered rocks in the Needle Creek Igneous Center of the Absaroka Mountains, Wyoming

Directory of Open Access Journals (Sweden)

M. E. Gettings

2005-01-01

Full Text Available Magnetic susceptibility was measured for 700 samples of drill core from thirteen drill holes in the porphyry copper-molybdenum deposit of the Stinkingwater mining district in the Absaroka Mountains, Wyoming. The magnetic susceptibility measurements, chemical analyses, and alteration class provided a database for study of magnetic susceptibility in these altered rocks. The distribution of the magnetic susceptibilities for all samples is multi-modal, with overlapping peaked distributions for samples in the propylitic and phyllic alteration class, a tail of higher susceptibilities for potassic alteration, and an approximately uniform distribution over a narrow range at the highest susceptibilities for unaltered rocks. Samples from all alteration and mineralization classes show susceptibilities across a wide range of values. Samples with secondary (supergene alteration due to oxidation or enrichment show lower susceptibilities than primary (hypogene alteration rock. Observed magnetic susceptibility variations and the monolithological character of the host rock suggest that the variations are due to varying degrees of alteration of blocks of rock between fractures that conducted hydrothermal fluids. Alteration of rock from the fractures inward progressively reduces the bulk magnetic susceptibility of the rock. The model introduced in this paper consists of a simulation of the fracture pattern and a simulation of the alteration of the rock between fractures. A multifractal model generated from multiplicative cascades with unequal ratios produces distributions statistically similar to the observed distributions. The reduction in susceptibility in the altered rocks was modelled as a diffusion process operating on the fracture distribution support. The average magnetic susceptibility was then computed for each block. For the purpose of comparing the model results with observation, the simulated magnetic susceptibilities were then averaged over the same

Multifractal magnetic susceptibility distribution models of hydrothermally altered rocks in the Needle Creek Igneous Center of the Absaroka Mountains, Wyoming

Science.gov (United States)

Gettings, M.E.

2005-01-01

Magnetic susceptibility was measured for 700 samples of drill core from thirteen drill holes in the porphyry copper-molybdenum deposit of the Stinkingwater mining district in the Absaroka Mountains, Wyoming. The magnetic susceptibility measurements, chemical analyses, and alteration class provided a database for study of magnetic susceptibility in these altered rocks. The distribution of the magnetic susceptibilities for all samples is multi-modal, with overlapping peaked distributions for samples in the propylitic and phyllic alteration class, a tail of higher susceptibilities for potassic alteration, and an approximately uniform distribution over a narrow range at the highest susceptibilities for unaltered rocks. Samples from all alteration and mineralization classes show susceptibilities across a wide range of values. Samples with secondary (supergene) alteration due to oxidation or enrichment show lower susceptibilities than primary (hypogene) alteration rock. Observed magnetic susceptibility variations and the monolithological character of the host rock suggest that the variations are due to varying degrees of alteration of blocks of rock between fractures that conducted hydrothermal fluids. Alteration of rock from the fractures inward progressively reduces the bulk magnetic susceptibility of the rock. The model introduced in this paper consists of a simulation of the fracture pattern and a simulation of the alteration of the rock between fractures. A multifractal model generated from multiplicative cascades with unequal ratios produces distributions statistically similar to the observed distributions. The reduction in susceptibility in the altered rocks was modelled as a diffusion process operating on the fracture distribution support. The average magnetic susceptibility was then computed for each block. For the purpose of comparing the model results with observation, the simulated magnetic susceptibilities were then averaged over the same interval as the

Laboratory measurements of P- and S-wave anisotropy in synthetic rocks by 3D printing

Science.gov (United States)

Kong, L.; Ostadhassan, M.; Tamimi, N.; Li, C.; Alexeyev, A.

2017-12-01

Synthetic rocks have been widely used to realize the models with controlled factors in rock physics and geomechanics experiments. Additive manufacturing technology, known as 3D printing, is becoming a popular method to produce the synthetic rocks as the advantages of timesaving, economics, and control. In terms of mechanical properties, the duplicability of 3D printed rock towards a natural rock has been studied whereas the seismic anisotropy still remains unknown as being the key factor in conducting rock physics experiments. This study utilized a 3D printer with gypsum as the ink to manufacture a series of synthetic rocks that have the shapes of octagonal prisms, with half of them printed from lateral and another half from the bottom. An ultrasonic investigation system was set up to measure the P- and S- wave velocities at different frequencies while samples were under dry conditions. The results show the impact of layered property on the P- and S- wave velocities. The measurement results were compared with the predicted results of Hudson model, demonstrating that the synthetic rock from 3D printing is a transverse isotropic model. The seismic anisotropy indicates that the availability of using 3D printed rocks to duplicate natural rocks for the purpose of recreating the experiments of rock physics. Future experiments will be performed on the dependence of seismic anisotropy on fracture geometry and density in 3D printed synthetic rocks.

Rockfall Modelling with Remedial Design and Measures along Part of a Mountainous Settlement Area, Southern Turkey

Science.gov (United States)

Güntel, Berna; Acar, Altay

2016-10-01

In June 2011, a heavy rainfall triggered a number of rockfalls from steep slopes and on slopes made of soft to loose soils capped by inhomogeneous hard rock blocks and masses in the Düziçi Town of Osmaniye Province in Turkey. Large rock blocks had damaged 15 prefabricated hotel rooms whereas the slope movement blocked the major road between Duzigi and hot spring facilities at numerous locations along 280 m. This paper describes remedial measures and design recommended according to the modelling process based on the collection of data and simulation of rockfall with Rocscience RockFall 5.0 software.

The Breakdown: Hillslope Sources of Channel Blocks in Bedrock Landscapes

Science.gov (United States)

Selander, B.; Anderson, S. P.; Rossi, M.

2017-12-01

Block delivery from hillslopes is a poorly understood process that influences bedrock channel incision rates and shapes steep terrain. Previous studies demonstrate that hillslope sediment delivery rate and grain size increases with channel downcutting rate or fracture density (Attal et al., 2015, ESurf). However, blocks that exceed the competence of the channel can inhibit incision. In Boulder Creek, a bedrock channel in the Colorado Front Range, large boulders (>1 m diameter) are most numerous in the steepest channel reaches; their distribution seems to reflect autogenic channel-hillslope feedback between incision rate and block delivery (Shobe et al., 2016, GRL). It is clear that the processes, rates of production, and delivery of large blocks from hillslopes into channels are critical to our understanding of steep terrain evolution. Fundamental questions are 1) whether block production or block delivery is rate limiting, 2) what mechanisms release blocks, and 3) how block production and transport affect slope morphology. As a first step, we map rock outcrops on the granodiorite hillslopes lining Boulder Creek within Boulder Canyon using a high resolution DEM. Our algorithm uses high ranges of curvature values in conjunction with slopes steeper than the angle of repose to quickly identify rock outcrops. We field verified mapped outcrop and sediment-mantled locations on hillslopes above and below the channel knickzone. We find a greater abundance of exposed rock outcrops on steeper hillslopes in Boulder Canyon. Additionally, we find that channel reaches with large in-channel blocks are located at the base of hillslopes with large areas of exposed bedrock, while reaches lacking large in-channel blocks tend to be at the base of predominately soil mantled and forested hillslopes. These observations support the model of block delivery and channel incision of Shobe et al. (2016, GRL). Moreover, these results highlight the conundrum of how rapid channel incision is

Complex Contact Angles Calculated from Capillary Rise Measurements on Rock Fracture Faces

Science.gov (United States)

Perfect, E.; Gates, C. H.; Brabazon, J. W.; Santodonato, L. J.; Dhiman, I.; Bilheux, H.; Bilheux, J. C.; Lokitz, B. S.

2017-12-01

Contact angles for fluids in unconventional reservoir rocks are needed for modeling hydraulic fracturing leakoff and subsequent oil and gas extraction. Contact angle measurements for wetting fluids on rocks are normally performed using polished flat surfaces. However, such prepared surfaces are not representative of natural rock fracture faces, which have been shown to be rough over multiple scales. We applied a variant of the Wilhelmy plate method for determining contact angle from the height of capillary rise on a vertical surface to the wetting of rock fracture faces by water in the presence of air. Cylindrical core samples (5.05 cm long x 2.54 cm diameter) of Mancos shale and 6 other rock types were investigated. Mode I fractures were created within the cores using the Brazilian method. Each fractured core was then separated into halves exposing the fracture faces. One fracture face from each rock type was oriented parallel to a collimated neutron beam in the CG-1D imaging instrument at ORNL's High Flux Isotope Reactor. Neutron radiography was performed using the multi-channel plate detector with a spatial resolution of 50 μm. Images were acquired every 60 s after a water reservoir contacted the base of the fracture face. The images were normalized to the initial dry condition so that the upward movement of water on the fracture face was clearly visible. The height of wetting at equilibrium was measured on the normalized images using ImageJ. Contact angles were also measured on polished flat surfaces using the conventional sessile drop method. Equilibrium capillary rise on the exposed fracture faces was up to 8.5 times greater than that predicted for polished flat surfaces from the sessile drop measurements. These results indicate that rock fracture faces are hyperhydrophilic (i.e., the height of capillary rise is greater than that predicted for a contact angle of zero degrees). The use of complex numbers permitted calculation of imaginary contact angles for

Preparation of rock samples for measurement of the thermal neutron macroscopic absorption cross-section

International Nuclear Information System (INIS)

Czubek, J.A.; Burda, J.; Drozdowicz, K.; Igielski, A.; Kowalik, W.; Krynicka-Drozdowicz, E.; Woznicka, U.

1986-03-01

Preparation of rock samples for the measurement of the thermal neutron macroscopic absorption cross-section in small cylindrical two-region systems by a pulsed technique is presented. Requirements which should be fulfilled during the preparation of the samples due to physical assumptions of the method are given. A cylindrical vessel is filled with crushed rock and saturated with a medium strongly absorbing thermal neutrons. Water solutions of boric acid of well-known macroscopic absorption cross-section are used. Mass contributions of the components in the sample are specified. This is necessary for the calculation of the thermal neutron macroscopic absorption cross-section of the rock matrix. The conditions necessary for assuring the required accuracy of the measurement are given and the detailed procedure of preparation of the rock sample is described. (author)

Retardation of radionuclide transport by fracture flow in granite and argillaceous rocks

International Nuclear Information System (INIS)

Bradbury, M.H.; Green, A.

1985-11-01

Laboratory techniques have been developed for the measurement of diffusion rates and permeabilities through highly consolidated rock samples. The work has predominantly concentrated on the generation of diffusion data for slates and granites in particular. Rock properties fundamental to mass transfer processes have been obtained. Diffusion rates have been measured through weathered granite fissure surfaces and as a function of distance from such surfaces on core samples obtained from Troon, Cornwall. Pore connectivity over metre distances in granite cores has been shown to exist and diffusion coefficients were measured as a function of confining pressure in a specially designed rig. The Dsub(i) (intrinsic diffusion coefficient) values determined at ambient pressure were approximately a factor of 2 greater than those measured at pressures equivalent to 500 m of rock overburden. Some initial experiments on the accessibility of the pore space in granites to colloids based on a permeability technique indicated that such particles neither blocked pores nor penetrated through 15 mm thick samples over times of the order 2 to 3 thousand hours. Diffusion rates through samples of Canadian granites, some of which contained weathered fissure surfaces, were measured. (author)

ONKALO rock mechanics model (RMM) - Version 2.0

International Nuclear Information System (INIS)

Moenkkoenen, H.; Hakala, M.; Paananen, M.; Laine, E.

2012-02-01

The Rock Mechanics Model of the ONKALO rock volume is a description of the significant features and parameters related to rock mechanics. The main objective is to develop a tool to predict the rock properties, quality and hence the potential for stress failure which can then be used for continuing design of the ONKALO and the repository. This is the second implementation of the Rock Mechanics Model and it includes sub-models of the intact rock strength, in situ stress, thermal properties, rock mass quality and properties of the brittle deformation zones. Because of the varying quantities of available data for the different parameters, the types of presentations also vary: some data sets can be presented in the style of a 3D block model but, in other cases, a single distribution represents the whole rock volume hosting the ONKALO. (orig.)

Permeability Measurements of Rock Samples from Conduit Drilling at Unzen Volcano, Japan

Science.gov (United States)

Watanabe, T.; Shimizu, Y.; Noguchi, S.; Nakada, S.

2006-12-01

The last eruption of Unzen Volcano (1990-1995) was effusive to form lava domes, though magmas at depths are estimated to have contained volatile materials enough to cause explosive eruptions [e.g., Sato et al., 1995]. Most of volatile materials should have escaped from ascending magmas. The escape of gas is controlled by permeability of magmas and country rocks. Unzen Scientific Drilling Project sampled both the latest conduit and its country rock (USDP-4). In order to understand degassing processes, we have measured the permeability of these rock samples. Four cube samples with edges of 25 mm were cut from USDP-4 cores C1, C12 (country rock), C13 and C14 (conduit). Sample C1 is considered as Old Unzen Lava, and Sample C12 volcanic breccia. The transient pulse method was employed to measure the permeability. It applies a step of the fluid pressure difference across a specimen, and measures the decay rate of the fluid pressure difference. This method can be applied to samples with very low permeability, since it determines the permeability without measuring the fluid flux. Nitrogen gas was used as a pore fluid. Our permeametry system is built in a pressure vessel, and the confining pressure and the pore fluid pressure can be controlled independently. The temperature of the measurement system is kept constant within 0.1 degree. The temperature control and the background leak rate limit the measurable permeability to be higher than 10^{-20} m2. Measurements were first conducted under the atmospheric pressure. The permeability in a rock sample varies with the direction by a factor less than 5. Sample C1 has the lowest permeability (10^{-19} m2), and Sample C12 the highest value (10^{-17 m2). The permeability of C13 and C14 is of the order of 10^{- 18} m2. Though only a trace of vesicles can be seen in conduit samples, the interconnection is still maintained. The pressure dependence of the permeability is now investigated up to 50 MPa. The permeability of C13 and C14

Application of proving-ring technology to measure thermally induced displacements in large boreholes in rock

International Nuclear Information System (INIS)

Patrick, W.C.; Reactor, N.L.; Butkovich, T.R.

1984-03-01

A strain-gauged proving-ring transducer was designed and deployed to measure small diametral displacements in 0.61-m diameter boreholes in rock. The rock surrounding the boreholes was previously heated by storage of spent nuclear fuel assemblies and measurements during post-retrieval cooling of the rock were made. To accomplish this, a transducer was designed to measure displacements in the range of 10 to 100 μm, to function in a time-varying temperature regime of 30 0 to 60 0 C at a relative humidity of 100%, to be of low stiffness, and to be easily and quickly installed. 7 references, 6 figures, 1 table

Rb-Sr measurements on metamorphic rocks from the Barro Alto Complex, Goias, Brazil

International Nuclear Information System (INIS)

Fuck, R.A.; Neves, B.B.B.; Cordani, U.G.; Kawashita, K.

1988-01-01

The Barro Alto Complex comprises a highly deformed and metamorphosed association of plutonic, volcanic, and sedimentary rocks exposed in a 150 x 25 Km boomerang-like strip in Central Goias, Brazil. It is the southernmost tip of an extensive yet discontinuous belt of granulite and amphibolite facies metamorphic rocks which include the Niquelandia and Cana Brava complexes to the north. Two rock associations are distinguished within the granulite belt. The first one comprises a sequence of fine-grained mafic granulite, hypersthene-quartz-feldspar granulite, garnet quartzite, sillimanite-garnet-cordierite gneiss, calc-silicate rock, and magnetite-rich iron formation. The second association comprises medium-to coarse-grained mafic rocks. The medium-grade rocks of the western/northern portion (Barro Alto Complex) comprise both layered mafic rocks and a volcanic-sedimentary sequence, deformed and metamorphosed under amphibolite facies conditions. The fine-grained amphibolite form the basal part of the Juscelandia meta volcanic-sedimentary sequence. A geochronologic investigation by the Rb-Sr method has been carried out mainly on felsic rocks from the granulite belt and gneisses of the Juscelandia sequence. The analytical results for the Juscelandia sequence are presented. Isotope results for rocks from different outcrops along the gneiss layer near Juscelandia are also presented. In conclusion, Rb-Sr isotope measurements suggest that the Barro Alto rocks have undergone at least one important metamorphic event during Middle Proterozoic times, around 1300 Ma ago. During that event volcanic and sedimentary rocks of the Juscelandia sequence, as well as the underlying gabbro-anorthosite layered complex, underwent deformation and recrystallization under amphibolite facies conditions. (author)

The role of the microfissuration of the rock matrix in the abrasion resistance of ornamental granitic rocks

Science.gov (United States)

Rodríguez-Rey, Angel; Sanchez-Delgado, Nuria; Camino, Clara; Calleja, Lope; Ruiz de Argandoña, Vicente G.; Setien, Alexia

2015-04-01

The microcrack density and the abrasion resistance of five ornamental granites (Albero, Gris Alba, Mondariz, Rosa Porriño and Traspieles) from Galicia (NW Spain) have been quantified as part of a research aimed to interpret the cuttability of the rocks in relation to the petrophysical properties of the rock matrix. Large blocks from the quarries have been cut with an industrial saw and the microcrack density and the abrasion resistance have been measured in two surfaces: H, parallel to the cut surface; T, perpendicular both to the cut surface and the cutting direction. Both planes are perpendicular to the rift plane, as it is known in quarry works. The microcrack density has been quantified following an stereological procedure applied to polished sections imaged under scanning electron microscopy. The magnification of the images allowed the study of microcracks as narrow as 2 microns in aperture. The density has been quantified in terms of length of microcrack traces per surface unit so possible anisotropies of the microcrack network could be detected. The obtained values are in the typical range for this type of rocks although the Traspieles granite shows a higher value due to its weathering degree (H: 5.11, T: 5.37 mm/mm2). The values measured in the two surfaces (H and T) are quite similar in four of the rocks; only the Albero granite shows a marked anisotropy (H: 2.76 T: 3.53 mm/mm2). The abrasion resistance of the rocks has been measured following the european standard EN 14157:2004 using the capon method. The rocks can be classified in two groups according to their abrasion resistance. Rosa Porriño, Gris Alba and Mondariz granites are the more resistant to abrasion with values around 16-17 mm. Albero and Traspieles granites are less resistant with values higher than 19 mm. The results show a good correlation between the microcrack density and the abrasion resistance. As can be expected the rocks with high microcrack density show low abrasion resistance. The

Method of measuring material properties of rock in the wall of a borehole

Science.gov (United States)

Overmier, David K.

1985-01-01

To measure the modulus of elasticity of the rock in the wall of a borehole, a plug is cut in the borehole wall. The plug, its base attached to the surrounding rock, acts as a short column in response to applied forces. A loading piston is applied to the top of the plug and compression of the plug is measured as load is increased. Measurement of piston load and plug longitudinal deformation are made to determine the elastic modulus of the plug material. Poisson's ratio can be determined by simultaneous measurements of longitudinal and lateral deformation of the plug in response to loading. To determine shear modulus, the top of the plug is twisted while measurements are taken of torsional deformation.

ELECTRICAL IMAGING AT THE LARGE BLOCK TEST YUCCA MOUNTAIN, NEVADA

International Nuclear Information System (INIS)

Ramirez, A.

2000-01-01

A monolithic block of densely welded tuff was excavated from a site on Fran Ridge near Yucca Mountain, Nevada so that coupled thermohydrological processes could be studied in a controlled, in situ experiment. A series of heaters were placed in a horizontal plane about 3 m from the top of the 3 m by 3 m by 4.5 m high block. Temperatures were measured at many points within and on the block surface and a suite of other measurements were taken to define the thermal and hydrologic response. Electrical resistance tomography (ERT) was used to map 2 dimensional images of moisture content changes along four planes in the block. The ERT images clearly delineate the drying and wetting of the rockmass during the 13 months of heating and subsequent six months of cool down. The main feature is a prominent dry zone that forms around the heaters then gradually disappears as the rock cools down. Other features include linear anomalies of decreasing moisture content which are fractures dehydrating as the block heats up. There are also examples of compact anomalies of wetting. Some of these appear to be water accumulation in fractures which are draining condensate from the block. Others may be rain water entering a fracture at the top of the block. During cooldown a general rewetting is observed although this is less certain because of poor data quality during this stage of the experiment

Study on flow and mass transport through fractured soft sedimentary rocks (Contact research)

International Nuclear Information System (INIS)

Shimo, Michito; Kumamoto, Sou; Maekawa, Keisuke

2007-03-01

It is important for safety assessment of HLW geological disposal to evaluate groundwater flow and mass transport in deep underground accurately. Though it is considered that the mass transport in sedimentary rock occurs in pores between grains mainly, fractures of sedimentary rock can be main paths. The objective of this study is to establish a conceptual model for flow and mass transport in fractured soft sedimentary rock. In previous study, a series of laboratory hydraulic and tracer tests and numerical analyses were carried out using sedimentary rock specimens obtained from Koetoi and Wakkanai formation. Single natural fractured cores and rock block specimen were used for the tests and analyses. The results indicated that the matrix diffusion played an important role for mass transport in the fractured soft sedimentary rocks. In this study, the following two tasks were carried out: (1) laboratory hydraulic and tracer experiments of rock cores of Koetoi and Wakkanai formation obtained at HDB-9, HDB-10 and HDB-11 boreholes and a rock block specimen, Wakkanai formation, obtained at an outcrop in the Horonobe area, (2) a numerical study on the conceptual model of flow and mass transport through fractured soft sedimentary rocks. Non-sorbing tracer experiments using naturally fractured cores and rock block specimens were carried out. Pottasium iodide was used as a tracer. The obtained breakthrough curves were interpreted and fitted by using a numerical simulator, and mass transport parameters, such as longitudinal dispersivity, matrix diffusion coefficient, transport aperture, were obtained. Mass transport simulations using a fracture network model, a continuum model and a double porosity model were performed to study the applicability of continuum model and double porosity model for transport in fractured sedimentary rock. (author)

Localized damage in soft rock: experiments with field measurement techniques

International Nuclear Information System (INIS)

Nguyen, T.L.

2011-01-01

The research presented in this thesis concerns, firstly, an experimental study on the process of fracture in uniaxial compression of rock samples containing narrow, rectilinear notches inclined with respect to the axis of loading. Secondly, we study the evolution of shear strain localisation towards fracturing and failure in specimens of the same materials with a particular geometry, involving two rounded notches. This geometry, inspired by the work of Meuwissen et al. (1998) for tension tests on metals, promotes the localisation of shear strain in simple compression before fracture. Two different materials were studied: a natural rock of volcanic origin (Neapolitan Tuff) and an artificial 'roc' (CPIR09). In the studies presented, three full-field measurement techniques have been employed in combination: (i) the Digital Image Correlation (DIC), for measurement of kinematic fields at a sample's surface; (ii)acoustic Emission measurements (AE) and AE source location, to follow the evolution of damage in samples during loading; (iii) X-ray tomography (pre-and post-mortem studies), to characterise preexisting defects and discontinuities in the specimens and to better understand the fracturing in 3D. (author)

Measured sections and analyses of uranium host rocks of the Dockum Group, New Mexico and Texas

International Nuclear Information System (INIS)

Dickson, R.E.; Drake, D.P.; Reese, T.J.

1977-02-01

This report presents 27 measured sections from the Dockum Group of Late Triassic age, in the southern High Plains of eastern New Mexico and northwestern Texas. Many of the measured sections are only partial; the intent in those cases was to measure the parts of sections that had prominent sandstone/conglomerate beds or that had uranium deposits. No attempt was made to relate rock color to a rock color chart; rock colors are therefore approximate. Modal analyses (by thin-section examination) of sandstone and conglomerate samples and gamma-ray spectrometric analyses of the samples are presented in appendices

Process of long-term tunnel instability by temperature and humidity variation in sedimentary rock

International Nuclear Information System (INIS)

Sawada, Masataka; Okada, Tetsuji; Nakata, Eiji

2009-01-01

It is concerned that tunnels in the sedimentary rock are seriously damaged during the long operation after excavation, while there are various plans to construct significant underground facilities such as a high-level radioactive waste disposal facility. A case history study on tunnel instability is important in order to assess and evaluate tunnel instability behavior. In this respect, an accelerated tunnel deformation test by removing tunnel supports was conducted. Instability of tunnel wall was observed before and after this test in the summer, when it is warm and humid in the test tunnel. Fiber optic sensing detected the instability. Scale of collapsed rock was evaluated from the variation of shape of tunnel cross-section measured by a 3-D lazar measurement tool. The maximum size of collapsed rock block is 1m in diameter. Surrounding sandstone has such a characteristic that crack growth is much faster and its strength decreases gradually in the condition of high relative humidity. Numerical simulation considering this decrease of rock strength reproduced the instable zone around the test tunnel. (author)

The Application of Normal Stress Reduction Function in Tilt Tests for Different Block Shapes

Science.gov (United States)

Kim, Dong Hyun; Gratchev, Ivan; Hein, Maw; Balasubramaniam, Arumugam

2016-08-01

This paper focuses on the influence of the shapes of rock cores, which control the sliding or toppling behaviours in tilt tests for the estimation of rock joint roughness coefficients (JRC). When the JRC values are estimated by performing tilt tests, the values are directly proportional to the basic friction of the rock material and the applied normal stress on the sliding planes. Normal stress obviously varies with the shape of the sliding block, and the basic friction angle is also affected by the sample shapes in tilt tests. In this study, the shapes of core blocks are classified into three representative shapes and those are created using plaster. Using the various shaped artificial cores, a set of tilt tests is carried out to identify the shape influences on the normal stress and the basic friction angle in tilt tests. The test results propose a normal stress reduction function to estimate the normal stress for tilt tests according to the sample shapes based on Barton's empirical equation. The proposed normal stress reduction functions are verified by tilt tests using artificial plaster joints and real rock joint sets. The plaster joint sets are well matched and cast in detailed printed moulds using a 3D printing technique. With the application of the functions, the obtained JRC values from the tilt tests using the plaster samples and the natural rock samples are distributed within a reasonable JRC range when compared with the measured values.

Distribution of base rock depth estimated from Rayleigh wave measurement by forced vibration tests

International Nuclear Information System (INIS)

Hiroshi Hibino; Toshiro Maeda; Chiaki Yoshimura; Yasuo Uchiyama

2005-01-01

This paper shows an application of Rayleigh wave methods to a real site, which was performed to determine spatial distribution of base rock depth from the ground surface. At a certain site in Sagami Plain in Japan, the base rock depth from surface is assumed to be distributed up to 10 m according to boring investigation. Possible accuracy of the base rock depth distribution has been needed for the pile design and construction. In order to measure Rayleigh wave phase velocity, forced vibration tests were conducted with a 500 N vertical shaker and linear arrays of three vertical sensors situated at several points in two zones around the edges of the site. Then, inversion analysis was carried out for soil profile by genetic algorithm, simulating measured Rayleigh wave phase velocity with the computed counterpart. Distribution of the base rock depth inverted from the analysis was consistent with the roughly estimated inclination of the base rock obtained from the boring tests, that is, the base rock is shallow around edge of the site and gradually inclines towards the center of the site. By the inversion analysis, the depth of base rock was determined as from 5 m to 6 m in the edge of the site, 10 m in the center of the site. The determined distribution of the base rock depth by this method showed good agreement on most of the points where boring investigation were performed. As a result, it was confirmed that the forced vibration tests on the ground by Rayleigh wave methods can be useful as the practical technique for estimating surface soil profiles to a depth of up to 10 m. (authors)

Strength Assessment of Broken Rock Postgrouting Reinforcement Based on Initial Broken Rock Quality and Grouting Quality

Directory of Open Access Journals (Sweden)

Hongfa Xu

2017-01-01

Full Text Available To estimate postgrouting rock mass strength growth is important for engineering design. In this paper, using self-developed indoor pressure-grouting devices, 19 groups of test cubic blocks were made of the different water cement ratio grouting into the broken rock of three kinds of particle sizes. The shear strength parameters of each group under different conditions were tested. Then this paper presents a quantitative calculation method for predicting the strength growth of grouted broken rock. Relational equations were developed to investigate the relationship between the growth rates of uniaxial compressive strength (UCS, absolute value of uniaxial tensile strength (AUTS, internal friction angle, and cohesion for post- to pregrouting broken rock based on Mohr-Coulomb strength criterion. From previous test data, the empirical equation between the growth rate of UCS and the ratio of the initial rock mass UCS to the grout concretion UCS has been determined. The equations of the growth rates of the internal friction coefficient and UCS for grouting broken rock with rock mass rating (RMR and its increment have been established. The calculated results are consistent with the experimental results. These observations are important for engineered design of grouting reinforcement for broken rock mass.

Rock slope instabilities in Norway: First systematic hazard and risk classification of 22 unstable rock slopes

Science.gov (United States)

Böhme, Martina; Hermanns, Reginald L.; Oppikofer, Thierry; Penna, Ivanna

2016-04-01

Unstable rock slopes that can cause large failures of the rock-avalanche type have been mapped in Norway for almost two decades. Four sites have earlier been characterized as high-risk objects based on expertise of few researchers. This resulted in installing continuous monitoring systems and set-up of an early-warning system for those four sites. Other unstable rock slopes have not been ranked related to their hazard or risk. There are ca. 300 other sites known of which 70 sites were installed for periodic deformation measurements using multiple techniques (Global Navigation Satellite Systems, extensometers, measurement bolts, and others). In 2012 a systematic hazard and risk classification system for unstable rock slopes was established in Norway and the mapping approach adapted to that in 2013. Now, the first 22 sites were classified for hazard, consequences and risk using this classification system. The selection of the first group of sites to be classified was based on an assumed high hazard or risk and importance given to the sites by Norwegian media and the public. Nine of the classified 22 unstable rock slopes are large sites that deform inhomogeneously or are strongly broken up in individual blocks. This suggests that different failure scenarios are possible that need to be analyzed individually. A total of 35 failure scenarios for those nine unstable rock slopes were considered. The hazard analyses were based on 9 geological parameters defined in the classification system. The classification system will be presented based on the Gamanjunni unstable rock slope. This slope has a well developed back scarp that exposes 150 m preceding displacement. The lateral limits of the unstable slope are clearly visible in the morphology and InSAR displacement data. There have been no single structures observed that allow sliding kinematically. The lower extend of the displacing rock mass is clearly defined in InSAR data and by a zone of higher rock fall activity. Yearly

Investigation of the THM behaviour of the buffer and rock-buffer interaction during the canister retrieval test performed in the ASPÖ Hard Rock Laboratory

International Nuclear Information System (INIS)

Millard, A.; Barnichon, J.D.

2014-01-01

In the framework of the THERESA European project, numerical modelling of coupled thermo-hydro-mechanical (THM) and thermo-hydro-mechanical-chemical (THMC) behaviour of buffer (bentonite) and buffer-rock interfaces for deep underground nuclear waste repositories has been undertaken, with focus on the performance assessments. A major step of the project was the analysis of a large scale test, called the Canister Retrieval test, which has been performed in Aspö Hard Rock Laboratory. It consists in a full scale test of the emplacement of a canister with the surrounding buffer material. A deposition hole was first bored, and then the canister with heaters was installed together with bentonite blocks. The gap between the rock and the bentonite blocks was filled with bentonite pellets. The whole set was artificially wetted from its external boundary in order to accelerate the expected natural rehydration by the surrounding rock. The evolution of the THM processes was recorded over 5 years. Before analysing the whole CRT experiment, a preliminary simpler problem has been defined, which consisted in modelling a disc of buffer at canister mid-height. Thanks to the available experimental recorded measurements, it has been possible to numerically investigate the respective influence of the various THM parameters involved in the modelling of the physical processes. The theoretical model is based on one hand on the Richard's approximation for the flow calculation, and on the other hand on a Biot's type model for the hydro-mechanical behaviour. It has revealed the large influence of the liquid relative permeability, which is unfortunately in general not directly available from experiments and must be determined through inverse analysis techniques. Then, in a second stage, the whole CRT experiment has been analysed. For simplicity reasons, an axisymetrical model has been adopted, although the presence of a neighbouring experiment did influence the CRT results. The comparisons of

Investigation of the THM behaviour of the buffer and rock-buffer interaction during the canister retrieval test performed in the ASPÖ Hard Rock Laboratory

Energy Technology Data Exchange (ETDEWEB)

Millard, A., E-mail: alain.millard@cea.fr [CEA, DEN, DANS, DM2S, SEMT, LM2S, F91191 Gif sur Yvette (France); Barnichon, J.D. [IRSN/DEI/SARG/LR2S, F-92260 Fontenay-aux-Roses (France)

2014-04-01

In the framework of the THERESA European project, numerical modelling of coupled thermo-hydro-mechanical (THM) and thermo-hydro-mechanical-chemical (THMC) behaviour of buffer (bentonite) and buffer-rock interfaces for deep underground nuclear waste repositories has been undertaken, with focus on the performance assessments. A major step of the project was the analysis of a large scale test, called the Canister Retrieval test, which has been performed in Aspö Hard Rock Laboratory. It consists in a full scale test of the emplacement of a canister with the surrounding buffer material. A deposition hole was first bored, and then the canister with heaters was installed together with bentonite blocks. The gap between the rock and the bentonite blocks was filled with bentonite pellets. The whole set was artificially wetted from its external boundary in order to accelerate the expected natural rehydration by the surrounding rock. The evolution of the THM processes was recorded over 5 years. Before analysing the whole CRT experiment, a preliminary simpler problem has been defined, which consisted in modelling a disc of buffer at canister mid-height. Thanks to the available experimental recorded measurements, it has been possible to numerically investigate the respective influence of the various THM parameters involved in the modelling of the physical processes. The theoretical model is based on one hand on the Richard's approximation for the flow calculation, and on the other hand on a Biot's type model for the hydro-mechanical behaviour. It has revealed the large influence of the liquid relative permeability, which is unfortunately in general not directly available from experiments and must be determined through inverse analysis techniques. Then, in a second stage, the whole CRT experiment has been analysed. For simplicity reasons, an axisymetrical model has been adopted, although the presence of a neighbouring experiment did influence the CRT results. The

Using Resistivity Measurements to Determine Anisotropy in Soil and Weathered Rock

Directory of Open Access Journals (Sweden)

S. Soto-Caban

2013-08-01

Full Text Available This study uses electrical resistivity measurements of soils and weathered rock to perform a fast and reliable evaluation of field anisotropy. Two test sites at New Concord, Ohio were used for the study. These sites are characterized by different landform and slightly east dipping limestone and siltstone formations of Pennsylvanian age. The measured resistivity ranged from 19 Ω∙m to 100 ��∙m, and varied with depth, landform, and season. The anisotropy was determined by a comparison of resistance values along the directions of strike and the dip. Measurements showed that the orientation of electrical anisotropy in the shallow ground may vary due to fluid connection, which is determined by the pore geometry in soil and rock, as well as by the direction of fluid movement. Results from this study indicated that a portable electrical resistivity meter is sensitive and reliable enough to be used for shallow ground fluid monitoring.

Stantardization problems in radioisotopic techniques for measuring rock density and humidity

International Nuclear Information System (INIS)

Golubin, O.V.; Pavlov, L.S.

1977-01-01

A description of the main technical characteristics is given of radioisotope densimeters and hydrometers taken as a base for the State Standard design for field radioisotope instruments for measuring density and moisture of the soil and rocks

Rock properties influencing impedance spectra (IS) studied by lab measurements on porous model systems

Energy Technology Data Exchange (ETDEWEB)

Volkmann, J.; Klitzsch, N.; Mohnke, O. [RWTH Aachen Univ. (Germany). Applied Geophysics and Geothermal Energy; Schleifer, N. [Wintershall Holding GmbH, Barnstorf (Germany)

2013-08-01

The wetting condition of reservoir rocks is a crucial parameter for the estimation of reservoir characteristics like permeability and saturation with residual oil or water. Since standard methods are often costly, at least in terms of time, we aim at assessing wettability of reservoir rocks using impedance spectroscopy (IS), a frequency dependent measurement of complex electric resistivity. This approach is promising, because IS is sensitive to the electrochemical properties of the inner surface of rocks which, on the other hand, are decisively influencing wettability. Unfortunately, there is large number of rock parameters - besides wettability - influencing the impedance spectra often not exactly known for natural rock samples. Therefore, we study model systems to improve the understanding of the underlying mechanisms and to quantify the influencing parameters. The model systems consist of sintered porous silica beads of different sizes leading to samples with different pore sizes. The main advantage of these samples compared to natural rocks is their well-defined and uniform mineralogical composition and thus their uniform electrochemical surface property. In order to distinguish pore geometry and fluid electrochemistry effects on the IS properties we measured the IS response of the fully water saturated model systems in a wide frequency range - from 1 mHz to 35 MHz - to capture different often overlapping polarization processes. With these measurements we study the influence of pore or grain size, fluid conductivity, and wettability (contact angle) on the impedance spectra. The influence of wettability was studied by modifying the originally hydrophilic inner surface into a hydrophobic state. The wettability change was verified by contact angle measurements. As results, we find pore size dependent relaxation times and salinity dependent chargeabilities for the hydrophilic samples in the low frequency range (< 10 kHz), whereas for the hydrophobic samples

Range sections as rock models for intensity rock scene segmentation

CSIR Research Space (South Africa)

Mkwelo, S

2007-11-01

Full Text Available This paper presents another approach to segmenting a scene of rocks on a conveyor belt for the purposes of measuring rock size. Rock size estimation instruments are used to monitor, optimize and control milling and crushing in the mining industry...

Hydro-mechanical and gas transport properties of bentonite blocks - role of interfaces

International Nuclear Information System (INIS)

Popp, Till; Roehlke, Christopher; Salzer, Klaus; Gruner, Matthias

2012-01-01

sealing elements. The investigations consist of: - long-term water injection tests in a new designed oedometer cell with different sample constellations under well controlled stress and swelling conditions to provide data about - time dependent interface 'permeability' changes during long-term compaction and fluid injection - gas entry pressures and relative gas permeability changes during pressure dependent gas injection; - shear tests to quantify mechanical interface properties of pre-saturated bentonite blocks under well controlled shear forces or displacements. As initial characterization both, triaxial and direct strength tests were performed, which allow to separate between matrix and interface properties. The investigations are being performed in the framework of the pan-European project FORGE project which aims on the generation and movement of repository gases. Results and interpretation The performed lab investigations cover a wide field of hydro-mechanical properties of bentonite blocks, which represent a favorable option for constructing sealing plugs in different host rock environments. Based on the experimental results the following conclusions can be drawn: - At dry conditions gas flow along interfaces is at least 4 orders higher than through the matrix. Increase of confinement significantly lowers the gas flow but the effect is more pronounced for interfaces → crack sealing. - Saturation of bentonite block assembly, i.e. blocks with a common interface, is not affected by the interfaces and only weakly by the acting confining pressure. - During gas injection a significant effect is only observed if the minimal stress is passed resulting in some minor gas flow. - The gas break through results in stationary inflow but no significant effect on the total stress is measured, probably due to the central gas injection. - The measured gas threshold pressures under constant volume conditions significantly exceed the sum of the swelling pressure and externally

Qualitative and quantitative changes in detrital reservoir rocks caused by CO2-brine-rock interactions during first injection phases (Utrillas sandstones, northern Spain)

Science.gov (United States)

Berrezueta, E.; Ordóñez-Casado, B.; Quintana, L.

2016-01-01

The aim of this article is to describe and interpret qualitative and quantitative changes at rock matrix scale of lower-upper Cretaceous sandstones exposed to supercritical (SC) CO2 and brine. The effects of experimental injection of CO2-rich brine during the first injection phases were studied at rock matrix scale, in a potential deep sedimentary reservoir in northern Spain (Utrillas unit, at the base of the Cenozoic Duero Basin).Experimental CO2-rich brine was exposed to sandstone in a reactor chamber under realistic conditions of deep saline formations (P ≈ 7.8 MPa, T ≈ 38 °C and 24 h exposure time). After the experiment, exposed and non-exposed equivalent sample sets were compared with the aim of assessing possible changes due to the effect of the CO2-rich brine exposure. Optical microscopy (OpM) and scanning electron microscopy (SEM) aided by optical image analysis (OIA) were used to compare the rock samples and get qualitative and quantitative information about mineralogy, texture and pore network distribution. Complementary chemical analyses were performed to refine the mineralogical information and to obtain whole rock geochemical data. Brine composition was also analyzed before and after the experiment.The petrographic study of contiguous sandstone samples (more external area of sample blocks) before and after CO2-rich brine injection indicates an evolution of the pore network (porosity increase ≈ 2 %). It is probable that these measured pore changes could be due to intergranular quartz matrix detachment and partial removal from the rock sample, considering them as the early features produced by the CO2-rich brine. Nevertheless, the whole rock and brine chemical analyses after interaction with CO2-rich brine do not present important changes in the mineralogical and chemical configuration of the rock with respect to initial conditions, ruling out relevant precipitation or dissolution at these early stages to rock-block scale. These results

In situ measurement of the thermal conductivity in propylite rock mass

International Nuclear Information System (INIS)

Shimooka, Kenji; Araki, Kunio; Suda, Shintaro.

1982-11-01

The safety evaluation for the geological disposal of the high level waste becomes an urgent problem to establish the backend of nuclear fuel cycle. The stability of the original host rock and the flow of groundwater will be perturbed by the thermal disturbances from the waste. So the heater experiment at a depth of 90 m below the surface was carried out to study the conduction of decay heat. For measuring the thermal conductivity of propylite rock mass, a cylindrical heater and 13 thermocouples were inserted in 6 boreholes. The power output of the heater was kept at 880 W constant during the experimental periods of 61 days. From the observed temperature rise around the heater, the thermal conductivity 2.1 W/m 0 C was calculated by steady-state calculation. The value of the rock mass was found to be slightly bigger compared with 1.5 - 1.6 W/m 0 C of core samples. (author)

PALEOARCHEAN MAFIC ROCKS OF THE SOUTHWESTERN SIBERIAN CRATON: PRELIMINARY GEOCHRONOLOGY AND GEOCHEMICAL CHARACTERIZATION

Directory of Open Access Journals (Sweden)

A. V. Ivanov

2017-01-01

Full Text Available The Siberian craton consists of Archean blocks, which were welded up into the same large unit by ca 1.9 Ga [Gladkochub et al., 2006; Rojas-Agramonte et al., 2011]. The history of the constituent Archean blocks is mosaic because of limited number of outcrops, insufficient sampling coverage because of their location in remote regions and deep forest and difficulties with analytical studies of ancient rocks, which commonly underwent metamorphic modifications and secondary alterations. In this short note, we report data on discovery of unusual for Archean mafic rocks of ultimate fresh appearance. These rocks were discovered within southwestern Siberian craton in a region near a boundary between Kitoy granulites of the Sharyzhalgai highgrade metamorphic complex and Onot green-schist belt (Fig. 1. Here we present preliminary data on geochronology of these rocks and provide their geochemical characterization.

Core Cutting Test with Vertical Rock Cutting Rig (VRCR)

Science.gov (United States)

Yasar, Serdar; Osman Yilmaz, Ali

2017-12-01

Roadheaders are frequently used machines in mining and tunnelling, and performance prediction of roadheaders is important for project economics and stability. Several methods were proposed so far for this purpose and, rock cutting tests are the best choice. Rock cutting tests are generally divided into two groups which are namely, full scale rock cutting tests and small scale rock cutting tests. These two tests have some superiorities and deficiencies over themselves. However, in many cases, where rock sampling becomes problematic, small scale rock cutting test (core cutting test) is preferred for performance prediction, since small block samples and core samples can be conducted to rock cutting testing. Common problem for rock cutting tests are that they can be found in very limited research centres. In this study, a new mobile rock cutting testing equipment, vertical rock cutting rig (VRCR) was introduced. Standard testing procedure was conducted on seven rock samples which were the part of a former study on cutting rocks with another small scale rock cutting test. Results showed that core cutting test can be realized successfully with VRCR with the validation of paired samples t-test.

Permeability measurements on rock samples from Unzen Scientific Drilling Project Drill Hole 4 (USDP-4)

Science.gov (United States)

Watanabe, Tohru; Shimizu, Yuhta; Noguchi, Satoshi; Nakada, Setsuya

2008-07-01

Permeability measurement was made on five rock samples from USDP-4 cores. Rock samples were collected from the conduit zone and its country rock. One sample (C14-1-1) is considered as a part of the feeder dyke for the 1991-1995 eruption. The transient pulse method was employed under confining pressure up to 50 MPa. Compressional wave velocity was measured along with permeability. The measured permeability ranges from 10 - 19 to 10 - 17 m 2 at the atmospheric pressure, and is as low as that reported for tight rocks such as granite. The permeability decreases with increasing confining pressure, while the compressional wave velocity increases. Assuming that pores are parallel elliptical tubes, the pressure dependence of permeability requires aspect ratio of 10 - 4 -10 - 2 at the atmospheric pressure. The pore aperture is estimated to be less than 1 μm. The estimated aspect ratio and pore aperture suggest that connectivity of pores is maintained by narrow cracks. The existence of cracks is supported by the pressure dependence of compressional wave velocity. Narrow cracks (< 1 μm) are observed in dyke samples, and they must have been created after solidification. Dyke samples do not provide us information of pore structures during degassing, since exsolved gas has mostly escaped and pores governing the gas permeable flow should have been lost. Both dyke and country rock samples provide us information of materials around ascending magma. Although the measured small-scale permeability cannot be directly applied to geological-scale processes, it gives constrains on studies of large-scale permeability.

Naesliden Project: rock mechanics observations and measurements in the Naesliden mine

Energy Technology Data Exchange (ETDEWEB)

Nilsson, G.; Krauland, N.

1980-05-15

Observations and measurements of the reaction of the rock mass to mining have been made in the Naesliden Mine since the very start of mining operations in 1970. This observation program originated in the need of better understanding of the rock mechanics of cut-and-fill mining. The program comprises the following types of measurement - in the backfilled excavation convergence of the sidewalls pressure in the fill - in the orebody and alteration zones above the stopes horizontal deformation of the orebody and of the adjoining alteration zones horizontal stresses changes in horizontal stresses - in the stope amount and direction of roof and sidewall displacements convergence and sidewall deformation successively in roof and floor - in the sidewall surface subsidence horizontal displacements at 260 m level. Purpose, extent, methods and results of measurements are described. Qualitative observations concerning fracture processes due to mining are reported. The results are discussed and used for estimation of in situ modulus of elasticity of the orebody as well as the ratio of the modulus of elasticity of the orebody to the modulus of the alteration zone.

New paleomagnetic results from the Permian and Mesozoic rocks in central and northeast Thailand: their implications for the construction of the Indochina block in Pangea

Science.gov (United States)

Zhang, D.; Yan, Y.; Huang, B.; Zhao, J.

2015-12-01

Paleomagnetic studies of the Indochina block, aiming to reconstruct the paleogeography, have been undertaken for several decades. Since the Indochina block is lack of reliable paleomagnetic data to constraint its paleo-positions during the Middle Permian to Upper Triassic, the paleogeography reconstruction is still in debate between different models reported. Here we present new paleomagnetic data of Middle Permian to Upper Triassic sediment rocks from the Indochina block in Thailand, and recalculate paleomagnetic data reported by different authors. We collected the Permian samples in 20 sites distributed in the central Thailand, and Triassic samples from the Huai Hin Lat and Nam Phong formations in 13 sites in the northern Thailand.The magnetic directions of the 11 sites of Permian limestones are not significantly clustered after tilt correction which implying a remagnetized result. Remarkably, in geographic coordinate, the 11 sites were distributed along a circle showing a similar inclination which is 22.9° implying the paleolatitude to be about 12°. Totally, 13 sites from the Huai Hin Lat formation are included in the calculation of the formation mean direction Dg/Ig = 21.4°/38.1°, kg = 19.5, α95 = 9.6° before and Ds/Is = 43.0°/48.0°, ks = 47.4, α95 = 6.1°, N = 13 after bedding correction. A pre-folding characteristic magnetization is suggested by the positive fold test result derived from the Huai Hin Lat formation, and thus implies a primary remanence of the Norian Stage Upper Triassic rocks. A new Nam Phong formation mean direction derived from 11 sites is Dg/Ig = 36.5°/31.3°, kg = 14.7, α95 = 12.3°before and Ds/Is = 36.4°/37.8°, ks = 68.5, α95 = 5.6°, N = 11 after bedding correction. The two formation mean directions correspond to the magnetic pole positions , Plat./Plon=48.7°N/165.9°E, A95=7.2° and Plat./Plon=55.2°N/178.0°E, A95=5.9°, respectively. A remarkable tectonic movement (~8° southward) of the Indochina block from the age of

Development of a Unified Rock Bolt Model in Discontinuous Deformation Analysis

Science.gov (United States)

He, L.; An, X. M.; Zhao, X. B.; Zhao, Z. Y.; Zhao, J.

2018-03-01

In this paper, a unified rock bolt model is proposed and incorporated into the two-dimensional discontinuous deformation analysis. In the model, the bolt shank is discretized into a finite number of (modified) Euler-Bernoulli beam elements with the degrees of freedom represented at the end nodes, while the face plate is treated as solid blocks. The rock mass and the bolt shank deform independently, but interact with each other through a few anchored points. The interactions between the rock mass and the face plate are handled via general contact algorithm. Different types of rock bolts (e.g., Expansion Shell, fully grouted rebar, Split Set, cone bolt, Roofex, Garford and D-bolt) can be realized by specifying the corresponding constitutive model for the tangential behavior of the anchored points. Four failure modes, namely tensile failure and shear failure of the bolt shank, debonding along the bolt/rock interface and loss of the face plate, are available in the analysis procedure. The performance of a typical conventional rock bolt (fully grouted rebar) and a typical energy-absorbing rock bolt (D-bolt) under the scenarios of suspending loosened blocks and rock dilation is investigated using the proposed model. The reliability of the proposed model is verified by comparing the simulation results with theoretical predictions and experimental observations. The proposed model could be used to reveal the mechanism of each type of rock bolt in realistic scenarios and to provide a numerical way for presenting the detailed profile about the behavior of bolts, in particular at intermediate loading stages.

From Rocks to Cement. What We Make. Science and Technology Education in Philippine Society.

Science.gov (United States)

Philippines Univ., Quezon City. Science Education Center.

This module deals with the materials used in making concrete hollow blocks. Topics discussed include: (1) igneous, metamorphic, and sedimentary rocks; (2) weathering (the process of breaking down rocks) and its effects on rocks; (3) cement; (4) stages in the manufacturing of Portland cement; and (5) the transformation of cement into concrete…

Block Copolymer Adhesion Measured by Contact Mechanics Methods

Science.gov (United States)

Falsafi, A.; Bates, S.; Tirrell, M.; Pocius, A. V.

1997-03-01

Adhesion measurements for a series of polyolefin diblocks and triblocks are presented. These materials have poly(ethylene-propylene) or poly(ethyl-ethylene) rubbery block, and semicrystalline polyethylene block as physical crosslinker. The experiments consist of compression and decompression profiles of contact area between the samples as a function of normal load, analyzed by the JKR Theory. The samples are prepared either by formation of caps from the bulk material in melting and subsequent cooling, and/or coating them in thin films on surface modified elastic foundations of polydimethylsiloxane caps. The latter minimizes the viscoelastic losses which are dominant in the bulk of material. The effect of molecular architecture and microstructure on adhesion energy and dynamics of separation, obtained from decompression experiments, is discussed in view of their influence on molecular arrangements at the contacting surfaces.

Ambient temperature testing of the G-tunnel heated block

International Nuclear Information System (INIS)

Zimmerman, R.M.; Board, M.P.; Hardin, E.L.; Voegele, M.D.

1984-01-01

The G-Tunnel heated block experiment is being conducted on the Nevada Test Site (NTS) as part of the Nevada Nuclear Waste Storage Investigations project (NNWSI). The purpose of the ambient temperature testing phase is to evaluate rock-mass mechanical properties of a block (≅8 m/sup 3/) under biaxial stress changes up to 7.5 MPa above an initialization in situ value of 3.1 MPa. Results indicate that the modulus of deformation ranges from 9.7 to 17.0 GPa and Poisson's ratio ranges from 0.21 to 0.33. In general, the higher values of the modulus and Poisson's ratio were influenced by fracture propagations parallel to the compressive stress field. Other measurements indicated that cross-hole compression (p) wave velocities and single fracture permeability values were relatively insensitive to stress changes above the in situ value

Research of compression strength of fissured rock mass

Directory of Open Access Journals (Sweden)

А. Г. Протосеня

2017-03-01

Full Text Available The article examines a method of forecasting strength properties and their scale effect in fissured rock mass using computational modelling with final elements method in ABAQUS software. It shows advantages of this approach for solving tasks of determining mechanical properties of fissured rock mass, main stages of creating computational geomechanic model of rock mass and conducting a numerical experiment. The article presents connections between deformation during loading of numerical model, inclination angle of main fracture system from uniaxial and biaxial compression strength value, size of the sample of fissured rock mass and biaxial compression strength value under conditions of apatite-nepheline rock deposit at Plateau Rasvumchorr OAO «Apatit» in Kirovsky region of Murmanskaya oblast. We have conducted computational modelling of rock mass blocks testing in discontinuities based on real experiment using non-linear shear strength criterion of Barton – Bandis and compared results of computational experiments with data from field studies and laboratory tests. The calculation results have a high-quality match to laboratory results when testing fissured rock mass samples.

Measurement of cosmogenic 36Cl/Cl in young volcanic rocks: An application of accelerator mass spectrometry in geochronology

International Nuclear Information System (INIS)

Leavy, B.D.; Phillips, F.M.; Elmore, D.; Kubik, P.W.

1987-01-01

We have measured 36 Cl/Cl ratios in a number of young volcanic rocks in order to test the feasibility of using 36 Cl buildup as a geochronometer for materials less than about 700,000 years old. All of the analyzed rocks have been dated independently using K-Ar or other radiometric dating methods and have exposure histories that are known or can be reasonably assumed. Measured 36 Cl/Cl ratios in these rocks are in good agreement with the calculated in-situ 36 Cl buildup curve. These analyses indicate that AMS measurement of 36 Cl buildup in young rocks is a potentially powerful new method for dating materials that had previously been undatable, and as such will have broad applications in volcanology, tectonics, geophysics, and Quaternary research

Thermally induced rock stress increment and rock reinforcement response

International Nuclear Information System (INIS)

Hakala, M.; Stroem, J.; Nujiten, G.; Uotinen, L.; Siren, T.; Suikkanen, J.

2014-07-01

This report describes a detailed study of the effect of thermal heating by the spent nuclear fuel containers on the in situ rock stress, any potential rock failure, and associated rock reinforcement strategies for the Olkiluoto underground repository. The modelling approach and input data are presented together repository layout diagrams. The numerical codes used to establish the effects of heating on the in situ stress field are outlined, together with the rock mass parameters, in situ stress values, radiogenic temperatures and reinforcement structures. This is followed by a study of the temperature and stress evolution during the repository's operational period and the effect of the heating on the reinforcement structures. It is found that, during excavation, the maximum principal stress is concentrated at the transition areas where the profile changes and that, due to the heating from the deposition of spent nuclear fuel, the maximum principal stress rises significantly in the tunnel arch area of NW/SW oriented central tunnels. However, it is predicted that the rock's crack damage (CD, short term strength) value of 99 MPa will not be exceeded anywhere within the model. Loads onto the reinforcement structures will come from damaged and loosened rock which is assumed in the modelling as a free rock wedge - but this is very much a worst case scenario because there is no guarantee that rock cracking would form a free rock block. The structural capacity of the reinforcement structures is described and it is predicted that the current quantity of the rock reinforcement is strong enough to provide a stable tunnel opening during the peak of the long term stress state, with damage predicted on the sprayed concrete liner. However, the long term stability and safety can be improved through the implementation of the principles of the Observational Method. The effect of ventilation is also considered and an additional study of the radiogenic heating effect on the brittle

Thermally induced rock stress increment and rock reinforcement response

Energy Technology Data Exchange (ETDEWEB)

Hakala, M. [KMS Hakala Oy, Nokia (Finland); Stroem, J.; Nujiten, G.; Uotinen, L. [Rockplan, Helsinki (Finland); Siren, T.; Suikkanen, J.

2014-07-15

This report describes a detailed study of the effect of thermal heating by the spent nuclear fuel containers on the in situ rock stress, any potential rock failure, and associated rock reinforcement strategies for the Olkiluoto underground repository. The modelling approach and input data are presented together repository layout diagrams. The numerical codes used to establish the effects of heating on the in situ stress field are outlined, together with the rock mass parameters, in situ stress values, radiogenic temperatures and reinforcement structures. This is followed by a study of the temperature and stress evolution during the repository's operational period and the effect of the heating on the reinforcement structures. It is found that, during excavation, the maximum principal stress is concentrated at the transition areas where the profile changes and that, due to the heating from the deposition of spent nuclear fuel, the maximum principal stress rises significantly in the tunnel arch area of NW/SW oriented central tunnels. However, it is predicted that the rock's crack damage (CD, short term strength) value of 99 MPa will not be exceeded anywhere within the model. Loads onto the reinforcement structures will come from damaged and loosened rock which is assumed in the modelling as a free rock wedge - but this is very much a worst case scenario because there is no guarantee that rock cracking would form a free rock block. The structural capacity of the reinforcement structures is described and it is predicted that the current quantity of the rock reinforcement is strong enough to provide a stable tunnel opening during the peak of the long term stress state, with damage predicted on the sprayed concrete liner. However, the long term stability and safety can be improved through the implementation of the principles of the Observational Method. The effect of ventilation is also considered and an additional study of the radiogenic heating effect on the

Models for calibration of radiometric probes for measurement of natural radioactivity of rocks

International Nuclear Information System (INIS)

Czubek, J.A.; Lenda, A.

1978-01-01

The physical problems connected with the depth of investigation in the natural gamma-ray log measurements in the rocks are solved. The primary and the scattered radiation from gamma-ray lines of potassium, uranium and thorium series have been considered. The scattered radiation has been taken into account using the build-up factor approximation. The dimensions of rock models are calculated assuming the cylindrical form. Some recommendations for the realization of such models using the concrete mixtures are given. (author)

Ground reaction curve based upon block theory

International Nuclear Information System (INIS)

Yow, J.L. Jr.; Goodman, R.E.

1985-09-01

Discontinuities in a rock mass can intersect an excavation surface to form discrete blocks (keyblocks) which can be unstable. Once a potentially unstable block is identified, the forces affecting it can be calculated to assess its stability. The normal and shear stresses on each block face before displacement are calculated using elastic theory and are modified in a nonlinear way by discontinuity deformations as the keyblock displaces. The stresses are summed into resultant forces to evaluate block stability. Since the resultant forces change with displacement, successive increments of block movement are examined to see whether the block ultimately becomes stable or fails. Two-dimensional (2D) and three-dimensional (3D) analytic models for the stability of simple pyramidal keyblocks were evaluated. Calculated stability is greater for 3D analyses than for 2D analyses. Calculated keyblock stability increases with larger in situ stress magnitudes, larger lateral stress ratios, and larger shear strengths. Discontinuity stiffness controls blocks displacement more strongly than it does stability itself. Large keyblocks are less stable than small ones, and stability increases as blocks become more slender

The Gran Sasso underground laboratories (measurements of rock radioactivity and neutron fluxes)

International Nuclear Information System (INIS)

Bellotti, E.; Buraschi, M.; Fiorini, E.; Liguori, C.

1985-01-01

The authors report on measurements of rock radioactivity and neutron flux performed in the Gran Sasso underground laboratories of the INFN in Italy. The Gran Sasso' Laboratories of the INFN are located underground, in galleries which have been excavated under the Gran Sasso mountain range. The minimum rock thickness covering the laboratories is about 1400 m of rock of average density 2.8 g cm/sup -3/, corresponding to a thickness of some 4000 m of water equivalent. The laboratories are located at about 1000 m above sea level. The main destination of these laboratories is to shelter very huge particle detectors which shall detect extremely rare nuclear events of extraordinary interest for particle physics as well as for astrophysics and cosmology. In these laboratories, the radiation background is expected to be extremely low, which is the main condition for performing the proposed experiments

Hillslope evolution in landscapes dominated by layered rocks

Science.gov (United States)

Glade, R.; Anderson, R. S.

2016-12-01

Geologic structure and lithology can exert fundamental control over hillslope evolution. Landforms common across the western US, such as mesas, hogbacks, flatirons, and symmetric ridges bounding dikes, develop in the face of differential weathering of layered rocks in a horizontal, tilted, or vertical structural orientation. These features exhibit a characteristic form distinct from that of homogeneous, soil-mantled hillslopes; linear-to-concave up slopes developed on soft underlying rock typically display a thin, non-uniform layer of mobile regolith and are armored by debris derived from the resistant layers. Feedbacks between weathering and transport of both easily eroded rock and embedded resistant material can explain this general form where debris is dominated by large resistant blocks. In the more general case, however, relationships between the size distribution of the resistant material, relative weathering rates, and boundary condition history are not well-understood. Here we use a 1-D numerical model to explore the evolution of two end-member landforms: a hogback associated with a tilted sandstone bed, and a symmetrical ridge associated with a vertical basalt dike, both bounded by shale bedrock. The first, modeled after the Dakota Hogback near Boulder, Colorado, produces large sandstone blocks that both armor the underlying slope from weathering and stall regolith motion. The vertical dike, modeled after Shiprock, New Mexico, produces both large blocks and small basalt chips that armor the bounding slopes. We show that in both settings, feedbacks between armor and soft rock lead to autogenic processes that modulate base level signals, alter hillslope form, and increase relief over time when compared to a control case with no armor. We explore a variety of boundary conditions in which the presence of these feedbacks leads to a quasi-steady state hillslope form that differs both quantitatively and qualitatively from that expected of a traditional parabolic

Rock stresses (Grimsel rock laboratory)

International Nuclear Information System (INIS)

Pahl, A.; Heusermann, S.; Braeuer, V.; Gloeggler, W.

1989-01-01

On the research and development project 'Rock Stress Measurements' the BGR has developed and tested several test devices and methods at GTS for use in boreholes at a depth of 200 m and has carried out rock mechanical and engineering geological investigations for the evaluation and interpretation of the stress measurements. The first time a computer for data processing was installed in the borehole together with the BGR-probe. Laboratory tests on hollow cylinders were made to study the stress-deformation behavior. To validate and to interprete the measurement results some test methods were modelled using the finite-element method. The dilatometer-tests yielded high values of Young's modulus, whereas laboratory tests showed lower values with a distinct deformation anisotropy. Stress measurements with the BGR-probe yielded horizontal stresses being higher than the theoretical overburden pressure and vertical stresses which agree well with the theoretical overburden pressure. These results are comparable to the results of the hydraulic fracturing tests, whereas stresses obtained with CSIR-triaxial cells are generally lower. The detailed geological mapping of the borehole indicated relationships between stress and geology. With regard to borehole depth different zones of rock structure joint frequency, joint orientation, and orientation of microfissures as well as stress magnitude, stress direction, and degree of deformation anisotropy could be distinguished. (orig./HP) [de

An interlaboratory comparison of methods for measuring rock matrix porosity

International Nuclear Information System (INIS)

Rasilainen, K.; Hellmuth, K.H.; Kivekaes, L.; Ruskeeniemi, T.; Melamed, A.; Siitari-Kauppi, M.

1996-09-01

An interlaboratory comparison study was conducted for the available Finnish methods of rock matrix porosity measurements. The aim was first to compare different experimental methods for future applications, and second to obtain quality assured data for the needs of matrix diffusion modelling. Three different versions of water immersion techniques, a tracer elution method, a helium gas through-diffusion method, and a C-14-PMMA method were tested. All methods selected for this study were established experimental tools in the respective laboratories, and they had already been individually tested. Rock samples for the study were obtained from a homogeneous granitic drill core section from the natural analogue site at Palmottu. The drill core section was cut into slabs that were expected to be practically identical. The subsamples were then circulated between the different laboratories using a round robin approach. The circulation was possible because all methods were non-destructive, except the C-14-PMMA method, which was always the last method to be applied. The possible effect of drying temperature on the measured porosity was also preliminarily tested. These measurements were done in the order of increasing drying temperature. Based on the study, it can be concluded that all methods are comparable in their accuracy. The selection of methods for future applications can therefore be based on practical considerations. Drying temperature seemed to have very little effect on the measured porosity, but a more detailed study is needed for definite conclusions. (author) (4 refs.)

Study on Excitation-triggered Damage Mechanism in Perilous Rock

Science.gov (United States)

Chen, Hongkai; Wang, Shengjuan

2017-12-01

Chain collapse is easy to happen for perilous rock aggregate locating on steep high slope, and one of the key scientific problems is the damage mechanism of perilous rock under excitation action at perilous rock rupture. This paper studies excitation-triggered damage mechanism in perilous rock by wave mechanics, which gives three conclusions. Firstly, when only the normal incidence attenuation spread of excitation wave is considered, while the energy loss is ignored for excitation wave to spread in perilous rock aggregate, the paper establishes one method to calculate peak velocity when excitation wave passes through boundary between any two perilous rock blocks in perilous rock aggregate. Secondly, following by Sweden and Canmet criteria, the paper provides one wave velocity criterion for excitation-triggered damage in the aggregate. Thirdly, assuming double parameters of volume strain of cracks or fissures in rock meet the Weibull distribution, one method to estimate micro-fissure in excitation-triggered damage zone in perilous rock aggregate is established. The studies solve the mechanical description problem for excitation-triggered damage in perilous rock, which is valuable in studies on profoundly rupture mechanism.

The thin section rock physics: Modeling and measurement of seismic wave velocity on the slice of carbonates

Energy Technology Data Exchange (ETDEWEB)

Wardaya, P. D., E-mail: pongga.wardaya@utp.edu.my; Noh, K. A. B. M., E-mail: pongga.wardaya@utp.edu.my; Yusoff, W. I. B. W., E-mail: pongga.wardaya@utp.edu.my [Petroleum Geosciences Department, Universiti Teknologi PETRONAS, Tronoh, Perak, 31750 (Malaysia); Ridha, S. [Petroleum Engineering Department, Universiti Teknologi PETRONAS, Tronoh, Perak, 31750 (Malaysia); Nurhandoko, B. E. B. [Wave Inversion and Subsurface Fluid Imaging Research Laboratory (WISFIR), Dept. of Physics, Institute of Technology Bandung, Bandung, Indonesia and Rock Fluid Imaging Lab, Bandung (Indonesia)

2014-09-25

This paper discusses a new approach for investigating the seismic wave velocity of rock, specifically carbonates, as affected by their pore structures. While the conventional routine of seismic velocity measurement highly depends on the extensive laboratory experiment, the proposed approach utilizes the digital rock physics view which lies on the numerical experiment. Thus, instead of using core sample, we use the thin section image of carbonate rock to measure the effective seismic wave velocity when travelling on it. In the numerical experiment, thin section images act as the medium on which wave propagation will be simulated. For the modeling, an advanced technique based on artificial neural network was employed for building the velocity and density profile, replacing image's RGB pixel value with the seismic velocity and density of each rock constituent. Then, ultrasonic wave was simulated to propagate in the thin section image by using finite difference time domain method, based on assumption of an acoustic-isotropic medium. Effective velocities were drawn from the recorded signal and being compared to the velocity modeling from Wyllie time average model and Kuster-Toksoz rock physics model. To perform the modeling, image analysis routines were undertaken for quantifying the pore aspect ratio that is assumed to represent the rocks pore structure. In addition, porosity and mineral fraction required for velocity modeling were also quantified by using integrated neural network and image analysis technique. It was found that the Kuster-Toksoz gives the closer prediction to the measured velocity as compared to the Wyllie time average model. We also conclude that Wyllie time average that does not incorporate the pore structure parameter deviates significantly for samples having more than 40% porosity. Utilizing this approach we found a good agreement between numerical experiment and theoretically derived rock physics model for estimating the effective seismic

The thin section rock physics: Modeling and measurement of seismic wave velocity on the slice of carbonates

International Nuclear Information System (INIS)

Wardaya, P. D.; Noh, K. A. B. M.; Yusoff, W. I. B. W.; Ridha, S.; Nurhandoko, B. E. B.

2014-01-01

This paper discusses a new approach for investigating the seismic wave velocity of rock, specifically carbonates, as affected by their pore structures. While the conventional routine of seismic velocity measurement highly depends on the extensive laboratory experiment, the proposed approach utilizes the digital rock physics view which lies on the numerical experiment. Thus, instead of using core sample, we use the thin section image of carbonate rock to measure the effective seismic wave velocity when travelling on it. In the numerical experiment, thin section images act as the medium on which wave propagation will be simulated. For the modeling, an advanced technique based on artificial neural network was employed for building the velocity and density profile, replacing image's RGB pixel value with the seismic velocity and density of each rock constituent. Then, ultrasonic wave was simulated to propagate in the thin section image by using finite difference time domain method, based on assumption of an acoustic-isotropic medium. Effective velocities were drawn from the recorded signal and being compared to the velocity modeling from Wyllie time average model and Kuster-Toksoz rock physics model. To perform the modeling, image analysis routines were undertaken for quantifying the pore aspect ratio that is assumed to represent the rocks pore structure. In addition, porosity and mineral fraction required for velocity modeling were also quantified by using integrated neural network and image analysis technique. It was found that the Kuster-Toksoz gives the closer prediction to the measured velocity as compared to the Wyllie time average model. We also conclude that Wyllie time average that does not incorporate the pore structure parameter deviates significantly for samples having more than 40% porosity. Utilizing this approach we found a good agreement between numerical experiment and theoretically derived rock physics model for estimating the effective seismic wave

Backfilling of deposition tunnels, block alternative

International Nuclear Information System (INIS)

Keto, P.; Roennqvist, P.-E.

2007-03-01

This report presents a preliminary process description of backfilling the deposition tunnels with pre-compacted blocks consisting of a mixture of bentonite and ballast (30:70). The process was modified for the Finnish KBS-3V type repository assuming that the amount of spent fuel canisters disposed of yearly is 40. Backfilling blocks (400 x 300 x 300 mm) are prepared in a block production plant with a hydraulic press with an estimated production capacity of 840 blocks per day. Some of the blocks are modified further to fit the profile of the tunnel roof. Prior to the installation of the blocks, the deposition tunnel floor is levelled with a mixture of bentonite and ballast (15:85). The blocks are placed in the tunnel with a modified reach truck. Centrifugal pellet throwing equipment is used to fill the gap between the blocks and the rock surface with bentonite pellets. Based on a preliminary assessment, the average dry density achieved with block backfill is sufficient to fulfil the criteria set for the backfill in order to ensure long-term safety and radiation protection. However, there are uncertainties concerning saturation, homogenisation, erosion, piping and self-healing of the block backfill that need to be studied further with laboratory and field tests. In addition, development efforts and testing concerning block manufacturing and installation are required to verify the technical feasibility of the concept. (orig.)

Cutaneous Sensory Block Area, Muscle-Relaxing Effect, and Block Duration of the Transversus Abdominis Plane Block

DEFF Research Database (Denmark)

Støving, Kion; Rothe, Christian; Rosenstock, Charlotte V

2015-01-01

BACKGROUND AND OBJECTIVES: The transversus abdominis plane (TAP) block is a widely used nerve block. However, basic block characteristics are poorly described. The purpose of this study was to assess the cutaneous sensory block area, muscle-relaxing effect, and block duration. METHODS: Sixteen...... healthy volunteers were randomized to receive an ultrasound-guided unilateral TAP block with 20 mL 7.5 mg/mL ropivacaine and placebo on the contralateral side. Measurements were performed at baseline and 90 minutes after performing the block. Cutaneous sensory block area was mapped and separated...... into a medial and lateral part by a vertical line through the anterior superior iliac spine. We measured muscle thickness of the 3 lateral abdominal muscle layers with ultrasound in the relaxed state and during maximal voluntary muscle contraction. The volunteers reported the duration of the sensory block...

The formation of separation cracks in the extraction of block stone

Directory of Open Access Journals (Sweden)

S.M. Stovpnik

2017-12-01

Full Text Available Currently, the undisputed leader of the destruction of strong rocks by mining as open-pit and underground mining is drilling and blasting method. The main disadvantage of this method is the seismic effect of the explosion to rock, the violation of their integrity, the development of cracks and weakening of the array. The most acute effect is visible while production of block materials, delineation of mine workings. The use of low-blasting explosives, cartridges and charges for special constructions allow us to reduce dynamic impact on blasthole area, however, their use leads to higher costs and in some cases does not provide the necessary end results. For example, in the extraction of block stone losses reach more than thirty percent. One of the possible ways of solving this problem is the use of static methods of destruction of rocks. Currently, a variety of ways of non-explosive destruction, in particular, mechanical methods are developed. Most of these methods are under research and design development. Their industrial use is hampered by lack of equipment, low reliability, high energy consumption, hazardous impact on human, high cost. All these drawbacks force to look for ways to create a cheap and promising way of cutting hard rocks. One of the perspective directions of the static fracture of rocks is the use of non-explosive destructive compositions of LDCs. The features of the management of cracking in holes in the separation of the stone blocks with the use of non-explosive destructive compositions (LDCs with industrial unit that contains control panels are analyzed. The conditions of crack growth of the split relative to the axes of anisotropy with the maximum or minimum strength are defined. The features of the control the direction of fracturing in boreholes in the separation of the stone blocks using a non-explosive mixtures destructive (LDCs with industrial units, which include the control panels are analyzed. The conditions of crack

Evaluation of fracturing process of soft rocks at great depth by AE measurement and DEM simulation

International Nuclear Information System (INIS)

Aoki, Kenji; Mito, Yoshitada; Kurokawa, Susumu; Matsui, Hiroya; Niunoya, Sumio; Minami, Masayuki

2007-01-01

The authors developed the stress-based evaluation system of EDZ by AE monitoring and Distinct Element Method (DEM) simulation. In order to apply this system to the soft rock site, the authors try to grasp the relationship between AE parameters, stress change and rock fracturing process by performing the high stiffness tri-axial compression tests including AE measurements on the soft rock samples, and its simulations by DEM using bonded particle model. As the result, it is found that change in predominant AE frequency is effective to evaluate fracturing process in sedimentary soft rocks, and the relationship between stress change and fracturing process is also clarified. (author)

Measurement of IgG-blocking antibodies: development and application of a radioimmunoassay. [/sup 125/I tracer techniques

Energy Technology Data Exchange (ETDEWEB)

Sobotka, A.K.; Valentine, M.D.; Ishizaka, K.; Lichtenstein, L.M.

1976-07-01

A radioimmunoassay for measuring blocking antibodies has been developed. We used the ragweed antigen E system to show that the same blocking antibodies (IgG) measured by inhibition of antigen-induced leukocyte histamine release were precipitated in the binding assay (r/sub s/ = 0.96 p less than 0.001), thus validating a widely applicable technique for measuring blocking antibodies. Binding of phospholipase-A (Phos-A), the major allergen in honey bee venom, was also shown to correlate significantly with inhibition of histamine release. Hymenoptera (insect) hypersensitivity was used as a model to demonstrate application of the binding assay. Sera obtained from patients undergoing whole body extract therapy contained negligible amounts of specific blocking antibodies. Significantly higher blocking antibody titers to both whole honey bee venom and Phos-A were measured in sera drawn from patients immunized with whole venom. The use of the binding radioimmunoassay should facilitate management of allergic disease processes in which blocking antibodies are thought to be protective.

Approximating the imbibition and absorption behavior of a distribution of matrix blocks by an equivalent spherical block

International Nuclear Information System (INIS)

Zimmerman, R.W.; Bodvarsson, G.S.

1994-03-01

A theoretical study is presented of the effect of matrix block shape and matrix block size distribution on liquid imbibition and solute absorption in a fractured rock mass. It is shown that the behavior of an individual irregularly-shaped matrix block can be modeled with reasonable accuracy by using the results for a spherical matrix block, if one uses an effective radius a = 3V/A, where V is the volume of the block and A is its surface area. In the early-time regime of matrix imbibition, it is shown that a collection of blocks of different sizes can be modeled by a single equivalent block, with an equivalent radius of -1 > -1 , where the average is taken on a volumetrically-weighted basis. In an intermediate time regime, it is shown for the case where the radii are normally distributed that the equivalent radius is reasonably well approximated by the mean radius . In the long-time limit, where no equivalent radius can be rigorously defined, an asymptotic expression is derived for the cumulative diffusion as a function of the mean and the standard deviation of the radius distribution function

Rock burst governance of working face under igneous rock

Science.gov (United States)

Chang, Zhenxing; Yu, Yue

2017-01-01

As a typical failure phenomenon, rock burst occurs in many mines. It can not only cause the working face to cease production, but also cause serious damage to production equipment, and even result in casualties. To explore how to govern rock burst of working face under igneous rock, the 10416 working face in some mine is taken as engineering background. The supports damaged extensively and rock burst took place when the working face advanced. This paper establishes the mechanical model and conducts theoretical analysis and calculation to predict the fracture and migration mechanism and energy release of the thick hard igneous rock above the working face, and to obtain the advancing distance of the working face when the igneous rock fractures and critical value of the energy when rock burst occurs. Based on the specific conditions of the mine, this paper put forward three kinds of governance measures, which are borehole pressure relief, coal seam water injection and blasting pressure relief.

Dynamic response of tunnels in jointed rocks

International Nuclear Information System (INIS)

Heuze, F.E.; Shaffer, R.J.; Walton, O.R.; Maddix, D.M.

1992-03-01

We describe the application of the Discrete Element Method (DEM) to the dynamic analysis of the response of tunnels in jointed rocks to earthquake loading. In situations where large motions of many blocks and collapse occur, the discontinuum-based DEM approach appears superior to other methods of analysis

Development of soda-lime glasses from ornamental rock wastes

International Nuclear Information System (INIS)

Babisk, Michelle Pereira

2009-01-01

During the ornamental rocks production, among other steps, one saw the rock blocks in order to transform them into semi-finished plates. In this step, expressive amounts of residues are generated, which are not properly discharged in nature, without any programmed utilization. The residues of silicide rocks present, in their compositions, oxides which are raw materials employed to fabricate soda-lime type glasses (containing SiO_2, Al_2O_3, CaO, Na_2O and K_2O). On the other hand the residues of carbonatic rocks are constituted of glass net modifier oxides, like CaO and MgO. In this work it was developed four types of soda-lime glasses using ornamental rock residues, where the glasses compositions were adjusted by adding sand, as silica source, as well as sodium and calcium carbonates as sources of Na_2O and CaO, respectively. The obtained glasses were characterized by means of Archimed's method for densities measurements, microstructure by using optical and electronic microscopy, phases by means of X-ray diffraction (XRD), hardness by Vickers indentation, spectroscopy (UV/VIS), and hydrolytic resistance according to ISO 719. The XRD analyses confirmed the compositions total vitrification, where the greened aspect of the samples was due to the presence of the iron oxides. The produced glasses properties were compared with those of commercial glasses aiming their industrial employment. The main difference between the produced glasses and those commercials varied primarily regarding the amount of carbonates incorporated. The results showed that the ornamental rocks residues may be used as raw materials for glasses fabrication, and they found a useful economic destination rather than discharge which promotes undesirable environmental impact. (author)

The testing of thermal-mechanical-hydrological-chemical processes using a large block

International Nuclear Information System (INIS)

Lin, W.; Wilder, D.G.; Blink, J.A.; Blair, S.C.; Buscheck, T.A.; Chesnut, D.A.; Glassley, W.E.; Lee, K.; Roberts, J.J.

1994-01-01

The radioactive decay heat from nuclear waste packages may, depending on the thermal load, create coupled thermal-mechanical-hydrological-chemical (TMHC) processes in the near-field environment of a repository. A group of tests on a large block (LBT) are planned to provide a timely opportunity to test and calibrate some of the TMHC model concepts. The LBT is advantageous for testing and verifying model concepts because the boundary conditions are controlled, and the block can be characterized before and after the experiment. A block of Topopah Spring tuff of about 3 x 3 x 4.5 m will be sawed and isolated at Fran Ridge, Nevada Test Site. Small blocks of the rock adjacent to the large block will be collected for laboratory testing of some individual thermal-mechanical, hydrological, and chemical processes. A constant load of about 4 MPa will be applied to the top and sides of the large block. The sides will be sealed with moisture and thermal barriers. The large block will be heated with one heater in each borehole and guard heaters on the sides so that a dry-out zone and a condensate zone will exist simultaneously. Temperature, moisture content, pore pressure, chemical composition, stress and displacement will be measured throughout the block during the heating and cool-down phases. The results from the experiments on small blocks and the tests on the large block will provide a better understanding of some concepts of the coupled TMHC processes

Some results from the demonstration of indoor radon reduction measures in block basement houses

International Nuclear Information System (INIS)

Henschel, D.B.; Scott, A.G.

1989-01-01

Active soil ventilation techniques have been tested in 26 block-wall basement houses in eastern Pennsylvania with significantly elevated indoor radon concentrations, generally above 740 Bq/m 3 , and the results indicate that radon levels can be reduced substantially often below the U.S. Environmental Protection Agency (EPA) guideline of 148 Bq/m 3 , if effective suction can be drawn on the soil underneath the concrete slabs of these houses. Such effective suction appears achievable when either: (1) the house has a complete loop of drain tile around its footings for water drainage purposes, and suction is drawn on that loop; or (2) a sufficient number of suction pipes can be inserted at the proper locations into the crushed rock or the soil underneath the slab

Block ground interaction of rockfalls

Science.gov (United States)

Volkwein, Axel; Gerber, Werner; Kummer, Peter

2016-04-01

During a rockfall the interaction of the falling block with the ground is one of the most important factors that define the evolution of a rockfall trajectory. It steers the rebound, the rotational movement, possibly brake effects, friction losses and damping effects. Therefore, if most reliable rockfall /trajectory simulation software is sought a good understanding of the block ground interaction is necessary. Today's rockfall codes enable the simulation of a fully 3D modelled block within a full 3D surface . However, the details during the contact, i.e. the contact duration, the penetration depth or the dimension of the marks in the ground are usually not part of the simulation. Recent field tests with rocks between 20 and 80 kg have been conducted on a grassy slope in 2014 [1]. A special rockfall sensor [2] within the blocks measured the rotational velocity and the acting accelerations during the tests. External video records and a so-called LocalPositioningSystem deliver information on the travel velocity. With these data not only the flight phases of the trajectories but also the contacts with the ground can be analysed. During the single jumps of a block the flight time, jump length, the velocity, and the rotation are known. During the single impacts their duration and the acting accelerations are visible. Further, the changes of rotational and translational velocity influence the next jump of the block. The change of the rotational velocity over the whole trajectory nicely visualizes the different phases of a rockfall regarding general acceleration and deceleration in respect to the inclination and the topography of the field. References: [1] Volkwein A, Krummenacher B, Gerber W, Lardon J, Gees F, Brügger L, Ott T (2015) Repeated controlled rockfall trajectory testing. [Abstract] Geophys. Res. Abstr. 17: EGU2015-9779. [2] Volkwein A, Klette J (2014) Semi-Automatic Determination of Rockfall Trajectories. Sensors 14: 18187-18210.

Precise measurement of remanent magnetism of rocks under non-magnetic fields; Mujikaika deno ganseki zanryu jiki no seimitsu sokutei

Energy Technology Data Exchange (ETDEWEB)

Oda, Y; Nakatsuka, K [Tohoku University, Sendai (Japan)

1997-10-22

Various magnetic information data from solidification or deposition up to date are contained in rocks. For the analysis of remanent magnetism, in general, the stable thermal remanent magnetization and the secondary magnetization are separately evaluated using vector variations determined by the location changes of magnetic pole from ac demagnetization or thermal demagnetization. Especially, in geothermal fields, the remanent magnetism in rocks is complicated due to the predominant alteration. When the remanent magnetism of rocks can be precisely measured and the primary and secondary magnetization can be evaluated, important data can be obtained, which represent oriented core samples required for evaluating the geothermal reservoirs. A rock remanent magnetism measuring system using superconductive magnetic shield has been developed, to evaluate the location of magnetic pole. This system can distinguish the remanent magnetization in rocks, and can be applied to the remanent magnetism in rocks in which the location of dipole model is shifted from the center of core. Important basic data of orientation information in rocks can be provided. 6 figs.

Practical aspects of phase correction determination for gauge blocks measured by optical interferometry

International Nuclear Information System (INIS)

Ramotowski, Zbigniew; Salbut, Leszek

2012-01-01

Determination of a phase correction is necessary when making interferometric measurements of gauge blocks with an auxiliary platen. The phase correction compensates for the differences in the reflecting properties of the gauge block and the platen surfaces. Different phase corrections are reported for gauge blocks of different manufacturers, made from different materials and with different surface roughness compared to the platen. In this paper, the process of selection of the best surface roughness parameter and the influence of different complex refractive indices of the same type of material are analysed. The new surface roughness parameter based on the difference between the weighted mean of maximum and minimum asperities of 3D surface roughness measured by a modernized Linnik phase shifting interferometer is introduced. The results of comparison of the phase correction values calculated from the difference between the weighted mean values and calculated from stack method measurements are presented and discussed. The complementary method of phase correction measurement based on the cross-wringing method with the use of the modernized phase shifting Kösters interferometer is proposed. (paper)

Rock stress measurements in ONKALO underground characterisation facility at Olkiluoto at depth of 120 m

International Nuclear Information System (INIS)

Fecker, E.

2007-04-01

In November and December 2006 overcoring stress measurements have been conducted in the boreholes ONK-PP74, ONK-PP75 and ONK-PP77 in a niche of the access tunnel of the ONKALO underground characterisation facility at the Olkiluoto site. Measurements have been done using the CSIRO 3D stress measuring cell. This cell is one of the mostly used cells in the whole world for estimation of the state of stress in rock when doing the borehole measurements. The boreholes are at a depth of about 120 m under the ground surface. The rock where the measurements have been conducted is a foliated migmatitic gneiss (subtypes veined and diatexitic gneiss). Parallel to the overcoring measurements a glue test has been conducted in the laboratory to check the quality of the bonding of the stress cells to the rock. The result showed that the glue makes a good contact between the rock and the stress cell, but air bubbles, which have normally been observed within the glue and at the edges, proved this time to be disadvantageous. Normally such air bubbles have dimensions of about one millimetre, but sometimes certain bubbles may become notably bigger. In the ONKALO overcored probes sawn apart such air bubbles were found both in wet and dry probe conditions. In the test series eight stress measurements have been provided, three of them failed for technical reasons. At one of these three tests the glue has extruded too early, at the other two tests the overcoring was not conducted deep enough. At the remaining five tests in spite of the glue test results a calculation of the stress tensor could be made. Four of these five measurements can be seen as relatively successful. The results of these measurements show a major principal stress of 14.8 MPa in average, trending northwest - southeast, and with a dipping of 11 degrees in average. (orig.)

STRESSES AND DEFORMABILITY OF ROCK MASS UPON OPEN PIT EXPLOITATION OF DIMENSION STONE

Directory of Open Access Journals (Sweden)

Siniša Dunda

2003-12-01

Full Text Available The appearance of increased stresses and deformability of rock mass in the quarry of Zečevo (exploitation field of Selca – island of Brač has caused a considerable decrease of usability of mineral raw materials, which put into question the survival of the pit. Therefore the research and measurements of the state of stresses and deformability of rock mass within the pit were carried out. Besides detailed laboratory testings (testings on small samples performed were trial in-situ testings on large samples including the corresponding numerical analyses. The exploitation of dimension stone by sowing regularly shaped rectangular blocks has been proved to be appropriate for in-situ testing of bending strength. The paper presents the results of carried out laboratory testings, in-situ testings of bending strength including measuring of deformations after sowing cuts and numerical analyses by which the possible range of horizontal stresses was determined. Since for the case of massive rocks, for which the continuum concept is applied, there are no specifically defined methods of corrections, presented is a possible relation for correction of input size values based on the carried out laboratory and in-situ testings.

Studies on microphase-separated structures of block copolymers by neutron reflectivity measurement

International Nuclear Information System (INIS)

Torikai, Naoya; Noda, Ichiro; Matsushita, Yushu; Karim, A.; Satija, S.K.; Han, C.C.; Ebisawa, Toru.

1996-01-01

Segmental distributions of block copolymer chains in lamellar microphase-separated structure and those of homopolymers in block copolymer/homopolymer blends also with lamellar structures were studied by neutron reflectivity measurements. It was revealed that polystyrene and poly(2-vinylpyridine) lamellae were alternately stacked within the thin films of pure block copolymers spin-coated on silicon wafers, and they were preferentially oriented along the direction parallel to film surface. Polystyrene lamella appeared at air surfaces of the films, while poly(2-vinylpyridine) lamella did on silicon surfaces. Segment distribution at lamellar interface was well described by an error function, and the width of the lamellar interface, defined by a full-width half-maximum value of interfacial profile, was estimated to be about 4.5 nm. Segments of block chains adjacent to the chemical junction points connecting different block chains were strongly localized near the lamellar interfaces, while those on the free ends of block chains were distributed all over the lamellar microdomains with their distribution maxima at the centers of lamellae. On the other hand, it was clarified that homopolymers dissolved in the corresponding lamellar microdomains of block copolymers were also distributed throughout the microdomains with their concentration maxima at the centers of the lamellae. (author)

Measuring procedure of experimental data acquisition and data evaluation of acoustic emission in rock disintegration

Directory of Open Access Journals (Sweden)

Lucia Ivaničová

2009-12-01

Full Text Available The paper describes the results of measurements of acoustic signal arising in rock disintegration on the drilling standof the Institute of Geotechnics SAS in Košice. The acoustic signal was registered with sonometer Mediator 2238. Registrationand processing of the acoustic signal is solved as a part of the research grant task within the basic research of the rock disintegrationby drilling.

Final report of the TRUE Block Scale project. 1. Characterisation and model development

Energy Technology Data Exchange (ETDEWEB)

Andersson, Peter; Byegaard, Johan [Geosigma AB, Uppsala (Sweden); Dershowitz, Bill; Doe, Thomas [Golder Associates Inc., Redmond, WA (United States); Hermanson, Jan [Golder Associates AB (Sweden); Meier, Peter [ANDRA, Chatenay-Malabry (France); Tullborg, Eva-Lena [Terralogica AB (Sweden); Winberg, Anders (ed.) [Conterra AB, Partille (Sweden)

2002-04-01

conductors. The remainder of conductive fractures/structures was assigned to the background fracture population. The principal experience from the characterisation and subsequent construction of hydro-structural models is that it is difficult to decouple structural-geological and hydraulic data in building the hydro-structural model. For the most part the hydraulic and geological/structural information was integrated simultaneously in the interpretation. The major conducting structures and their extents between boreholes were determined. The basic hydro-structural model was established using information from the first three boreholes. No major changes to the model were required on the basis of the additional information acquired from the last two boreholes, but more detail was added in terms of a few additional structures and more information about heterogeneity. Difficulties remain with regards to the actual extent of interpreted deterministic structures outside the borehole array. The developed hydro-structural model combined with the understanding of the hydraulic behaviour obtained from performed cross-hole and tracer dilution tests made it possible to identify a target area for well-controlled tracer experiments. The central parts of the TRUE Block Scale rock volume contained water of mixed origin including Deep brine water that is older and more saline than Baltic seawater. The hydraulic head information showed an expected movement of water across the studied block towards the underground openings of the Aespoe Hard Rock Laboratory. The gradient over the central part of the TRUE Block Scale rock volume was about 0.05 m/m. Ambient flow measurements from tracer dilution tests provided a useful complement to other information available on the flow field. The tracer test design had to consider these ambient flows carefully to avoid losing tracer in the flow paths. Transport parameters were presented for the wall rock of structures involved in the TRUE Block Scale tracer

Final report of the TRUE Block Scale project. 1. Characterisation and model development

International Nuclear Information System (INIS)

Andersson, Peter; Byegaard, Johan; Dershowitz, Bill; Doe, Thomas; Hermanson, Jan; Meier, Peter; Tullborg, Eva-Lena; Winberg, Anders

2002-04-01

conductors. The remainder of conductive fractures/structures was assigned to the background fracture population. The principal experience from the characterisation and subsequent construction of hydro-structural models is that it is difficult to decouple structural-geological and hydraulic data in building the hydro-structural model. For the most part the hydraulic and geological/structural information was integrated simultaneously in the interpretation. The major conducting structures and their extents between boreholes were determined. The basic hydro-structural model was established using information from the first three boreholes. No major changes to the model were required on the basis of the additional information acquired from the last two boreholes, but more detail was added in terms of a few additional structures and more information about heterogeneity. Difficulties remain with regards to the actual extent of interpreted deterministic structures outside the borehole array. The developed hydro-structural model combined with the understanding of the hydraulic behaviour obtained from performed cross-hole and tracer dilution tests made it possible to identify a target area for well-controlled tracer experiments. The central parts of the TRUE Block Scale rock volume contained water of mixed origin including Deep brine water that is older and more saline than Baltic seawater. The hydraulic head information showed an expected movement of water across the studied block towards the underground openings of the Aespoe Hard Rock Laboratory. The gradient over the central part of the TRUE Block Scale rock volume was about 0.05 m/m. Ambient flow measurements from tracer dilution tests provided a useful complement to other information available on the flow field. The tracer test design had to consider these ambient flows carefully to avoid losing tracer in the flow paths. Transport parameters were presented for the wall rock of structures involved in the TRUE Block Scale tracer

Complex weathering in drylands: Implications of ‘stress’ history for rock debris breakdown and sediment release

Science.gov (United States)

Warke, P. A.

2007-03-01

Weathering studies have often sought to explain features in terms of a prevailing set of environmental conditions. However, it is clear that in most present-day hot desert regions, the surface rock debris has been exposed to a range of weathering environments and processes. These different weathering conditions can arise in two ways, either from the effects of long-term climate change acting on debris that remains relatively static within the landscape or through the spatial relocation of debris from high to low altitude. Consequently, each fragment of rock may contain a unique weathering-related legacy of damage and alteration — a legacy that may greatly influence its response to present-day weathering activity. Experiments are described in which blocks of limestone, sandstone, granite and basalt are given 'stress histories' by subjecting them to varying numbers of heating and freezing cycles as a form of pre-treatment. These imposed stress histories act as proxies for a weathering history. Some blocks were used in a laboratory salt weathering simulation study while others underwent a 2 year field exposure trial at high, mid and low altitude sites in Death Valley, California. Weight loss and ultrasonic pulse velocity measurements suggest that blocks with stress histories deteriorate more rapidly than unstressed samples of the same rock type exposed to the same environmental conditions. Laboratory data also indicate that the result of imposing a known 'weathering history' on samples by pre-stressing them is an increase in the amount of fine sediment released during salt weathering over a given period of time in comparison to unstressed samples.

Aqueous phase transport through granitic rocks

International Nuclear Information System (INIS)

Bradbury, M.H.; Green, A.

1984-03-01

Using Scottish granites of UK origin it has been established that : (1) pore connectivity exists over metre distances and does not vary significantly with distance. (2) The formation factor may show an increase by a factor of approx. 2 for thin samples (approx. 1 cm). Since diffusion samples are of this order of thickness, laboratory measurements may be overestimating the diffusion coefficient appropriate for use in migration model calculations by a factor of approx. 2. (3) The effect of confining pressures up to approx. 16 MPa is to reduce diffusion coefficients by 50 to 60%. This implies that diffusion coefficients appropriate to granite at depths of approx. 500 m are approximately a factor of two lower than those obtained in the laboratory. (4) Diffusion rates through weathered fissure surfaces can be significantly greater (up to approx. 200 times) than through 'good' rock and are strongly dependent on the severity of the weathering. No evidence for pore blocking by weathering products was found. (5) Latex colloids having a diameter of 0.312 μm neither cause pore blocking nor do they penetrate the pore structure. (author)

The Usability of Rock-Like Materials for Numerical Studies on Rocks

Science.gov (United States)

Zengin, Enes; Abiddin Erguler, Zeynal

2017-04-01

The approaches of synthetic rock material and mass are widely used by many researchers for understanding the failure behavior of different rocks. In order to model the failure behavior of rock material, researchers take advantageous of different techniques and software. But, the majority of all these instruments are based on distinct element method (DEM). For modeling the failure behavior of rocks, and so to create a fundamental synthetic rock material model, it is required to perform related laboratory experiments for providing strength parameters. In modelling studies, model calibration processes are performed by using parameters of intact rocks such as porosity, grain size, modulus of elasticity and Poisson ratio. In some cases, it can be difficult or even impossible to acquire representative rock samples for laboratory experiments from heavily jointed rock masses and vuggy rocks. Considering this limitation, in this study, it was aimed to investigate the applicability of rock-like material (e.g. concrete) to understand and model the failure behavior of rock materials having complex inherent structures. For this purpose, concrete samples having a mixture of %65 cement dust and %35 water were utilized. Accordingly, intact concrete samples representing rocks were prepared in laboratory conditions and their physical properties such as porosity, pore size and density etc. were determined. In addition, to acquire the mechanical parameters of concrete samples, uniaxial compressive strength (UCS) tests were also performed by simultaneously measuring strain during testing. The measured physical and mechanical properties of these extracted concrete samples were used to create synthetic material and then uniaxial compressive tests were modeled and performed by using two dimensional discontinuum program known as Particle Flow Code (PFC2D). After modeling studies in PFC2D, approximately similar failure mechanism and testing results were achieved from both experimental and

Shear-flow coupling in non-planar rock joints

International Nuclear Information System (INIS)

Makurat, A.; Barton, N.

1985-01-01

Crystalline rock masses are regarded as a possible host rock for permanent nuclear waste disposal. During the excavation of the required shafts and tunnels, the initial state of stress will be changed and cause a deformation of the rock mass and discontinuities. During the lifetime of the nuclear repository joint apertures may change due to thermally induced stress variations during the heating and cooling phase. As the conductivity of a joint is very sensitive to its aperture, fluid flow from and towards a repository, as well as the potential transport times of radionuclides are highly dependent on the deformability of the joints. Theoretical calculations of coupled flow in rock joints (Barton et al. 1984) predict an increase of conductivity of several orders of magnitude for the first few millimeters for shear displacement. The shear-dilation-conductivity coupling for two block sizes at two effective stress levels is shown

Petrogenesis of late Paleozoic-to-early Mesozoic granitoids and metagabbroic rocks of the Tengchong Block, SW China: implications for the evolution of the eastern Paleo-Tethys

Science.gov (United States)

Zhu, Ren-Zhi; Lai, Shao-Cong; Qin, Jiang-Feng; Zhao, Shao-Wei

2018-03-01

This paper presents precise zircon U-Pb, bulk-rock geochemical, and Sr-Nd-Pb isotopic data for metagabbro, quartz diorite, and granite units within the Tengchong Block of SW China, which forms the southeastern extension of the Himalayan orogeny and the southwestern section of the Sanjiang orogenic belt, a key region for furthering our understanding of the evolution of the eastern Paleo-Tethys. These data reveal four groups of zircon U-Pb ages that range from the late Paleozoic to the early Mesozoic, including a 263.6 ± 3.6 Ma quartz diorite, a 218.5 ± 5.4 Ma two-mica granite, a 205.7 ± 3.1 Ma metagabbroic unit, and a 195.5 ± 2.2 Ma biotite granite. The quartz diorite in this area contains low concentrations of SiO2 (60.71-64.32 wt%), is sodium-rich, and is metaluminous, indicating formation from magmas generated by a mixed source of metamafic rocks with a significant metapelitic sedimentary material within lower arc crust. The two-mica granites contain high concentrations of SiO2 (73.2-74.3 wt%), are strongly peraluminous, and have evolved Sr-Nd-Pb isotopic compositions, all of which are indicative of a crustal source, most probably from the partial melting of felsic pelite and metagreywacke/psammite material. The metagabbros contain low concentrations of SiO2 (50.17-50.96 wt%), are sodium-rich, contain high concentrations of Fe2O3T (9.79-10.06 wt%) and CaO (6.88-7.12 wt%), and are significantly enriched in the Sr (869-894 ppm) and LREE (198.14-464.60 ppm), indicative of derivation from magmas generated by a metasomatized mantle wedge modified by the sedimentary-derived component. The biotite granites are weakly peraluminous and formed from magmas generated by melting of metasedimentary sources dominated by metagreywacke/psammite material. Combining the petrology and geochemistry of these units with the regional geology of the Indosinian orogenic belt provides evidence for two stages of magmatism: an initial stage that generated magmas during partial melting of

Thermal conductivity of the rocks in the Bureau of Mines Standard Rock Suite

International Nuclear Information System (INIS)

Morgan, M.T.; West, G.A.

1980-01-01

Thermal conductivities of eight rocks from the Bureau of Mines Standard Rock Suite were measured in air over the temperature range 373 to 533 0 K (100 to 260 0 C). The thermal conductivities of these rocks were measured to furnish standards for future comparisons with host rock from prospective nuclear waste repository sites. The thermal conductivity at a given temperature decreased by as much as 9% after a specimen had been heated to the maximum temperature (533 0 K), but additional heating cycles had no further effect. This decrease was smallest in the igneous rocks and largest in the sedimentary types. Variations due to orientation were within the precision of measurements (+- 5%). In most cases the thermal conductivities were linear with the reciprocal of the temperature and were within 14% of published data obtained by other methods. Measurements were made by a cut-bar comparison method in which the sample was sandwiched between two reference or metering bars made of Pyroceram 9606 glass-ceramic. The apparatus consisted of a Dynatech Model TCFCM-N20 comparative thermal conductivity analyzer controlled by a Hewlett Packard Model 3052A data acquisition system. A program was written to increment and cycle the temperature in steps between predetermined initial and maximum values. At each step the thermal conductivity was measured after steady-state conditions were established. The rocks furnished by the Bureau of Mines were quarried in large and fairly homogeneous lots for use by researchers at various laboratories. To investigate any anisotropy, cores were taken from each rock cube perpendicular to each of the cube faces. Samples 2 in. in diameter and approx. 0.75 in. thick were prepared from the cores and were dried in a vacuum oven for at least one month prior to taking measurements

Radiation damage studies on natural and synthetic rock salt utilizing measurements made during electron irradiation

International Nuclear Information System (INIS)

Swyler, K.J.; Levy, P.W.

1977-01-01

The numerous radiation damage effects which will occur in the rock salt surrounding radioactive waste disposal canisters are being investigated with unique apparatus for making optical and other measurements during 1 to 3 MeV electron irradiation. This equipment, consists of a computer controlled double beam spectrophotometer which simultaneously records 256 point absorption and radioluminescence spectra, in either the 200 to 400 or 400 to 800 nm region, every 40 seconds. Most often the measurements commence as the irradiation is started and continue after it is terminated. This procedure provides information on the kinetics and other details of the damage formation process and, when the irradiation is terminated, on both the transient and stable damage components. The exposure rates may be varied between 10 2 or 10 3 to more than 10 8 rad per hour and the sample temperature maintained between 25 and 800 or 900 0 C. Although this project was started recently, measurements have been made on synthetic NaCl and on natural rock salt from two disposal sites and two mines. Both unstrained and purposely strained samples have been used. Most recently, measurements at temperatures between 25 and 200 0 C have been started. The few measurements completed to date indicate that the damage formation kinetics in natural rock salt are quite different from those observed in synthetic NaCl

Radionuclide migration in crystalline rock fractures

International Nuclear Information System (INIS)

Hoelttae, P.

2002-01-01

Crystalline rock has been considered as a host medium for the repository of high radioactive spent nuclear fuel in Finland. The geosphere will act as an ultimate barrier retarding the migration of radionuclides to the biosphere if they are released through the technical barriers. Radionuclide transport is assumed to take place along watercarrying fractures, and retardation will occur both in the fracture and within the rock matrix. To be able to predict the transport and retardation of radionuclides in rock fractures and rock matrices, it is essential to understand the different phenomena involved. Matrix diffusion has been indicated to be an important mechanism, which will retard the transport of radionuclides in rock fractures. Both dispersion and matrix diffusion are processes, which can have similar influences on solute breakthrough curves in fractured crystalline rock. In this work, the migration of radionuclides in crystalline rock fractures was studied by means of laboratory scale column methods. The purpose of the research was to gain a better understanding of various phenomena - particularly matrix diffusion - affecting the transport and retardation behaviour of radionuclides in fracture flow. Interaction between radionuclides and the rock matrix was measured in order to test the compatibility of experimental retardation parameters and transport models used in assessing the safety of underground repositories for spent nuclear fuel. Rock samples of mica gneiss and of unaltered, moderately altered and strongly altered tonalite represented different rock features and porosities offering the possibility to determine experimental boundary limit values for parameters describing both the transport and retardation of radionuclides and rock matrix properties. The dominant matrix diffusion behaviour was demonstrated in porous ceramic column and gas diffusion experiments. Demonstration of the effects of matrix diffusion in crystalline rock fracture succeeded for the

Ferguson rock slide buries California State Highway near Yosemite National Park

Science.gov (United States)

Harp, Edwin L.; Reid, Mark E.; Godt, Jonathan W.; DeGraff, Jerome V.; Gallegos, Alan J.

2008-01-01

During spring 2006, talus from the toe area of a rock-block slide of about 800,000 m3 buried California State Highway 140, one of the main routes into heavily-visited Yosemite National Park, USA. Closure of the highway for 92 days caused business losses of about 4.8 million USD. The rock slide, composed of slate and phyllite, moved slowly downslope from April to June 2006, creating a fresh head scarp with 9-12 m of displacement. Movement of the main rock slide, a re-activation of an older slide, was triggered by an exceptionally wet spring 2006, following a very wet spring 2005. As of autumn 2006, most of the main slide appeared to be at rest, although rocks occasionally continued to fall from steep, fractured rock masses at the toe area of the slide. Future behavior of the slide is difficult to predict, but possible scenarios range from continued scattered rock fall to complete rapid failure of the entire mass. Although unlikely except under very destabilizing circumstances, a worst-case, rapid failure of the entire rock slide could extend across the Merced River, damming the river and creating a reservoir. As a temporary measure, traffic has been rerouted to the opposite side of the Merced River at about the same elevation as the buried section of Highway 140. A state-of-the-art monitoring system has been installed to detect movement in the steep talus slope, movement of the main slide mass, local strong ground motion from regional earthquakes, and sudden changes in stream levels, possibly indicating damming of the river by slide material.

Progress report on pre-test calculations for the large block test

International Nuclear Information System (INIS)

Lee, K.H.

1995-01-01

The U.S. Department of Energy's (DOE) Yucca Mountain Site Characterization Project (YMP) is investigating the suitability of the Topopah Spring tuff in the thick vadose zone at Yucca Mountain, Nevada, as a host rock for permanent disposal of high-level radioactive waste. As part of the YMP, a group of field tests, referred to as the Large Block Test (LBT), will be conducted on a large electrically heated block of Topopah Spring tuff, isolated at Fran Ridge, Nevada Test Site. The block, which will be 3 x 3 m in horizontal dimensions and 4.5 m in height, will be heated by electrical heaters. The goals of the LBT axe to gain information on the coupled thermal-mechanical-hydrological-chemical processes active in the near-field environment of a repository; to provide field data for testing and calibrating models; and to help the development of measurement systems and techniques. This progress report presents results of on-going numerical modeling calculations carried out in support of the LBT design. An equivalent continuum model with an upper boundary temperature of 60 degrees C was used to simulate the hydrothermal response of the block to heating over a one-year period. The total heating power was started at 1500 W and later reduced to maintain an approximately uniform temperature of 138-140 degrees C. For a homogeneous bulk permeability case, the results show the formation of a distinct dry-out zone in and around the heater plane, and well-developed condensation zones above and below the heater plane. For a heterogeneous permeability distribution, the condensation zone above the heater plane was not well developed. This difference in results suggests that water saturation changes might be sensitive to changes in bulk permeability distribution. Rock temperatures were almost unaffected by permeability distribution. Heat flow was dominated by conduction. No liquid flow through the top of the block was predicted

Measurements of cutter forces and cutter temperature of boring machine in Aespoe Hard Rock Laboratory

Energy Technology Data Exchange (ETDEWEB)

Zhang, Z.X.; Kou, S.Q.; Lindqvist, P.-A. [Luleaa Univ. of Technology (Sweden)

2001-04-01

This report presents both the testing methods used and the testing results obtained for cutter forces and cutter temperature during field boring in Aespoe Hard Rock Laboratory. In order to estimate the strains induced by cutter forces in the cutter shaft and choose proper transducers, first a numerical simulation was performed. The simulation results indicated that the cutter forces should be measurable by ordinary strain gauges. Furthermore, an independent three-direction loading system for laboratory calibration was set up to solve force-coupling problems appearing in field measurements. By means of the established measuring system, which was proved successfully in the laboratory, the normal forces, tangential forces, and side forces of two button cutters in the boring machine were measured in the field. In addition, the temperature in the shaft of the front cutter was measured. After the measurements of the cutter forces and cutter temperature, rock core samples were taken from the bottom and the wall of the testing borehole. Then the samples were cut, polished, and examined by means of the Scanning Electron Microscope (SEM). After that, the lengths of major cracks induced by the cutters in the rock samples were measured, and an approximate relationship between the length of the medium cracks and the relevant cutter forces was obtained. This relationship was compared with the theoretical relationship established before. Finally, according to the measured results, the cracked zones around the borehole were described. The results show that: (1) there are two kinds of cracked zones: one in the borehole wall and the other in the bottom of the borehole. The depth of the cracked zone in the borehole bottom is much larger than that in the borehole wall because the maximum normal force of the front cutter is always much larger than that of the gauge cutter. (2) Each cracked zone includes a densely cracked zone and all the longest medium cracks caused by mechanical

Three-dimensional Reconstruction of Block Shape Irregularity and its Effects on Block Impacts Using an Energy-Based Approach

Science.gov (United States)

Zhang, Yulong; Liu, Zaobao; Shi, Chong; Shao, Jianfu

2018-04-01

This study is devoted to three-dimensional modeling of small falling rocks in block impact analysis in energy view using the particle flow method. The restitution coefficient of rockfall collision is introduced from the energy consumption mechanism to describe rockfall-impacting properties. Three-dimensional reconstruction of falling block is conducted with the help of spherical harmonic functions that have satisfactory mathematical properties such as orthogonality and rotation invariance. Numerical modeling of the block impact to the bedrock is analyzed with both the sphere-simplified model and the 3D reconstructed model. Comparisons of the obtained results suggest that the 3D reconstructed model is advantageous in considering the combination effects of rockfall velocity and rotations during colliding process. Verification of the modeling is carried out with the results obtained from other experiments. In addition, the effects of rockfall morphology, surface characteristics, velocity, and volume, colliding damping and relative angle are investigated. A three-dimensional reconstruction modulus of falling blocks is to be developed and incorporated into the rockfall simulation tools in order to extend the modeling results at block scale to slope scale.

Rock pushing and sampling under rocks on Mars

Science.gov (United States)

Moore, H.J.; Liebes, S.; Crouch, D.S.; Clark, L.V.

1978-01-01

Viking Lander 2 acquired samples on Mars from beneath two rocks, where living organisms and organic molecules would be protected from ultraviolet radiation. Selection of rocks to be moved was based on scientific and engineering considerations, including rock size, rock shape, burial depth, and location in a sample field. Rock locations and topography were established using the computerized interactive video-stereophotogrammetric system and plotted on vertical profiles and in plan view. Sampler commands were developed and tested on Earth using a full-size lander and surface mock-up. The use of power by the sampler motor correlates with rock movements, which were by plowing, skidding, and rolling. Provenance of the samples was determined by measurements and interpretation of pictures and positions of the sampler arm. Analytical results demonstrate that the samples were, in fact, from beneath the rocks. Results from the Gas Chromatograph-Mass Spectrometer of the Molecular Analysis experiment and the Gas Exchange instrument of the Biology experiment indicate that more adsorbed(?) water occurs in samples under rocks than in samples exposed to the sun. This is consistent with terrestrial arid environments, where more moisture occurs in near-surface soil un- der rocks than in surrounding soil because the net heat flow is toward the soil beneath the rock and the rock cap inhibits evaporation. Inorganic analyses show that samples of soil from under the rocks have significantly less iron than soil exposed to the sun. The scientific significance of analyses of samples under the rocks is only partly evaluated, but some facts are clear. Detectable quantities of martian organic molecules were not found in the sample from under a rock by the Molecular Analysis experiment. The Biology experiments did not find definitive evidence for Earth-like living organisms in their sample. Significant amounts of adsorbed water may be present in the martian regolith. The response of the soil

Experimental Studies on Permeability of Intact and Singly Jointed Meta-Sedimentary Rocks Under Confining Pressure

Science.gov (United States)

Wong, Louis Ngai Yuen; Li, Diyuan; Liu, Gang

2013-01-01

Three different types of permeability tests were conducted on 23 intact and singly jointed rock specimens, which were cored from rock blocks collected from a rock cavern under construction in Singapore. The studied rock types belong to inter-bedded meta-sandstone and meta-siltstone with very low porosity and high uniaxial compressive strength. The transient pulse water flow method was employed to measure the permeability of intact meta-sandstone under a confining pressure up to 30 MPa. It showed that the magnitude order of meta-sandstone's intrinsic permeability is about 10-18 m2. The steady-state gas flow method was used to measure the permeability of both intact meta-siltstone and meta-sandstone in a triaxial cell under different confining pressures spanning from 2.5 to 10 MPa. The measured permeability of both rock types ranged from 10-21 to 10-20 m2. The influence of a single natural joint on the permeability of both rock types was studied by using the steady-state water flow method under different confining pressures spanning from 1.25 to 5.0 MPa, including loading and unloading phases. The measured permeability of both jointed rocks ranged from 10-13 to 10-11 m2, where the permeability of jointed meta-siltstone was usually slightly lower than that of jointed meta-sandstone. The permeability of jointed rocks decreases with increasing confining pressure, which can be well fitted by an empirical power law relationship between the permeability and confining pressure or effective pressure. The permeability of partly open cracked specimens is lower than that of open cracked specimens, but it is higher than that of the specimen with a dominant vein for the meta-sandstone under the same confining pressure. The permeability of open cracked rock specimens will partially recover during the unloading confining pressure process. The equivalent crack (joint) aperture is as narrow as a magnitude order of 10-6 m (1 μm) in the rock specimens under confining pressures

Plume-induced dynamic instabilities near cratonic blocks: Implications for P-T-t paths and metallogeny

NARCIS (Netherlands)

Guillou-Frottier, L.; Burov, E.; Cloetingh, S.; Le Goff, E.; Deschamps, Y.; Huet, B.; Bouchot, V.

2012-01-01

Plume head - lithosphere interactions around cratonic blocks result in thermo-mechanical disturbances that lead to heating and burial phases of crustal rocks. We present results from numerical models of plume head - cratonic blocks interactions where a free upper surface condition and realistic

Wave Shape and Impact Pressure Measurements at a Rock Coast Cliff

Science.gov (United States)

Varley, S. J.; Rosser, N. J.; Brain, M.; Vann Jones, E. C.

2016-02-01

Rock coast research focuses largely on wave behaviour across beaches and shore platforms but rarely considers direct wave interaction with cliffs. Hydraulic action is one of the most important drivers of erosion along rock coasts. The magnitude of wave impact pressure has been shown by numerical and laboratory studies to be related to the wave shape. In deep water, a structure is only subjected to the hydrostatic pressure due to the oscillating clapotis. Dynamic pressures, related to the wave celerity, are exerted in shallower water when the wave is breaking at the point of impact; very high magnitude, short duration shock pressures are theorised to occur when the approaching wavefront is vertical. As such, wave shape may directly influence the potential of the impact to weaken rock and cause erosion. Measurements of impact pressure at coastal cliffs are limited, and the occurrence and influence of this phenomenon is currently poorly constrained. To address this, we have undertaken a field monitoring study on the magnitude and vertical distribution of wave impact pressures at the rocky, macro-tidal coastline of Staithes, North Yorkshire, UK. A series of piezo-resistive pressure transducers and a camera were installed at the base of the cliff during low tide. Transducers were deployed vertically up the cliff face and aligned shore-normal to capture the variation in static and dynamic pressure with height during a full spring tidal cycle. Five minute bursts of 5 kHz pressure readings and 4 Hz wave imaging were sampled every 30 minutes for six hours during high tide. Pressure measurements were then compensated for temperature and combined with wave imaging to produce a pressure time series and qualitative wave shape category for each wave impact. Results indicate the presence of a non-linear relationship between pressure impact magnitude, the occurrence of shock pressures, wave shape and tidal stage, and suggest that breaker type on impact (and controls thereof) may

Using an Augmented Lagrangian Method and block fracturing in the DDA method

International Nuclear Information System (INIS)

Lin, C.T.; Amadei, B.; Sture, S.

1994-01-01

This paper presents two extensions to the Discontinuous Deformation Analysis (DDA) method orginally proposed by Shi for modeling the response of blocky rock masses to mechanical loading. The first extension consists of improving the block contact algorithm. An Augmented Lagrangian Method is used to replace the Penalty Method orginally proposed. It allows Lagrange multipliers to be introduced without increasing the number of equations that need to be solved and thus, block contract forces can be calculated more accurately. A block fracturing capability based on a three-parameter Mohr-Coulomb criterion represents the second extension. It allows for shear or tensile fracturing of intact blocks and the formation of smaller blocks

Rb-Sr geochronolgy of the Jervois Range area in the eastern part of the Arunta Block, NT

International Nuclear Information System (INIS)

Black, L.P.

1980-01-01

New Rb-Sr isotopic data are presented for the Jervois Range area in the eastern part of the Arunta Block. The post-metamorphic Jinka and Jervois Granites yield an age of about 1750 m.y. An alaskitic granite is dated at about 1460 m.y. Pegmatite formation occurred about 1660 m.y. ago. Mineral ages are generally younger than total-rock ages, but no values significantly less than that of the alaskitic granite were found. This means that the Alice Springs Orogeny, which extensively reset large areas of the Arunta Block to the west, did not effect the Jervois area. In this and other geochronological comparisons, the Jervois area seems more akin to the rocks of the Tennant Creek Block, 400 km to the northwest, than to those of the Arunta Block

The Usability of Noise Level from Rock Cutting for the Prediction of Physico-Mechanical Properties of Rocks

Science.gov (United States)

Delibalta, M. S.; Kahraman, S.; Comakli, R.

2015-11-01

Because the indirect tests are easier and cheaper than the direct tests, the prediction of rock properties from the indirect testing methods is important especially for the preliminary investigations. In this study, the predictability of the physico-mechanical rock properties from the noise level measured during cutting rock with diamond saw was investigated. Noise measurement test, uniaxial compressive strength (UCS) test, Brazilian tensile strength (BTS) test, point load strength (Is) test, density test, and porosity test were carried out on 54 different rock types in the laboratory. The results were statistically analyzed to derive estimation equations. Strong correlations between the noise level and the mechanical rock properties were found. The relations follow power functions. Increasing rock strength increases the noise level. Density and porosity also correlated strongly with the noise level. The relations follow linear functions. Increasing density increases the noise level while increasing porosity decreases the noise level. The developed equations are valid for the rocks with a compressive strength below 150 MPa. Concluding remark is that the physico-mechanical rock properties can reliably be estimated from the noise level measured during cutting the rock with diamond saw.

Strategy for a Rock Mechanics Site Descriptive Model. Development and testing of the theoretical approach

Energy Technology Data Exchange (ETDEWEB)

Staub, Isabelle; Fredriksson, Anders; Outters, Nils [Golder Associates AB, Uppsala (Sweden)

2002-05-01

In the purpose of studying the possibilities of a Deep Repository for spent fuel, the Swedish Nuclear and Fuel Management Company (SKB) is currently planning for Site Investigations. Data collected from these Site Investigations are interpreted and analysed to achieve the full Site Description, which is built up of models from all the disciplines that are considered of importance for the Site Description. One of these models is the Rock Mechanical Descriptive Model,which would be developed for any site in hard crystalline rock, and is a combination and evaluation of the characterisation of rock mass by means of empirical relationships and a theoretical approach based on numerical modelling. The present report describes the theoretical approach. The characterisation of the mechanical properties of the rock mass, viewed as a unit consisting of intact rock and fractures, is achieved by numerical simulations with following input parameters: initial stresses, fracture geometry, distribution of rock mechanical properties, such as deformation and strength parameters, for the intact rock and for the fractures. The numerical modelling was performed with the two-dimensional code UDEC, and the rock block models were generated from 2D trace sections extracted from the 3D Discrete Fracture Network (DFN) model. Assumptions and uncertainties related to the set-up of the model are considered. The numerical model was set-up to simulate a plain strain-loading test. Different boundary conditions were applied on the model for simulating stress conditions (I) in the undisturbed rock mass, and (II) at the proximity of a tunnel. In order to assess the reliability of the model sensitivity analyses have been conducted on some rock block models for defining the dependency of mechanical properties to in situ stresses, the influence of boundary conditions, rock material and joint constitutive models used to simulate the behaviour of intact rock and fractures, domain size and anisotropy. To

Strategy for a Rock Mechanics Site Descriptive Model. Development and testing of the theoretical approach

International Nuclear Information System (INIS)

Staub, Isabelle; Fredriksson, Anders; Outters, Nils

2002-05-01

In the purpose of studying the possibilities of a Deep Repository for spent fuel, the Swedish Nuclear and Fuel Management Company (SKB) is currently planning for Site Investigations. Data collected from these Site Investigations are interpreted and analysed to achieve the full Site Description, which is built up of models from all the disciplines that are considered of importance for the Site Description. One of these models is the Rock Mechanical Descriptive Model,which would be developed for any site in hard crystalline rock, and is a combination and evaluation of the characterisation of rock mass by means of empirical relationships and a theoretical approach based on numerical modelling. The present report describes the theoretical approach. The characterisation of the mechanical properties of the rock mass, viewed as a unit consisting of intact rock and fractures, is achieved by numerical simulations with following input parameters: initial stresses, fracture geometry, distribution of rock mechanical properties, such as deformation and strength parameters, for the intact rock and for the fractures. The numerical modelling was performed with the two-dimensional code UDEC, and the rock block models were generated from 2D trace sections extracted from the 3D Discrete Fracture Network (DFN) model. Assumptions and uncertainties related to the set-up of the model are considered. The numerical model was set-up to simulate a plain strain-loading test. Different boundary conditions were applied on the model for simulating stress conditions (I) in the undisturbed rock mass, and (II) at the proximity of a tunnel. In order to assess the reliability of the model sensitivity analyses have been conducted on some rock block models for defining the dependency of mechanical properties to in situ stresses, the influence of boundary conditions, rock material and joint constitutive models used to simulate the behaviour of intact rock and fractures, domain size and anisotropy. To

Measurement of rocking curve wings at high x-ray energies

International Nuclear Information System (INIS)

Chapman, D.; Hastings, J.; Moulin, H.; Siddons, D.P.; Garrett, R.F.; Nachaliel, E.; Dilmanian, F.A.

1991-01-01

Measurements done recently at the NSLS have indicated that the level of intensity found in the wings of diffraction peaks from silicon at higher x-ray energies (>20keV) far exceeds the value which would be predicted based on the dynamical theory. We have measured Si(220) double crystal rocking curves at the 40keV fundamental and harmonics with various crystal scattering geometries: Bragg-Bragg, Laue-Bragg, Laue-Lauel. The comparison of the Bragg and Laue case diffraction geometries was done to determine scattering volume effects. Comparisons with dynamical theory calculations will be discussed. These measurements have been carried out in order to assess the level of harmonic contamination which will be present from a double crystal monochromator being designed for the X17 Superconducting Wiggler Beamline

GEOMECHANICAL OBSERVATIONS DURING THE LARGE BLOCK TEST

International Nuclear Information System (INIS)

STEPHEN C. BLAIR AND STEPHANIE A. WOOD

1998-01-01

This paper presents an overview of the geomechanical studies conducted at the Large Block Test at Fran Ridge, near Yucca Mountain, Nevada. The 3-dimensional geomechanical response of the rock to heating is being monitored using instrumentation mounted in boreholes and on the surface of the block. Results show that thermal expansion of the block began a few hours after the start of heating, and is closely correlated with the thermal history. Horizontal expansion increases as a linear function of height. Comparison of observed deformations with continuum simulations shows that below the heater plane deformation is smaller than predicted, while above the heater plane, observed deformation is larger than predicted, and is consistent with opening of vertical fractures. Fracture monitors indicate that movement on a large horizontal fracture is associated with hydrothermal behavior

Igneous rocks formed by hypervelocity impact

Science.gov (United States)

Osinski, Gordon R.; Grieve, Richard A. F.; Bleacher, Jacob E.; Neish, Catherine D.; Pilles, Eric A.; Tornabene, Livio L.

2018-03-01

Igneous rocks are the primary building blocks of planetary crusts. Most igneous rocks originate via decompression melting and/or wet melting of protolith lithologies within planetary interiors and their classification and compositional, petrographic, and textural characteristics, are well-studied. As our exploration of the Solar System continues, so too does the inventory of intrusive and extrusive igneous rocks, settings, and processes. The results of planetary exploration have also clearly demonstrated that impact cratering is a ubiquitous geological process that has affected, and will continue to affect, all planetary objects with a solid surface, whether that be rock or ice. It is now recognized that the production of igneous rocks is a fundamental outcome of hypervelocity impact. The goal of this review is to provide an up-to-date synthesis of our knowledge and understanding of igneous rocks formed by hypervelocity impact. Following a brief overview of the basics of the impact process, we describe how and why melts are generated during impact events and how impact melting differs from endogenic igneous processes. While the process may differ, we show that the products of hypervelocity impact can share close similarities with volcanic and shallow intrusive igneous rocks of endogenic origin. Such impact melt rocks, as they are termed, can display lobate margins and cooling cracks, columnar joints and at the hand specimen and microscopic scale, such rocks can display mineral textures that are typical of volcanic rocks, such as quench crystallites, ophitic, porphyritic, as well as features such as vesicles, flow textures, and so on. Historically, these similarities led to the misidentification of some igneous rocks now known to be impact melt rocks as being of endogenic origin. This raises the question as to how to distinguish between an impact versus an endogenic origin for igneous-like rocks on other planetary bodies where fieldwork and sample analysis may not

An evaluation of the active fracture concept with modeling unsaturated flow and transport in a fractured meter-sized block of rock

International Nuclear Information System (INIS)

Seol, Yongkoo; Kneafsey, Timothy J.; Ito, Kazumasa

2003-01-01

Numerical simulation is an effective and economical tool for optimally designing laboratory experiments and deriving practical experimental conditions. We executed a detailed numerical simulation study to examine the active fracture concept (AFC, Liu et al., 1998) using a cubic meter-sized block model. The numerical simulations for this study were performed by applying various experimental conditions, including different bottom flow boundaries, varying injection rates, and different fracture-matrix interaction (by increasing absolute matrix permeability at the fracture matrix boundary) for a larger fracture interaction under transient or balanced-state flow regimes. Two conceptual block models were developed based on different numerical approaches: a two-dimensional discrete-fracture-network model (DFNM) and a one-dimensional dual continuum model (DCM). The DFNM was used as a surrogate for a natural block to produce synthetic breakthrough curves of water and tracer concentration under transient or balanced-state conditions. The DCM is the approach typically used for the Yucca Mountain Project because of its computational efficiency. The AFC was incorporated into the DCM to capture heterogeneous flow patterns that occur in unsaturated fractured rocks. The simulation results from the DCM were compared with the results from the DFNM to determine whether the DCM could predict the water flow and tracer transport observed in the DFNM at the scale of the experiment. It was found that implementing the AFC in the DCM improved the prediction of unsaturated flow and that the flow and transport experiments with low injection rates in the DFNM were compared better with the AFC implemented DCM at the meter scale. However, the estimated AFC parameter varied from 0.38 to 1.0 with different flow conditions, suggesting that the AFC parameter was not a sufficient to fully capture the complexity of the flow processes in a one meter sized discrete fracture network

Rock strength under explosive loading

International Nuclear Information System (INIS)

Rimer, N.; Proffer, W.

1993-01-01

This presentation emphasizes the importance of a detailed description of the nonlinear deviatoric (strength) response of the surrounding rock in the numerical simulation of underground nuclear explosion phenomenology to the late times needed for test ban monitoring applications. We will show how numerical simulations which match ground motion measurements in volcanic tuffs and in granite use the strength values obtained from laboratory measurements on small core samples of these rocks but also require much lower strength values after the ground motion has interacted with the rock. The underlying physical mechanisms for the implied strength reduction are not yet well understood, and in fact may depend on the particular rock type. However, constitutive models for shock damage and/or effective stress have been used successfully at S-Cubed in both the Geophysics Program (primarily for DARPA) and the Containment Support Program (for DNA) to simulate late time ground motions measured at NTS in many different rock types

Long-term solute diffusion in a granite block immersed in sea water

International Nuclear Information System (INIS)

Jefferies, N.L.

1988-01-01

Solute diffusion profiles for Cl - , Br - , F - and SO 4 -- have been measured in a granite block which was immersed in the sea at Falmouth, Cornwall, for 30 years. Leachable concentrations of Cl - and Br - were found to be higher in the block than in quarry samples of granite, which demonstrates that solutes from the sea water have diffused into the block. The Cl - and Br - profiles within the block were flat, implying that equilibrium has been reached between the seawater and granite porewater. The apparent diffusion coefficient and the solute accessible porosity have been estimated from these profiles, and these were used to calculate the intrinsic diffusion coefficient which was then compared with previously obtained laboratory data. Concentration profiles for F - and S0 4 -- indicate that these elements have high concentrations at the margins of the block (to depths of up to 15 cm) and are in the process of diffusing outwards into the surrounding seawater. The initially high porewater concentrations of F - and SO 4 -- in the block are believed to result from weathering of the granite prior to its immersion in the sea, due to the breakdown of primary minerals such as pyrite and the micas. F - and SO 4 -- sorptivity has been estimated from an analysis of the porewater concentration profiles. This preliminary experiment has demonstrated the potential for the measurement of solute migration in granite, as a result of the rock having been immersed in seawater. This work is part of the CEC project MIRAGE (radionuclide migration in the geosphere)- Second phase (1985-89) Research area 'Natural analogues'

Source rock

Directory of Open Access Journals (Sweden)

Abubakr F. Makky

2014-03-01

Full Text Available West Beni Suef Concession is located at the western part of Beni Suef Basin which is a relatively under-explored basin and lies about 150 km south of Cairo. The major goal of this study is to evaluate the source rock by using different techniques as Rock-Eval pyrolysis, Vitrinite reflectance (%Ro, and well log data of some Cretaceous sequences including Abu Roash (E, F and G members, Kharita and Betty formations. The BasinMod 1D program is used in this study to construct the burial history and calculate the levels of thermal maturity of the Fayoum-1X well based on calibration of measured %Ro and Tmax against calculated %Ro model. The calculated Total Organic Carbon (TOC content from well log data compared with the measured TOC from the Rock-Eval pyrolysis in Fayoum-1X well is shown to match against the shale source rock but gives high values against the limestone source rock. For that, a new model is derived from well log data to calculate accurately the TOC content against the limestone source rock in the study area. The organic matter existing in Abu Roash (F member is fair to excellent and capable of generating a significant amount of hydrocarbons (oil prone produced from (mixed type I/II kerogen. The generation potential of kerogen in Abu Roash (E and G members and Betty formations is ranging from poor to fair, and generating hydrocarbons of oil and gas prone (mixed type II/III kerogen. Eventually, kerogen (type III of Kharita Formation has poor to very good generation potential and mainly produces gas. Thermal maturation of the measured %Ro, calculated %Ro model, Tmax and Production index (PI indicates that Abu Roash (F member exciting in the onset of oil generation, whereas Abu Roash (E and G members, Kharita and Betty formations entered the peak of oil generation.

Elastic Rock Heterogeneity Controls Brittle Rock Failure during Hydraulic Fracturing

Science.gov (United States)

Langenbruch, C.; Shapiro, S. A.

2014-12-01

For interpretation and inversion of microseismic data it is important to understand, which properties of the reservoir rock control the occurrence probability of brittle rock failure and associated seismicity during hydraulic stimulation. This is especially important, when inverting for key properties like permeability and fracture conductivity. Although it became accepted that seismic events are triggered by fluid flow and the resulting perturbation of the stress field in the reservoir rock, the magnitude of stress perturbations, capable of triggering failure in rocks, can be highly variable. The controlling physical mechanism of this variability is still under discussion. We compare the occurrence of microseismic events at the Cotton Valley gas field to elastic rock heterogeneity, obtained from measurements along the treatment wells. The heterogeneity is characterized by scale invariant fluctuations of elastic properties. We observe that the elastic heterogeneity of the rock formation controls the occurrence of brittle failure. In particular, we find that the density of events is increasing with the Brittleness Index (BI) of the rock, which is defined as a combination of Young's modulus and Poisson's ratio. We evaluate the physical meaning of the BI. By applying geomechanical investigations we characterize the influence of fluctuating elastic properties in rocks on the probability of brittle rock failure. Our analysis is based on the computation of stress fluctuations caused by elastic heterogeneity of rocks. We find that elastic rock heterogeneity causes stress fluctuations of significant magnitude. Moreover, the stress changes necessary to open and reactivate fractures in rocks are strongly related to fluctuations of elastic moduli. Our analysis gives a physical explanation to the observed relation between elastic heterogeneity of the rock formation and the occurrence of brittle failure during hydraulic reservoir stimulations. A crucial factor for understanding

Tectonic constraints on a deep-seated rock slide in weathered crystalline rocks

Science.gov (United States)

Borrelli, Luigi; Gullà, Giovanni

2017-08-01

Deep-seated rock slides (DSRSs), recognised as one of the most important mass wasting processes worldwide, involve large areas and cause several consequences in terms of environmental and economic damage; they result from a complex of controlling features and processes. DSRSs are common in Calabria (southern Italy) where the complex geo-structural setting plays a key role in controlling the geometry of the failure surface and its development. This paper describes an integrated multi-disciplinary approach to investigate a DSRS in Palaeozoic high-grade metamorphic rocks of the Sila Massif; it focuses on the definition of the internal structure and the predisposing factors of the Serra di Buda landslide near the town of Acri, which is a paradigm for numerous landslides in this area. An integrated interdisciplinary study based on geological, structural, and geomorphological investigations-including field observations of weathering grade of rocks, minero-petrographic characterisations, geotechnical investigations and, in particular, fifteen years of displacement monitoring-is presented. Stereoscopic analysis of aerial photographs and field observations indicate that the Serra di Buda landslide consists of two distinct compounded bodies: (i) an older and dormant body ( 7 ha) and (ii) a more recent and active body ( 13 ha) that overlies the previous one. The active landslide shows movement linked to a deep-seated translational rock slide (block slide); the velocity scale ranges from slow (1.6 m/year during paroxysmal stages) to extremely slow (affected by weathering processes that significantly reduce the rock strength and facilitate the extensive failure of the Serra di Buda landslide. Finally, the landslide's internal structure, according to geotechnical investigations and displacement monitoring, is proposed. The proposed approach and the obtained results can be generalised to typify other deep landslides in similar geological settings.

Results of monitoring at Olkiluoto in 2013, rock mechanics

Energy Technology Data Exchange (ETDEWEB)

Johansson, E. (ed.) [Saanio and Riekkola Oy, Helsinki (Finland)

2014-10-15

The rock mechanics monitoring at Olkiluoto concentrates on the assessment of potential tectonic movements and stability of the bedrock. The rock mechanics monitoring programme 2013 consisted of seismic measurements, GPS measurements, surface levelling measurements and temperature measurements at Olkiluoto and vicinity and displacement measurements, temperature measurements and visual tunnel observations made in the ONKALO. The Posiva's microseismic network consists of 17 seismic stations and 21 triaxial sensors. Five stations are in the ONKALO. In spite of few breaks the network operated continuously and well during 2013. The number of located events (436) was slightly more than in 2012, but much less than in 2011. Nearly half of the observed explosions (237) in 2013 occurred inside the seismic semi-regional area and especially inside the seismic ONKALO block (137). One small induced earthquake (M{sub L} = -1.8) was detected at the depth of 429 m and was probably associated with smaller branches of the brittle fracture zone (OL-BFZ045). According to the seismic monitoring the rock mass has been stable in 2013. The local GPS network consists of 18 stations. Six new stations were set up for permanent tracking during 2013 and in total 12 permanent stations are now operating continuously. Manual measurements were carried out twice in 2013. Most of the inner network baselines showed very small motions as in the previous years: 75% of change rates were smaller than 0.10 mm/y. Roughly one third of the change rates are statistically significant. The surface levelling network currently consists of 87 fixed measuring points. During 2013 all the measuring loops were measured. The results indicated local subsidence area in the ONKALO loop and the rising area in the VLJ loop. Mean deformation rate has been +0.05 mm/y. Only elevation of one benchmark in the GPS station loop has changed more than one millimetre. The continuous displacement measurements in the technical rooms

Results of monitoring at Olkiluoto in 2013, rock mechanics

International Nuclear Information System (INIS)

Johansson, E.

2014-10-01

The rock mechanics monitoring at Olkiluoto concentrates on the assessment of potential tectonic movements and stability of the bedrock. The rock mechanics monitoring programme 2013 consisted of seismic measurements, GPS measurements, surface levelling measurements and temperature measurements at Olkiluoto and vicinity and displacement measurements, temperature measurements and visual tunnel observations made in the ONKALO. The Posiva's microseismic network consists of 17 seismic stations and 21 triaxial sensors. Five stations are in the ONKALO. In spite of few breaks the network operated continuously and well during 2013. The number of located events (436) was slightly more than in 2012, but much less than in 2011. Nearly half of the observed explosions (237) in 2013 occurred inside the seismic semi-regional area and especially inside the seismic ONKALO block (137). One small induced earthquake (M L = -1.8) was detected at the depth of 429 m and was probably associated with smaller branches of the brittle fracture zone (OL-BFZ045). According to the seismic monitoring the rock mass has been stable in 2013. The local GPS network consists of 18 stations. Six new stations were set up for permanent tracking during 2013 and in total 12 permanent stations are now operating continuously. Manual measurements were carried out twice in 2013. Most of the inner network baselines showed very small motions as in the previous years: 75% of change rates were smaller than 0.10 mm/y. Roughly one third of the change rates are statistically significant. The surface levelling network currently consists of 87 fixed measuring points. During 2013 all the measuring loops were measured. The results indicated local subsidence area in the ONKALO loop and the rising area in the VLJ loop. Mean deformation rate has been +0.05 mm/y. Only elevation of one benchmark in the GPS station loop has changed more than one millimetre. The continuous displacement measurements in the technical rooms of

Geology, mineralization, Rb-Sr & Sm-Nd geochemistry, and U–Pb zircon geochronology of Kalateh Ahani Cretaceous intrusive rocks, southeast Gonabad

Directory of Open Access Journals (Sweden)

Mohammad Hassan Karimpour

2013-10-01

Full Text Available Kalateh Ahani is located 27 km southeast of Gonabad within the Khorasan Razavi province. The area is part of Lut Block. Sub-volcanic monzonitic rocks intruded regional metamorphosed Shemshak Formation (Jurassic age. Magnetic susceptibility of less altered monzonitic rocks is 0.6%., As, Pb and Zn > 1%, Au up to 150 ppb and Sn = 133 ppm. The Sn content of vein in the northern part of Kalateh Ahani (Rud Gaz is > 1%. Based on mineralization, alteration and geochemistry, it seems that Sn mineralization is associated with the Cretaceous monzonitic rocks. Zircon U–Pb dating indicates that the age of the monzonitic rocks associated with mineralization is 109 Ma (Lower Cretaceous. Based on (87Sr/86Sri = 0.71089-0.710647 and (143Nd/144Ndi = 0.512113-0.51227 of the monzonitic rocks, the magma for these rocks were originated from the continental crust. This research has opened new window with respect to Sn-Cu mineralization and exploration within the Lut Block which is associated with Cretaceous granitoid rocks (reduced type, ilmenite series originated from the continental crust.

Tectonic blocks and suture zones of eastern Thailand: evidence from enhanced airborne geophysical analysis

Directory of Open Access Journals (Sweden)

Arak Sangsomphong

2013-04-01

Full Text Available Airborne geophysical data were used to analyze the complex structures of eastern Thailand. For visual interpretation, the magnetic data were enhanced by the analytical signal, and we used reduction to the pole (RTP and vertical derivative (VD grid methods, while the radiometric data were enhanced by false-colored composites and rectification. The main regional structure of this area trends roughly in northwest-southeast direction, with sinistral faulting movements. These are the result of compression tectonics (sigma_1 in an east-west direction that generated strike-slip movement during the pre Indian-Asian collision. These faults are cross-cut by the northeast-southwest-running sinistral fault and the northwest-southeast dextral fault, which occurred following the Indian-Asian collision, from the transpession sinistral shear in the northwest-southeast direction. Three distinct geophysical domains are discernible; the Northern, Central and Southern Domains. These three domains correspond very well with the established geotectonic units, as the Northern Domain with the Indochina block, the Central Domain with the Nakhonthai block, the Upper Southern Sub-domain with the Lampang-Chaing Rai block, and the Lower Southern Sub-domain with the Shan Thai block. The Indochina block is a single unit with moderate radiometric intensities and a high magnetic signature. The direction of the east-west lineament pattern is underlain by Mesozoic non-marine sedimentary rock, with mafic igneous bodies beneath this. The Nakhonthai block has a strong magnetic signature and a very weak radiometric intensity, with Late Paleozoic-Early Mesozoic volcanic rock and mélange zones that are largely covered by Cenozoic sediments. The boundaries of this block are the southern extension of the Mae Ping Faults and are oriented in the northwest-southeast direction. The Lampang-Chaing Rai and Shan Thai blocks, with very weak to moderate magnetic signatures and moderate to very

Effective media models for unsaturated fractured rock: A field experiment

International Nuclear Information System (INIS)

Nicholl, M.J.; Glass, R.J.

1995-01-01

A thick unsaturated rock mass at Yucca Mountain is currently under consideration as a potential repository site for disposal of high level radioactive waste. In accordance with standard industry and scientific practices, abstract numerical models will be used to evaluate the potential for radionuclide release through the groundwater system. At this time, currently available conceptual models used to develop effective media properties are based primarily on simplistic considerations. The work presented here is part of an integrated effort to develop effective media models at the intermediate block scale (approximately 8-125m) through a combination of physical observations, numerical simulations and theoretical considerations. A multi-purpose field experiment designed and conducted as part of this integrated effort is described. Specific goals of this experimental investigation were to: (1) obtain fracture network data from Topopah Spring Tuff for use in block scale simulations; (2) identity positions of the network conducting flow under three different boundary conditions; (3) visualize preferential flow paths and small-scale flow structures; (4) collect samples for subsequent hydraulic testing and use in block-scale simulations; and (5) demonstrate the ability of Electrical Resistance Tomography (ERT) to delineate fluid distribution within fractured rock

Geological site selection studies in Precambrian crystalline rocks in Finland

International Nuclear Information System (INIS)

Vuorela, P.

1988-01-01

In general geological investigations made since 1977 the Finnish crystalline bedrock has been determined to be suitable for the final disposal of the spent nuclear fuel. Regional investigations have been mainly based on already existing geological studies. Special attention has been paid on the international geological Finland as the Baltic Shield is stiff and stable and situated far outside the zones of volcanic and seismic activity. The present day crustal movements in Finland are related to landuplift process. Movements and possible faults in the bedrock follow fracture zones which devide the bedrock into mosaiclike blocks. As compared to small scale geological maps the bedrock blocks are often indicated as large granite rock formations which are less broken than the surrounding rocks, though the age of granite formations is at least 1500 millions of years. The large bedrock blocks (20-300 km 2 ) are divided to smaller units by different magnitudes of fractures and these smaller bedrock units (5-20 km 2 ) have been selected for further site selection investigations. At the first stage of investigations 327 suitable regional bedrock blocks have been identified on the basis of Landsat-1 winter and summer mosaics of Finland. After two years of investigations 134 investigation areas were selected inside 61 bedrock blocks and classified to four priority classes, the three first of which were redommended for further investigations. Geological criteries used in classification indicated clear differences between the classes one and three, however all classified areas are situated in large rather homogenous bedrock blocks and more exact three dimensional suitability errors may not be observed until deep bore holes have been made

Late Triassic paleolatitude of the Qiangtang block: Implications for the closure of the Paleo-Tethys Ocean

Science.gov (United States)

Song, Peiping; Ding, Lin; Li, Zhenyu; Lippert, Peter C.; Yang, Tianshui; Zhao, Xixi; Fu, Jiajun; Yue, Yahui

2015-08-01

To better constrain the Late Triassic paleolatitude of the Qiangtang block and the closure of the Paleo-Tethys Ocean, a combined paleomagnetic and zircon U/Pb geochronological study has been conducted on the Upper Triassic Jiapila Formation volcanic rocks on the northern edge of the Qiangtang block of Central Tibet (34.1°N, 92.4°E). These rocks are dated to 204-213 Ma. Progressive thermal or alternating field demagnetization successfully isolated stable characteristic remanent magnetizations (ChRM) that pass both the fold and reversal tests, consistent with a primary magnetization. These are the first volcanic-based paleomagnetic results from pre-Cretaceous rocks of the Qiangtang block that appear to average secular variation well enough to yield a reliable paleolatitude estimate. Based on our new paleomagnetic data from Upper Triassic lavas, we conclude that the Late Triassic pole of the Qiangtang block was located at 64.0°N, 174.7°E, with A95 = 6.6 ° (N = 29). We compile published paleomagnetic data from the Qiangtang block to calculate a Late Triassic latitude for the Qiangtang block at 31.7 ± 3.0°N. The central Paleo-Tethys Ocean basin was located between the North China (NCB) and Tarim blocks to the north and the Qiangtang block to the south during Late Paleozoic-Early Mesozoic. A comparison of published Early Triassic paleopole from the Qiangtang block with the coeval paleopoles from the NCB and Tarim indicates that the Paleo-Tethys Ocean could not have closed during the Early Triassic and that its width was approximately ∼32-38° latitude (∼3500-4200 km). However, the comparison of our new combined Late Triassic paleomagnetic result with the Late Triassic poles of the NCB and Tarim, as well as numerous geological observations, indicates that the closure of the Paleo-Tethys Ocean at the longitude of the Qiangtang block most likely occurred during the Late Triassic.

Sorption of radionuclides on hard rocks

International Nuclear Information System (INIS)

Berry, J.A.; Bourke, P.J.; Green, A.; Littleboy, A.K.

1987-09-01

Methods for measuring sorption on hard rocks, particularly of strontium, caesium, neptunium and americium on Darley Dale sandstone and Welsh slate have been investigated. The methods tried included batch tests with crushed rock and tests of simultaneous diffusion and convection with sorption on intact rock. High pressures (800m H 2 O) were used in the convective tests to pump water quickly through the rock samples and to measure high sorptivities in times shorter than those needed in the diffusive methods with intact samples. (author)

Planning, implementation and analysis of mine-surveying measurements to detect rock movements at the Asse salt mine

International Nuclear Information System (INIS)

Hensel, G.

1991-01-01

At the Asse pit, a former salt mine, research has been done since 1965 mainly for the ultimate disposal of radioactive wastes. Within this framework a mine-surveying measurement program has been developed to detect local and extensive rock movements in the mine structure and on the surface. The rock observation program consists of surface levelling, levellings in the mine structure, measurement of shaft depth, shaft sounding, position and gyroscopic measurements as well as cavity convergence and extensometer measurements. The results of that measuring program are taken into account to judge stability. The subject of this work is to analyse the position measurements by priorities to find out to which extent the results, that is the horizontal displacement components, are interpretable. Such analysis is carried out according to the rules of compensating calculation by means of strict compensation after mediating observations. (HS) [de

The analysis of creep characteristics of the surrounding rock of the carbonaceous rock tunnel based on Singh-Mitchell model

Science.gov (United States)

Luo, Junhui; Mi, Decai; Ye, Qiongyao; Deng, Shengqiang; Zeng, Fuquan; Zeng, Yongjun

2018-01-01

Carbonaceous rock has the characteristics of easy disintegration, softening, swelling and environmental sensitivity, which belongs to soft surrounding rock, and the deformation during excavation and long-term stability of the surrounding rock of carbonaceous rock tunnel are common problems in the construction of carbonaceous rock tunnel. According to the above, the Monitor and measure the displacement, temperature and osmotic pressure of the surrounding carbonaceous rock of the tunnel of Guangxi Hebai highway. Then it based on the obtaining data to study the creep mechanism of surrounding rock using Singh-Mitchell model and predict the deformation of surrounding rock before the tunnel is operation. The results show that the Singh-Mitchell creep model can effectively analyse and predict the deformation development law of surrounding rock of tunnel without considering temperature and osmotic pressure, it can provide reference for the construction of carbonaceous rock tunnel and the measures to prevent and reinforce it..

Volumetric measurement of rock movement using photogrammetry

Science.gov (United States)

Benton, Donovan J.; Iverson, Stephen R.; Martin, Lewis A.; Johnson, Jeffrey C.; Raffaldi, Michael J.

2016-01-01

NIOSH ground control safety research program at Spokane, Washington, is exploring applications of photogrammetry to rock mass and support monitoring. This paper describes two ways photogrammetric techniques are being used. First, photogrammetric data of laboratory testing is being used to correlate energy input and support deformation. This information can be used to infer remaining support toughness after ground deformation events. This technique is also demonstrated in a field application. Second, field photogrammetric data is compared to crackmeter data from a deep underground mine. Accuracies were found to average 8 mm, but have produced results within 0.2 mm of true displacement, as measured by crackmeters. Application of these techniques consists of monitoring overall fault activity by monitoring multiple points around the crackmeter. A case study is provided in which a crackmeter is clearly shown to have provided insufficient information regarding overall fault ground deformation. Photogrammetry is proving to be a useful ground monitoring tool due to its unobtrusiveness and ease of use. PMID:27110429

Application of in-situ stress measurement on bursts disasters of rock and CO{sub 2} in coal mine

Energy Technology Data Exchange (ETDEWEB)

Lian-Jie Wang; Dong-Sheng Sun; Li-Rong Zhang; Guan-Wu Zhou [Ministry of Land and Resources, Beijing (China)

2009-01-15

For the purpose of reduction and prevention of rock burst disasters and CO{sub 2}, measurements were made of in-situ stress and mechanical parameters of rock in Yingcheng mine. Geological structure and gas measurements were studied and the stress field was simulated and distribution of stress field was obtained in this area. On the basis of the study, the danger areas of rockbursts and CO{sub 2} were predicted. Preventive measures were suggested to decrease gas pressure and in-situ stress in front of the working face with advance boreholes relieving blasting. 12 refs., 5 figs., 1 tab.

An investigation of rock fall and pore water pressure using LIDAR in Highway 63 rock cuts.

Science.gov (United States)

2014-07-01

The purpose of this research work is compare LIDAR scanning measurements of rock fall with the natural changes in groundwater level to determining the effect of water pressures (levels) on rock fall. To collect the information of rock cut volume chan...

Assessing hydraulic connections across a complex sequence of volcanic rocks - Analysis of U-20 WW multiple-well aquifer test, Pahute Mesa, Nevada National Security Site, Nevada

Science.gov (United States)

Garcia, C. Amanda; Fenelon, Joseph M.; Halford, Keith J.; Reiner, Steven R.; Laczniak, Randell J.

2011-01-01

Groundwater beneath Pahute Mesa flows through a complexly layered sequence of volcanic rock aquifers and confining units that have been faulted into distinct structural blocks. Hydraulic property estimates of rocks and structures in this flow system are necessary to assess radionuclide migration near underground nuclear testing areas. The U.S. Geological Survey (USGS) used a 12 month (October 1, 2008— October 1, 2009) intermittent pumping schedule of well U-20 WW and continuously monitored water levels in observation wells ER-20-6 #3, UE-20bh 1, and U-20bg as a multi-well aquifer test to evaluate hydraulic connections across structural blocks, bulk hydraulic properties of volcanic rocks, and the hydraulic significance of a major fault. Measured water levels were approximated using synthetic water levels generated from an analytical model. Synthetic water levels are a summation of environmental water-level fluctuations and a Theis (1935) transform of the pumping signal from flow rate to water-level change. Drawdown was estimated by summing residual differences between measured and synthetic water levels and the Theis-transformed pumping signal from April to September 2009. Drawdown estimates were used in a three‑dimensional numerical model to estimate hydraulic properties of distinct aquifers, confining units, and a major fault.

Cracking and Failure in Rock Specimen Containing Combined Flaw and Hole under Uniaxial Compression

Directory of Open Access Journals (Sweden)

Xiang Fan

2018-01-01

Full Text Available Flaw is a key factor influencing failure behavior of a fractured specimen. In the present study, rectangular-flawed specimens were prepared using sandstone to investigate the effect of flaw on failure behavior of rock. Open flaw and cylindrical hole were simultaneously precut within rock specimens using high-pressure water jet cutting technology. Five series of specimens including intact, single-hole-alone, two-hole-alone, single-hole and two-flaw, and two-hole and single-flaw blocks were prepared. Uniaxial compressive tests using a rigid servo control instrument were carried out to investigate the fracture processes of these flawed specimens. It is observed that during loading, internal stress always intensively distributed at both sidewalls of open hole, especially at midpoint of sidewalls, so rock crumb flaking was firstly observed among all sandstone specimens containing single hole or two holes. Cracking around open hole is associated with the flaw inclination angle which was observed in Series III and V. Crack easily initiated at the tips of flaw with inclination angles of 0°, 30°, and 60° but hard for 90° in Series III and V. Rock burst was the major failure mode among most tested specimens, which generally induced new cracks and finally created crater shape. Additionally, due to extrusion between blocks, new shear or tensile cracks were generated and the rock specimen surface spalled. Eventually, four typical failure processes including rock crumb flaking, crack initiation and propagation, rock burst, and second rupture, were summarized.

Determination of the mechanical parameters of rock mass based on a GSI system and displacement back analysis

Science.gov (United States)

Kang, Kwang-Song; Hu, Nai-Lian; Sin, Chung-Sik; Rim, Song-Ho; Han, Eun-Cheol; Kim, Chol-Nam

2017-08-01

It is very important to obtain the mechanical paramerters of rock mass for excavation design, support design, slope design and stability analysis of the underground structure. In order to estimate the mechanical parameters of rock mass exactly, a new method of combining a geological strength index (GSI) system with intelligent displacment back analysis is proposed in this paper. Firstly, average spacing of joints (d) and rock mass block rating (RBR, a new quantitative factor), surface condition rating (SCR) and joint condition factor (J c) are obtained on in situ rock masses using the scanline method, and the GSI values of rock masses are obtained from a new quantitative GSI chart. A correction method of GSI value is newly introduced by considering the influence of joint orientation and groundwater on rock mass mechanical properties, and then value ranges of rock mass mechanical parameters are chosen by the Hoek-Brown failure criterion. Secondly, on the basis of the measurement result of vault settlements and horizontal convergence displacements of an in situ tunnel, optimal parameters are estimated by combination of genetic algorithm (GA) and numerical simulation analysis using FLAC3D. This method has been applied in a lead-zinc mine. By utilizing the improved GSI quantization, correction method and displacement back analysis, the mechanical parameters of the ore body, hanging wall and footwall rock mass were determined, so that reliable foundations were provided for mining design and stability analysis.

Rock stress measurements in the deep boreholes at Kuhmo, Hyrynsalmi, Sievi, Eurajoki and Konginkangas

International Nuclear Information System (INIS)

Klasson, H.; Leijon, B.

1990-11-01

Hydraulic fracturing rock stress measurements, conducted in five boreholes are presented. The boreholes are located in different site investigation areas in Finland: Kuhmo-Romuvaara, Hyrynsalmi-Veitsivaara, Sievi-Syyry, Eurajoki-Olkiluoto and Konginkangas-Kivetty. The aim of the measurements was to provide rock stress data, forming input to the site selection process for an underground facility for disposal of high level radioactive waste from the Olkiluoto Nuclear Power Plant. A summary is given of the theoretical background to the hydrofracturing method, whilst the equipment and experimental procedures used in the present case are described in more detail. All results obtained are presented and subjected to critical discussion. The final stress parameters evaluated are magnitudes and directions of the maximum and minimum horizontal stresses. Testing was successfully completed according to the clan at Syyry, Olkiluoto and Kivetty. Testing was partly successful at Romuvaara but unsuccessful in the borehole at Veitsivaara

Unsteady surface pressure measurements on a slender delta wing undergoing limit cycle wing rock

Science.gov (United States)

Arena, Andrew S., Jr.; Nelson, Robert C.

1991-01-01

An experimental investigation of slender wing limit cycle motion known as wing rock was investigated using two unique experimental systems. Dynamic roll moment measurements and visualization data on the leading edge vortices were obtained using a free to roll apparatus that incorporates an airbearing spindle. In addition, both static and unsteady surface pressure data was measured on the top and bottom surfaces of the model. To obtain the unsteady surface pressure data a new computer controller drive system was developed to accurately reproduce the free to roll time history motions. The data from these experiments include, roll angle time histories, vortex trajectory data on the position of the vortices relative to the model's surface, and surface pressure measurements as a function of roll angle when the model is stationary or undergoing a wing rock motion. The roll time history data was numerically differentiated to determine the dynamic roll moment coefficient. An analysis of these data revealed that the primary mechanism for the limit cycle behavior was a time lag in the position of the vortices normal to the wing surface.

Moment of inertia for rock blocks subject to bookshelf faulting with ...

Indian Academy of Sciences (India)

51

Knowing (empirical) algebraic relations of density with depth, which could also be ... In case of book-shelf sliding, fault blocks rotate and slip by simple shear along pre-existing planes (Fig. ... to seismicity studies (e.g., Wetzel et al. 1993), and ...

Capabilities for measuring physical and chemical properties of rocks at high pressure

Energy Technology Data Exchange (ETDEWEB)

Durham, W.B. (comp.)

1990-01-01

The Experimental Geophysics Group of the Earth Sciences Department at Lawrence Livermore National Laboratory (LLNL) has experimental equipment that measures a variety of physical properties and phase equilibria and kinetics on rocks and minerals at extreme pressures (to 500 GPa) and temperatures (from 10 to 2800 K). These experimental capabilities are described in this report in terms of published results, photographs, and schematic diagrams.

Applicability of initial stress measurement methods to Horonobe Siliceous rocks and initial stress state around Horonobe Underground Research Laboratory

International Nuclear Information System (INIS)

Sanada, Hiroyuki; Niunoya, Sumio; Matsui, Hiroya; Fujii, Yoshiaki

2009-01-01

Understanding initial stress condition in deep underground is important for such construction as rock cavern for geological disposal of HLW and underground power plant. Neogene sedimentary rock is widely distributed in Japan. There are only a few studies of initial stress measurement in Neogene sedimentary rock mass in Japan due to difficulty of measurement. Evaluation of initial stress condition around Horonobe Underground Research Laboratory Project was carried out in order to understand initial stress condition and applicability of AE, DSCA and hydraulic fracturing (HF) methods to Neogene sedimentary rock. Initial stress values obtained from AE method is smaller than overburden pressure due to time dependency of Kaizer effect. It would be difficult to use AE method as initial stress measurement method for Horonobe Siliceous rocks. Principal stress values by DSCA are similar to those by HF tests. Directions of maximum horizontal principal stresses are approximately in E-W and corresponded to HF results. In HF, rod type and wire-line type systems were compared. Workability of rod type was much better than wire-line type. However, re-opening pressure were not able to be precisely measured in case of rod type system due to the large compliance of the packers and rods. Horizontal maximum and minimum principal stresses increase linearly in HF results. Deviatoric stress is acting at shallow depth. Initial stress condition approaches hydrostatic condition with depth. Direction of maximum horizontal principal stress was in E-W direction which was similar to tectonic movement around Horonobe URL by triangular surveying. (author)

Renewing Rock-Tenn: A Biomass Fuels Assessment for Rock-Tenn's St. Paul Recycled Paper Mill.

Energy Technology Data Exchange (ETDEWEB)

Nelson, Carl

2007-03-31

In the summer of 2006 the Green Institute started the study for the RockTenn paper mill that would evaluate the economics and supply chain reliability of wood waste and other clean biomass as a fuel for the facility. The Green Institute obtained sponsorship from a broad coalition representing the community and the project team included other consultants and university researchers specializing in biomass issues. The final product from the project was a report to: 1) assess the availability of clean biomass fuel for use at the Rock-Tenn site; 2) roughly estimate costs at various annual usage quantities; and 3) develop the building blocks for a supply chain procurement plan. The initial report was completed and public presentations on the results were completed in spring of 2007.

Kinematic analysis for the implementation of landslide mitigation measures

Science.gov (United States)

Delmonaco, Giuseppe; Margottini, Claudio; Spizzichino, Daniele

2010-05-01

The present work is finalised at the implementation of a landslide risk mitigation master plan of the ancient citadel of Machu Picchu. After the warning launched in March 2001, by the scientific community on potential collapse of the citadel from a near-disastrous landslide event different studies have been promoted to reconstruct landslide activity and suggest landslide risk mitigation measures for the protection and conservation of Machu Picchu cultural heritage. A site-scale analysis has been implemented following the application and integration of geomechanical classifications, ambient noise measurements and structural and kinematical analysis. The geology of the area is characterized by granitoid bodies that had been emplaced in the axial zones of the main rift system that are now exposed at the highest altitudes, together with country rocks (Precambrian and Lower Paleozoic metamorphics) originally constituting the rift ‘roots'. The bedrock of the Inca citadel of Machu Picchu is mainly composed by granite and subordinately granodiorite. This is mainly located in the lower part of the slopes. Superficially, the granite is jointed in blocks with variable dimensions, promoted by local structural setting. Single blocks vary from 10-1 to about 200 m3. Soil cover, widely outcropping in the area, is mainly composed by individual blocks and subordinately by coarse materials originated by chemical and physical weathering of minerals. Regional tectonic uplift and structural setting rule the general morphological features of the area and as a consequence, landslide type and evolution. Rock falls, rock slides, debris flows and debris slides are the main landslide typologies affecting the citadel slopes. In the last mission in May 2009, elastic and deformation rock parameters have been collected using a passive seismic innovative technique based on natural microtremor measurements and geostructural scan lines elaboration. A landslide zoning of the citadel has been

Rock stress orientation measurements using induced thermal spalling in slim boreholes

International Nuclear Information System (INIS)

Hakami, Eva

2011-05-01

In the planning and design of a future underground storage for nuclear waste based on the KBS-3 method, one of the aims is to optimize the layout of deposition tunnels such that the rock stresses on the boundaries of deposition holes are minimized. Previous experiences from heating of larger scale boreholes at the Aespoe Hard Rock Laboratory (AHRL) gave rise to the idea that induced borehole breakouts using thermal loading in smaller diameter boreholes, could be a possible way of determining the stress orientation. Two pilot experiments were performed, one at the Aespoe Hard Rock Laboratory and one at ONKALO research site in Finland. An acoustic televiewer logger was used to measure the detailed geometrical condition of the borehole before and after heating periods. The acoustic televiewer gives a value for each 0.7 mm large pixel size around the borehole periphery. The results from the loggers are presented as images of the borehole wall, and as curves for the maximum, mean and minimum values at each depth. Any changes in the borehole wall geometry may thus be easily detected by comparisons of the logging result images. In addition, using an optical borehole televiewer a good and detailed realistic colour picture of the borehole wall is obtained. From these images the character of the spalls identified may be evaluated further. The heating was performed in a 4 m long section, using a heating cable centred in an 8 m deep vertical borehole, drilled from the floor of the tunnels. For the borehole in the Q-tunnel of AHRL the results from the loggings of the borehole before the heating revealed that breakouts existed even before this pilot test due to previous heating experiments at the site (CAPS). Quite consistent orientation and the typical shape of small breakouts were observed. After the heating the spalling increased slightly at the same locations and a new spalling location also developed at a deeper location in the borehole. At ONKALO three very small changes

Rock stress orientation measurements using induced thermal spalling in slim boreholes

Energy Technology Data Exchange (ETDEWEB)

Hakami, Eva [Geosigma AB, Uppsala (Sweden)

2011-05-15

In the planning and design of a future underground storage for nuclear waste based on the KBS-3 method, one of the aims is to optimize the layout of deposition tunnels such that the rock stresses on the boundaries of deposition holes are minimized. Previous experiences from heating of larger scale boreholes at the Aespoe Hard Rock Laboratory (AHRL) gave rise to the idea that induced borehole breakouts using thermal loading in smaller diameter boreholes, could be a possible way of determining the stress orientation. Two pilot experiments were performed, one at the Aespoe Hard Rock Laboratory and one at ONKALO research site in Finland. An acoustic televiewer logger was used to measure the detailed geometrical condition of the borehole before and after heating periods. The acoustic televiewer gives a value for each 0.7 mm large pixel size around the borehole periphery. The results from the loggers are presented as images of the borehole wall, and as curves for the maximum, mean and minimum values at each depth. Any changes in the borehole wall geometry may thus be easily detected by comparisons of the logging result images. In addition, using an optical borehole televiewer a good and detailed realistic colour picture of the borehole wall is obtained. From these images the character of the spalls identified may be evaluated further. The heating was performed in a 4 m long section, using a heating cable centred in an 8 m deep vertical borehole, drilled from the floor of the tunnels. For the borehole in the Q-tunnel of AHRL the results from the loggings of the borehole before the heating revealed that breakouts existed even before this pilot test due to previous heating experiments at the site (CAPS). Quite consistent orientation and the typical shape of small breakouts were observed. After the heating the spalling increased slightly at the same locations and a new spalling location also developed at a deeper location in the borehole. At ONKALO three very small changes

Aespoe hard rock laboratory. Annual report 2000

Energy Technology Data Exchange (ETDEWEB)

NONE

2001-06-01

the repository system, which are of importance for long-term safety. The Prototype Repository experiment is focused on testing and demonstrating repository system function in full scale, and consists of six deposition holes with canisters and electric heaters surrounded by highly compacted bentonite. The work during 2000 has focused on geoscientific characterisation and specially hydraulic properties and conditions of the rock. Preparatory work with design, purchase and manufacturing as well as rock work (slots for the two plugs) have been going on with the aim of preparing for start of installation during the second quarter of 2001. Equipment for installation of bentonite blocks and canisters were tested before start of installation in the Canister Retrieval Test. This test was completed in October and the heaters as well as the artificial saturation system was turned on immediately thereafter. The objectives of the Demonstration of Repository Technology are to develop, test, and demonstrate methodology and equipment for encapsulation and deposition of spent nuclear fuel. The demonstration of handling and deposition is made with the specially designed full scale prototype to a deposition machine at 420 m level. The Backfill and Plug Test includes tests of backfill materials and emplacement methods and a test of a full-scale plug. Half the test part is filled with a mixture of 30% bentonite and crushed granite rock. The other half is filled with crushed rock without addition of bentonite, except for the upper 100-200 mm, where a slot was filled with blocks of highly compacted bentonite/crushed rock mixture and bentonite pellets. The backfill and rock has been instrumented with about 230 transducers for measuring the thermo- hydro-mechanical processes. Water saturation has been going on the whole year and the saturation speed has been slower than expected due to a lower salt content in the water than expected. In order to increase the speed a water with a higher salt

Rho-associated kinase (ROCK) function is essential for cell cycle progression, senescence and tumorigenesis.

Science.gov (United States)

Kümper, Sandra; Mardakheh, Faraz K; McCarthy, Afshan; Yeo, Maggie; Stamp, Gordon W; Paul, Angela; Worboys, Jonathan; Sadok, Amine; Jørgensen, Claus; Guichard, Sabrina; Marshall, Christopher J

2016-01-14

Rho-associated kinases 1 and 2 (ROCK1/2) are Rho-GTPase effectors that control key aspects of the actin cytoskeleton, but their role in proliferation and cancer initiation or progression is not known. Here, we provide evidence that ROCK1 and ROCK2 act redundantly to maintain actomyosin contractility and cell proliferation and that their loss leads to cell-cycle arrest and cellular senescence. This phenotype arises from down-regulation of the essential cell-cycle proteins CyclinA, CKS1 and CDK1. Accordingly, while the loss of either Rock1 or Rock2 had no negative impact on tumorigenesis in mouse models of non-small cell lung cancer and melanoma, loss of both blocked tumor formation, as no tumors arise in which both Rock1 and Rock2 have been genetically deleted. Our results reveal an indispensable role for ROCK, yet redundant role for isoforms 1 and 2, in cell cycle progression and tumorigenesis, possibly through the maintenance of cellular contractility.

Aespoe Hard Rock Laboratory Annual Report 1999

Energy Technology Data Exchange (ETDEWEB)

NONE

2000-08-01

The Aespoe Hard Rock Laboratory has been constructed as part of the preparations for the deep geological repository for spent nuclear fuel in Sweden. The Tracer Retention Understanding Experiments are made to gain a better understanding of radionuclide retention in the rock and create confidence in the radionuclide transport models that are intended to be used in the licensing of a deep repository for spent fuel. The TRUE -1 experiment including tests with sorbing radioactive tracers in a single fracture over a distance of about 5 m has been completed. Diffusion and sorption in the rock matrix is the dominant retention mechanism over the time scales of the experiments. The main objective of the TRUE Block Scale Experiment is to increase understanding and our ability to predict tracer transport in a fracture network over spatial scales of 10 to 50 m. In total six boreholes have been drilled into the experimental volume located at the 450 m level. The Long-Term Diffusion Experiment is intended as a complement to the dynamic in-situ experiments and the laboratory experiments performed in the TRUE Programme. Diffusion from a fracture into the rock matrix will be studied in situ. The REX project focuses on the reduction of oxygen in a repository after closure due to reactions with rock minerals and microbial activity. Results show that oxygen is consumed within a few days both for the field and laboratory experiments. A new site for the CHEMLAB experiments was selected and prepared during 1999. All future experiment will be conducted in the J niche at 450 m depth. The Prototype Repository Test is focused on testing and demonstrating repository system function. A full-scale prototype including six deposition holes with canisters with electric heaters surrounded by highly compacted bentonite will be built and instrumented. Characterisation of the rock mass in the area of the Prototype repository is completed and the six deposition holes have been drilled. The Backfill and

Aespoe Hard Rock Laboratory Annual Report 1999

International Nuclear Information System (INIS)

2000-08-01

The Aespoe Hard Rock Laboratory has been constructed as part of the preparations for the deep geological repository for spent nuclear fuel in Sweden. The Tracer Retention Understanding Experiments are made to gain a better understanding of radionuclide retention in the rock and create confidence in the radionuclide transport models that are intended to be used in the licensing of a deep repository for spent fuel. The TRUE -1 experiment including tests with sorbing radioactive tracers in a single fracture over a distance of about 5 m has been completed. Diffusion and sorption in the rock matrix is the dominant retention mechanism over the time scales of the experiments. The main objective of the TRUE Block Scale Experiment is to increase understanding and our ability to predict tracer transport in a fracture network over spatial scales of 10 to 50 m. In total six boreholes have been drilled into the experimental volume located at the 450 m level. The Long-Term Diffusion Experiment is intended as a complement to the dynamic in-situ experiments and the laboratory experiments performed in the TRUE Programme. Diffusion from a fracture into the rock matrix will be studied in situ. The REX project focuses on the reduction of oxygen in a repository after closure due to reactions with rock minerals and microbial activity. Results show that oxygen is consumed within a few days both for the field and laboratory experiments. A new site for the CHEMLAB experiments was selected and prepared during 1999. All future experiment will be conducted in the J niche at 450 m depth. The Prototype Repository Test is focused on testing and demonstrating repository system function. A full-scale prototype including six deposition holes with canisters with electric heaters surrounded by highly compacted bentonite will be built and instrumented. Characterisation of the rock mass in the area of the Prototype repository is completed and the six deposition holes have been drilled. The Backfill and

Temperature loading and rocks mechanics at final storage of radioactive waste

International Nuclear Information System (INIS)

Leijon, B.; Stephansson, O.

1979-01-01

This report describes the rock mechanical effects - in the far field - from the thermal loading at a final storage of radioactive waste in crystalline rocks. The stress distribution of a two-storey storage is described in more details. The temperature rise in a final storage of radiactive waste will create thermal stresses which may cause a failure of the rock mass, and thereby an increase of its permeability. However, the state of stress in the Earth's crust is able to neutralize the thermal stresses. By this analysis we have been able to demonstrate that the thermal stresses due to heat conduction from the final storage are compensated by the state of stress in the upper part of the crust. The absolute stress, which is the superposition of thermal stress and virgin rock stress, is in all cases found to be below the limit of failure due to frictional resistance between surfaces of constituent blocks in the rock mass. Failure by sliding friction is the most conservative failure criterion for a rock mass. (author)

Determination of elastic anisotropy of rocks from P- and S-wave velocities: numerical modelling and lab measurements

Science.gov (United States)

Svitek, Tomáš; Vavryčuk, Václav; Lokajíček, Tomáš; Petružálek, Matěj

2014-12-01

The most common type of waves used for probing anisotropy of rocks in laboratory is the direct P wave. Information potential of the measured P-wave velocity, however, is limited. In rocks displaying weak triclinic anisotropy, the P-wave velocity depends just on 15 linear combinations of 21 elastic parameters, called the weak-anisotropy parameters. In strong triclinic anisotropy, the P-wave velocity depends on the whole set of 21 elastic parameters, but inversion for six of them is ill-conditioned and these parameters are retrieved with a low accuracy. Therefore, in order to retrieve the complete elastic tensor accurately, velocities of S waves must also be measured and inverted. For this purpose, we developed a lab facility which allows the P- and S-wave ultrasonic sounding of spherical rock samples in 132 directions distributed regularly over the sphere. The velocities are measured using a pair of P-wave sensors with the transmitter and receiver polarized along the radial direction and using two pairs of S-wave sensors with the transmitter and receiver polarized tangentially to the spherical sample in mutually perpendicular directions. We present inversion methods of phase and ray velocities for elastic parameters describing general triclinic anisotropy. We demonstrate on synthetic tests that the inversion becomes more robust and stable if the S-wave velocities are included. This applies even to the case when the velocity of the S waves is measured in a limited number of directions and with a significantly lower accuracy than that of the P wave. Finally, we analyse velocities measured on a rock sample from the Outokumpu deep drill hole, Finland. We present complete sets of elastic parameters of the sample including the error analysis for several levels of confining pressure ranging from 0.1 to 70 MPa.

U-Pb zircon geochronology and Sm-Nd-Pb isotopic constraint for precambrian plutonic rocks in the northeastern part of Ryeongnam massif, Korea

International Nuclear Information System (INIS)

Chang, Ho-Wan

2003-01-01

The Ryeongnam massif is composed of Precambrian gneisses, Paleozoic and Mesozoic sedimentary rocks and extensive Triassic-Jurassic plutonic rocks of felsic to mafic composition. In the northeast Ryeongnam massif, the oldest rocks belong to the Sobaegsan gneiss complex, which is composed of orthogneisses, paragneisses and mafic plutonic rocks. U-Pb zircon ages for the felsic and mafic intrusive bodies within the Sobaegsan gneiss complex are: the Icheon granite gneiss, 2357±43 and 2342±47 Ma; the Buncheon granite gneiss, 1963±5 Ma; the Pyeonghae granite gneiss, 1936±21 Ma; the Ogbang amphibolite, 1918±10 Ma; the Imwon leucogranite gneiss, 1826±20 Ma. The Hyeondong biotite schist, which is intruded by the Buncheon granite gneiss and the Ogbang amphibolite, yielded an age of 2271±44 Ma. The Nd-Sm-Pb isotopic data indicate that the felsic plutonic rocks are derived from an older Archean crust. The Nd T DM ages are Archean, and the εNd values are negative for the felsic rocks and positive for the amphibolite. Common Pb isotope compositions also indicate a crustal source for the felsic intrusives. The U-Pb ages of Precambrian rocks of the Ryeongnam massifs are similar to those in the Gyeonggi massif, and may have a similar crustal evolutionary history. The Precambrian rocks of South Korea could be related either to the North China block or to the South China block, as the isotope ages and patterns are not unique to either block. Similarly, a geologic correlation with Japan, although possible, is tenuous at present. (author)

Rock Physical Interpretation of the Relationship between Dynamic and Static Young's Moduli of Sedimentary Rocks

Science.gov (United States)

Takahashi, T.

2017-12-01

The static Young's modulus (deformability) of a rock is indispensable for designing and constructing tunnels, dams and underground caverns in civil engineering. Static Young's modulus which is an elastic modulus at large strain level is usually obtained with the laboratory tests of rock cores sampled in boreholes drilled in a rock mass. A deformability model of the entire rock mass is then built by extrapolating the measurements based on a rock mass classification obtained in geological site characterization. However, model-building using data obtained from a limited number of boreholes in the rock mass, especially a complex rock mass, may cause problems in the accuracy and reliability of the model. On the other hand, dynamic Young's modulus which is the modulus at small strain level can be obtained from seismic velocity. If dynamic Young's modulus can be rationally converted to static one, a seismic velocity model by the seismic method can be effectively used to build a deformability model of the rock mass. In this study, we have, therefore, developed a rock physics model (Mavko et al., 2009) to estimate static Young's modulus from dynamic one for sedimentary rocks. The rock physics model has been generally applied to seismic properties at small strain level. In the proposed model, however, the sandy shale model, one of rock physics models, is extended for modeling the static Young's modulus at large strain level by incorporating the mixture of frictional and frictionless grain contacts into the Hertz-Mindlin model. The proposed model is verified through its application to the dynamic Young's moduli derived from well log velocities and static Young's moduli measured in the tri-axial compression tests of rock cores sampled in the same borehole as the logs were acquired. This application proves that the proposed rock physics model can be possibly used to estimate static Young's modulus (deformability) which is required in many types of civil engineering applications

Blocking temperature distribution in implanted Co-Ni nanoparticles obtained by magneto-optical measurements

Energy Technology Data Exchange (ETDEWEB)

D' Orazio, F.; Lucari, F. E-mail: franco.lucari@aquila.infn.it; Melchiorri, M.; Julian Fernandez, C. de; Mattei, G.; Mazzoldi, P.; Sangregorio, C.; Gatteschi, D.; Fiorani, D

2003-05-01

Three samples of Co-Ni alloy nanoparticles with different compositions were prepared by sequential ion implantation in silica slides. Transmission electron microscopy (TEM) showed the presence of spherical nanoparticles dispersed in the matrix. Magneto-optical Kerr effect analysis identified two magnetic components attributed to superparamagnetic particles in unblocked and blocked states, respectively. Magnetic field loops were measured as a function of temperature. Blocking temperature distributions were obtained; and their comparison with the size distributions derived from TEM provided the average magnetic anisotropy of the particles.

Blocking temperature distribution in implanted Co-Ni nanoparticles obtained by magneto-optical measurements

International Nuclear Information System (INIS)

D'Orazio, F.; Lucari, F.; Melchiorri, M.; Julian Fernandez, C. de; Mattei, G.; Mazzoldi, P.; Sangregorio, C.; Gatteschi, D.; Fiorani, D.

2003-01-01

Three samples of Co-Ni alloy nanoparticles with different compositions were prepared by sequential ion implantation in silica slides. Transmission electron microscopy (TEM) showed the presence of spherical nanoparticles dispersed in the matrix. Magneto-optical Kerr effect analysis identified two magnetic components attributed to superparamagnetic particles in unblocked and blocked states, respectively. Magnetic field loops were measured as a function of temperature. Blocking temperature distributions were obtained; and their comparison with the size distributions derived from TEM provided the average magnetic anisotropy of the particles

An axisymmetric diffusion experiment for the determination of diffusion and sorption coefficients of rock samples.

Science.gov (United States)

Takeda, M; Hiratsuka, T; Ito, K; Finsterle, S

2011-04-25

Diffusion anisotropy is a critical property in predicting migration of substances in sedimentary formations with very low permeability. The diffusion anisotropy of sedimentary rocks has been evaluated mainly from laboratory diffusion experiments, in which the directional diffusivities are separately estimated by through-diffusion experiments using different rock samples, or concurrently by in-diffusion experiments in which only the tracer profile in a rock block is measured. To estimate the diffusion anisotropy from a single rock sample, this study proposes an axisymmetric diffusion test, in which tracer diffuses between a cylindrical rock sample and a surrounding solution reservoir. The tracer diffusion between the sample and reservoir can be monitored from the reservoir tracer concentrations, and the tracer profile could also be obtained after dismantling the sample. Semi-analytical solutions are derived for tracer concentrations in both the reservoir and sample, accounting for an anisotropic diffusion tensor of rank two as well as the dilution effects from sampling and replacement of reservoir solution. The transient and steady-state analyses were examined experimentally and numerically for different experimental configurations, but without the need for tracer profiling. These experimental configurations are tested for in- and out-diffusion experiments using Koetoi and Wakkanai mudstones and Shirahama sandstone, and are scrutinized by a numerical approach to identify favorable conditions for parameter estimation. The analysis reveals the difficulty in estimating diffusion anisotropy; test configurations are proposed for enhanced identifiability of diffusion anisotropy. Moreover, it is demonstrated that the axisymmetric diffusion test is efficient in obtaining the sorption parameter from both steady-state and transient data, and in determining the effective diffusion coefficient if isotropic diffusion is assumed. Moreover, measuring reservoir concentrations in an

An asixymmetric diffusion experiment for the determination of diffusion and sorption coefficients of rock samples

Energy Technology Data Exchange (ETDEWEB)

Takeda, M.; Hiratsuka, T.; Ito, K.; Finsterle, S.

2011-02-01

Diffusion anisotropy is a critical property in predicting migration of substances in sedimentary formations with very low permeability. The diffusion anisotropy of sedimentary rocks has been evaluated mainly from laboratory diffusion experiments, in which the directional diffusivities are separately estimated by through-diffusion experiments using different rock samples, or concurrently by in-diffusion experiments in which only the tracer profile in a rock block is measured. To estimate the diffusion anisotropy from a single rock sample, this study proposes an axisymmetric diffusion test, in which tracer diffuses between a cylindrical rock sample and a surrounding solution reservoir. The tracer diffusion between the sample and reservoir can be monitored from the reservoir tracer concentrations, and the tracer profile could also be obtained after dismantling the sample. Semi-analytical solutions are derived for tracer concentrations in both the reservoir and sample, accounting for an anisotropic diffusion tensor of rank two as well as the dilution effects from sampling and replacement of reservoir solution. The transient and steady-state analyses were examined experimentally and numerically for different experimental configurations, but without the need for tracer profiling. These experimental configurations are tested for in- and out-diffusion experiments using Koetoi and Wakkanai mudstones and Shirahama sandstone, and are scrutinized by a numerical approach to identify favorable conditions for parameter estimation. The analysis reveals the difficulty in estimating diffusion anisotropy; test configurations are proposed for enhanced identifiability of diffusion anisotropy. Moreover, it is demonstrated that the axisymmetric diffusion test is efficient in obtaining the sorption parameter from both steady-state and transient data, and in determining the effective diffusion coefficient if isotropic diffusion is assumed. Moreover, measuring reservoir concentrations in an

1963 Vajont rock slide: a comparison between 3D DEM and 3D FEM

Science.gov (United States)

Crosta, Giovanni; Utili, Stefano; Castellanza, Riccardo; Agliardi, Federico; Bistacchi, Andrea; Weng Boon, Chia

2013-04-01

Data on the exact location of the failure surface of the landslide have been used as the starting point for the modelling of the landslide. 3 dimensional numerical analyses were run employing both the discrete element method (DEM) and a Finite Element Method (FEM) code. In this work the focus is on the prediction of the movement of the landlside during its initial phase of detachment from Mount Toc. The results obtained by the two methods are compared and conjectures on the observed discrepancies of the predictions between the two methods are formulated. In the DEM simulations the internal interaction of the sliding blocks and the expansion of the debris is obtained as a result of the kinematic interaction among the rock blocks resulting from the jointing of the rock mass involved in the slide. In the FEM analyses, the c-phi reduction technique was employed along the predefine failure surface until the onset of the landslide occurred. In particular, two major blocks of the landslide were identified and the stress, strain and displacement fields at the interface between the two blocks were analysed in detail.

Hydro-thermo-mechanical response of a fractured rock block

International Nuclear Information System (INIS)

Kelkar, S.; Zyvoloski, G.

1990-01-01

Hydro-thermo-mechanical effects in fractured rocks are important in many engineering applications and geophysical processes. Modeling these effects is made difficult by the fact that the governing equations are nonlinear and coupled, and the problems to be solved are three dimensional. In this paper we describe a numerical code developed for this purpose. The code is finite element based to allow for complicated geometries, and the time differencing is implicit, allowing for large time steps. The use of state-of-the-art equation solvers has resulted in a practical code. The code is capable of fully three dimensional simulations, however, in this paper we consider only the case of two dimensional heat and mass flow coupled to one dimensional deformation. Partial verification of the code is obtained by comparison with published semianalytical results. Several examples are presented to demonstrate the effects of matrix expansion, due to pore pressure and heating, on fracture opening due to fluid injection. 16 refs., 11 figs

Detection block

International Nuclear Information System (INIS)

Bezak, A.

1987-01-01

A diagram is given of a detection block used for monitoring burnup of nuclear reactor fuel. A shielding block is an important part of the detection block. It stabilizes the fuel assembly in the fixing hole in front of a collimator where a suitable gamma beam is defined for gamma spectrometry determination of fuel burnup. The detector case and a neutron source case are placed on opposite sides of the fixing hole. For neutron measurement for which the water in the tank is used as a moderator, the neutron detector-fuel assembly configuration is selected such that neutrons from spontaneous fission and neutrons induced with the neutron source can both be measured. The patented design of the detection block permits longitudinal travel and rotation of the fuel assembly to any position, and thus more reliable determination of nuclear fuel burnup. (E.S.). 1 fig

IMPACT OF ROCK HARDNESS ON FRAGMENTATION BY HYDRAULIC HAMMER AND CRUSHING IN JAW CRUSHER

Directory of Open Access Journals (Sweden)

Trpimir Kujundžić

2008-12-01

Full Text Available The physical and mechanical characteristics of intact rocks depend on the way of their formation, sustained deformations and the process of wearing a specific rock has been exposed to. These characteristics have a rather high influence on the technological process of extraction and dressing of mineral raw materials. However, the mechanical characteristics of rocks due to use of explosives for their extraction in the open pit have a more significant impact. The rock blocks extracted by blasting which are larger than the opening of the primary crusher are usually fragmented by hydraulic hammer. The paper presents the results of the testing of impact of rock hardness on fragmentation of rocks by means of hydraulic hammer and during crushing in jaw crusher. The testing was carried out on the rock samples from five quarries. According to the obtained results the hardness has a considerably larger impact on the fragmentation energy by hydraulic hammer than on the crushing energy in jaw crusher.

First accelerator carbon-14 date for pigment from a rock painting

International Nuclear Information System (INIS)

Van der Merwe, N.J.; Sealy, J.; Yates, R.

1987-01-01

South Africa is particularly blessed with rock art: thousands of paintings and engravings provide a window on the cognitive systems of prehistoric populations. A major stumbling block in studying the art is the lack of a method for dating it. This article shows that some of the paintings can be directly dated by means of accelerator 14 C counting of carbon from black pigment. The advent of accelerator 14 C provides the capability of analysing very small samples and brings pigments from rock paintings into the realm of datable materials

Measuring geomechanical properties of Topopah Spring Tuff at the 1-meter scale

International Nuclear Information System (INIS)

Blair, S.C.; Berge, P.A.

1994-11-01

The Yucca Mountain Site Characterization Project is studying physical and chemical properties of Topopah Spring tuff and coupled thermal, mechanical, hydrological, and geochemical processes expected in the near-field environment of the potential waste repository at Yucca Mountain, Nevada. Investigating the suitability of Topopah Spring tuff as a host rock for radioactive waste disposal includes measuring mechanical properties. Since heterogeneities vary with scale, from vugs and cracks at the hand-sample scale to fractures and vertical variations in degree of welding at the outcrop scale, mechanical properties of the tuff depend on scale. The Lawrence Livermore National Laboratory has planned a Large Block Test (LBT) to investigate rock mass properties and coupled processes at elevated temperatures in Topopah Spring tuff at the scale of a few meters. This paper describes planned laboratory experiments in support of the LBT, to measure elastic properties and mechanical behavior of Topopah Spring tuff at the scale of a few cm to 1 m. The laboratory experiments will include measurement of stress-strain behavior, acoustic emissions during heating, and elastic wave velocities in small blocks of tuff

Blocking Modification of Eukaryotic Initiation 5A2 Antagonizes Cervical Carcinoma via Inhibition of RhoA/ROCK Signal Transduction Pathway.

Science.gov (United States)

Liu, Xiaojun; Chen, Dong; Liu, Jiamei; Chu, Zhangtao; Liu, Dongli

2017-10-01

Cervical carcinoma is one of the leading causes of cancer-related death for female worldwide. Eukaryotic initiation factor 5A2 belongs to the eukaryotic initiation factor 5A family and is proposed to be a key factor involved in the development of diverse cancers. In the current study, a series of in vivo and in vitro investigations were performed to characterize the role of eukaryotic initiation factor 5A2 in oncogenesis and metastasis of cervical carcinoma. The expression status of eukaryotic initiation factor 5A2 in 15 cervical carcinoma patients was quantified. Then, the effect of eukaryotic initiation factor 5A2 knockdown on in vivo tumorigenicity ability, cell proliferation, cell cycle distribution, and cell mobility of HeLa cells was measured. To uncover the mechanism driving the function of eukaryotic initiation factor 5A2 in cervical carcinoma, expression of members within RhoA/ROCK pathway was detected, and the results were further verified with an RhoA overexpression modification. The level of eukaryotic initiation factor 5A2 in cervical carcinoma samples was significantly higher than that in paired paratumor tissues ( P cycle arrest ( P ROCK I, and ROCK II were downregulated. The above-mentioned changes in eukaryotic initiation factor 5A2 knockdown cells were alleviated by the overexpression of RhoA. The major findings outlined in the current study confirmed the potential of eukaryotic initiation factor 5A2 as a promising prognosis predictor and therapeutic target for cervical carcinoma treatment. Also, our data inferred that eukaryotic initiation factor 5A2 might function in carcinogenesis of cervical carcinoma through an RhoA/ROCK-dependent manner.

Investigating Multiphase Flow Phenomena in Fine-Grained Reservoir Rocks: Insights from Using Ethane Permeability Measurements over a Range of Pore Pressures

Directory of Open Access Journals (Sweden)

Eric Aidan Letham

2018-01-01

Full Text Available The ability to quantify effective permeability at the various fluid saturations and stress states experienced during production from shale oil and shale gas reservoirs is required for efficient exploitation of the resources, but to date experimental challenges prevent measurement of the effective permeability of these materials over a range of fluid saturations. To work towards overcoming these challenges, we measured effective permeability of a suite of gas shales to gaseous ethane over a range of pore pressures up to the saturated vapour pressure. Liquid/semiliquid ethane saturation increases due to adsorption and capillary condensation with increasing pore pressure resulting in decreasing effective permeability to ethane gas. By how much effective permeability to ethane gas decreases with adsorption and capillary condensation depends on the pore size distribution of each sample and the stress state that effective permeability is measured at. Effective permeability decreases more at higher stress states because the pores are smaller at higher stress states. The largest effective permeability drops occur in samples with dominant pore sizes in the mesopore range. These pores are completely blocked due to capillary condensation at pore pressures near the saturated vapour pressure of ethane. Blockage of these pores cuts off the main fluid flow pathways in the rock, thereby drastically decreasing effective permeability to ethane gas.

Rock Directed Breaking Under the Impulse Load

Science.gov (United States)

Khomeriki, Sergo; Mataradze, Edgar; Chikhradze, Nikoloz; Losaberidze, Marine; Khomeriki, Davit; Shatberashvili, Grigol

2016-10-01

In the work the problem of directed chipping of facing stone material by means of managing of explosion process is considered. The technology of the mining of decorative stone by the use of explosion energy means the very rapid transfer of potential energy of elastic deformations to kinetic energy. As a result, the explosion impulse, in the expanse of the inertia of rock massive, does not cause the increase of existing cracks. In the course of explosion, the shock wave is propagated by ultrasonic velocity and in this case the medium parameters (pressure, density, temperature, velocity) increase in spurts. In spite of this fact the all three conservation laws of mechanics remain valid on basis of three laws the equations are derived by which the parameters of shock wave may be defined by means of the rock physical-mechanical properties. The load on the body volume at breaking under explosion acts over very small period of the time. Therefore, stressed-deformed state of the rock was studied when the impulse load acts on the boundary. It was considered that the mining of the blocks of facing stone is performed from the hard rocks. This means that the breaking proceeds in the zone of elastic deformation. In the conditions of mentioned assumptions, the expression of the stress tensor and displacement of vector components initiated by stressed-deformed state in the rock are written.

Introduction to numerical modeling of thermohydrologic flow in fractured rock masses

International Nuclear Information System (INIS)

Wang, J.S.Y.

1980-01-01

More attention is being given to the possibility of nuclear waste isolation in hard rock formations. The waste will generate heat which raises the temperature of the surrounding fractured rock masses and induces buoyancy flow and pressure change in the fluid. These effects introduce the potential hazard of radionuclides being carried to the biosphere, and affect the structure of a repository by stress changes in the rock formation. The thermohydrological and thermomechanical responses are determined by the fractures as well as the intact rock blocks. The capability of modeling fractured rock masses is essential to site characterization and repository evaluation. The fractures can be modeled either as a discrete system, taking into account the detailed fracture distributions, or as a continuum representing the spatial average of the fractures. A numerical model is characterized by the governing equations, the numerical methods, the computer codes, the validations, and the applications. These elements of the thermohydrological models are discussed. Along with the general review, some of the considerations in modeling fractures are also discussed. Some remarks on the research needs in modeling fractured rock mass conclude the paper

Implementation of the full-scale emplacement (FE) experiment at the Mont Terri rock laboratory

Energy Technology Data Exchange (ETDEWEB)

Müller, H.R.; Garitte, B.; Vogt, T.; and others

2017-04-15

Opalinus Clay is currently being assessed as the host rock for a deep geological repository for high-level and low- and intermediate-level radioactive wastes in Switzerland. Within this framework, the 'Full-Scale Emplacement' (FE) experiment was initiated at the Mont Terri rock laboratory close to the small town of St-Ursanne in Switzerland. The FE experiment simulates, as realistically as possible, the construction, waste emplacement, backfilling and early post-closure evolution of a spent fuel/vitrified high-level waste disposal tunnel according to the Swiss repository concept. The main aim of this multiple heater test is the investigation of repository-induced thermo-hydro-mechanical (THM) coupled effects on the host rock at this scale and the validation of existing coupled THM models. For this, several hundred sensors were installed in the rock, the tunnel lining, the bentonite buffer, the heaters and the plug. This paper is structured according to the implementation timeline of the FE experiment. It documents relevant details about the instrumentation, the tunnel construction, the production of the bentonite blocks and the highly compacted 'granulated bentonite mixture' (GBM), the development and construction of the prototype 'backfilling machine' (BFM) and its testing for horizontal GBM emplacement. Finally, the plug construction and the start of all 3 heaters (with a thermal output of 1350 Watt each) in February 2015 are briefly described. In this paper, measurement results representative of the different experimental steps are also presented. Tunnel construction aspects are discussed on the basis of tunnel wall displacements, permeability testing and relative humidity measurements around the tunnel. GBM densities achieved with the BFM in the different off-site mock-up tests and, finally, in the FE tunnel are presented. Finally, in situ thermal conductivity and temperature measurements recorded during the first heating months

Comparison of sorption measurements on argillaceous rocks and bentonite with predictions using the SGT-E2 approach to derive sorption data bases

Energy Technology Data Exchange (ETDEWEB)

Bradbury, M. H.; Baeyens, B; Marques Fernandes, M.

2014-11-15

In Stage 1 of the Sectoral Plan for Deep Geological Repositories, four rock types have been identified as being suitable host rocks for a radioactive waste repository, namely, Opalinus Clay for a high-level (HLW) and a low- and intermediate-level (L/ILW) repository, and 'Brauner Dogger', Effingen Member and Helvetic Marls for a L/ILW repository. Sorption data bases (SDBs) for all of these host rocks are required for the provisional safety analyses, including all of the bounding porewater and mineralogical composition combinations. In addition, SDBs are needed for the rock formations lying below Opalinus Clay (lower confining units) and for the bentonite backfill in the HLW repository. A detailed procedure was developed for deriving SDBs for argillaceous rocks (and bentonite) based on sorption edge measurements on illite (and montmorillonite), the hypothesis that 2:1 clay minerals are the dominant sorbents and a series of so called conversion factors which take into account the different radionuclide speciations in the different porewaters. Since this methodology for generating SDBs is relatively new, a validation and demonstration of the robustness and reliability of the sorption values derived was required. This report describes an extensive piece of work in which blind predictions of sorption values were compared with measured ones. Sorption isotherms were measured for the following metal ions Cs(I), Co(II), Ni(II), Eu(III), Th(IV) and U(VI) in a range of realistic porewater chemistries for a range of host rock mineralogies. In the end 53 isotherm data sets were measured. For each of these isotherms a prediction was made of the sorption at trace concentrations using the SDB derivation methodology. A comparison between measured and predicted values for each case was then made. This validation study shows that the methodology used for the derivation of the sorption data bases for argillaceous rocks and bentonite produces reliable sorption values. (authors)

Charge Generation and Propagation in Igneous Rocks

Science.gov (United States)

Freund, Friedemann

2002-01-01

Various electrical phenomena have been reported prior to or concurrent with earthquakes such as resistivity changes, ground potentials, electromagnetic (EM), and luminous signals. Doubts have been raised as to whether some of these phenomena are real and indeed precursory. One of the reasons for uncertainty is that, despite decades of intense work, there is still no physically coherent model. Using low- to medium-velocity impacts to measure electrical signals with microsecond time resolution, it has now been observed that when dry gabbro and diorite cores are impacted at relatively low velocities, approximately 100 m/s, highly mobile charge carriers are generated in a small volume near the impact point. They spread through the rocks, causing electric potentials exceeding +400 mV, EM, and light emission. As the charge cloud spreads, the rock becomes momentarily conductive. When a dry granite block is impacted at higher velocity, approximately 1.5 km/s, the propagation of the P and S waves is registered through the transient piezoelectric response of quartz. After the sound waves have passed, the surface of the granite block becomes positively charged, suggesting the same charge carriers as observed during the low-velocity impact experiments, expanding from within the bulk. During the next 2-3 ms the surface potential oscillates, indicating pulses of electrons injected from ground and contact electrodes. The observations are consistent with positive holes, e.g., defect electrons in the O(2-) sublattice, traveling via the O 2p-dominated valence band of the silicate minerals. Before activation, the positive holes lay dormant in the form of electrically inactive positive hole pairs (PHP), chemically equivalent to peroxy links, O3X/OO\\XO3, with X=Si(4+), Al(3+), etc. PHPs are introduced into the minerals by way of hydroxyl,O3X-OH, which all nominally anhydrous minerals incorporate when crystallizing in H2O-laden environments. The fact that positive holes can be

Lichenometric age measured on rock-falls related to historic seismicity affecting Lorca and its surroundings (Murcia, SE Spain); Datacion mediante liquenometria de los desprendimientos rocosos asociados a la sismicidad historica en Lorca (Murcia, SE de Espana)

Energy Technology Data Exchange (ETDEWEB)

Perez-Lopez, R.; Martin-Gonzalez, F.; Martinez-Diaz, J. J.; Rodriguez-Pascua, M. A.

2012-11-01

During the earthquake at Lorca (Murcia, SE Spain) in 2011 (5.2 Mw, 4km depth) several rock-falls occurred, mobilizing an estimated volume of close to 2,000 m3. All these rock-falls took place within the Estancias and La Tercia mountain ranges, the topography of which is composed of Tortonian calcarenitic sandstones with steep scarps more than 30 m in height. We have conducted a lichenometric study to obtain the age of the ancient rock-falls within the Las Estancias Range. We have assumed an annual growth rate of 0.24 mm for lichen species classified as calcicolous and related to warm climatic conditions. Our aim was to corroborate the hypothesis that seismic events triggered these massive rock-falls. The city of Lorca had experienced two nearfield historic earthquakes (1674 EMS VIII and 1818 EMS VI) and one far-field tremor during the great Lisbon earthquake in 1755 (EMS VI). Results obtained here indicate that the earthquakes of 1674 and 2011 were quite similar, except that the 1674 one mobilised a greater quantity and twenty times the volume of blocks mobilised during the 2011 earthquake. Therefore, we conclude that the size of the earthquake of 1674 was possibly between 6.0 < M < 6.8, assuming similar focal and seismotectonic conditions to those of the instrumentally measured earthquake of 2011. (Author) 34 refs.

Aespoe hard rock laboratory. Annual report 2000

International Nuclear Information System (INIS)

2001-06-01

repository system, which are of importance for long-term safety. The Prototype Repository experiment is focused on testing and demonstrating repository system function in full scale, and consists of six deposition holes with canisters and electric heaters surrounded by highly compacted bentonite. The work during 2000 has focused on geoscientific characterisation and specially hydraulic properties and conditions of the rock. Preparatory work with design, purchase and manufacturing as well as rock work (slots for the two plugs) have been going on with the aim of preparing for start of installation during the second quarter of 2001. Equipment for installation of bentonite blocks and canisters were tested before start of installation in the Canister Retrieval Test. This test was completed in October and the heaters as well as the artificial saturation system was turned on immediately thereafter. The objectives of the Demonstration of Repository Technology are to develop, test, and demonstrate methodology and equipment for encapsulation and deposition of spent nuclear fuel. The demonstration of handling and deposition is made with the specially designed full scale prototype to a deposition machine at 420 m level. The Backfill and Plug Test includes tests of backfill materials and emplacement methods and a test of a full-scale plug. Half the test part is filled with a mixture of 30% bentonite and crushed granite rock. The other half is filled with crushed rock without addition of bentonite, except for the upper 100-200 mm, where a slot was filled with blocks of highly compacted bentonite/crushed rock mixture and bentonite pellets. The backfill and rock has been instrumented with about 230 transducers for measuring the thermo- hydro-mechanical processes. Water saturation has been going on the whole year and the saturation speed has been slower than expected due to a lower salt content in the water than expected. In order to increase the speed a water with a higher salt content can

In situ measurements of rock salt permeability changes due to nearby excavation

International Nuclear Information System (INIS)

Stormont, J.C.; Howard, C.L.; Daemen, J.J.K.

1991-07-01

The Small-Scale Mine-By was an in situ experiment to measure changes in brine and gas permeability of rock salt as a result of nearby excavation. A series of small-volume pressurized brine- and gas-filled test intervals were established 8 m beneath the floor of Room L1 in the WIPP underground. The test intervals were isolated in the bottom of the 4.8-cm diameter monitoring boreholes with inflatable rubber packers, and are initially pressurized to about 2 MPa. Both brine- and gas-filled test intervals were located 1.25, 1.5, 2, 3, and 4 r from the center of a planned large-diameter hole, where r is the radius of the large-diameter hole. Prior to the drilling of the large-diameter borehole, the responses of both the brine- and gas-filled test intervals were consistent with the formation modeled as a very low permeability, low porosity porous medium with a significant pore (brine) pressure and no measurable gas permeability. The drilling of the mine-by borehole created a zone of dilated, partially saturated rock out to about 1.5 r. The formation pressure increases from near zero at 1.5 r to the pre-excavation value at 4 r. Injection tests reveal a gradient of brine permeabilities from 5 x 10 -18 m 2 at 1.25 r to about the pre-excavation value (10 -21 m 2 ) by 3 r. Gas-injection tests reveal measurable gas permeability is limited to within 1.5 r. 17 refs., 24 figs., 6 tabs

Industrial tests of rock consolidation for fighting floor swelling

Energy Technology Data Exchange (ETDEWEB)

Pirskii, A A; Stovpnik, S N [KPI (USSR)

1990-04-01

Reports on investigations into the mechanism of floor swelling in main roadways and into rock mass stabilization by consolidating fluid injection combined with blasting. The principal cause of deterioration in the stability of workings is considered to be the state of stress in the rock mass, rock destruction in side walls where rock blocks are being pressed into the floor while the floor rock is squeezed out into the working space. A case study of fluid injection combined with blasting applied in several mines in the Donbass is presented where holes were drilled 1.5-3 m deep and explosive charges of 0.07-0.1 kg/hole and injection of hardening solutions (0.56-0.83 m{sup 3}/m of workings) were applied. As a result floor swelling rates were reduced by up to about 5 times (e.g. from 2.5 mm/d to 0.5 mm/d.). The period of maintenence free upkeep of workings was extended to 6-8 years. The economic effect in maintenance of 1 m of workings was 11.7 rubles for floor consolidation without sidewall bolting and 51.4 rubles for floor consolidation combined with sidewall bolting. Recommendations that concern the technology of floor consolidation by fluid injection and blasting are made. 4 refs.

Thermal history of rocks in southern San Joaquin Valley, California: evidence from fission-track analysis

Science.gov (United States)

Naeser, N.D.; Naeser, C.W.; McCulloh, T.H.

1990-01-01

Fission-track analysis has been used to study the thermal and depositional history of the subsurface Tertiary sedimentary rocks on both sides of the active White Wolf reverse fault in the southern San Joaquin Valley. The distinctly different thermal histories of the rocks in the two structural blocks are clearly reflected in the apatite fission-track data, which suggest that rocks in the rapidly subsiding basin northwest of the fault have been near their present temperature for only about 1 m.y. compared with about 10 m.y. for rocks southeast of the fault. These estimates of heating time agree with previous estimates for these rocks. Zircon fission-track data indicate that the Tertiary sediments were derived from parent rocks of more than one age. However, from at least the Eocene to late Miocene or Pliocene, the major sediment source was rocks related to the youngest Sierra Nevada Mesozoic intrusive complexes, which are presently exposed east and south of the southern San Joaquin Valley. -from Authors

Fabrication and handling of bentonite blocks

International Nuclear Information System (INIS)

1978-06-01

In accordance with the project for the final storage of spent nuclear fuel, the waste will be encapsulated into copper canisters, which will be deposited in a final repository located in rock 500 m below ground level. The canisters will be placed in vertical holes in the bottoms of the tunnels, where the copper cylinders will be surrounded by blocks of highly compacted bentonite. When the blocks are saturated with water and expansion is essentially retained as in the actual case, a very high swelling pressure will arise. The bentonite will be extremely impermeable and thus it will form a barrier against transport of corrosive matters to the canister. The blocks are fabricated by means of cold isostatic pressing of bentonite powder. The base material in the form of powder is enclosed in flexible forms, which are introduced into pressure vessels where the forms are surrounded by oil or water. Thus the powder is compacted into rigid bodies with a bulk density of about 2.2 t/m 3 for ''air dry'' bentonite, which might be compared with a specific density of about 2.7 t/m 3 . The placing of a canister is preceded by piling up bentonite blocks to a level just below the canister lid position, after which the slot around the blocks is filled with bentonite powder. The rest of the blocks are mounted after filling bentonite powder into the inner slot around the canister as well. Finally the storage tunnels will be sealed by filling them with a mixture o02067NRM 0000181 45

Rock mass and shaft concrete lining temperature measurement procedure: Final draft

International Nuclear Information System (INIS)

1986-10-01

This procedure document describes the equipment and procedures which will be used to obtain temperature data from within rock-mass and shaft linings at the Deaf Smith Exploratory Shaft Facility. Temperature measurement methods for instrument temperature correction, fluid temperature correction, heated surface monitoring and air temperature monitoring are outside the scope of this procedure, and are covered in the appropriate individual test procedures. Calibration, acceptance testing and the assignment of transducer reference numbers are outside the scope of this procedure. Section 2.0 provides a summary of the temperature measurement methods which will be employed, together with the measurement locations, environmental considerations and measurement requirements. Test layouts, including detailed descriptions of instruments, support requirements and detailed installation procedures are also presented. Section 3.0 describes the requirements for data recording, ADAS monitoring, and data reporting. Section 4.0 defines personnel responsibilities and qualifications. In addition a measurement and installation schedule is provided, and safety and contingency plans are described. Section 5.0 discusses management and quality assurance requirements. Cited references are listed in Section 6.0. 7 refs., 9 figs

Indirect deformation (strain) measurements and calibrations in Sandia triaxial apparatus for rock testing to 2500C

International Nuclear Information System (INIS)

Wawersik, W.R.

1979-09-01

Indirect procedures for axial and radial strain measurements on rock in triaxial tests to 250 0 C are presented. The description of techniques includes discussions of all calibrations and of the accuracies of measurements. In addition, two examples are given to show how the techniques are implemented in triaxial compression and triaxial extension experiments. 10 figures

Current status of crushed rock and whole rock column studies

International Nuclear Information System (INIS)

Vine, E.N.; Daniels, W.R.; Rundberg, R.S.; Thompson, J.L.

1980-01-01

Measurements on a large number of crushed rock columns of tuff, granite, and argillite are discussed. The isotopes 85 Sr, 137 Cs, 133 Ba, 141 Ce, 152 Eu, /sup 95m/Tc, and 233 U were used. Flow rates were varied from approx. 30 to approx. 30000 m/y. Other parameters studied include isotope concentration and atmosphere. The sorption ratios calculated were compared with batch sorption ratios on the same samples. Methods of studying the movement of radionuclides through whole rock cores are described. The problems associated with sealing the cores to prevent leaking along the exterior surface and one possible solution are discussed. The strontium sorption ratio obtained by elution of one solid tuff core is compared with the batch and crushed rock column sorption ratios

On the description of the properties of fractured rock using the concept of a porous medium

International Nuclear Information System (INIS)

Stokes, J.

1980-05-01

In order to describe the flow of groundwater through fractured rock, water is either assumed to flow through a pervious continuum of through descrete fractures between impervious blocks of rock. The latter approach being the one demanding more information on the rock, problems on groundwater flow are usually discussed using the porous medium approach. It is often a question of debate wether the continuum approach is applicable to the fractured rock under consideration. Therefore, it is essential that after assuming that a certain flow region acts as a porous medium, we use a procedure for measuring the properties that at the same time gives a test of this assumption. When giving a description of groundwater flow, the goal is often a presentation of pathlines and flowtimes between points of interest and the ground surface. Using a porous medium approach, this means that hydraulic conductivity and porosity must be known through the medium. In order to cope with transient flow, we must also know the time constant governing the development of the flow. The pathlines depend to a great extent on the variation of conductivity through space. A conductivity decreasing with depth will force the pathlines to the surface giving local flow. If instead the conductivity is constant, the flow is regional. It is therefore important to know the gradient of hydraulic conductivity. Finally, as we know that the flow takes place through a geological structure, the anisotropic behaviour of the rock must be known in order to describe the flow. In this report a procedure to measure the properties listed above is developed. (author)

Ionization and Corona Discharges from Stressed Rocks

Science.gov (United States)

Winnick, M. J.; Kulahci, I.; Cyr, G.; Tregloan-Reed, J.; Freund, F. T.

2008-12-01

Pre-earthquake signals have long been observed and documented, though they have not been adequately explained scientifically. These signals include air ionization, occasional flashes of light from the ground, radio frequency emissions, and effects on the ionosphere that occur hours or even days before large earthquakes. The theory that rocks function as p-type semiconductors when deviatoric stresses are applied offers a mechanism for this group of earthquake precursors. When an igneous or high-grade metamorphic rock is subjected to deviatoric stresses, peroxy bonds that exist in the rock's minerals as point defects dissociate, releasing positive hole charge carriers. The positive holes travel by phonon-assisted electron hopping from the stressed into and through the unstressed rock volume and build up a positive surface charge. At sufficiently large electric fields, especially along edges and sharp points of the rock, air molecules become field-ionized, loosing an electron to the rock surface and turning into airborne positive ions. This in turn can lead to corona discharges, which manifest themselves by flashes of light and radio frequency emissions. We applied concentrated stresses to one end of a block of gabbro, 30 x 15 x 10 cm3, inside a shielded Faraday cage and observed positive ion currents through an air gap about 25 cm from the place where the stresses were applied, punctuated by short bursts, accompanied by flashes of light and radio frequency emissions characteristic of a corona discharge. These observations may serve to explain a range of pre-earthquake signals, in particular changes in air conductivity, luminous phenomena, radio frequency noise, and ionospheric perturbations.

Evaluation of the instability problems in rock slopes surrounding historical Safranbolu by kinematic analysis

Directory of Open Access Journals (Sweden)

İnan Keskin

2017-10-01

Full Text Available Safranbolu which has high probability for slope-induced disasters is a very worthwhile settlement for our country and also for the world with its historical and cultural heritage. Finding out potential hazards that may affect the wealth of this world heritage city is very crucial. The historic Safranbolu is surrounded by very steep rock slopes, and occasionally instability occurs in the rock mass that forms these slopes. The rock blocks that are relaesed in various causes and shapes can damage the historic town living spaces by creating a source for the rock fallings and moving down the slope in these very steep slopes. The rock slopes were evaluated by kinematic analysis in order to reduce the mentioned damages and to reveal potential hazards. In the study, characteristics of mass that causes rock fallings are analysed, kinematic controlled instability types are determined considering the obtained data and characteristic of slopes.

Failure mechanism and supporting measures for large deformation of Tertiary deep soft rock

Institute of Scientific and Technical Information of China (English)

Guo Zhibiao; Wang Jiong; Zhang Yuelin

2015-01-01

The Shenbei mining area in China contains typical soft rock from the Tertiary Period. As mining depths increase, deep soft rock roadways are damaged by large deformations and constantly need to be repaired to meet safety requirements, which is a great security risk. In this study, the characteristics of deformation and failure of typical roadway were analyzed, and the fundamental reason for the roadway deformation was that traditional support methods and materials cannot control the large deformation of deep soft rock. Deep soft rock support technology was developed based on constant resistance energy absorption using constant resistance large deformation bolts. The correlative deformation mechanisms of surrounding rock and bolt were analyzed to understand the principle of constant resistance energy absorption. The new technology works well on-site and provides a new method for the excavation of roadways in Tertiary deep soft rock.

I. Some results from a field investigation of thermo-mechanical loading of a rock mass when heaters are emplaced in the rock

International Nuclear Information System (INIS)

Hood, M.

1979-01-01

Results are presented of a field experiment to monitor the response of a rock mass to thermomechanical loading from electrically heated canisters emplaced in the rock at a depth of 340 m. Measurements made to date of temperature, displacement, and stress fields indicate that heat is transferred through the rock mainly by conduction; discontinuities within the rock mass have a minimal effect on the heat flow. Displacements within the rock from thermal expansion are shown to be much less than those predicted by linear thermoelastic theory. A plausible, though not complete, reason for these reduced displacements is the absorption of the initial rock expansions into discontinuities within the rock mass. Difficulties have been experienced in obtaining reliable stress measurement data using borehole deformation gauges to monitor changes in rock stress. Some data have been obtained and are being analyzed. Rock decrepitation in the heater boreholes is discussed

Effect of excavation method on rock mass displacement

International Nuclear Information System (INIS)

Sato, Toshinori; Kikuchi, Tadashi; Sugihara, Kozo

1998-01-01

Rock mass displacement measurements have been performed to understand rock mass behavior and its dependence on excavation method during drift excavation at the Tono mine. Rock mass displacements of 1.46 mm and 0.67 mm have been measured at one meter (0.33D: blasting, 0.42D: machine, D: width of drift) from the walls of drifts excavated by the drill and blasting method and machine, respectively. Numerical analysis of rock mass displacements with Finite Element Method has been performed assuming an excavation disturbed zone. Measured and analysed rock mass displacements are consistent with each other for the drift excavation by the drill and blasting method. The excavation disturbed zone was narrower for the drift excavated by machine than for the drift excavated by the drill and blasting method. (author)

Structural characterization of the rock mass of the underground mine Oro Descanso

Directory of Open Access Journals (Sweden)

Adeoluwa Olajesu Oluwaseyi

2017-10-01

Full Text Available In the rocky massif where the Oro Descanso underground mine is located, an assessment was made of the physical-mechanical properties of rocks, cracking and blocking, in order to propose safe tillage measures for underground mining excavations using appropriate empirical methods. From the evaluation made it was concluded that the massif is composed of areas of rocks of different quality: good, fair and poor. It is proposed for the area of good quality to work excavations with complete advance, of free length 1.0-1.5 m, using in the crown the support of cemented anchors of diameter 20 mm, length 3 m and spaced 2.5 m and apply concrete released 50 mm thick. For the zone of bad and regular quality, it is suggested to work in stepwise progression, of free length of 1-3 m and after each blasting, to install in the crown, cemented anchors of diameter 20 mm, length 4-5 m and spacing 1-2 m, placing on the sides metallic mesh, with concrete cast 50-150 mm thick.

Mizunami Underground Research Laboratory project. Rock mechanical investigations measurement of the rock strain and displacement during shaft excavation at GL.-200m level of research galley

International Nuclear Information System (INIS)

Hirano, Toru; Seno, Yasuhiro; Hikima, Ryoichi; Matsui, Hiroya

2011-09-01

In order to establish the scientific and technical basis for geological disposal of high-level radioactive waste, Japan Atomic Energy Agency (JAEA) is proceeding with the geoscientific research in the research galleries excavated at the Mizunami Underground Research Laboratory (MIU). One of the scientific and technical objectives of this project is to understand the change of geological environment due to excavation of research galleries. The investigation described herein is the measurement of the rock strain / displacement while pre-excavation grouting or excavating of the shaft around the GL.-200m level of research gallery. A brief summary is presented as follows. 1) Apparent strain with pre-excavation grouting: Injection pressure during pre-excavation grouting could explain the observed strain. Maximum principal strain 'E1' (extension) was oriented to NS direction. The measured fracture system at the site includes a fracture set perpendicular to E1. We infer that these fracture expanded due to grout injection pressure. 2) Apparent strain during excavation of the shaft: Rock behavior of stress release was observed when the bottom of shaft passed by and lining of shaft was constructed. The observed strain was very small and almost same scale as the expected strain for elastic material. But the observed strain of radial direction was compression whereas the expected strain was extension. Therefore it was estimated that rock behavior was affected by cracks. 3) Applicability of the FBG sensors for in situ displacement measurement near the shaft: FBG sensors were stable and reliable in comparison to strain meters or inclinometers. There was no electrical equipment trouble nor large drift in measurements. FBG results can lead to understand bending mode of borehole. But we cannot specify the displacement direction from these data in some cases. (author)

Radioactivities (dose rates) of rocks in Japan

International Nuclear Information System (INIS)

Matsuda, Hideharu; Minato, Susumu

1995-01-01

The radioactive distribution (radiation doses) of major rocks in Japan was monitored to clarify the factors influencing terrestrial gamma-ray absorbed dose rates. The rock samples were reduced to powder and analyzed by well-type NaI(Tl) scintillation detector and pulse height analyzer. Terrestrial gamma-ray dose rates were estimated in terms of gamma radiation dose rate 1 m above the ground. The radioactivity concentration was highest in acidic rock which contains much SiO 2 among igneous rock, followed by neutral rock, basic rock, and ultrabasic rock. The radioactive concentration was 30-40% lower in acidic and clastic rocks than those of the world average concentration. Higher radioactive concentration was observed in soils than the parent rocks of sedimentary rock and metamorphic rock. The gamma radiation dose rate was in proportion to the radioactive concentration of the rocks. To clarify the radioactive effect in the change course of rocks into soils, comparative measurement of outcrop and soil radioactive concentrations is important. (S.Y.)

Pore Type Classification on Carbonate Reservoir in Offshore Sarawak using Rock Physics Model and Rock Digital Images

International Nuclear Information System (INIS)

Lubis, L A; Harith, Z Z T

2014-01-01

It has been recognized that carbonate reservoirs are one of the biggest sources of hydrocarbon. Clearly, the evaluation of these reservoirs is important and critical. For rigorous reservoir characterization and performance prediction from geophysical measurements, the exact interpretation of geophysical response of different carbonate pore types is crucial. Yet, the characterization of carbonate reservoir rocks is difficult due to their complex pore systems. The significant diagenesis process and complex depositional environment makes pore systems in carbonates far more complicated than in clastics. Therefore, it is difficult to establish rock physics model for carbonate rock type. In this paper, we evaluate the possible rock physics model of 20 core plugs of a Miocene carbonate platform in Central Luconia, Sarawak. The published laboratory data of this area were used as an input to create the carbonate rock physics models. The elastic properties were analyzed to examine the validity of an existing analytical carbonate rock physics model. We integrate the Xu-Payne Differential Effective Medium (DEM) Model and the elastic modulus which was simulated from a digital carbonate rock image using Finite Element Modeling. The results of this integration matched well for the separation of carbonate pore types and sonic P-wave velocity obtained from laboratory measurement. Thus, the results of this study show that the integration of rock digital image and theoretical rock physics might improve the elastic properties prediction and useful for more advance geophysical techniques (e.g. Seismic Inversion) of carbonate reservoir in Sarawak

Use of an Android application "clinometer" for measurement of head down tilt given during subarachnoid block.

Science.gov (United States)

Dixit, R B; Neema, M M

2016-01-01

Head down tilt is given to patients after sub arachnoid block for adjustment of height of block. However, the amount of tilt given is subjective and cannot be documented. We used an android application named "clinometer" to measure exact degree of tilt given by anesthesiologists as their routine practice. This observational study, at a medical college hospital, was done in 130 patients given sub arachnoid block for lower abdominal surgeries. We observed and documented vital data of patients and measured tilt given by application "clinometer." We observed that the application was easy to use and measured tilt each time. The result obtained can be documented, digitally saved and transferred. In 130 patients studied, we observed incidence of degree of tilt as follows: 6-8° tilt in 38 patients (29.23%), 8-10 in 36 patients (27.69%), 10-12 in 30 patients (23.08%), 12-14 in 12 patients (9.23%) and 14-16° tilt in 14 patients (10.77%). Use of application was received with enthusiasm by practicing anesthesiologists. Various possible uses of this application are discussed.

Using a Remotely Piloted Aircraft System (RPAS) to analyze the stability of a natural rock slope

Science.gov (United States)

Salvini, Riccardo; Esposito, Giuseppe; Mastrorocco, Giovanni; Seddaiu, Marcello

2016-04-01

orientation. The coordinates of GCPs were calculated through the post-processing of data collected by using two GPS receivers, operating in static modality, and a Total Station. The photogrammetric processing of image blocks allowed us to create the 3D point cloud, DTM, orthophoto, and 3D textured model with high level of cartographic detail. Discontinuities were deterministically characterized in terms of attitude, persistence, and spacing. Moreover, the main discontinuity sets were identified through a density analysis of attitudes in stereographic projection. In addition, the size and shape of potentially unstable blocks identified along the rock slope were measured. Finally, using additional data from traditional engineering-geological surveys executed in accessible outcrops, the kinematic and dynamic stability analysis of the rocky slope was performed. Results from this step have indicated the deterministic safety factors of rock blocks and wedges, and will be used by local Authorities to plan the protection works for safety guarantee. Results from this application show the great advantage of modern RPAS that can be successfully applied for the analysis of sub-vertical rocky slopes, especially in areas either difficult to access with traditional techniques or masked by the presence of vegetation. KEY WORDS: 3D point cloud, RPAS photogrammetry, Terrestrial laser scanning, Rock slope, Fracture mapping, Stability analysis

Thermal-cycle testing of the G-tunnel heated block

International Nuclear Information System (INIS)

Zimmerman, R.M.; Wilson, M.L.; Board, M.P.; Hall, M.E.; Schuch, R.L.

1985-01-01

Volcanic tuffs are being considered by the Department of Energy (DOE) as a medium for disposal of high-level radioactive wastes. The Nevada Nuclear Waste Storage Investigations (NNWSI) Project was established in 1977 to evaluate such disposal in geologic formations on or adjacent to the Nevada Test Site (NTS). Sandia National Laboratories (SNL), as one of the NNWSI project participants, is responsible for the rock mechanics program to support the design of underground portions of a radioactive-waste repository in tuff. A rock mechanics field testing program is underway in G-Tunnel in Rainier Mesa on the NTS, where tuffs similar to those at Yucca Mountain, the potential candidate site, are found; later experiments are planned as part of the exploratory shaft investigations in Yucca Mountain. Science Applications International Corporation has been under contract to SNL to prepare and install instrumentation and control systems and to aid in the evaluation of the heated-block rock mechanics experiment

Rock Crushing Using Microwave Pre-Treatment

KAUST Repository

Kim, Seunghee; Santamarina, Carlos

2016-01-01

Crushing and grinding are primary contributors to a high energy demand in the mining industry, yet, both are surprisingly inefficient processes, often with efficiencies as low as 1%. We analyze size reductions during crushing and grinding operations and explore the potential of multiplying internal weaknesses in rock materials by non-mechanical means. In particular, when rock blocks (wet or even dry if polycrystalline) are exposed to microwaves, internal cracks can develop along grain boundaries via differential thermal expansion between grains and volumetric thermal expansion of water in pores. Brazilian tests conducted on granite and cement mortar specimens show that the tensile strength decreases proportional to the duration of microwave treatment. Thermal changes, excessive fluid pressure buildup and induced stresses are analyzed in the context of hydro-Thermo-mechanically coupled processes. Results confirm that both differential thermal expansion of mineral grains and volumetric thermal expansion of water can generate cracks upon microwave exposure. Optimal conditions are suggested to lower the combined consumption of electric and mechanical energy.

Rock Crushing Using Microwave Pre-Treatment

KAUST Repository

Kim, Seunghee

2016-08-11

Crushing and grinding are primary contributors to a high energy demand in the mining industry, yet, both are surprisingly inefficient processes, often with efficiencies as low as 1%. We analyze size reductions during crushing and grinding operations and explore the potential of multiplying internal weaknesses in rock materials by non-mechanical means. In particular, when rock blocks (wet or even dry if polycrystalline) are exposed to microwaves, internal cracks can develop along grain boundaries via differential thermal expansion between grains and volumetric thermal expansion of water in pores. Brazilian tests conducted on granite and cement mortar specimens show that the tensile strength decreases proportional to the duration of microwave treatment. Thermal changes, excessive fluid pressure buildup and induced stresses are analyzed in the context of hydro-Thermo-mechanically coupled processes. Results confirm that both differential thermal expansion of mineral grains and volumetric thermal expansion of water can generate cracks upon microwave exposure. Optimal conditions are suggested to lower the combined consumption of electric and mechanical energy.

Interpreting strain measurements when drilling anisotropic rocks: return of experience from using CSIRO cells in Tournemire argillite

International Nuclear Information System (INIS)

Ben Ouanas, Abdelmonem

2010-01-01

In Geomechanics, determining the state of stress and the rheology of rock massif can be obtained by measuring the strain response of the ground under the effect of a known stress. A method among others is to use a cell integrated (with strain gauges oriented in different directions) installed in a borehole and secured to the mass through an epoxy glue. This measurement is used, notably, to determine the stress state in situ by the 'overcoring' method and the elastic parameters of the rock from the 'biaxial' test. Between November 2005 and January 2006, a geomechanical testing campaign was conducted in the argillaceous formation of the Tournemire experimental site (Aveyron, France) using CSIRO Hi cells. The strain measurements obtained during overcoring and biaxial tests have shown unusual phenomena, which have made difficult the determination of anisotropic elastic parameters of the rock and the access to the site stress. Therefore, through researches for explanations of the origin of these phenomena, this thesis aimed to improve and contribute to the understanding of the Tournemire argillite behaviour and to upgrade the measurement protocol as well as the interpretation of cells CSIRO's strain. The approach was, firstly, to issue a number of hypotheses to explain certain phenomena observed in literature. In a second step, these hypotheses were tested through analytical and numerical modelling of the biaxial and overcoring tests then through the realization of new experiments in situ within laboratory on argillite, and also on materials tests (cement, sample of glue). It is concluded that the unusual phenomena observed are essentially the result of the conditions for implementing in situ CSIRO's cell. The study particularly focused on the artefacts induced by the visco-plastic behaviour of the epoxy glue when it is incompletely polymerised. The role of damage on the rock generated by drilling operations is also discussed. Some practical recommendations for

Temperature measurements of Transdanubian Mesozoic rocks by the oxygen isotope method

International Nuclear Information System (INIS)

Cornides, I.; Csaszar, G.; Haas, J.; Jochane Edelenyi, E.

1979-01-01

Subjected to paleotemperature measurements with the use of oxygen and carbon isotopes were Upper Triassic, Jurassic and Cretaceous sedimentary rocks and their fossils from the Transdanubian Central Mountains, the Mecsek and the Villany Mts. In determining formation temperature, an important parameter of the environment of formation, the authors relied on the fact that the oxygen isotope composition of calcium carbonate precipitating from its aqueous solution deviates, in dependence on the temperature of the solution concerned, from that of the water. Consequently, the temperature of the water of the one-time seas must have been recorded by the 18 O/ 16 O ratio in the calcite of fossils or sediments. The results reported indicate smaller changes in temperature as compared to international results. In the Jurassic the values of temperature remain consistently below those quoted for Swiss and French territories, being around the values reported from/sroe/thern Germany. These u curves have their maxima in the Toarcian, Aalenian, sediments for which unfortunately no Hungarian results are available. The few results of Cretaceous belemnites are values higher than their international counterparts. The high temperature value obtained for the Albian correlates very well with the formation of rocks known from this stratigraphic stage (red clays, bauxites). (A.L.)

Water - rock interaction in different rock environments

International Nuclear Information System (INIS)

Lamminen, S.

1995-01-01

The study assesses the groundwater geochemistry and geological environment of 44 study sites for radioactive waste disposal. Initially, the study sites were divided by rock type into 5 groups: (1) acid - intermediate rocks, (2) mafic - ultramafic rocks, (3) gabbros, amphibolites and gneisses that contain calc-silicate (skarn) rocks, (4) carbonates and (5) sandstones. Separate assessments are made of acid - intermediate plutonic rocks and of a subgroup that comprises migmatites, granite and mica gneiss. These all belong to the group of acid - intermediate rocks. Within the mafic -ultramafic rock group, a subgroup that comprises mafic - ultramafic plutonic rocks, serpentinites, mafic - ultramafic volcanic rocks and volcanic - sedimentary schists is also evaluated separately. Bedrock groundwaters are classified by their concentration of total dissolved solids as fresh, brackish, saline, strongly saline and brine-class groundwaters. (75 refs., 24 figs., 3 tabs.)

Measurement of hydrogeologic parameters of Indian volcanic rocks by sub-surface hydronuclear techniques

International Nuclear Information System (INIS)

Bardhan, M.

1977-01-01

Sub-surface hydronuclear techniques namely neutron-neutron, gamma-gamma and tracer dilution logging and single and double well tracer methods were adopted to investigate the hitherto inadequately studied hydrophysical properties of the Deccan lava flows which constitute the principal Indian volcanic suit of rocks. The hydrogeologic parameters measured in the field pertain to hydrostratigraphy, hydrostorage properties and geohydraulic characteristics of these layered hard formations. Results of the studies are presented and discussed briefly. (author)

Modeling rock specimens through 3D printing: Tentative experiments and prospects

Science.gov (United States)

Jiang, Quan; Feng, Xiating; Song, Lvbo; Gong, Yahua; Zheng, Hong; Cui, Jie

2016-02-01

Current developments in 3D printing (3DP) technology provide the opportunity to produce rock-like specimens and geotechnical models through additive manufacturing, that is, from a file viewed with a computer to a real object. This study investigated the serviceability of 3DP products as substitutes for rock specimens and rock-type materials in experimental analysis of deformation and failure in the laboratory. These experiments were performed on two types of materials as follows: (1) compressive experiments on printed sand-powder specimens in different shapes and structures, including intact cylinders, cylinders with small holes, and cuboids with pre-existing cracks, and (2) compressive and shearing experiments on printed polylactic acid cylinders and molded shearing blocks. These tentative tests for 3DP technology have exposed its advantages in producing complicated specimens with special external forms and internal structures, the mechanical similarity of its product to rock-type material in terms of deformation and failure, and its precision in mapping shapes from the original body to the trial sample (such as a natural rock joint). These experiments and analyses also successfully demonstrate the potential and prospects of 3DP technology to assist in the deformation and failure analysis of rock-type materials, as well as in the simulation of similar material modeling experiments.

RhoA/ROCK signaling regulates smooth muscle phenotypic modulation and vascular remodeling via the JNK pathway and vimentin cytoskeleton.

Science.gov (United States)

Tang, Lian; Dai, Fan; Liu, Yan; Yu, Xiaoqiang; Huang, Chao; Wang, Yuqin; Yao, Wenjuan

2018-05-20

The RhoA/ROCK signaling pathway regulates cell morphology, adhesion, proliferation, and migration. In this study, we investigated the regulatory role of RhoA/ROCK signaling on PDGF-BB-mediated smooth muscle phenotypic modulation and vascular remodeling and clarified the molecular mechanisms behind these effects. PDGF-BB treatment induced the activation of RhoA, ROCK, PDGF-Rβ, and the expression of PDGF-Rβ in HA-VSMCs (human aortic vascular smooth muscle cells). PDGF-Rβ inhibition and RhoA suppression blocked PDGF-BB-induced RhoA activation and ROCK induction. In addition, PDGF-BB-mediated cell proliferation and migration were suppressed by PDGF-Rβ inhibition, RhoA suppression, and ROCK inhibition, suggesting that PDGF-BB promotes phenotypic modulation of HA-VSMCs by activating the RhoA/ROCK pathway via the PDGF receptor. Moreover, suppressing both ROCK1 and ROCK2 blocked cell cycle progression from G0/G1 to S phase by decreasing the transcription and protein expression of cyclin D1, CDK2, and CDK4 via JNK/c-Jun pathway, thus reducing cell proliferation in PDGF-BB-treated HA-VSMCs. ROCK1 deletion, rather than ROCK2 suppression, significantly inhibited PDGF-BB-induced migration by reducing the expression of vimentin and preventing the remodeling of vimentin and phospho-vimentin. Furthermore, ROCK1 deletion suppressed vimentin by inhibiting the phosphorylation of Smad2/3 and the nuclear translocation of Smad4. These findings suggested that ROCK1 and ROCK2 might play different roles in PDGF-BB-mediated cell proliferation and migration in HA-VSMCs. In addition, PDGF-BB and its receptor participated in neointima formation and vascular remodeling by promoting cell cycle protein expression via the JNK pathway and enhancing vimentin expression in a rat balloon injury model; effects that were inhibited by treatment with fasudil. Together, the results of this study reveal a novel mechanism through which RhoA/ROCK signaling regulates smooth muscle phenotypic modulation and

The LUT-Gauge for overcoring rock stress measurements - Technical description and laboratory evaluation

International Nuclear Information System (INIS)

Leijon, B.

1988-03-01

The development of the LUT-Gauge - a triaxial borehole instrument for overcoring rock stress measurements - is reported. The borehole gauge and the associated equipment is described in some detail. The experimental procedures applicable to field measurements with the device are presented. A series of laboratory tests, aimed at investigating the performance of the instrumentation, are reported, This included basic tests of mechanical and electrical reliability, as well as investigations of the thermal sensitivity of the measuring method. These factors are significant with respect to the applicability of the method under field conditions. The results from the laboratory tests showed that instrument performance was in all respects satisfactory. Furthermore, that the effects of temperature changes, expressed as the corresponding measuring error to be expected under typical field conditions, was less than ± 1 MPa. (author)

Fracture toughness properties of rocks in Olkiluoto: Laboratory measurements 2008-2009

Energy Technology Data Exchange (ETDEWEB)

Siren, T.

2012-05-15

In Olkiluoto an underground rock characterization facility (ONKALO) for the final disposal site of spent nuclear fuel has been under thorough research many years, but further knowledge is needed on fracture toughness parameters. Fracture toughness parameters are important for example in fracture mechanics prediction for Posiva's Olkiluoto Spalling Experiment (POSE). This working report describes a laboratory campaign that was done between 2008 and 2009. The campaign aimed at determining the fracture mechanics parameters as well as density and ultrasonic velocities for Olkiluoto rocks. The specimens delivered were selected by Posiva; the core showed no damage and the quality of the delivered cores was good with varying sample diameter. Most of the test samples (9 out of 12) are gneissic rock. The Mode I fracture toughness was determined using two different methods to account for two different fracturing directions. The methods are the Chevron Bend (CB) test as proposed in the ISRM Suggested Method and a method based on the Brazilian Disk (BD) experiment. The Mode II fracture toughness was determined using the Punch-Through Shear with Confining Pressure experiment on the remaining pieces from the CB testing. The scatter in the results is very large, even within one piece of core sample. Usually the scatter of results is less than 5 %. The high scatter in the data at hand is believed to be due to the very inhomogeneous nature of the rock material. The magnitude of the determined Mode I fracture toughness compares well with available reported data for medium to coarse grained granitoide rocks. However the scatter of the mode II fracture toughness values is higher than experienced on other rock types, but the variability is reasonable for the inhomogeneous rock type. Distinguishing the fracture toughness values for different anisotropy directions would require more thorough testing with quality samples at different anisotropy directions. However since fracture

Results of monitoring at Olkiluoto in 2004. Rock mechanics

International Nuclear Information System (INIS)

Riikonen, S.

2005-09-01

This report presents Posiva Oy's results of the rock mechanical monitoring programme from the year 2004. Monitoring programme was established for long time monitoring of modifications in the bedrock during the excavation of the ONKALO underground research facility stated in Olkiluoto island. This is the first annual report where rock mechanical research work has being reported also from the monitoring point of view. Rock mechanical research work consists of both GPS measurements and microseismic measurements carried out in Olkiluoto island. Both measurements have been performed during several years even before monitoring programme was established. GPS measurements have been carried out since 1995 and microseismic network has operated since 2002. There have been no significant changes in observations when studying rock mechanical results from the year 2004 and comparing them to results from the previous years. Therefore it can be said, that so far ONKALO has barely had any effect on rock mechanics in Olkiluoto. Report has been composed from the annual reports of GPS measurements.(orig.)

Self-Healing Characteristics of Damaged Rock Salt under Different Healing Conditions

Directory of Open Access Journals (Sweden)

Lin Li

2013-08-01

Full Text Available Salt deposits are commonly regarded as ideal hosts for geologic energy reservoirs. Underground cavern construction-induced damage in salt is reduced by self-healing. Thus, studying the influencing factors on such healing processes is important. This research uses ultrasonic technology to monitor the longitudinal wave velocity variations of stress-damaged rock salts during self-recovery experiments under different recovery conditions. The influences of stress-induced initial damage, temperature, humidity, and oil on the self-recovery of damaged rock salts are analyzed. The wave velocity values of the damaged rock salts increase rapidly during the first 200 h of recovery, and the values gradually increase toward stabilization after 600 h. The recovery of damaged rock salts is subjected to higher initial damage stress. Water is important in damage recovery. The increase in temperature improves damage recovery when water is abundant, but hinders recovery when water evaporates. The presence of residual hydraulic oil blocks the inter-granular role of water and restrains the recovery under triaxial compression. The results indicate that rock salt damage recovery is related to the damage degree, pore pressure, temperature, humidity, and presence of oil due to the sealing integrity of the jacket material.

Bootstrapped efficiency measures of oil blocks in Angola

International Nuclear Information System (INIS)

Barros, C.P.; Assaf, A.

2009-01-01

This paper investigates the technical efficiency of Angola oil blocks over the period 2002-2007. A double bootstrap data envelopment analysis (DEA) model is adopted composed in the first stage of a DEA-variable returns to scale (VRS) model and then followed in the second stage by a bootstrapped truncated regression. Results showed that on average, the technical efficiency has fluctuated over the period of study, but deep and ultradeep oil blocks have generally maintained a consistent efficiency level. Policy implications are derived.

Professional users handbook for rock bolting

Energy Technology Data Exchange (ETDEWEB)

Stillborg, B.

1986-01-01

The paper is a practical handbook which reviews the basic principles of rock bolting and sets out the design considerations used for most types of rockbolts in current use. It discusses the characteristics of these bolts and gives information on installation procedures and the observations and measurement of rockbolt performance. Rockbolting is considered under the following chapter headings: review of typical rockbolt systems; rockbolt installation; testing of rockbolts; design considerations; design of rock reinforcement; monitoring; cost of rock bolting; and Atlas Lopco auxillary equipment for rock bolting. 45 refs.

Minimum description length block finder, a method to identify haplotype blocks and to compare the strength of block boundaries.

Science.gov (United States)

Mannila, H; Koivisto, M; Perola, M; Varilo, T; Hennah, W; Ekelund, J; Lukk, M; Peltonen, L; Ukkonen, E

2003-07-01

We describe a new probabilistic method for finding haplotype blocks that is based on the use of the minimum description length (MDL) principle. We give a rigorous definition of the quality of a segmentation of a genomic region into blocks and describe a dynamic programming algorithm for finding the optimal segmentation with respect to this measure. We also describe a method for finding the probability of a block boundary for each pair of adjacent markers: this gives a tool for evaluating the significance of each block boundary. We have applied the method to the published data of Daly and colleagues. The results expose some problems that exist in the current methods for the evaluation of the significance of predicted block boundaries. Our method, MDL block finder, can be used to compare block borders in different sample sets, and we demonstrate this by applying the MDL-based method to define the block structure in chromosomes from population isolates.

Determining the Accuracy of Paleomagnetic Remanence and High-Resolution Chronostratigraphy for Sedimentary Rocks using Rock Magnetics

Science.gov (United States)

Kodama, K. P.

2017-12-01

The talk will consider two broad topics in rock magnetism and paleomagnetism: the accuracy of paleomagnetic remanence and the use of rock magnetics to measure geologic time in sedimentary sequences. The accuracy of the inclination recorded by sedimentary rocks is crucial to paleogeographic reconstructions. Laboratory compaction experiments show that inclination shallows on the order of 10˚-15˚. Corrections to the inclination can be made using the effects of compaction on the directional distribution of secular variation recorded by sediments or the anisotropy of the magnetic grains carrying the ancient remanence. A summary of all the compaction correction studies as of 2012 shows that 85% of sedimentary rocks studied have enjoyed some amount of inclination shallowing. Future work should also consider the effect of grain-scale strain on paleomagnetic remanence. High resolution chronostratigraphy can be assigned to a sedimentary sequence using rock magnetics to detect astronomically-forced climate cycles. The power of the technique is relatively quick, non-destructive measurements, the objective identification of the cycles compared to facies interpretations, and the sensitivity of rock magnetics to subtle changes in sedimentary source. An example of this technique comes from using rock magnetics to identify astronomically-forced climate cycles in three globally distributed occurrences of the Shuram carbon isotope excursion. The Shuram excursion may record the oxidation of the world ocean in the Ediacaran, just before the Cambrian explosion of metazoans. Using rock magnetic cyclostratigraphy, the excursion is shown to have the same duration (8-9 Myr) in southern California, south China and south Australia. Magnetostratigraphy of the rocks carrying the excursion in California and Australia shows a reversed to normal geomagnetic field polarity transition at the excursion's nadir, thus supporting the synchroneity of the excursion globally. Both results point to a

Modelling and Analysis of the Excavation Phase by the Theory of Blocks Method of Tunnel 4 Kherrata Gorge, Algeria

Science.gov (United States)

Boukarm, Riadh; Houam, Abdelkader; Fredj, Mohammed; Boucif, Rima

2017-12-01

The aim of our work is to check the stability during excavation tunnel work in the rock mass of Kherrata, connecting the cities of Bejaia to Setif. The characterization methods through the Q system (method of Barton), RMR (Bieniawski classification) allowed us to conclude that the quality of rock mass is average in limestone, and poor in fractured limestone. Then modelling of excavation phase using the theory of blocks method (Software UNWEDGE) with the parameters from the recommendations of classification allowed us to check stability and to finally conclude that the use of geomechanical classification and the theory of blocks can be considered reliable in preliminary design.

Busted Butte Phase 2: Analysis of Post-Test Mineback and Overcore Rock Samples

International Nuclear Information System (INIS)

Turin, H.J.; McGraw, M.A.; Jones, C.L.; Scism, C.D.; Soll, W.E.

2002-01-01

A complex tracer mixture was injected continuously for over two years into a 10 x 10 x 7 m block of tuff as part of the unsaturated-zone (UZ) tracer test at Busted Butte. The test was designed to address uncertainties associated with flow and transport models within the Topopah Springs and Calico Hills tuffs. The tracer mixture included nonreactive (Br, I, and FBAs) and reactive tracers (Li, Ce, Sm, Ni, Coy and Mn) and synthetic colloids. Once injection was completed, samples from the block were collected in two ways. Overcores were taken from around and below injection holes. Then, the entire block was excavated via mineback--during which progressive vertical planes of the block were exposed. Samples from the overcores and mineback were analyzed to determine the distribution of tracers on different spatial scales than available from collection borehole data. Rock analyses confirmed collection pad results that the nonreactive tracers, Br and FBAs, moved several meters. Furthermore, Br and FBAs are observed above and lateral to the injector planes suggesting that capillarity was an important process for tracer movement. Lithium, the most mobile of the metals, was transported on a scale of meters. This is consistent with laboratory sorption measurements and observed breakthrough on the collection pads. Co and Ni show transport distances of tens of cm, while Sm and Ce moved far less, possibly due to precipitation and sorption effects. Colloid transport was assessed using 1 ft3 blocks extracted from the BB Phase 2 block. In the Calico Hills material, after 15 L of water was injected over 3.5 months, less than 1% of the colloids injected were recovered. Flow patterns in the block indicate that water injected at the center imbibed outward from the injection point. In a block taken from a boundary of the Calico Hills ashfall layer, breakthrough was observed only due to fractures formed during drying of the block. The colloid transport module for FEHM was tested against

DETERMINATION OF RESOLUTION LIMITS OF ELECTRICAL TOMOGRAPHY ON THE BLOCK MODEL IN A HOMOGENOUS ENVIRONMENT BY MEANS OF ELECTRICAL MODELLING

Directory of Open Access Journals (Sweden)

Franjo Šumanovac

2007-12-01

Full Text Available The block model in a homogenous environment can generally serve for presentation of some geological models: changes of facies, changes of rock compactness-fragmentation, underground cavities, bauxite deposits, etc. Therefore, on the block model of increased resistivities in a homogenous environment of low resistivity, the potentials of the electrical tomography method were tested for the purpose of their detection. Regarding potentials of block detection, resolution methods depend on: depth of block location, ratio between block resistivity and the environment in which it is located as well as applied survey geometry, i.e. electrode array. Thus the analyses carried out for the most frequently used electrode arrays in the investigations are the following: the Wenner, Wenner-Schlumberger, dipole-dipole and pole-pole arrays. For each array, maximum depths at which a block can be detected relative to the ratio between block resistivity and parent rock environment were analyzed. The results are shown in the two-dimensional graphs, where the ratio between the block resistivity and the environment is shown on the X-axis, and the resolution depth on the Y-axis, after which the curves defining the resolution limits were drawn. These graphs have a practical use, since they enable a fast, simple determination of potentials of the method application on a specific geological model.

Evaluation of early Archean volcaniclastic and volcanic flow rocks as possible sites for carbonaceous fossil microbes.

Science.gov (United States)

Walsh, Maud M

2004-01-01

Sedimentary rocks have traditionally been the focus of the search for Archean microfossils; the Earth's oldest fossil bacteria are associated with carbonaceous matter in sedimentary cherts in greenstone belts in the eastern Pilbara block of Western Australia and Barberton greenstone belt of South Africa. Reports of possible fossils in a martian meteorite composed of igneous rock and the discovery of modern bacteria associated with basalts have stimulated a new look at Archean volcanic rocks as possible sites for fossil microbes. This study examines silicified volcaniclastic rocks, near-surface altered volcanic flow rocks, and associated stromatolite- like structures from the Archean Barberton greenstone belt to evaluate their potential for the preservation of carbonaceous fossils. Detrital carbonaceous particles are widely admixed with current-deposited debris. Carbonaceous matter is also present in altered volcanic flow rocks as sparse particles in silica veins that appear to be fed by overlying carbonaceous chert layers. Neither microfossils nor mat-like material was identified in the altered volcanic rocks or adjacent stromatolite-like structures. Ancient volcanic flow and volcaniclastic rocks are not promising sites for carbonaceous fossil preservation.

Reconstruction of crustal blocks of California on the basis of initial strontium isotopic compositions of Mesozoic granitic rocks

Science.gov (United States)

Kistler, Ronald Wayne; Peterman, Zell E.

1978-01-01

Initial 87Sr/ 86 Sr was determined for samples of Mesozoic granitic rocks in the vicinity of the Garlock fault zone in California. These data along with similar data from the Sierra Nevada and along the San Andreas fault system permit a reconstruction of basement rocks offset by the Cenozoic lateral faulting along both the San Andreas and Garlock fault systems. The location of the line of initial 87Sr/ 86 Sr = 0.7060 can be related to the edge of the Precambrian continental crust in the western United States. Our model explains the present configuration of the edge of Precambrian continental crust as the result of two stages of rifting that occurred about 1,250 to 800 m.y. ago, during Belt sedimentation, and about 600 to 350 m.y. ago, prior to and during the development of the Cordilleran geosyncline and to left-lateral translation along a locus of disturbance identified in the central Mojave Desert. The variations in Rb, Sr, and initial 87Sr/ 86 Sr of the Mesozoic granitic rocks are interpreted as due to variations in composition and age of the source materials of the granitic rocks. The variations of Rb, Sr, and initial 87Sr/ 86 Sr in Mesozoic granitic rocks, the sedimentation history during the late Precambrian and Paleozoic, and the geographic position of loci of Mesozoic magmatism in the western United States are related to the development of the continental margin and different types of lithosphere during rifting.

Radon health hazards of some rocks of Iranian origin, frequently used as building stones

International Nuclear Information System (INIS)

Noori, H.; Ranjbar, A.H.

2011-01-01

Radon exhalation rate from various types of stones, used inside the living buildings, is a major factor for evaluation of the environmental radon level. To verify the significance and lethal impacts of this unknown and obscure source of radiation upon the people around the world, the exhaled radon gas concentrations from the rocks, granodiorite, granite, limestone and aragonite, and the effect of their block sizes on the exhalation rate, have been studied. The block samples, collected from their ores, were transferred to plastic containers in which the CR-39 detectors could properly be placed and air tightened, for concentration measurements. The results show the radon concentration of 7.4 ± 0.8, 6.6 ± 0.6, 0.08 ± 0.02 and 0.09 ± 0.02 kBq m -3 for granodiorite, granite, limestone and aragonite, respectively. The corresponding annual dose values in a closed environment are: 186 ± 20, 166 ± 15, 2.5 ± 1 and 2 ± 1 mSv y -1 . These absorbed dose values indicate that granodiorite and granite when used inside the buildings could increase the risk of various cancers while aragonite and limestone have much lower risks and are recommended for use inside the buildings. The former ones when used in the closure areas remedial action should be implemented. The results do not show obvious dependence between the rock size of the samples and their radon exhalation rate. (author)

Rock Magnetic Properties of Remagnetised Devonian and Carboniferous Carbonate and Clastic Rocks From The NE Rhenish Massif, Germany

Science.gov (United States)

Zwing, A.; Matzka, J.; Bachtadse, V.; Soffel, H. C.

Previous studies on remagnetised carbonate rocks from the North American and Eu- ropean Variscides reported characteristic rock magnetic properties which are thought to be diagnostic for a chemical remagnetisation event. Their hysteresis properties with high ratios of Mrs/Ms and Hcr/Hc indicate the presence of a mixture of single-domain and superparamagnetic magnetite (Jackson, et al. 1990). In order to test if this fin- gerprint can be identified in remagnetised carbonate and clastic rocks from the NE Rhenish Massif, Germany, a series of rock magnetic experiments has been carried out. The hysteresis properties of the remagnetised clastic rocks indicate the domi- nance of large MD particles, as can be expected for detrital sediments. The carbon- ates yield significantly higher ratios of Mrs/Ms and Hcr/Hc than the clastic rocks, but only partly correspond to the characteristic properties of remagnetised carbon- ates described above. The latter might be attributed to detrital input into the carbonate platforms. Additional low-temperature remanence measurements show a wide vari- ety of phenomena, including Verwey transitions and indications for the presence of superparamagnetic grains. However, the low-temperature experiments do not allow a straightforward discrimination between the clastic and carbonate rocks and suggest more complex magnetomineralogies than expected from the hysteresis measurements alone.

Rock-block configuration in Uppland and the Aalands-hav basin, the regional surroundings of the SKB site in Forsmark, Sea and land areas, eastern Sweden

Energy Technology Data Exchange (ETDEWEB)

Beckholmen, Monica; Tiren, Sven A. (GEOSIGMA AB (Sweden))

2010-12-15

The Forsmark SKB site lies at the west-northwest trending shoreline in northern Uppland, sheltered from the sea by one of the larger islands in the Uppland archipelago, Graesoe. To assess the structures around Forsmark also in the sea area, the bottom structures of the Aalands-hav basin were investigated by means of depth readings from sea charts. Two rock-block maps with rock blocks at different scales were constructed and analysed for their top surface elevation. The topography in Uppland is more broken in the sea area east and northeast of Forsmark than it is on land. The major structure in the Aalands-hav basin is a westnorth- westerly line that passes southwest of Aaland, with a very steep gradient from the Aaland archipelago down to an exceptionally low sea-floor valley. On its southern side it rises in steps to a low flat basin divided into a deeper western half and a somewhat shallower eastern half. The deep west-north-westerly zone can be traced on-land past Oeregrund and Forsmark. West of Oeregrund however, the main trough swings into a north-northwesterly direction, just west of Graesoe. The southern border south of Oeregrund and Forsmark, shows a major drop in elevation northern side down. Forsmark thus lies on a ribbon with lower ground on both its southern and northern boundaries. This west-north-westerly belt is cut in two by a major north-south lineament that cuts through the archipelago between Aaland and Graesoe with a very deep canyon. This structure was seismically active in June 2006. The southern part of this line constitutes the western border of the low basin and has a steep gradient on its western side up to the Uppland mainland. The deep basin is filled with Jotnian metasediments. South of this basin, the Uppland mainland continues under water towards the east. South of Aaland an east-north-easterly ridge separates the low basin to the north from an east-west trending trough which is the eastern continuation of a major onland structure

Rock-block configuration in Uppland and the Aalands-hav basin, the regional surroundings of the SKB site in Forsmark, Sea and land areas, eastern Sweden

International Nuclear Information System (INIS)

Beckholmen, Monica; Tiren, Sven A.

2010-12-01

The Forsmark SKB site lies at the west-northwest trending shoreline in northern Uppland, sheltered from the sea by one of the larger islands in the Uppland archipelago, Graesoe. To assess the structures around Forsmark also in the sea area, the bottom structures of the Aalands-hav basin were investigated by means of depth readings from sea charts. Two rock-block maps with rock blocks at different scales were constructed and analysed for their top surface elevation. The topography in Uppland is more broken in the sea area east and northeast of Forsmark than it is on land. The major structure in the Aalands-hav basin is a westnorth- westerly line that passes southwest of Aaland, with a very steep gradient from the Aaland archipelago down to an exceptionally low sea-floor valley. On its southern side it rises in steps to a low flat basin divided into a deeper western half and a somewhat shallower eastern half. The deep west-north-westerly zone can be traced on-land past Oeregrund and Forsmark. West of Oeregrund however, the main trough swings into a north-northwesterly direction, just west of Graesoe. The southern border south of Oeregrund and Forsmark, shows a major drop in elevation northern side down. Forsmark thus lies on a ribbon with lower ground on both its southern and northern boundaries. This west-north-westerly belt is cut in two by a major north-south lineament that cuts through the archipelago between Aaland and Graesoe with a very deep canyon. This structure was seismically active in June 2006. The southern part of this line constitutes the western border of the low basin and has a steep gradient on its western side up to the Uppland mainland. The deep basin is filled with Jotnian metasediments. South of this basin, the Uppland mainland continues under water towards the east. South of Aaland an east-north-easterly ridge separates the low basin to the north from an east-west trending trough which is the eastern continuation of a major onland structure

Range and intensity vision for rock-scene segmentation

CSIR Research Space (South Africa)

Mkwelo, SG

2007-11-01

Full Text Available This paper presents another approach to segmenting a scene of rocks on a conveyor belt for the purposes of measuring rock size. Rock size estimation instruments are used to monitor, optimize and control milling and crushing in the mining industry...

Stripa Project. Part II: Measurement of triaxial rock stresses in borehole V1

International Nuclear Information System (INIS)

Strindell, L.; Andersson, M.

1981-07-01

The investigation was performed December 16-18, 1980 and February 2-5, 1981 by Lars Strindell and Mats Andersson, Swedish State Power Board. The drilling was carried out by Hagby Bruk, Nora. One of the tasks within the project is to drill a vertical hole with a diameter of 76 mm to 1050 meters depth. The drilling is performed from a place in the mine at about 360 m below ground level. Hydrologic investigations will be performed in the borehole and knowledge about the existing rock pressure will aid the interpretation of the hydrology data. The intention was to perform 4 measurements at depth of 150, 300 and 450 m respectively. At present, measurements have been carried out at 150 and 300 m depth. At 450 m the quality of the rock was too poor to allow any measurements. The drilling has been interrupted at 506 m depth but the plan is to continue when the borehole has been stabilized along the highly fractured zone. At 150 m the average stresses in the horizontal plane is about 25 MPa in E-W direction and about 20 MPa in the N-S direction. In the region just below 300 m the average stresses is about 20 MPa in the NE-SW direction and about 12 MPa in NW-SE direction. The average vertical stress at 150 m depth is 13.5 MPa and this is in good agreement with the theoretical value. At 300 m the vertical stress is about 13.8 MPa which is somewhat lower than the theoretical value. (author)

Runoff velocity behaviour on smooth pavement and paving blocks surfaces measured by a tilted plot

Directory of Open Access Journals (Sweden)

Sedyowati Laksni

2017-06-01

Full Text Available Paving blocks have been widely known as an alternative technology for reducing runoff discharge due to their infiltration performance and capability of retarding the flow. Surface configuration of the different paving blocks types and the openings area play important role in decreasing the runoff velocity. In this study, we investigated the surface runoff velocity on two types of paving blocks layers, and a smooth pavement as comparison. The paving blocks type were rectangular blocks, which have 3.2% openings ratio and hexagonal blocks, which have 6.5% openings ratio. We used a tilted plot covering area of 2 × 6 m, equipped by a rainfall simulator to accommodate the variation of surface slope and rainfall intensity. We measured the velocity by using modification of dye tracer and buoyancy method. The data were then tabulated and graphed based on the paving types and the surface slopes. Generally, the velocity-slope relationship has demonstrated that the increase in surface slope leads to the increase in velocity. In this study, the result showed that slope and rainfall intensity simultaneously influenced the velocity (F = 19.91 > Ftable = 5.14; P < 0.05. However, the findings of this study showed a weak relationship between the changes of surface slope and the changes of runoff velocity on the rectangular blocks (R2 = 0.38. The greater slope did not always invariably lead to the greater runoff velocity. It was likely that there was other predictor variable that was not identified before, and need to be further investigated.

Determination of the thermal conductivity of sediment rock from measurements on cuttings; Ermittlung der Gesteinswaermeleitfaehigkeit von Sedimentgesteinen aus Messungen am Bohrklein

Energy Technology Data Exchange (ETDEWEB)

Troschke, B; Burkhardt, H [Technische Univ. Berlin (Germany). Fachgebiet Angewandte Goephysik

1997-12-01

Due to high costs core recovery in many wells is strongly restricted. To determine thermal conductivity in these cases measurements on cuttings are necessary, since in situ measurements are expensive and protracted, too. Therefore cores from three hydrogeothermal wells of the north-east part of the German sedimentary basin were grinded to compare the results of measurements on cuttings with known values of thermal conductivity from the original cores. By a suitable model of the two-phase-system cuttings-water it is possible to calculate the thermal conductivity of the rock-matrix. On the basis of this value and a suitable rock-model an average thermal conductivity for the water saturated rock can be estimated. Certainly all influences of the texture (anisotropy, grain bond) and of the characteristics of the porespace (porosity, internal surface, saturation, permeability) are lost with measurements on cuttings. Therefore for the different systems cuttings-water and rock-porefluid as well as for different rock types different models are necessary. (orig.) [Deutsch] In vielen Bohrungen werden aus Kostengruenden keine Kerne gezogen. Fuer die Ermittlung der Waermeleitfaehigkeit koennen deshalb nur in-situ-Messungen, die ebenfalls zeit- und kostenintensiv sind, oder Messungen am Bohrklein herangezogen werden. Es wurden daher Kerne aus drei Hydrogeothermalbohrungen des nordostdeutschen Beckens aufgemahlen, um so vergleichende Messungen am `Bohrklein` aus Kernen mit bekannter Waermeleitfaehigkeit durzhzufuehren. Durch eine geeignete Modellvorstellung des Zwei-Phasen-Systems Bohrklein/Wasser laesst sich die Waermeleitfaehigkeit der Gesteinsmatrix bestimmen und aus dieser durch ein Gesteinsmodell auch eine mittlere Waermeleitfaehigkeit des wassergesaettigten Festgesteins berechnen. Klar ist, dass bei Messungen am Bohrklein Einfluesse, die durch Gefuege (Anisotropie, Kornbindung) und Porenraumeigenschaften (Porositaet, Saettigung, Permeabilitaet) hervorgerufen werden

Structural analysis of superposed fault systems of the Bornholm horst block, Tornquist Zone, Denmark

DEFF Research Database (Denmark)

Graversen, Ole

2009-01-01

The Bornholm horst block is composed of Precambrian crystalline basement overlain by Palaeozoicand Mesozoic cover rocks. The cover intervals are separated by an angular unconformity and a hiatus spanning the Devonian through Middle Triassic interval. Late Palaeozoic faulting of the Early Palaeozo...

Small-scale electrical resistivity tomography of wet fractured rocks.

Science.gov (United States)

LaBrecque, Douglas J; Sharpe, Roger; Wood, Thomas; Heath, Gail

2004-01-01

This paper describes a series of experiments that tested the ability of the electrical resistivity tomography (ERT) method to locate correctly wet and dry fractures in a meso-scale model. The goal was to develop a method of monitoring the flow of water through a fractured rock matrix. The model was a four by six array of limestone blocks equipped with 28 stainless steel electrodes. Dry fractures were created by placing pieces of vinyl between one or more blocks. Wet fractures were created by injecting tap water into a joint between blocks. In electrical terms, the dry fractures are resistive and the wet fractures are conductive. The quantities measured by the ERT system are current and voltage around the outside edge of the model. The raw ERT data were translated to resistivity values inside the model using a three-dimensional Occam's inversion routine. This routine was one of the key components of ERT being tested. The model presented several challenges. First, the resistivity of both the blocks and the joints was highly variable. Second, the resistive targets introduced extreme changes the software could not precisely quantify. Third, the abrupt changes inherent in a fracture system were contrary to the smoothly varying changes expected by the Occam's inversion routine. Fourth, the response of the conductive fractures was small compared to the background variability. In general, ERT was able to locate correctly resistive fractures. Problems occurred, however, when the resistive fracture was near the edges of the model or when multiple fractures were close together. In particular, ERT tended to position the fracture closer to the model center than its true location. Conductive fractures yielded much smaller responses than the resistive case. A difference-inversion method was able to correctly locate these targets.

Second progress report on pre-test calculations for the large block test

International Nuclear Information System (INIS)

Lee, K.H.

1995-01-01

The US Department of Energy's (DOE) Yucca Mountain Site Characterization Project (YMP) is investigating the suitability of the Topopah Spring tuff in the thick vadose zone at Yucca Mountain, Nevada, as a host rock for permanent disposal of high-level radioactive waste. As part of the YMP, a group of field tests, called the Large Block Test (LBT), will be conducted on a large electrically heated block of Topopah Spring tuff. The block will be heated by electrical heaters. The goals of the LBT are to gain information on the coupled thermal-mechanical-hydrological-chemical processes that will be active in the near-field environment of a repository; to provide field data for testing and calibrating models; and to help in the development of measurement systems and techniques. In this second progress report, we present results of the final set of numerical modeling calculations performed in support of the LBT design. The results include block temperatures and heat fluxes across the surfaces. The results are applied primarily to the design of guard heaters to enforce adiabatic conditions along the block walls. Conduction-only runs are adequate to estimate the thermal behavior of the system, because earlier calculations showed that heat transfer in the block is expected to be dominated by conduction. In addition, conduction-only runs can be made at substantially shorter execution times than full hydrothermal runs. We also run a two-dimensional, hydrothermal, discrete fracture model, with 200-μm vertical fractures parallel to the heaters and occurring at a uniform spacing of 30 cm. The results show the development of distinct dryout and recondensation zones. The dryout zones are thickest at the fractures and thinnest in the matrix midway between the fractures

Thermal Inertia of Rocks and Rock Populations

Science.gov (United States)

Golombek, M. P.; Jakosky, B. M.; Mellon, M. T.

2001-01-01

The effective thermal inertia of rock populations on Mars and Earth is derived from a model of effective inertia versus rock diameter. Results allow a parameterization of the effective rock inertia versus rock abundance and bulk and fine component inertia. Additional information is contained in the original extended abstract.

Reinforcement of Underground Excavation with Expansion Shell Rock Bolt Equipped with Deformable Component

Directory of Open Access Journals (Sweden)

Korzeniowski Waldemar

2017-03-01

Full Text Available The basic type of rock mass reinforcement method for both preparatory and operational workings in underground metal ore mines, both in Poland and in different countries across the world, is the expansion shell or adhesive-bonded rock bolt. The article discusses results of static loading test of the expansion shell rock bolts equipped with originally developed deformable component. This component consists of two profiled rock bolt washers, two disk springs, and three guide bars. The disk spring and disk washer material differs in stiffness. The construction materials ensure that at first the springs under loading are partially compressed, and then the rock bolt washer is plastically deformed. The rock bolts tested were installed in blocks simulating a rock mass with rock compressive strength of 80 MPa. The rock bolt was loaded statically until its ultimate loading capacity was exceeded. The study presents the results obtained under laboratory conditions in the test rig allowing testing of the rock bolts at their natural size, as used in underground metal ore mines. The stress-strain/displacement characteristics of the expansion shell rock bolt with the deformable component were determined experimentally. The relationships between the geometric parameters and specific strains or displacements of the bolt rod were described, and the percentage contribution of those values in total displacements, resulting from the deformation of rock bolt support components (washer, thread and the expansion shell head displacements, were estimated. The stiffness of the yielded and stiff bolts was empirically determined, including stiffness parameters of every individual part (deformable component, steel rod. There were two phases of displacement observed during the static tension of the rock bolt which differed in their intensity.

Distribution of Pa-231 and Ra-226 in rock. An indicator of rock matrix diffusion

International Nuclear Information System (INIS)

Saarinen, L.; Suksi, J.

1995-01-01

Distribution of Ra-226 and Pa-231 in rock has been studied to find signatures that may be attributed to diffusion. The idea of studying these nuclides originated from the need to obtain interpretative support to the findings of U movement in rock. Concentration profiles of Ra-226 and Pa-231 with other U series nuclides were measured across the secondary U accumulations observed in altered rock close to a fracture in the vicinity of U deposit, and in a radioactivity anomaly. (27 refs., 10 figs., 2 tabs.)

Study on investigation and evaluation methods of deep seated sedimentary rocks. Chemical weathering, pore water squeezing and relationships of physical properties of sedimentary rocks

International Nuclear Information System (INIS)

Oyama, Takahiro; Suzuki, Koichi

2006-01-01

Chemical weathering, porewater squeezing and physical properties for the sedimentary rocks were examined. Chemical weathering potential of rocks was described by the sulfur as a acceleration factor of weathering and carbonate contents as a neutralization factor of it. The carbonate contents in the rocks were measured accurately by the gas pressure measurement method. Pore water squeezing method was applied for the semi-hard sedimentary rocks (Opalinusclay). The chemical change of extracted pore water under high pressure conditions was estimated. Physical property of sedimentary rocks have relationship among the porosity and permeability and resistivity coefficient in the same rock types. It is possible to estimate the water permeability from the geophysical tests. (author)

Combined rock-physical modelling and seismic inversion techniques for characterisation of stacked sandstone reservoir

NARCIS (Netherlands)

Justiniano, A.; Jaya, Y.; Diephuis, G.; Veenhof, R.; Pringle, T.

2015-01-01

The objective of the study is to characterise the Triassic massive stacked sandstone deposits of the Main Buntsandstein Subgroup at Block Q16 located in the West Netherlands Basin. The characterisation was carried out through combining rock-physics modelling and seismic inversion techniques. The

Exact effective-stress rules in rock mechanics

International Nuclear Information System (INIS)

Berryman, J.G.

1992-01-01

The standard paradigm for analysis of rock deformation arises from postulating the existence of ''an equivalent homogeneous porous rock.'' However, data on the pore-pressure dependence of fluid permeability for some rocks cannot be explained using any equivalent homogeneous porous medium. In contrast, a positive result shows that deformation measurements on both high-porosity sandstones and low-porosity granites can be explained adequately in terms of an equivalent two-constituent model of porous rocks, for which exact results have recently been discovered

Analytical tools for managing rock fall hazards in Australian coal mine roadways

Energy Technology Data Exchange (ETDEWEB)

Ross Seedsman; Nick Gordon; Naj Aziz [University of Wollongong (Australia)

2009-03-15

This report provides a reference source for the design of ground control measures in coal mine roadways using analytical methods. Collapse models are provided for roof and rib. The roof models recognise that different collapse modes can apply in different stress fields - high, intermediate, and zero compressive stresses. The rib models draw analogies to rock slope stability and also the impact of high vertical stresses. Methods for determining support or reinforcement requirements are provided. Suspension of collapsed masses is identified as the basis for roof support in both very high and zero compressive stress regimes. Reinforcement of bedding discontinuities is advocated for intermediate compressive stresses. For the ribs, restraint of coal blocks defined by pre-existing joints or by mining induced fractures is required.

Petrogenesis of siliceous high-Mg series rocks as exemplified by the Early Paleoproterozoic mafic volcanic rocks of the Eastern Baltic Shield: enriched mantle versus crustal contamination

Science.gov (United States)

Bogina, Maria; Zlobin, Valeriy; Sharkov, Evgenii; Chistyakov, Alexeii

2015-04-01

The Early Paleoproterozoic stage in the Earth's evolution was marked by the initiation of global rift systems, the tectonic nature of which was determined by plume geodynamics. These processes caused the voluminous emplacement of mantle melts with the formation of dike swarms, mafic-ultramafic layered intrusions, and volcanic rocks. All these rocks are usually considered as derivatives of SHMS (siliceous high-magnesian series). Within the Eastern Baltic Shield, the SHMS volcanic rocks are localized in the domains with different crustal history: in the Vodlozero block of the Karelian craton with the oldest (Middle Archean) crust, in the Central Block of the same craton with the Neoarchean crust, and in the Kola Craton with a heterogeneous crust. At the same time, these rocks are characterized by sufficiently close geochemical characteristics: high REE fractionation ((La/Yb)N = 4.9-11.7, (La/Sm)N=2.3-3.6, (Gd/Yb)N =1.66-2.74)), LILE enrichment, negative Nb anomaly, low to moderate Ti content, and sufficiently narrow variations in Nd isotope composition from -2.0 to -0.4 epsilon units. The tectonomagmatic interpretation of these rocks was ambiguous, because such characteristics may be produced by both crustal contamination of depleted mantle melts, and by generation from a mantle source metasomatized during previous subduction event. Similar REE patterns and overlapping Nd isotope compositions indicate that the studied basaltic rocks were formed from similar sources. If crustal contamination en route to the surface would play a significant role in the formation of the studied basalts, then almost equal amounts of contaminant of similar composition are required to produce the mafic rocks with similar geochemical signatures and close Nd isotopic compositions, which is hardly possible for the rocks spaced far apart in a heterogeneous crust. This conclusion is consistent with analysis of some relations between incompatible elements and their ratios. In particular, the

A comprehensive review of radon emanation measurements for mineral, rock, soil, mill tailing and fly ash

International Nuclear Information System (INIS)

Sakoda, Akihiro; Ishimori, Yuu; Yamaoka, Kiyonori

2011-01-01

To our knowledge, this paper is the most comprehensive review to cover most studies, published in the past three decades at least, of radon emanation measurements. The radon emanation fraction, a possibility of radon atoms generated in a material escaping from its grains, has been widely measured for a variety of materials. The aim of this review is to organize a huge number of such data accumulated. The representative values of the emanation fraction for minerals, rocks, soils, mill tailings and fly ashes were derived to be 0.03, 0.13, 0.20, 0.17 and 0.03, respectively. Current knowledge of the emanation processes was also summarized to discuss their affected factors. - Highlights: → Recent radon emanation measurements were thoroughly reviewed. → Averages of radon emanation fractions: 0.03 (mineral), 0.13 (rock), 0.20 (soil), 0.17 (mill tailing) and 0.03 (fly ash). → Grain-size effect was not significantly found for size larger than 1 μm. → Pore water generally enhances the emanation fraction by a factor of 5 or less. → Definition of 'radon emanation' should be shared among researchers.

Measurement of field-saturated hydraulic conductivity on fractured rock outcrops near Altamura (Southern Italy) with an adjustable large ring infiltrometer

Science.gov (United States)

Caputo, Maria C.; de Carlo, L.; Masciopinto, C.; Nimmo, J.R.

2010-01-01

Up to now, field studies set up to measure field-saturated hydraulic conductivity to evaluate contamination risks, have employed small cylinders that may not be representative of the scale of measurements in heterogeneous media. In this study, a large adjustable ring infiltrometer was designed to be installed on-site directly on rock to measure its field-saturated hydraulic conductivity. The proposed device is inexpensive and simple to implement, yet also very versatile, due to its large adjustable diameter that can be fixed on-site. It thus allows an improved representation of the natural system's heterogeneity, while also taking into consideration irregularities in the soil/rock surface. The new apparatus was tested on an outcrop of karstic fractured limestone overlying the deep Murge aquifer in the South of Italy, which has recently been affected by untreated sludge disposal, derived from municipal and industrial wastewater treatment plants. The quasi-steady vertical flow into the unsaturated fractures was investigated by measuring water levels during infiltrometer tests. Simultaneously, subsurface electrical resistivity measurements were used to visualize the infiltration of water in the subsoil, due to unsaturated water flow in the fractures. The proposed experimental apparatus works well on rock outcrops, and allows the repetition of infiltration tests at many locations in order to reduce model uncertainties in heterogeneous media. ?? 2009 Springer-Verlag.

Waste disposal in granitic rocks: analysis of thermal microcracks

International Nuclear Information System (INIS)

Montoto, M.; Roeshoff, K.; Leojon, B.; Bel-Lan, A.

1981-04-01

The possible development of microcracks from a thermal origin has been researched in the granitic rocks of Shipa (Sweden), within which in a real scale have been originated some thermal gradients similar to the ones which could take place in the waste disposal. To achieve an optimal fratographic information, with some petrographic meaning, different microscopic techniques, optical and electronic, have been combined and an automatized quantification methodology has also been developed by means of digitals. Between warmed and unwarmed granitis no microfractographic differences have been detected. The observed variations are only apparent and may be explained as a function of the inherent petrographic heterogeneity of rocky blocks. In any case in the internal temperatures generated within these rocks have not attained its own threshold of thermal microcracking. (author)

Channelling of flow through fractures in rock

International Nuclear Information System (INIS)

Bourke, P.J.

1987-05-01

A method of mapping the channelling of flow in rock fractures formed by contacts between rock faces and of measuring the effective apertures of channels has been developed. Some typical results are given. (author)

A summary of Rb-Sr isotope studies in the Archean Hopedale Block and the adjacent proterozoic Makkovik subprovince, Labrador

International Nuclear Information System (INIS)

Grant, N.K.; Hickman, M.H.; Marzano, M.S.; Ermanovics, I.F.

1983-01-01

Rb-Sr isotope study of thirteen whole-rock suites of Archean and Proterozoic rocks from Hopedale block and Makkovik Subprovince shows that the crustal history began about 3115 Ma ago. We tentatively recognize younger crustal segments that formed 2920 Ma ago, from which Kanairktok intrusives were derived at 2832 +- 178 Ma. In Makkovik Subprovince the Island Harbour granites range in age from 1843 +- 90 to 1794 +- 71 Ma. These ages overlap with the 1847 +-87 Ma age for Kanairktok shear zone mylonites. The Island Harbour granodiorites from inland localities to the southwest are contaminated with Archean rocks in Makkovik Subprovince and their initial 87 Sr/ 86 ratios imply a crustal contribution to their source. In contrast, the Island Harbour granites of Striped Island were derived from a mantle source. The sills of Striped Island are 1635 +- 47 Ma old. An undeformed northeast trending Kikkertavak dolerite dyke from Hopedale block is 1206 +- 120 Ma

Calculation and measurement of the intensity distribution of 60Co radiation behind block filters

International Nuclear Information System (INIS)

Gerlach, R.; Kranepuhl, H.; Salewski, D.

1987-01-01

A method for determining the absorption length in block filters with non-focussing edges is described. It accounts for geometric parameters as source diameter, source-surface-distance and the position of the absorber relative to the central ray. The model was checked by intensity measurements. Behind the absorber as well as in the penumbra regions good agreement between calculation and measurement of the intensity distribution was observed. (author)

Rock stress investigations

International Nuclear Information System (INIS)

Pahl, A.; Heusermann, St.; Braeuer, V.; Gloeggler, W.

1989-04-01

On the research project 'Rock Stress Mesurements' the BGR has developed and tested several methods for use in boreholes at a depth of 200 m. Indirect stress measurements using overcoring methods with BGR-probes and CSIR-triaxial cells as well as direct stress measurements using the hydraulic-fracturing method were made. To determine in-situ rock deformation behavior borehole deformation tests, using a BGR-dilatometer, were performed. Two types of the BGR-probe were applied: a four-component-probe to determine horizontal stresses and a five-component-probe to determine a quasi three-dimensional stress field. The first time a computer for data processing was installed in the borehole together with the BGR-probe. Laboratory tests on low cylinders were made to study the stress-deformation behavior. To validate and to interprete the measurement results some test methods were modelled using the finite-element method. The dilatometer-tests yielded high values of Young's modulus, whereas laboratory tests showed lower values with a distinct deformation anisotropy. Stress measurements with the BGR-probe yielded horizontal stresses being higher than the theoretical overburden pressure. These results are comparable to the results of the hydraulic fracturing tests, whereas stresses obtained with CSIR-triaxial cells are lower. The detailed geological mapping of the borehole indicated relationships between stress and geology. With regard to borehole depth different zones of rock structure joint frequency, joint orientation, and orientation of microfissures as well as stress magnitude, stress direction, and degree of deformation anisotropy could be distinguished. (author) 4 tabs., 76 figs., 31 refs

Minimum Description Length Block Finder, a Method to Identify Haplotype Blocks and to Compare the Strength of Block Boundaries

OpenAIRE

Mannila, H.; Koivisto, M.; Perola, M.; Varilo, T.; Hennah, W.; Ekelund, J.; Lukk, M.; Peltonen, L.; Ukkonen, E.

2003-01-01

We describe a new probabilistic method for finding haplotype blocks that is based on the use of the minimum description length (MDL) principle. We give a rigorous definition of the quality of a segmentation of a genomic region into blocks and describe a dynamic programming algorithm for finding the optimal segmentation with respect to this measure. We also describe a method for finding the probability of a block boundary for each pair of adjacent markers: this gives a tool for evaluating the ...

A review of shear strength models for rock joints subjected to constant normal stiffness

Directory of Open Access Journals (Sweden)

Sivanathan Thirukumaran

2016-06-01

Full Text Available The typical shear behaviour of rough joints has been studied under constant normal load/stress (CNL boundary conditions, but recent studies have shown that this boundary condition may not replicate true practical situations. Constant normal stiffness (CNS is more appropriate to describe the stress–strain response of field joints since the CNS boundary condition is more realistic than CNL. The practical implications of CNS are movements of unstable blocks in the roof or walls of an underground excavation, reinforced rock wedges sliding in a rock slope or foundation, and the vertical movement of rock-socketed concrete piles. In this paper, the highlights and limitations of the existing models used to predict the shear strength/behaviour of joints under CNS conditions are discussed in depth.

Petrography, geochemistry and tectonic setting of Rigi granitoid body (east of Lut Block, Central Iran)

International Nuclear Information System (INIS)

Ghonjalipour, R.; Biabangard, H.; Ahmadi, A.

2016-01-01

The Rigi Granitoid Mountain is located in 5 Km West of Dehsalm and 85 Km West of Nehbandan city, southeast of Birjand province and east of Lut Block. This granitoid with Eocene-Oligocene age was penetrated into sedimentary rocks (shale, limestone and sandstone) and changes theses rocks to skarn, hornfels and calcsilicate rocks. This granitoid consist of granodiorite, quartz monzonite and syenogranite with plagioclase, orthose, biotite, hornblende and quartz minerals. Sericite, chlorite, and Magnetite are secondary mineral in these rocks. Geochemical properties this pluton showes that it subalkaline and has metaluminous. Geochemical diagrams and presence of hornblende mineral in this pluton shows that belong to I-type granite. The rocks in granitoid pluton are enrichment LREE compare to HREE, high contents of LILE relative to HFSE and negative anomalies of Nb, Ti and P show it granitoid related to subduction zone. Also, tectonomagmatic diagrams improve that this pluton has belong to active continental margin.

K-U-Th systematics of terrestrial igneous rocks for planetological comparisons: volcanic rocks of the Earth oceanic island arc and Venus surface material

International Nuclear Information System (INIS)

Nikolaeva, O.V.

1997-01-01

Principles of the formation o data base for 339 samples of oceanic island arc (OIA) igneous rocks of the Earth available in literature are described as well as of the formation of fresh rock sample, characteristics of this sample, and K-U-Th-systematics of the fresh igneous rocks of Earth OIA. Results of comparison of the Venus measured rocks and Earth OIA rocks by K, U, Th

Assessment of the potential for rock spalling in the technical rooms of the ONKALO

International Nuclear Information System (INIS)

Siren, T.; Martinelli, D.; Uotinen, L.

2011-06-01

It is important to be able to predict the rock spalling in the ONKALO while the excavation advances deeper. When stresses at the excavation boundary reach the rock mass spalling strength, a brittle failure occurs that is often called 'spalling'. The spalling phenomenon occurs as a strong compressive stress induces crack growth behind the excavated surface. Spalling is, expressly, an event that can create problems in the ONKALO, not so much for the overall stability of all of the excavations, but rather in particular areas that can cause unnecessary and unintended over-excavations and hazards. For rock engineering and layout design purposes, the knowledge of the predicted spalling in the excavation surface is crucial. Optimization of the design is mainly done by directing the tunnels parallel to the major principal stress direction. However, due to the complex forms and crossing tunnels, especially at the shaft access drift area, sophisticated methods are required in order to minimize spalling and to support the unavoidable spalling that occurs. The complex tunnels require three-dimensional analysis. The software used for the main calculation has been MIDAS/GTS, a geotechnical 3-D FEM that is able to calculate complex geometries rather easily. Most of the models have also been verified with Rocscience Examine3D, which returns the results with a high precision at boundary. The area to model is large, and due to the computational limits, it is divided into six blocks. This analysis, carried out step by step for each block, permitted to draw a map of the spalling depth prevision in the whole tunnel contract 5 (TU5) area. The dominating rock types in the area are migmatitic gneiss and pegmatitic granite. The strength of these rocks has been broadly tested with point load and uniaxial compressive strength tests. The test results show a deviation of the UCS as well as other parameters. Due to this large deviation, a Monte Carlo has been used as an auxiliary analysis

Some results from the demonstration of indoor radon reduction measures in block basement houses. Report for June 1985-February 1987

International Nuclear Information System (INIS)

Henschel, D.B.; Scott, A.G.

1987-03-01

The paper gives results of tests of active soil-ventilation techniques in 24 block-wall basement houses in eastern Pennsylvania having significantly elevated indoor radon concentrations, generally above 740 Bq/cu m. The results indicate that radon levels can be reduced substantially (often below the U.S. EPA guideline of 148 Bq/cu m) if effective suction can be drawn on the soil underneath the concrete slabs of these houses. Such effective suction appears achievable when either: (a) the house has a complete loop of drain tile around its footings for water drainage purposes, and suction is drawn on that loop; or (b) a sufficient number of suction pipes can be inserted at the proper locations into the crushed rock or soil underneath the slab

Compact rock material gas permeability properties

Energy Technology Data Exchange (ETDEWEB)

Wang, Huanling, E-mail: whl_hm@163.com [Key Laboratory of Coastal Disaster and Defence, Ministry of Education, Hohai University, Nanjing 210098 (China); LML, University of Lille, Cite Scientifique, 59655 Villeneuve d’Ascq (France); Xu, Weiya; Zuo, Jing [Institutes of Geotechnical Engineering, Hohai University, Nanjing 210098 (China)

2014-09-15

Natural compact rocks, such as sandstone, granite, and rock salt, are the main materials and geological environment for storing underground oil, gas, CO{sub 2,} shale gas, and radioactive waste because they have extremely low permeabilities and high mechanical strengths. Using the inert gas argon as the fluid medium, the stress-dependent permeability and porosity of monzonitic granite and granite gneiss from an underground oil storage depot were measured using a permeability and porosity measurement system. Based on the test results, models for describing the relationships among the permeability, porosity, and confining pressure of rock specimens were analyzed and are discussed. A power law is suggested to describe the relationship between the stress-dependent porosity and permeability; for the monzonitic granite and granite gneiss (for monzonitic granite (A-2), the initial porosity is approximately 4.05%, and the permeability is approximately 10{sup −19} m{sup 2}; for the granite gneiss (B-2), the initial porosity is approximately 7.09%, the permeability is approximately 10{sup −17} m{sup 2}; and the porosity-sensitivity exponents that link porosity and permeability are 0.98 and 3.11, respectively). Compared with moderate-porosity and high-porosity rocks, for which φ > 15%, low-porosity rock permeability has a relatively lower sensitivity to stress, but the porosity is more sensitive to stress, and different types of rocks show similar trends. From the test results, it can be inferred that the test rock specimens’ permeability evolution is related to the relative particle movements and microcrack closure.

Permian arc evolution associated with Panthalassa subduction along the eastern margin of the South China block, based on sandstone provenance and U-Pb detrital zircon ages of the Kurosegawa belt, Southwest Japan

Science.gov (United States)

Hara, Hidetoshi; Hirano, Miho; Kurihara, Toshiyuki; Takahashi, Toshiro; Ueda, Hayato

2018-01-01

We have studied the petrography, geochemistry, and detrital zircon U-Pb ages of sandstones from shallow-marine forearc sediments, accretionary complexes (ACs), and metamorphosed accretionary complexes (Meta-ACs) within the Kurosegawa belt of Southwest Japan. Those rocks formed in a forearc region of a Permian island arc associated with subduction of the Panthalassa oceanic crust along the eastern margin of the South China block (Yangtze block). The provenance of the shallow-marine sediments was dominated by basaltic to andesitic volcanic rocks and minor granitic rocks during the late Middle to Late Permian. The ACs were derived from felsic to andesitic volcanic rocks during the Late Permian. The provenance of Meta-ACs was dominated by andesitic volcanic rocks in the Middle Permian. The provenance, source rock compositions, and zircon age distribution for the forearc sediments, ACs and Meta-ACs have allowed us to reconstruct the geological history of the Permian arc system of the Kurosegawa belt. During the Middle Permian, the ACs were accreted along the eastern margin of the South China block. The Middle Permian arc was an immature oceanic island arc consisting of andesitic volcanic rocks. During the Late Permian, the ACs formed in a mature arc, producing voluminous felsic to andesitic volcanic rocks. A forearc basin developed during the late Middle to Late Permian. Subsequently, the Middle Permian ACs and part of the Late Permian AC underwent low-grade metamorphism in the Late to Early Jurassic, presenting the Meta-ACs.

The peculiarities of structurizing enclosing rock massif while developing a coal seam

Science.gov (United States)

Kozyreva, E. N.; Shinkevich, M. V.

2017-09-01

Different concepts of the development of geo-mechanical processes during longwall mining of a seam which are fundamentally different from the conventional ones are introduced in the article. Fundamental principles of the model for structurizing enclosing rock mass while longwall mining along the strike are described. The model was developed on the bases of non-linear geomechanical laws. According to the model, rock mass in the area of mining operation is organized as rock geomechanical layers with shifting arches. And the formation period of shifting arches in disintegrated rock mass is divisible by the length of the stope. Undulate characteristic of a massif as a peculiarity of man-made structurization of a massif is defined. It is shown that structuring the broken massif causes the formation of block-structured system and it can be detected while monitoring the ground pressure in powered support props. The results of the research allow decreasing the negative influence of a ground pressure and can be applied to specify parameters for controlling the roof, defining geometrical dimensions of a mining section and positioning of holing chute (face entry).

Use of an Android application “clinometer” for measurement of head down tilt given during subarachnoid block

Science.gov (United States)

Dixit, RB; Neema, MM

2016-01-01

Context: Head down tilt is given to patients after sub arachnoid block for adjustment of height of block. However, the amount of tilt given is subjective and cannot be documented. Aims: We used an android application named “clinometer” to measure exact degree of tilt given by anesthesiologists as their routine practice. Settings and Design: This observational study, at a medical college hospital, was done in 130 patients given sub arachnoid block for lower abdominal surgeries. Materials and Methods: We observed and documented vital data of patients and measured tilt given by application “clinometer.” Results: We observed that the application was easy to use and measured tilt each time. The result obtained can be documented, digitally saved and transferred. In 130 patients studied, we observed incidence of degree of tilt as follows: 6-8° tilt in 38 patients (29.23%), 8-10 in 36 patients (27.69%), 10-12 in 30 patients (23.08%), 12-14 in 12 patients (9.23%) and 14-16° tilt in 14 patients (10.77%). Use of application was received with enthusiasm by practicing anesthesiologists. Various possible uses of this application are discussed. PMID:26955307

Abraded Target on Rock 'Champagne' in Gusev Crater

Science.gov (United States)

2005-01-01

NASA's Mars Exploration Rover Spirit took this microscopic image of a target called 'Bubbles' on a rock called 'Champagne' after using its rock abrasion tool to grind a hole through the rock's outer surface. The circular area where the rock's interior is exposed is about 5 centimeters (2 inches) across. This rock is different from rocks out on the plains of Gusev Crater but is similar to other rocks in this area of the 'Columbia Hills' in that it rich in phosphorus. Plagioclase, a mineral commonly found in igneous rocks, is also present in these rocks, according to analysis with Spirit's miniature thermal emission spectrometer. By using the rover's alpha particle X-ray spectrometer to collect data for multiple martian days, or sols, scientists are also beginning to get measurements of trace elements in the rocks. Spirit took the images that are combined into this mosaic on sol 358 (Jan. 3, 2005).

Energy Efficiency, Water Efficiency, and Renewable Energy Site Assessment: Seneca Rocks Discovery Center, Seneca Rocks, West Virginia

Energy Technology Data Exchange (ETDEWEB)

Kiatreungwattana, Kosol [National Renewable Energy Lab. (NREL), Golden, CO (United States); Salasovich, James [National Renewable Energy Lab. (NREL), Golden, CO (United States); Kandt, Alicen [National Renewable Energy Lab. (NREL), Golden, CO (United States)

2016-03-22

As part of ongoing efforts by the U.S. Forest Service to reduce energy use and incorporate renewable energy technologies into its facilities, the Department of Energy's National Renewable Energy Laboratory performed an energy efficiency and renewable energy site assessment of the Seneca Rocks Discovery Center in Seneca Rocks, West Virginia. This report documents the findings of this assessment, and provides site-specific information for the implementation of energy and water conservation measures, and renewable energy measures.

USING DISPERSION MEASURES FOR DETERMINING BLOCK-SIZE IN-MOTION ESTIMATION

Directory of Open Access Journals (Sweden)

CARLOS MERA

2012-01-01

Full Text Available Las técnicas de compresión de video disminuyen la redundancia temporal entre los fotogramas del video para realizar una compresión eficiente del mismo. Dicha reducción se logra mediante la compensación de movimiento, la cual está basada en la estimación de movimiento. Block matching es quizás la técnica más robusta y fiable para la estimación de movimiento, en compresión de video. Sin embargo, el block-matching es un proceso computacionalmente costoso. Diferentes enfoques han sido propuestos con el fin de mejorar la precisión y la eficiencia del block-matching. En este trabajo se presenta una estrategia de block-matching para la estimación de movimiento. En el enfoque propuesto el tamaño de los bloques se determina teniendo en cuenta las variaciones de las intensidades de la luz en las regiones de los fotogramas. Las variaciones de las intensidades de la luz se evalúa usando dos medidas de variabilidad: la varianza y la desviación media absoluta. Los resultados experimentales muestran un mejor desempeño de los algoritmos de block-matching usando el enfoque propuesto.

A heat source probe for measuring thermal conductivity in waste rock dumps

International Nuclear Information System (INIS)

Blackford, M.G.; Harries, J.R.

1985-10-01

The development and use of a heat source probe to measure the thermal conductivity of the material in a waste rock dump is described. The probe releases heat at a constant rate into the surrounding material and the resulting temperature rise is inversely related to the thermal conductivity. The probe was designed for use in holes in the dump which are lined with 50 mm i.d. polyethylene liners. The poor thermal contact between the probe and the liner and the unknown conductivity of the backfill material around the liner necessitated long heating and cooling times (>10 hours) to ensure that the thermal conductivity of the dump material was being measured. Temperature data acquired in the field were analysed by comparing them with temperatures calculated using a two-dimensional cylindrical model of the probe and surrounding material, and the heat transfer code HEATRAN

Characterization of deep-seated rock masses by means of borehole investigation

International Nuclear Information System (INIS)

1982-04-01

Swedish State Power Board. The main objective of the programme was to test a method of measuring in-situ rock stresses in the deep, water-filled boreholes and to correlate measured rock stresses with the hydraulic and geological properties of the rock mass. The investigations consist of the following activities: - Coredrillin of two main boreholes with a depth of 500 m and 250 m respectively. - Rock stress measurements at 11 and 9 main levels in the boreholes respectively. At each level at least 3 complete measurements were made. - Logging of the cores with respect to rock type, fractures and fracture characteristics. - Water injection tests in the boreholes. The rock mass investigated is composed of a gneiss granite of Svecocarelian age (1500 Ma), with inclusions of younger pegmatites and greenstones of variable ages. The fracture density is as a mean 2 fractures per meter with a marked decrease in frequency with increased depth. The fractures are generally coated with calcite and chlorite as the dominating coating minerals. For the rock stress measurements, the method of Leeman and Hayes was chosen. The result show that there is a very high stress level in the rock mass, recordings of about 70 MPa were taken below a horizontal fracture zone at 320 m depth. In this lower rock masses the high stresses were also illustrated by intense disking of the hollow core which made measurements impossible in large sections of the boreholes. Water injection tests were performed, mainly as double-packer tests alon the entire boreholes. For the evaluation, both stationary and transient calculation theories were used and the results show a good agreement. The hyddraulic conductivities of the rock mass vary from below 10 -10 m/s up to 10 -7 m/s. The conductivity decreases with depth, though there are zones even at great depth with high conductivity. (Author)

Self-healing of excavation-disturbed rocks in the near field of underground cavities - exemplary measurements in rock salt and interpretation of preliminary results

International Nuclear Information System (INIS)

Wieczorek, K.; Schwarzianeck, P.; Rothfuchs, T.

2001-01-01

Excavation disturbed zones develop in all kinds of rock as a consequence of the opening of cavities. Such zones are characterized by a change in hydraulic behaviour which can form a problem with regard to the sealing of waste disposal areas. Rocks showing a plastic behaviour, like rock salt, have the potential of healing when the stress state which was disturbed by excavation returns to an advantageous state. If healing can reliably be predicted, the excavation disturbed zone may not form a long-term safety issue in rock salt. Investigations of permeability and stress state around lined and open excavations have been performed in order to relate hydraulic behaviour to stress state. First results which are presented here are promising. (authors)

Thermography as an early predictive measurement for evaluating epidural and femoral-sciatic block success in dogs.

Science.gov (United States)

Küls, Nina; Blissitt, Karen J; Shaw, Darren J; Schöffmann, Gudrun; Clutton, Richard E

2017-09-01

To evaluate skin temperature increase as an early predictive measure for evaluating epidural and femoral-sciatic block success in dogs. Prospective clinical trial. A total of 29 dogs undergoing orthopaedic surgery on one hindlimb. Dogs were anaesthetized and placed into lateral recumbency with the affected limb uppermost and the coat was clipped. Baseline infrared thermographic images (T0) of the affected limb, of the paw pad of the affected leg and of the ipsilateral paw pad were taken. Subsequently, dogs were administered either an epidural (EPI; n=11) or a femoral-sciatic block (FS; n=18) using bupivacaine 1 mg kg -1 . Then, 2 minutes after placement of the block, thermographic images were obtained every 3 minutes for a total of four measurements (T1-T4) and surgery was commenced. Rescue analgesia consisting of fentanyl 1 μg kg -1 was administered if needed. A regional block was considered successful if the dose of fentanyl administered was less than the lower 95% confidence interval of the geometric mean of the total fentanyl used in each group. A ≥ 1 °C increase of skin temperature was considered as the minimum increase required for detection of a successful block. A total of 12 out of 18 blocks in the FS and eight of 11 in the EPI group were considered successful based on fentanyl consumption. Out of these, only four of 12 in the FS and one of eight in the EPI group developed an increase in temperature of ≥ 1 °C. Contrarily, four of six of the nonsuccessful cases in the FS and three of three in the EPI group developed an increase in temperature of ≥ 1 °C. Contrary to reports in humans, thermography did not indicate regional block success prior to surgery in dogs. However further studies under more controlled conditions are needed to determine whether thermography can be used to indicate failure of regional blockade. Copyright © 2017 Association of Veterinary Anaesthetists and American College of Veterinary Anesthesia and Analgesia. Published

An efficient, block-by-block algorithm for inverting a block tridiagonal, nearly block Toeplitz matrix

International Nuclear Information System (INIS)

Reuter, Matthew G; Hill, Judith C

2012-01-01

We present an algorithm for computing any block of the inverse of a block tridiagonal, nearly block Toeplitz matrix (defined as a block tridiagonal matrix with a small number of deviations from the purely block Toeplitz structure). By exploiting both the block tridiagonal and the nearly block Toeplitz structures, this method scales independently of the total number of blocks in the matrix and linearly with the number of deviations. Numerical studies demonstrate this scaling and the advantages of our method over alternatives.

Application of air hammer drilling technology in igneous rocks of Junggar basin

Science.gov (United States)

Zhao, Hongshan; Feng, Guangtong; Yu, Haiye

2018-03-01

There were many technical problems such as serious well deviation, low penetration rate and long drilling cycle in igneous rocks because of its hardness, strong abrasive and poor drillability, which severely influenced the exploration and development process of Junggar basin. Through analyzing the difficulties of gas drilling with roller bits in Well HS 2, conducting the mechanics experiments about igneous rock, and deeply describing the rock-breaking mechanism of air hammer drilling and its adaptability in igneous rocks, air hammer drilling can realize deviation control and fast drilling in igneous rocks of piedmont zone and avoid the wear and fatigue fracture of drilling strings due to its characteristics of low WOB, low RPM and high frequency impact. Through firstly used in igneous rocks of Well HS 201, compared with gas drilling with cone bit, the average penetration rate and one-trip footage of air hammer drilling respectively increased by more than 2.45 times and 6.42 times while the well deviation was always controlled less than 2 degrees. Two records for Block HS were set up such as the fastest penetration rate of 14.29m/h in Φ444.5mm well hole and the highest one-trip footage of 470.62m in Φ311.2mm well hole. So air hammer drilling was an effective way to realize optimal and fast drilling in the igneous rock formation of Junggar basin.

Rock models at Zielona Gora, Poland applied to the semi-empirical neutron tool calibration

International Nuclear Information System (INIS)

Czubek, J.A.; Ossowski, A.; Zorski, T.; Massalski, T.

1995-01-01

The semi-empirical calibration method applied to the neutron porosity tool is presented in this paper. It was used with the ODSN-102 tool of 70 mm diameter and equipped with an Am-Be neutron source at the calibration facility of Zielona Gora, Poland, inside natural and artificial rocks: four sandstone, four limestone and one dolomite block with borehole diameters of 143 and 216 mm, and three artificial ceramic blocks with borehole diameters of 90 and 180 mm. All blocks were saturated with fresh water, and fresh water was also inside all boreholes. In five blocks mineralized water (200,000 ppm NaCl) was introduced inside the boreholes. All neutron characteristics of the calibration blocks are given in this paper. The semi-empirical method of calibration correlates the tool readings observed experimentally with the general neutron parameter (GNP). This results in a general calibration curve, where the tool readings (TR) vs GNP are situated at one curve irrespective of their origin, i.e. of the formation lithology, borehole diameter, tool stand-off, brine salinity, etc. The n and m power coefficients are obtained experimentally during the calibration procedure. The apparent neutron parameters are defined as those sensed by a neutron tool situated inside the borehole and in real environmental conditions. When they are known, the GNP parameter can be computed analytically for the whole range of porosity at any kind of borehole diameter, formation lithology (including variable rock matrix absorption cross-section and density), borehole and formation salinity, tool stand-off and drilling fluid physical parameters. By this approach all porosity corrections with respect to the standard (e.g. limestone) calibration curve can be generated. (author)

Mineralogical aspects of fluid migration in the Salt Block II experiment

International Nuclear Information System (INIS)

Lambert, S.J.

1980-05-01

A block of evaporite rock containing the mineral assemblage halite (88%) - polyhalite (8%) - sylvite (4%) was machined into a cylinder one meter in diameter and one meter high, and was fitted with an axial heater, thermocouples and an off-gas collection system. After about 100 days of heating, identification of mineral efflorescences at the heater hole (carnallite and bischofite) showed that a significant portion of the 111 grams of water recovered (out of around 8500 grams available in the rock) migrated as a liquid, not as a vapor. A microscopic examination of rock slices from within 15 cm of the heater hole (where the temperature was 100 to 200 0 C, and the gradient was 3 to 15 0 C/cm) revealed that: (1) fluid inclusions had migrated, but rarely across grain boundaries; (2) fluid inclusions had not been mobilized at distances greater than about 15 cm from the heater hole; and (3) intergranular liquid had been conspicuously mobilized within 15 cm of the heater hole

Paleomagnetic and Rock Magnetic Study of Oligocene-Holocene Sedimentary Rocks from Northern Dominican Republic: Evidence of Vertical Axis Rotations

Science.gov (United States)

Anson Sanchez, M.; Kodama, K. P.; Pueyo, E. L.; Soto, R.; Garcia-Senz, J.; Escuder-Viruete, J.; Pastor-Galan, D.

2017-12-01

A paleomagnetic and rock magnetic study was conducted in the northern Dominican Republic to detect vertical axis rotations in an active left-lateral, strike slip fault zone. 191 samples from 21 sites were collected from a variety of lithologies including limestones, conglomerates, calcarenites and marls that ranged in age from the Oligocene to the Holocene. The rock magnetic portion of the study focused on the identification of magnetic minerals using coercivity, and Curie temperature (c vs temperature) measurement, modeling of IRM acquisition curves, and thermal demagnetization of IRMs (Lowrie, 19901). In the paleomagnetic portion of the study characteristic remanences (ChRMs) were isolated using thermal demagnetization (19 steps up to 680ºC) and alternating field (AF) demagnetization (17 steps up to 100 mT). In most cases the characteristic remanence is carried by magnetite, with peak unblocking temperatures of 575ºC. This interpretation was supported by c vs. T results that yielded Curie temperatures of 580˚C. In only a few cases (7 samples) higher unblocking temperatures suggested hematite as the magnetic carrier. The modeling of IRM acquisition curves, that shows two coercivity components, further supports the presence of magnetite. 75% of the IRM is carried by the low-coercivity component (100-300 mT, magnetite). 25% of the IRM is carried by the high-coercivity component (1.2-1.6T) characteristic of hematite. The IRM acquisition data was collected from 24 samples (3-4 from each of the lithologies sampled). IRMs were acquired in fields from 4mT to 1T in 23 steps. The paleomagnetic results show a grouping by tectonic blocks with one group having westerly ChRM declinations (268˚-295˚) and a second group having northerly ChRM declinations (357˚-035˚). In most cases, inclinations are intermediate ( 35˚), in agreement with the 24˚-31˚ expected inclinations for Dominican Republic in the period Oligocene to Holocene. The rotation of the tectonic blocks, as

Low-flow, low-permeability measurements in largely impermeable rocks. Proceedings of the NEA/AIEA workshop, Paris, 19-21 Mar 1979

Energy Technology Data Exchange (ETDEWEB)

1979-01-01

Geological formations considered as potential candidates for the siting of radioactive waste repositories must contain no or little circulating ground water since, over the long term, ground water could transport particular radionuclides over long distances and even back to the biosphere. It is therefore essential that every candidate disposal formation be carefully evaluated in relation to its potential for transmitting fluids. Since suitable formations are necessarily characterized by negligible fluid flows, the above requirement implies some capability of measuring extremely low permeabilities in situ. The types of rocks that have been frequently considered as potential host materials for radioactive waste are rock salt, argillaceous sediments and crystalline rocks. Some countries with geologic disposal programmes are conducting or planning field experiments of various kinds. They are all confronted with the problem of how to measure very low permeabilities in situ. The OECD Nuclear Energy Agency in cooperation with the International Atomic Energy Agency organized this meeting. These proceedings constitute a record of the papers presented and the discussions held during the workshop.

Interesting insights into instability of slopes and rock fall in the morphodynamic Himalayan terrane

Science.gov (United States)

Singh, T. N.; Vishal, V.; Pradhan, S. P.

2015-12-01

Himalayan mountain ranges are tectonically and seismically very active and experience many disastrous events with time due to slope failure. Frequent failures of rock cut slopes cause obstruction in traffic and often lead to fatalities. In recent years, the number of tragedies has increased when associated with regional phenomena such at the Kedarnath tragedy of 2013 and the Gorkha earthquake of 2015. The influence of such phenomena on the stability of slopes along important national highways and key settlement areas only raise the risk to lives and property. We conducted a multi-approach investigation for some key slopes along the National Highway 58 in Uttarakhand Himalaya, India. A very detailed field work was conducted to identify the unstable slopes and those with some history of failure. The pertinent geomechanical characteristics of the representative rock samples were determined in the laboratory. Based on the structural data, kinematic analysis was carried out. Finally the slopes were simulated using FDM based simulator, Flac/Slope for analysing the health of the slopes and Rockfall 4.0 to investigate the phenomenon of rockfall along the Highway. It was found that few slopes were weak due to the inherent weak rock materials while few slopes made up of high strength rocks were effectively weak due to prone-to-failure orientation of the joints. Quantification of bounce-height of rock blocks during fall, their energy, velocity and displacement along the slope was also done. Using 3-D simulations, few critically-stable slopes that appear to be stable, were identified. Little ground movement could be capable of triggering a large scale failure in the area. Slopes in the studied region are under threat to failure and need immediate proper planning using the suggested remedial measures.

OPAL Various Lead Glass Blocks

CERN Multimedia

These lead glass blocks were part of a CERN detector called OPAL (one of the four experiments at the LEP particle detector). OPAL uses some 12 000 blocks of glass like this to measure particle energies in the electromagnetic calorimeter. This detector measured the energy deposited when electrons and photons were slowed down and stopped.

A large block heater test for high level nuclear waste management

International Nuclear Information System (INIS)

Lin, W.; Wilder, D.G.; Blink, J.A.

1994-07-01

The radioactive decay heat from nuclear waste packages may, depending on the thermal load, create coupled thermal-mechanical-hydrological-chemical (TMHC) processes in the near-field environment of a repository. A group of tests on a large block (LBT) are planned to provide a timely opportunity to test and calibrate some of the TMHC model concepts. The LBT is advantageous for testing and verifying model concepts because the boundary conditions are controlled, and the block can be characterized before and after the experiment. A block of Topopah Spring tuff of about 3 x 3 x 4.5 m will be sawed and isolated at Fran Ridge, Nevada Test Site. Small blocks of the rock adjacent to the large block will be collected for laboratory testing of some individual thermal-mechanical hydrological and chemical processes. A constant load of about 4 MPa will be applied to the top and sides of the large block. The sides will be sealed with moisture and thermal barriers. The large block will be heated by heaters within and guard heaters on the sides so that a dry-out zone and a condensate zone will exist simultaneously. Temperature, moisture content, pore pressure, chemical composition, stress, and displacement will be throughout the block during the heating and cool-down phases. The results from the experiments on small blocks and the tests on the large block will provide a better understanding of some concepts of the coupled TMHC processes. The progress of the project is presented in this paper

Smart Rocking Armour Units

OpenAIRE

Hofland, B.; Arefin, Syed Shamsil; van der Lem, Cock; van gent, Marcel

2018-01-01

This paper describes a method to measure the rocking motion of lab-scale armour units. Sensors as found in mobile phones are used. These sensors, data-storage and battery are all embedded in the model units, such that they can be applied without wires attached to them. The technique is applied to double-layer units in order to compare the results to the existing knowledge for this type of armour layers. In contrast to previous research, the gyroscope reading is used to determine the (rocking)...

Application of the collapsing method to acoustic emissions in a rock salt sample during a triaxial compression experiment

International Nuclear Information System (INIS)

Manthei, G.; Eisenblaetter, J.; Moriya, H.; Niitsuma, H.; Jones, R.H.

2003-01-01

Collapsing is a relatively new method. It is used for detecting patterns and structures in blurred and cloudy pictures of multiple soundings. In the case described here, the measurements were made in a very small region with a length of only a few decimeters. The events were registered during a triaxial compression experiment on a compact block of rock salt. The collapsing method showed a cellular structure of the salt block across the whole length of the test piece. The cells had a length of several cm, enclosing several grains of salt with an average grain size of less than one cm. In view of the fact that not all cell walls corresponded to acoustic emission events, it was assumed that only those grain boundaries are activated that are oriented at a favourable angle to the field of tension of the test piece [de

Measurement of void swelling in thick non-uniformly irradiated 304 stainless steel blocks using nondestructive ultrasonic techniques

International Nuclear Information System (INIS)

Garner, F.A.; Okita, T.; Isobe, Y.; Etoh, J.; Sagisaka, M.; Matsunaga, T.; Freyer, P.D.; Huang, Y.; Wiezorek, J.M.K.; Porter, D.L.

2015-01-01

Void swelling is of potential importance in PWR austenitic internals, especially in components that will see higher doses during plant lives beyond 40 years. Proactive surveillance of void swelling is required to identify its emergence before swelling reaches levels that cause high levels of embrittlement and distortion. Non-destructive measurements of ultrasonic velocity can measure swelling at fractions of a percent. To demonstrate the feasibility of this technique for PWR application we have investigated five blocks of 304 stainless steel that were irradiated in the EBR-II fast reactor. These blocks were of hexagonal cross-section, with thickness of about 50 mm and lengths of about 218-245 mm. They were subjected to significant axial and radial gradients in gamma heating, temperature and dpa rate, producing complex internal distributions of swelling, reaching about 3.5% maximum at an off-center mid-core position. Swelling decreases both the density and the elastic moduli, thereby impacting the ultrasonic velocity. Concurrently, carbide precipitates form, producing increases in density and decreases in elastic moduli. Using blocks from both low and high dpa levels it was possible to separate the ultrasonic contributions of voids and carbides. Time-of-flight ultrasonic measurements were used to non-destructively measure the internal distribution of void swelling. These distributions were confirmed using non-destructive profilometry followed by destructive cutting to provide density change and electron microscopy data. It was demonstrated that the four measurement types produce remarkably consistent results. Therefore ultrasonic measurements offer great promise for in-situ surveillance of voids in PWR core internals. (authors)

A theoretical and numerical consideration of rock mass behaviour under thermal loading of radioactive waste repository

International Nuclear Information System (INIS)

Reivinen, M.; Freund, J.; Eloranta, E.

1996-08-01

The aim of the study is to model the geodynamic response of a ground rock block under horizontal stresses and also consider the thermal fields and deformations, especially on the ground surface, caused by the heat produced by nuclear waste. (12 refs.)

Assessment of groundwater quality in Kashipur Block, Purulia district, West Bengal

Science.gov (United States)

Kundu, Anindita; Nag, S. K.

2018-03-01

Hydrogeochemical investigation of groundwater resources of Kashipur Block, Purulia district, West Bengal has been carried out to assess the water quality for domestic and irrigation uses. Twenty groundwater samples were collected and analyzed for pH, electrical conductivity, total dissolved solids, hardness, major anions (CO3 2-, HCO3 -, Cl-, SO4 2-, F-) and cations (Ca2+, Mg2+, Fe2+, Na+, K+). Study results reveal that the groundwater of the area is mostly acidic in nature. The trend amongst average ionic concentrations of cations and anions is Mg2+ > Ca2+ > Na+ > Fe2+ > K+ and Cl- > HCO3 - > CO3 2- > SO4 2- > F- respectively during the post monsoon whereas the trend for cations and anions are Mg2+ > Ca2+> Na+ > K+ > Fe and Cl- > HCO3 - > SO4 2- > F- > CO3 - in pre monsoon session, respectively. To explore the ionic toxicity of the study area, the derived parameters like sodium adsorption ratio, soluble sodium percentage, residual sodium carbonate, magnesium adsorption ratio, Kelly's ratio and permeability index were calculated. The hydro geochemical data suggest that weathering of rock forming minerals along with secondary contributions from agricultural and anthropogenic sources are mainly controlling the groundwater composition of Kashipur Block, Purulia District. According to piper diagram, water samples of most of the area of the block are fresh water and in some areas sulphate rich throughout the year. All samples are distributed to central rock dominance category. Groundwater chemistry of this block is mainly controlled by the interaction existing between the litho units and the percolating water into the subsurface domain. However, the groundwater quality and suitability of this study area can be termed as good to moderate with a few exceptions which have been encountered on a local scale.

GEODYNAMICS AS WAVE DYNAMICS OF THE MEDIUM COMPOSED OF ROTATING BLOCKS

Directory of Open Access Journals (Sweden)

Alexander V. Vikulin

2015-01-01

Full Text Available The geomedium block concept envisages that stresses in the medium composed of rotating blocks have torque and thus predetermine the medium's energy capacity (in terms of [Ponomarev, 2008]. The present paper describes the wave nature of the global geodynamic process taking place in the medium characterized by the existence of slow and fast rotation strain waves that are classified as a new type of waves. Movements may also occur as rheid, superplastic and/or superfluid motions and facilitate the formation of vortex geological structures in the geomedium.Our analysis of data on almost 800 strong volcanic eruptions shows that the magma chamber’s thickness is generally small, about 0.5 km, and this value is constant, independent of the volcanic process and predetermined by properties of the crust. A new magma chamber model is based on the idea of 'thermal explosion’/‘self-acceleration' manifested by intensive plastic movements along boundaries between the blocks in conditions of the low thermal conductivity of the geomedium. It is shown that if the solid rock in the magma chamber is overheated above its melting point, high stresses may occur in the surrounding area, and their elastic energy may amount to 1015 joules per 1 km3 of the overheated solid rock. In view of such stresses, it is possible to consider the interaction between volcano’s magma chambers as the migration of volcanic activity along the volcanic arc and provide an explanation of the interaction between volcanic activity and seismicity within the adjacent parallel arcs.The thin overheated interlayer/magma chamber concept may be valid for the entire Earth's crust. In our hypothesis, properties of the Moho are determined by the phase transition from the block structure of the crust to the nonblock structure of the upper mantle.

Multiscale heterogeneity characterization of tidal channel, tidal delta and foreshore facies, Almond Formation outcrops, Rock Springs uplift, Wyoming

Energy Technology Data Exchange (ETDEWEB)

Schatzinger, R.A.; Tomutsa, L. [BDM Petroleum Technologies, Bartlesville, OK (United States)

1997-08-01

In order to accurately predict fluid flow within a reservoir, variability in the rock properties at all scales relevant to the specific depositional environment needs to be taken into account. The present work describes rock variability at scales from hundreds of meters (facies level) to millimeters (laminae) based on outcrop studies of the Almond Formation. Tidal channel, tidal delta and foreshore facies were sampled on the eastern flank of the Rock Springs uplift, southeast of Rock Springs, Wyoming. The Almond Fm. was deposited as part of a mesotidal Upper Cretaceous transgressive systems tract within the greater Green River Basin. Bedding style, lithology, lateral extent of beds of bedsets, bed thickness, amount and distribution of depositional clay matrix, bioturbation and grain sorting provide controls on sandstone properties that may vary more than an order of magnitude within and between depositional facies in outcrops of the Almond Formation. These features can be mapped on the scale of an outcrop. The products of diagenesis such as the relative timing of carbonate cement, scale of cemented zones, continuity of cemented zones, selectively leached framework grains, lateral variability of compaction of sedimentary rock fragments, and the resultant pore structure play an equally important, although less predictable role in determining rock property heterogeneity. A knowledge of the spatial distribution of the products of diagenesis such as calcite cement or compaction is critical to modeling variation even within a single facies in the Almond Fin. because diagenesis can enhance or reduce primary (depositional) rock property heterogeneity. Application of outcrop heterogeneity models to the subsurface is greatly hindered by differences in diagenesis between the two settings. The measurements upon which this study is based were performed both on drilled outcrop plugs and on blocks.

Longwave thermal infrared spectral variability in individual rocks

Energy Technology Data Exchange (ETDEWEB)

Balick, Lee K [Los Alamos National Laboratory; Gillespie, Alan [UN. WASHINGTON; French, Andrew [USDA-ARS; Danilina, Iryna [UN. WASHINGTON

2008-01-01

A hyperspectral imaging spectrometer measuring in the longwave thermal infrared (7.6-11.6 {micro}m) with a spatial resolution less than 4 mm was used in the field to observe the variability of emissivity spectra within individual rocks. The rocks were obtained commercially, were on the order of 20 cm in size and were selected to have distinct spectral features: they include alabaster (gypsum), soapstone (steatite with talc), obsidian (volcanic glass), norite (plagioclase and orthopyroxene), and 'jasper' (silica with iron oxides). The advantages of using an imaging spectrometer to spectrally characterize these rocks are apparent. Large spectral variations were observed within individual rocks that may be attributed to roughness, surface geometry, and compositional variation. Non-imaging spectrometers would normally miss these variations as would small samples used in laboratory measurements, spatially averaged spectra can miss the optimum spectra for identification materials and spatially localized components of the rock can be obscured.

Dynamic elastic moduli of rocks under pressure

Energy Technology Data Exchange (ETDEWEB)

Schock, R N [Lawrence Radiation Laboratory, University of California, Livermore, CA (United States)

1970-05-01

Elastic moduli are determined as a function of confining pressure to 10 kb on rocks in which Plowshare shots are to be fired. Numerical simulation codes require accurate information on the mechanical response of the rock medium to various stress levels in order to predict cavity dimensions. The theoretical treatment of small strains in an elastic medium relates the propagation velocity of compressional and shear waves to the elastic moduli. Velocity measurements can provide, as unique code input data, the rigidity modulus, Poisson' ratio and the shear wave velocity, as well as providing checks on independent determinations of the other moduli. Velocities are determined using pulsed electro-mechanical transducers and measuring the time-of-flight in the rock specimen. A resonant frequency of 1 MHz is used to insure that the wavelength exceeds the average grain dimension and is subject to bulk rock properties. Data obtained on a variety of rock types are presented and analyzed. These data are discussed in terms of their relationship to moduli measured by static methods as well as the effect of anisotropy, porosity, and fractures. In general, fractured rocks with incipient cracks show large increases in velocity and moduli in the first 1 to 2 kb of compression as a result of the closing of these voids. After this, the velocities increase much more slowly. Dynamic moduli for these rocks are often 10% higher than corresponding static moduli at low pressure, but this difference decreases as the voids are closed until the moduli agree within experimental error. The discrepancy at low pressure is a result of the elastic energy in the wave pulse being propagated around cracks, with little effect on propagation velocity averaged over the entire specimen. (author)

Dynamic elastic moduli of rocks under pressure

International Nuclear Information System (INIS)

Schock, R.N.

1970-01-01

Elastic moduli are determined as a function of confining pressure to 10 kb on rocks in which Plowshare shots are to be fired. Numerical simulation codes require accurate information on the mechanical response of the rock medium to various stress levels in order to predict cavity dimensions. The theoretical treatment of small strains in an elastic medium relates the propagation velocity of compressional and shear waves to the elastic moduli. Velocity measurements can provide, as unique code input data, the rigidity modulus, Poisson' ratio and the shear wave velocity, as well as providing checks on independent determinations of the other moduli. Velocities are determined using pulsed electro-mechanical transducers and measuring the time-of-flight in the rock specimen. A resonant frequency of 1 MHz is used to insure that the wavelength exceeds the average grain dimension and is subject to bulk rock properties. Data obtained on a variety of rock types are presented and analyzed. These data are discussed in terms of their relationship to moduli measured by static methods as well as the effect of anisotropy, porosity, and fractures. In general, fractured rocks with incipient cracks show large increases in velocity and moduli in the first 1 to 2 kb of compression as a result of the closing of these voids. After this, the velocities increase much more slowly. Dynamic moduli for these rocks are often 10% higher than corresponding static moduli at low pressure, but this difference decreases as the voids are closed until the moduli agree within experimental error. The discrepancy at low pressure is a result of the elastic energy in the wave pulse being propagated around cracks, with little effect on propagation velocity averaged over the entire specimen. (author)

Ages, geochemistry and tectonic implications of the Cambrian igneous rocks in the northern Great Xing'an Range, NE China

Science.gov (United States)

Feng, Zhiqiang; Liu, Yongjiang; Li, Yanrong; Li, Weimin; Wen, Quanbo; Liu, Binqiang; Zhou, Jianping; Zhao, Yingli

2017-08-01

The Xinlin-Xiguitu suture zone, located in the Great Xing'an Range, NE China, in the eastern segment of the Central Asian Orogenic Belt (CAOB), represents the boundary between the Erguna and Xing'an micro-continental blocks. The exact location of the Xinlin-Xiguitu suture zone has been debated, especially, the location of the northern extension of the suture zone. In this study, based on a detailed field, geochemical, geochronological and Sr-Nd-Hf isotope study, we focus our work on the Cambrian igneous rocks in the Erguna-Xing'an block. The Xinglong granitoids, mainly include ∼520 Ma diorite, ∼470 Ma monzogranite and ∼480 Ma pyroxene diorite. The granitoids show medium to high-K calc-alkaline series characteristics with post-collision granite affinity. The circa 500 Ma granitoids have low εHf (t) values (-16.6 to +2.2) and ancient two-stage model (TDM2) ages between 1317 Ma and 2528 Ma. These results indicate the primary magmas of the Xinglong granitoids were probably derived from the partial melting of a dominantly Paleo-Mesoproterozoic ;old; crustal source with possible different degrees of addition of juvenile materials, and formed in a post-collision tectonic setting after the amalgamation of the Erguna and Xing'an blocks. Compared with the Xinglong granitoids, the Duobaoshan igneous rocks are consisted of the approximately coeval rhyolitic tuffs (491 ± 5 Ma) and ultramafic intrusions (497 ± 5 Ma) within the Duobaoshan Formation. They are generally enriched in large ion lithophile elements (LILEs) and depleted in high field strength elements (HFSEs; e.g., Nb, Ta, and Ti), consistent with the geochemistry of igneous rocks from island arcs or active continental margins. The ultramafic rocks have high positive εHf (t) values (+1.3 to +15) and εNd (t) (+1.86 to +2.28), and relatively young two-stage model (TDM2) ages and low initial 87Sr/86Sr ratios (0.70628-0.70853), indicating the partial melting of a depleted mantle source from a subducted slab in

Brushed Target on Rock 'Champagne' in Gusev Crater

Science.gov (United States)

2005-01-01

NASA's Mars Exploration Rover Spirit took this microscopic image of a target called 'Bubbles' on a rock called 'Champagne' after using its rock abrasion tool to brush away a coating of dust. The circular brushed area is about 5 centimeters (2 inches) across. This rock is different from rocks out on the plains of Gusev Crater but is similar to other rocks in this area of the 'Columbia Hills' in that it has higher levels of phosphorus. Plagioclase, a mineral commonly found in igneous rocks, is also present in these rocks, according to analysis with the minature thermal emission spectrometer. By using the alpha particle X-ray spectrometer to collect data over multiple martian days, or sols, scientists are also beginning to get measurements of trace elements in these rocks. Spirit took the images that are combined into this mosaic on sol 354 (Dec. 30, 2004).

A progress report for the large block test of the coupled thermal-mechanical-hydrological-chemical processes

International Nuclear Information System (INIS)

Lin, W.; Wilder, D.G.; Blink, J.

1994-10-01

This is a progress report on the Large Block Test (LBT) project. The purpose of the LBT is to study some of the coupled thermal-mechanical-hydrological-chemical (TMHC) processes in the near field of a nuclear waste repository under controlled boundary conditions. To do so, a large block of Topopah Spring tuff will be heated from within for about 4 to 6 months, then cooled down for about the same duration. Instruments to measure temperature, moisture content, stress, displacement, and chemical changes will be installed in three directions in the block. Meanwhile, laboratory tests will be conducted on small blocks to investigate individual thermal-mechanical, thermal-hydrological, and thermal-chemical processes. The fractures in the large block will be characterized from five exposed surfaces. The minerals on fracture surfaces will be studied before and after the test. The results from the LBT will be useful for testing and building confidence in models that will be used to predict TMHC processes in a repository. The boundary conditions to be controlled on the block include zero moisture flux and zero heat flux on the sides, constant temperature on the top, and constant stress on the outside surfaces of the block. To control these boundary conditions, a load-retaining frame is required. A 3 x 3 x 4.5 m block of Topopah Spring tuff has been isolated on the outcrop at Fran Ridge, Nevada Test Site. Pre-test model calculations indicate that a permeability of at least 10 -15 m 2 is required so that a dryout zone can be created within a practical time frame when the block is heated from within. Neutron logging was conducted in some of the vertical holes to estimate the initial moisture content of the block. It was found that about 60 to 80% of the pore volume of the block is saturated with water. Cores from the vertical holes have been used to map the fractures and to determine the properties of the rock. A current schedule is included in the report

New method for protecting mine roadways in thin coal seams by means of prefabricated yielding blocks

Energy Technology Data Exchange (ETDEWEB)

Peknik, J

1983-05-01

The use of concrete blocks for strata control in mine roadways driven in thin coal seams is evaluated. Two types of prefabricated blocks are used: BZT blocks made of reinforced concrete and yielding elements or popilbet blocks made of a mixture of fly ash (from coal power plants) and concrete. When the popilbet blocks were used no yielding elements were necessary. Mechanical properties of blocks made of reinforced concrete were controlled by yielding elements. Mechanical properties (compression strength) of the popilbet blocks were controlled by proportion of water, cement and fly ash. The BZT and the popilbet blocks were used for strata control in mine roadways in coal seams from 60 to 80 cm thick and dip angle from 5 to 18 degrees. Use of the BZT and the popilbet blocks reduced roadway deformation by about 50% in comparison to traditional strata control methods (timber cribbings, use of waste rock, etc.). Use of the blocks is explained. The BZT and the popilbet blocks were placed in a roadway wall. Height of the block wall equaled coal seam thickness. Yielding arched steel supports and timber liners were used for strata control in the roadway. The popilbet blocks were 50% less expensive than the BZT blocks. 9 references

Elastic wave velocities, chemistry and modal mineralogy of crustal rocks sampled by the Outokumpu scientific drill hole: Evidence from lab measurements and modeling

Science.gov (United States)

Kern, H.; Mengel, K.; Strauss, K. W.; Ivankina, T. I.; Nikitin, A. N.; Kukkonen, I. T.

2009-07-01

The Outokumpu scientific deep drill hole intersects a 2500 m deep Precambrian crustal section comprising a 1300 m thick biotite-gneiss series (mica schists) at top, followed by a 200 m thick meta-ophiolite sequence, underlain again by biotite gneisses (mica schists) (500 m thick) with intercalations of amphibolite and meta-pegmatoids (pegmatitic granite). From 2000 m downward the dominating rock types are meta-pegmatoids (pegmatitic granite). Average isotropic intrinsic P- and S-wave velocities and densities of rocks were calculated on the basis of the volume fraction of the constituent minerals and their single crystal properties for 29 core samples covering the depth range 198-2491 m. The modal composition of the rocks is obtained from bulk rock (XRF) and mineral chemistry (microprobe), using least squares fitting. Laboratory seismic measurements on 13 selected samples representing the main lithologies revealed strong anisotropy of P- and S-wave velocities and shear wave splitting. Seismic anisotropy is strongly related to foliation and is, in particular, an important property of the biotite gneisses, which dominate the upper and lower gneiss series. At in situ conditions, velocity anisotropy is largely caused by oriented microcracks, which are not completely closed at the pressures corresponding to the relatively shallow depth drilled by the borehole, in addition to crystallographic preferred orientation (CPO) of the phyllosilicates. The contribution of CPO to bulk anisotropy is confirmed by 3D velocity calculations based on neutron diffraction texture measurements. For vertical incidence of the wave train, the in situ velocities derived from the lab measurements are significantly lower than the measured and calculated intrinsic velocities. The experimental results give evidence that the strong reflective nature of the ophiolite-derived rock assemblages is largely affected by oriented microcracks and preferred crystallographic orientation of major minerals, in

Relationship between natural radioactivity and rock type in the Van lake basin - Turkey

International Nuclear Information System (INIS)

Tolluoglu, A. U.; Eral, M.; Aytas, S.

2004-01-01

The Van Lake basin located at eastern part of Turkey. The Van lake basin essentially comprises two province, these are namely Van and Bitlis. The former geochemistry research indicated that the uranium concentrations of Van lake water and deep sediments are 78-116 ppb and 0.1-0.5 ppm respectively. Uranium was transported to Van Lake by rivers and streams, flow through to outcrops of Paleozoic Bitlis Massive, and young Pleistocene alkaline/calkalkaline volcanic rocks. This study focused on the revealing natural radioactivity and secondary dispersion of radioactivity related to rock types surface environments in the Van Lake Basin. The Van Lake Basin essentially subdivided into three different parts; the Eastern parts characterized by Mesozoic basic and ultra basic rocks, southern parts dominated by metamorphic rocks of Bitlis Massive, Western and Northwestern parts covered by volcanic rocks of Pleistocene. Volcanic rocks can be subdivided into two different types. The first type is mafic rocks mainly composed of basalts. The second type is felsic rocks represented by rhyolites, dacites and pumice tuff. Surface gamma measurements (cps) and dose rate measurements (μR/h) show different values according to rock type. Surface gamma measurement and surface dose rate values in the basaltic rocks are slightly higher than the average values (130 cps, 11 μR/h). In the felsic volcanic rocks such as rhyolites and dacites surface gamma measurement values and surface dose rate values, occasionally exceed the background. Highest values were obtained in the pumice tuffs. Rhyolitic eruptions related to Quaternary volcanic activity formed thick pumice (natural glassy froth related to felsic volcanic rocks and exhibit spongy texture) sequences Northern and Western part of Van Lake basin. The dose rate of pumice rocks was measured mean 15 μR/h. The highest value for surface gamma measurements was recorded as 200 cps. The pumice has very big water capacity, due to porous texture of

Results of monitoring at Olkiluoto in 2012. Rock mechanics

International Nuclear Information System (INIS)

Johansson, E.; Siren, T.

2014-01-01

The rock mechanics monitoring at Olkiluoto concentrates on the assessment of potential tectonic movements and stability of the bedrock. The rock mechanics monitoring programme 2012 consisted of seismic measurements, GPS measurements, surface levelling measurements and temperature measurements at Olkiluoto and vicinity and displacement measurements, temperature measurements and visual tunnel observations carried out in the ONKALO. The Posiva's microseismic network consists of 17 seismic stations and 22 triaxial sensors. Six stations are in the ONKALO. In spite of few breaks the network operated continuously and well during 2012. The number of located events was much smaller in 2012 than during the previous years due to the interruption of the excavation. Altogether 337 events were located in the Olkiluoto area of which about half (181) were explosions. Two excavation induced earthquakes were observed at -420 m level and were associated with a known tunnel crosscutting fracture. According to the seismic monitoring the rock mass has been stable in 2012. The local GPS network consists of 19 stations. The whole network was measured twice in 2012. Most of the inner network baselines showed very small motions as in the previous years: 80 % of change rates were smaller than 0.10 mm/a. Roughly one third of the change rates are statistically significant. One baseline was also measured using electronic distance measurements (EDM) and the results fitted well to the times series. The surface levelling network currently consists of 87 fixed measuring points. During 2012 only measuring loops VLJ, ONKALO and Olkiluoto Strait were measured. The results indicated that vertical deformations were small compared to 2011 results. The largest deformations around 0.6 mm upwards existed above the VLJ-repository. The displacement measurements in 2012 consisted of the extensometer measurements in the technical rooms of the ONKALO. Readings were taken continuously once a hour by a

'Escher' Rock

Science.gov (United States)

2004-01-01

[figure removed for brevity, see original site] Chemical Changes in 'Endurance' Rocks [figure removed for brevity, see original site] Figure 1 This false-color image taken by NASA's Mars Exploration Rover Opportunity shows a rock dubbed 'Escher' on the southwestern slopes of 'Endurance Crater.' Scientists believe the rock's fractures, which divide the surface into polygons, may have been formed by one of several processes. They may have been caused by the impact that created Endurance Crater, or they might have arisen when water leftover from the rock's formation dried up. A third possibility is that much later, after the rock was formed, and after the crater was created, the rock became wet once again, then dried up and developed cracks. Opportunity has spent the last 14 sols investigating Escher, specifically the target dubbed 'Kirchner,' and other similar rocks with its scientific instruments. This image was taken on sol 208 (Aug. 24, 2004) by the rover's panoramic camera, using the 750-, 530- and 430-nanometer filters. The graph above shows that rocks located deeper into 'Endurance Crater' are chemically altered to a greater degree than rocks located higher up. This chemical alteration is believed to result from exposure to water. Specifically, the graph compares ratios of chemicals between the deep rock dubbed 'Escher,' and the more shallow rock called 'Virginia,' before (red and blue lines) and after (green line) the Mars Exploration Rover Opportunity drilled into the rocks. As the red and blue lines indicate, Escher's levels of chlorine relative to Virginia's went up, and sulfur down, before the rover dug a hole into the rocks. This implies that the surface of Escher has been chemically altered to a greater extent than the surface of Virginia. Scientists are still investigating the role water played in influencing this trend. These data were taken by the rover's alpha particle X-ray spectrometer.

Effects of water inflow into a deposition hole - Influence of pellets type and of buffer block manufacturing technique

Energy Technology Data Exchange (ETDEWEB)

Johannesson, Lars-Erik; Jense, Viktor [Clay Technology AB, Lund (Sweden)

2012-10-15

During the installation of buffer and canister in a deposition hole a number of different problems can arise. The problems are mainly connected to water flow from fractures in the rock into the deposition hole. According to the reference design for the KBS-3V concept, the buffer is protected with a special sheet made of rubber during the installation phase. This protection sheet will at some stage be removed and the outer gap between the buffer blocks and the rock surface will be filled with bentonite pellets. The interaction of buffer blocks and pellets have previously been investigated. The focuses of those studies were the following processes: 1. Erosion. Erosion of bentonite from the deposition hole up into the tunnel backfill material. This process will continue until a tunnel plug has been installed and the backfill is saturated. 2. Heave. Early wetting of the pellets filling may cause a heave of the buffer blocks into the backfill that will decrease the density of the buffer. The laboratory tests presented in this study are complementing previous investigations by focusing on how the choice of manufacturing process for the bentonite blocks (isostatic or uniaxial compaction) and pellets (roller compaction or extrusion) are affecting erosion and the heaving effect.

Effects of water inflow into a deposition hole - Influence of pellets type and of buffer block manufacturing technique

International Nuclear Information System (INIS)

Johannesson, Lars-Erik; Jense, Viktor

2012-10-01

During the installation of buffer and canister in a deposition hole a number of different problems can arise. The problems are mainly connected to water flow from fractures in the rock into the deposition hole. According to the reference design for the KBS-3V concept, the buffer is protected with a special sheet made of rubber during the installation phase. This protection sheet will at some stage be removed and the outer gap between the buffer blocks and the rock surface will be filled with bentonite pellets. The interaction of buffer blocks and pellets have previously been investigated. The focuses of those studies were the following processes: 1. Erosion. Erosion of bentonite from the deposition hole up into the tunnel backfill material. This process will continue until a tunnel plug has been installed and the backfill is saturated. 2. Heave. Early wetting of the pellets filling may cause a heave of the buffer blocks into the backfill that will decrease the density of the buffer. The laboratory tests presented in this study are complementing previous investigations by focusing on how the choice of manufacturing process for the bentonite blocks (isostatic or uniaxial compaction) and pellets (roller compaction or extrusion) are affecting erosion and the heaving effect

Geophysical and transport properties of reservoir rocks. Final report for task 4: Measurements and analysis of seismic properties

Energy Technology Data Exchange (ETDEWEB)

Cook, N.G.W.

1993-05-01

The principal objective of research on the seismic properties of reservoir rocks is to develop a basic understanding of the effects of rock microstructure and its contained pore fluids on seismic velocities and attenuation. Ultimately, this knowledge would be used to extract reservoir properties information such as the porosity, permeability, clay content, fluid saturation, and fluid type from borehole, cross-borehole, and surface seismic measurements to improve the planning and control of oil and gas recovery. This thesis presents laboratory ultrasonic measurements for three granular materials and attempts to relate the microstructural properties and the properties of the pore fluids to P- and S-wave velocities and attenuation. These experimental results show that artificial porous materials with sintered grains and a sandstone with partially cemented grains exhibit complexities in P- and S-wave attenuation that cannot be adequately explained by existing micromechanical theories. It is likely that some of the complexity observed in the seismic attenuation is controlled by details of the rock microstructure, such as the grain contact area and grain shape, and by the arrangement of the grain packing. To examine these effects, a numerical method was developed for analyzing wave propagation in a grain packing. The method is based on a dynamic boundary integral equation and incorporates generalized stiffness boundary conditions between individual grains to account for viscous losses and grain contact scattering.

A comparative study on seismic response of two unstable rock slopes within same tectonic setting but different activity level

Science.gov (United States)

Kleinbrod, Ulrike; Burjánek, Jan; Hugentobler, Marc; Amann, Florian; Fäh, Donat

2017-12-01

In this study, the seismic response of two slope instabilities is investigated with seismic ambient vibration analysis. Two similar sites have been chosen: an active deep-seated slope instability at Cuolm da Vi and the geologically, structurally and morphologically similar, but presently not moving Alp Caschlè slope. Both slopes are located at the upper Vorderrheintal (Canton Graubünden, Switzerland). Ambient vibrations were recorded on both slopes and processed by time-frequency polarization and site-to-reference spectral ratio analysis. The data interpretation shows correlations between degree of disintegration of the rock mass and amplification. However, the ambient vibration analysis conducted, does not allow retrieving a resonance frequency that can be related to the total depth of the instability of Cuolm da Vi. Even though seismic waves can be hardly traced in rock instabilities containing open fractures, it was possible to retrieve a dispersion curve and a velocity profile from the array measurement at Cuolm da Vi due to the high level of disintegration of the rock material down to a depth of about 100 m. From the similar amplification pattern at the two sites, we expect a similar structure, indicating that also the slope at Alp Caschlè was active in the past in a similar manner as Cuolm da Vi. However, a smoother increase of amplification with frequency is observed at Alp Caschlè, which might indicate less disintegration of the rock mass in a particular depth range at this site, when comparing to Cuolm da Vi where a high level of disintegration is observed, resulting from the high activity at the slope. From the frequency-dependent amplification, we can distinguish between two parts within both instabilities, one part showing decreasing disintegration of the rock mass with increasing depth, for the other parts less-fractured blocks are observed. Since the block structures are found in the lower part of the instabilities, they might contribute to the

Hydraulic gradients in rock aquifers

International Nuclear Information System (INIS)

Dahlblom, P.

1992-05-01

This report deals with fractured rock as a host for deposits of hazardous waste. In this context the rock, with its fractures containing moving groundwater, is called the geological barrier. The desired properties of the geological barrier are low permeability to water, low hydraulic gradients and ability to retain matter dissolved in the water. The hydraulic gradient together with the permeability and the porosity determines the migration velocity. Mathematical modelling of the migration involves calculation of the water flow and the hydrodynamic dispersion of the contaminant. The porous medium approach can be used to calculate mean flow velocities and hydrodynamic dispersion of a large number of fractures are connected, which means that a large volume have to be considered. It is assumed that the porous medium approach can be applied, and a number of idealized examples are shown. It is assumed that the groundwater table is replenished by percolation at a constant rate. One-dimensional analytical calculations show that zero hydraulic gradients may exist at relatively large distance from the coast. Two-dimensional numerical calculations show that it may be possible to find areas with low hydraulic gradients and flow velocities within blocks surrounded by areas with high hydraulic conductivity. (au)

Rapid detailed characterization of concrete shielding blocks utilizing internal natural radionuclides for calibration

International Nuclear Information System (INIS)

McDonald, R.J.; Smith, A.R.; Hurley, D.L.; Norman, E.B.; Schoonover, M.R.

1998-01-01

Following many years of productive research, the 184-inch Cyclotron, the SuperHILAC, and the BEVALAC accelerators at the Berkeley Laboratory were closed, leaving thousands of concrete shielding blocks available for reuse, recycling, or disposal. The process history of these blocks precludes free release pending radiological characterization. This paper describes a procedure whereby a high efficiency shielded germanium spectrometer is used to rapidly characterize natural and man-made activity within the blocks. The spectrometer is moved up to the block and 5 minutes of data are collected at the point on the block that registers highest on a micro-R meter. Sensitivity is better than 1 pCi/g (0.037 Bq/g) for Co-60 and Eu-152, the prominent man-made activities observed. One-time calibration of the detector system is obtained from a sample of concrete, drilled with a hammer drill, counted in our low-background facility, and compared to crushed rock with known U, Th, and K activity. A simple relationship exists between the counts/minute observed in a characteristic gamma-ray peak and the activity in the block. (author)

Determination of the thermal neutron absorption cross section for rock samples by a single measurement of the time decay constant

International Nuclear Information System (INIS)

Krynicka, E.

1993-01-01

A calibration method for the determination of the thermal neutron macroscopic mass absorption cross section for rock samples is presented. The standard deviation of the final results is discussed in detail. A big advantage of the presented method is that the calibration curves have been found using the results obtained for a variety of natural rock samples of different stratigraphies and lithologies measured by Czubek's methods. An important part of the paper is a through analysis of the standard deviation of the final result. (author). 13 refs, 11 figs, 5 tabs

Oxygen and U-Th isotopes and the timescales of hydrothermal exchange and melting in granitoid wall rocks at Mount Mazama, Crater Lake, Oregon

Science.gov (United States)

Ankney, Meagan E.; Bacon, Charles R.; Valley, John W.; Beard, Brian L.; Johnson, Clark M.

2017-01-01

We report new whole rock U-Th and in-situ oxygen isotope compositions for partially melted (0–50 vol% melt), low-δ18O Pleistocene granitoid blocks ejected during the ∼7.7 ka caldera-forming eruption of Mt. Mazama (Crater Lake, Oregon). The blocks are interpreted to represent wall rocks of the climactic magma chamber that, prior to eruption, experienced variable amounts of exchange with meteoric hydrothermal fluids and subsequent partial melting. U-Th and oxygen isotope results allow us to examine the timescales of hydrothermal circulation and partial melting, and provide an “outside in” perspective on the buildup to the climactic eruption of Mt. Mazama. Oxygen isotope compositions measured in the cores and rims of individual quartz (n = 126) and plagioclase (n = 91) crystals, and for transects across ten quartz crystals, document zonation in quartz (Δ18OCore-Rim ≤ 0.1–5.5‰), but show homogeneity in plagioclase (Δ18OCore-Rim ≤ ±0.8‰). We propose that oxygen isotope zonation in quartz records hydrothermal exchange followed by high-temperature exchange in response to partial melting caused by injection of basaltic to andesitic recharge magma into the deeper portions of the chamber. Results of modeling of oxygen diffusion in quartz indicates that hydrothermal exchange in quartz occurred over a period of ∼1000–63,000 years. Models also suggest that the onset of melting of the granitoids occurred a minimum of ∼10–200 years prior to the Mazama climactic eruption, an inference which is broadly consistent with results for magnetite homogenization and for Zr diffusion in melt previously reported by others.Uranium-thorium isotope compositions of most granitoid blocks are in 238U excess, and are in agreement with a 238U enriched array previously measured for volcanic rocks at Mt. Mazama. Uranium excess in the granitoids is likely due to enrichment via hydrothermal circulation, given their low δ18O values. The sample with the

Rock fragmentation

Energy Technology Data Exchange (ETDEWEB)

Brown, W.S.; Green, S.J.; Hakala, W.W.; Hustrulid, W.A.; Maurer, W.C. (eds.)

1976-01-01

Experts in rock mechanics, mining, excavation, drilling, tunneling and use of underground space met to discuss the relative merits of a wide variety of rock fragmentation schemes. Information is presented on novel rock fracturing techniques; tunneling using electron beams, thermocorer, electric spark drills, water jets, and diamond drills; and rock fracturing research needs for mining and underground construction. (LCL)

A review of numerical techniques approaching microstructures of crystalline rocks

Science.gov (United States)

Zhang, Yahui; Wong, Louis Ngai Yuen

2018-06-01

The macro-mechanical behavior of crystalline rocks including strength, deformability and failure pattern are dominantly influenced by their grain-scale structures. Numerical technique is commonly used to assist understanding the complicated mechanisms from a microscopic perspective. Each numerical method has its respective strengths and limitations. This review paper elucidates how numerical techniques take geometrical aspects of the grain into consideration. Four categories of numerical methods are examined: particle-based methods, block-based methods, grain-based methods, and node-based methods. Focusing on the grain-scale characters, specific relevant issues including increasing complexity of micro-structure, deformation and breakage of model elements, fracturing and fragmentation process are described in more detail. Therefore, the intrinsic capabilities and limitations of different numerical approaches in terms of accounting for the micro-mechanics of crystalline rocks and their phenomenal mechanical behavior are explicitly presented.

Aespoe Hard Rock Laboratory. Annual report 1998

International Nuclear Information System (INIS)

1999-05-01

The Aespoe Hard Rock Laboratory has been constructed as part of the preparations for the deep geological repository for spent nuclear fuel in Sweden. The Tracer Retention Understanding Experiments are made to gain a better understanding of radionuclide retention in the rock and create confidence in the radionuclide transport models that are intended to be used in the licensing of a deep repository for spent fuel. Experiments with sorbing radioactive tracers have been completed in a single fracture over a distance of about 5 m. These tests have been subject to blind predictions by the Aespoe Task Force on groundwater flow and transports of solutes. Breakthrough of sorbing tracers in the TRUE-I tests is retarded more strongly than would be expected based on laboratory data alone. Results are consistent for all tracers and tracer tests. The main objective of the TRUE Block Scale Experiment is to increase understanding and our ability to predict tracer transport in a fracture network over spatial scales of 10 to 50 m. The total duration of the project is approximately 4.5 years with a scheduled finish at the end of the year 2000. The REX project focuses on the reduction of oxygen in a repository after closure due to reactions with rock minerals and microbial activity. Results show that oxygen is consumed within a few days both for the field and laboratory experiments. The project Degassing of groundwater and two phase flow was initiated to improve our understanding of observations of hydraulic conditions made in drifts and interpretation of experiments performed close to drifts. The analysis performed so far shows that the experimentally observed flow reductions indeed are consistent with the degassing hypothesis. The Prototype Repository Test is focused on testing and demonstrating repository system function. A full-scale prototype including six deposition holes with canisters with electric heaters surrounded by highly compacted bentonite will be built and

Aespoe Hard Rock Laboratory. Annual report 1998

Energy Technology Data Exchange (ETDEWEB)

NONE

1999-05-01

The Aespoe Hard Rock Laboratory has been constructed as part of the preparations for the deep geological repository for spent nuclear fuel in Sweden. The Tracer Retention Understanding Experiments are made to gain a better understanding of radionuclide retention in the rock and create confidence in the radionuclide transport models that are intended to be used in the licensing of a deep repository for spent fuel. Experiments with sorbing radioactive tracers have been completed in a single fracture over a distance of about 5 m. These tests have been subject to blind predictions by the Aespoe Task Force on groundwater flow and transports of solutes. Breakthrough of sorbing tracers in the TRUE-I tests is retarded more strongly than would be expected based on laboratory data alone. Results are consistent for all tracers and tracer tests. The main objective of the TRUE Block Scale Experiment is to increase understanding and our ability to predict tracer transport in a fracture network over spatial scales of 10 to 50 m. The total duration of the project is approximately 4.5 years with a scheduled finish at the end of the year 2000. The REX project focuses on the reduction of oxygen in a repository after closure due to reactions with rock minerals and microbial activity. Results show that oxygen is consumed within a few days both for the field and laboratory experiments. The project Degassing of groundwater and two phase flow was initiated to improve our understanding of observations of hydraulic conditions made in drifts and interpretation of experiments performed close to drifts. The analysis performed so far shows that the experimentally observed flow reductions indeed are consistent with the degassing hypothesis. The Prototype Repository Test is focused on testing and demonstrating repository system function. A full-scale prototype including six deposition holes with canisters with electric heaters surrounded by highly compacted bentonite will be built and

Comparative measurements of proton dechanneling in silicon under channeling, blocking and double alignment conditions