Evolution of an interfacial crack on the concrete-embankment boundary

Energy Technology Data Exchange (ETDEWEB)

Glascoe, Lee [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Antoun, Tarabay [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Kanarska, Yuliya [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Lomove, Ilya [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Hall, Robert [US Army Corps of Engineers, Washington, DC (United States); Woodson, Stan [US Army Corps of Engineers, Washington, DC (United States); Smith, Jerrell [US Army Corps of Engineers, Washington, DC (United States); Ezzedine, Souheil [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

2013-07-10

Failure of a dam can have subtle beginnings. A small crack or dislocation at the interface of the concrete dam and the surrounding embankment soil initiated by, for example, a seismic or an explosive event can lead to a catastrophic failure of the dam. The dam may ‘self-rehabilitate’ if a properly designed granular filter is engineered around the embankment. Currently, the design criteria for such filters have only been based on experimental studies. We demonstrate the numerical prediction of filter effectiveness at the soil grain scale. This joint LLNL-ERDC basic research project, funded by the Department of Homeland Security’s Science and Technology Directorate (DHS S&T), consists of validating advanced high performance computer simulations of soil erosion and transport of grain- and dam-scale models to detailed centrifuge and soil erosion tests. Validated computer predictions highlight that a resilient filter is consistent with the current design specifications for dam filters. These predictive simulations, unlike the design specifications, can be used to assess filter success or failure under different soil or loading conditions and can lead to meaningful estimates of the timing and nature of full-scale dam failure.

Application of thermometric methods for detection and characterization of leakages in embankment dams

Energy Technology Data Exchange (ETDEWEB)

Beck, Y.L.; Cunat, P.; Fry, J.J. [EDF, Grenoble (France); Faure, Y.H. [LTHE, Saint Martin d' Heres (France)

2010-07-01

The earliest possible detection of leakages in dikes is essential. Distributed temperature measurements using fibre optics allow the monitoring of large sections of the dike with a high spatial and temperature resolution. This paper presented the application of thermometric methods for detection and characterization of leakage in embankment dams. After a brief description of the system used, its application on a controlled experimental site and an EDF industrial site instrumented with fibre optics was presented. The instrumentation is complemented by installation of local temperature and pressure sensors in the piezometers for complete characterization of the detected leakages. The analysis of the results data clearly allowed detecting the leakages. The vertical location, intensity and location of the detected leakages were also identified. It was found that thermometry is potentially very powerful for detecting leaks and as a diagnostic tool.

Grouting design for slope stability of kedung uling earthfill dam

Directory of Open Access Journals (Sweden)

Najib

2018-01-01

Full Text Available Kedung Uling earthfill dam locates at Wonogiri Regency, Central Java, Indonesia. The dam encountered sliding and settlement at the embankment wall. To minimize sliding and settlement and to optimize the dam, both field investigation and laboratory tests have been proceeded for slope stability analysis and remedial embankment wall. Soil and rock investigation around the dam, which is followed by 10 core drillings, have been conducted. Laboratory tests such as direct shear and index properties have also been carried on. The results were further used for dam slope stability model using slide 6.0 and were used to analyzed factor of safety (FS of Kedunguling dam. 10 conditions of dam were simulated and strengthening body of dam with grouting was designed. The results showed two conditions, which are condition of maximum water level with and without earthquake at downstream, were unsatisfy Indonesia National Standard (SNI for building and infrastructure. These conditions can be managed by using grouting for increasing stabilization of embankment wall. By setting up grouting, factor of safety increases and meet the SNI standard requirement.

Advances in crosshole seismic instrumentation for dam safety monitoring

Energy Technology Data Exchange (ETDEWEB)

Anderlini, G.; Anderlini, C. [BC Hydro, Burnaby, BC (Canada); Taylor, R. [RST Instruments Ltd., Coquitlam, BC (Canada)

2009-07-01

Since 1996, crosshole shear wave velocity measurements have been performed annually at the WAC Bennett Dam in order to monitor the performance of the dam core and integrity of the 1997 sinkhole repairs. As the testing showed to be responsive to embankment conditions and capable of detecting subtle changes, the testing program was expanded to include the development of an electrical shear wave source capable of carrying out crosshole seismic testing in Mica and Revelstoke Dams over distances of 100 metres and depths of 250 metres. This paper discussed the development and capabilities of the crosshole seismic instrumentation and presented preliminary results obtained during initial testing. Specific topics that were discussed included conventional crosshole seismic equipment; design basics; description of new crosshole seismic equipment; and automated in-situ crosshole seismic system (ACSS) system description and operation. It was concluded that the ACSS and accompanying electrical shear wave source, developed as part of the project, has advanced and improved on traditional crosshole seismic equipment. 7 refs., 9 figs.

Advances in crosshole seismic measurements to characterise and monitor the internal condition of embankment dams

Energy Technology Data Exchange (ETDEWEB)

Vazinkhoo, S.; Anderlini, C.; Gaffran, P. [BC Hydro, Burnaby, BC (Canada); Jefferies, M. [Golder Associates Ltd., Vancouver, BC (Canada)

2008-07-01

The WAC Bennett Dam Sinkhole investigation project was launched in June 1996 in British Columbia following the discovery of a sinkhole. This paper provided information on crosshole seismic velocity testing that was conducted at the WAC Bennett Dam, along with background information on the methods developed to interpret the results of crosshole seismic testing that has been conducted on an annual basis at the dam since 1996. Additional laboratory and field testing conducted at the Mica and Revelstoke dams were also reviewed with particular focus on how the results have improved the interpretation and assessment methods. This paper described the laboratory testing program which consisted of bender element tests, in which shear wave velocities were measured under controlled void ratio, stress and fines content conditions, and critical state triaxial tests to determine the Critical State Lines (CSLs). It was concluded that crosshole seismic shear wave velocity measurements have proven to be a very useful tool for monitoring void ratio and stress conditions at the WAC Bennett Dam and continue to be employed at the dam on an annual basis. Variations in shear wave velocity can be correlated to local construction features at the WAC Bennett and other BC Hydro dams. 16 refs., 4 tabs., 7 figs.

Dynamic analyzing procedures adopted for concrete-faced rockfill dams in Turkey

Energy Technology Data Exchange (ETDEWEB)

Tosun, H. [Dam Safety Association, Ankara (Turkey); Tosun, K. [TVT Hydrotech Bureau, Ankara (Turkey)

2008-07-01

A concrete faced rockfill dam (CFRD) has some advantages compared to other embankment types. The advantages include minimal settlement problems through the use of compacted rockfill; increased overall stability of the dam since the water pressure acts on the upstream face; and pore water pressure does not develop in the rockfill zone if it is well designed and constructed. It is thought that well-compacted CFRD has a high resistance to earthquake loading, as based on several factors including acceptable past performance of similar dams. While numerical solutions performed for this type of dams indicate that it is as safe as other embankment dams, their behavior is still questionable when they are subjected to severe seismic loading. This paper outlined the key principals of the dynamic analyzing method adopted for CFRDs in Turkey and summarized the practice of CFRDs with heights ranging from 54 to 135 metres throughout the country. Two-dimensional finite element models were executed to estimate displacements on the crest under the different loadings of earthquake. Dams that were discussed included the Kurtun Dam, the Torul Dam, the Atasu Dam, the Dim Dam, the Gordes Dam, and the Marmaris Dam. The paper also discussed the limitation about permanent settlement provided in the national dam specification and introduced the results obtained from a case study of the Pamukluk Dam located in southern Turkey. Geology and geotechnics as well as the embankment details and materials were discussed. The case study also summarized the selection of seismic parameters and dynamic analyses. 35 refs., 1 tab., 8 figs.

Odelouca Dam Construction: Numerical Analysis

OpenAIRE

Brito, A.; Maranha, J. R.; Caldeira, L.

2012-01-01

Odelouca dam is an embankment dam, with 76 m height, recently constructed in the south of Portugal. It is zoned with a core consisting of colluvial and residual schist soil and with soil-rockfill mixtures making up the shells (weathered schist with a significant fraction of coarse sized particles). This paper presents a numerical analysis of Odelouca Dam`s construction. The material con-stants of the soil model used are determined from a comprehensive testing programme carried out in the C...

Effect of water on the triaxial response under monotonic loading of asphalt concrete used in dams

Science.gov (United States)

Gaxiola Hernández, Alberto; Ossa López, Alexandra

2018-01-01

Embankment dams with asphalt concrete cores have been constructed on practically all continents with satisfactory results. Nowadays many advantages, such as the mechanical strength, are known that makes asphalt concrete a competitive alternative for the construction of the impervious elements of dams. However, the current available information does not describe the effect of prolonged contact between asphalt concrete and water on the structure of an embankment dam. In this research cylindrical asphalt concrete specimens with a void content similar to that used in impervious barriers of dams were fabricated and submerged in water for a prolonged period to simulate the conditions experienced by asphalt concrete placed inside an embankment dam as its core material. Subsequently, triaxial compression tests were conducted on the specimens. The results indicated that the asphalt concrete exhibited a reduction in strength because of the saturation process to which the material was subjected. However, no changes were observed in the mechanical response to prolonged contact with water for periods of up to 12 months.

Numerical modelling for stability of tailings dams

OpenAIRE

Auchar, Muhammad; Mattsson, Hans; Knutsson, Sven

2013-01-01

A tailings dam is a large embankment structure that is constructed to store the waste from the mining industry. Stability problems may occur in a tailings dam due to factors such as quick rate of raising, internal erosion and liquefaction. The failure of a tailings dam may cause loss of human life and environmental degradation. Tailings Dams must not only be stable during the time the tailings storage facility is in operation, but also long time after the mine is closed. In Sweden, the licens...

Measurement of peak discharge at dams by indirect methods

Science.gov (United States)

Hulsing, Harry

1967-01-01

This chapter describes procedures for measuring peak discharges using dams, weirs, and embankments. Field and office procedures limited to this method are described. Discharge coefficients and formulas are given for three general classes of weirs-sharp-crested, broad-crested, and round-crested-and for highway embankments and weirs of unusual shape. The effects of submergence are defined for most forms.

ESTIMATION OF FILTRATION CAPACITY OF POSTFLOTATION TAILINGS EMBEDDED IN DAMS OF TAILINGS DEPOSITION SITES

Directory of Open Access Journals (Sweden)

Wojciech Tschuschke

2015-10-01

Full Text Available Construction of very big mine tailings deposition sites, such as postflotation tailings ponds, is a complicated engineering task, in which several technical and environmental problems need to be solved. Designing, construction and operation of such an object applying the monitoring method consists in the verification of design assumptions based on continuous observations. One of the primary tasks of monitoring while the deposition site is being filled with tailings is to control quality of the formed dam embankments, as the structural element of the object responsible for its stability. In order to use material selected from deposited tailings in the construction of dams it is necessary to define grain size and compaction criteria, which directly affect load bearing capacity and deformation of the structure. For this reason main control tests include the analyses of grain size distribution and physical properties of the material embedded in the dams. These data may also be used to estimate filtration capacity of the embankment. A lack of drainage, causing accumulation of water within the embankment, may potentially deteriorate stability conditions. This paper presents the use of empirical formulas, i.e. formulas typically applied to natural soils, to assess permeability coefficient of tailings. A simple empirical formula was also proposed for the estimation of permeability coefficient of tailings based on grain size and compaction parameters determined in routine quality tests of constructed dam embankments.

Study of Dam-break Due to Overtopping of Four Small Dams in the Czech Republic

Directory of Open Access Journals (Sweden)

Zakaraya Alhasan

2015-01-01

Full Text Available Dam-break due to overtopping is one of the most common types of embankment dam failures. During the floods in August 2002 in the Czech Republic, several small dams collapsed due to overtopping. In this paper, an analysis of the dam break process at the Luh, Velký Bělčický, Melín, and Metelský dams breached during the 2002 flood is presented. Comprehensive identification and analysis of the dam shape, properties of dam material and failure scenarios were carried out after the flood event to assemble data for the calibration of a numerical dam break model. A simple one-dimensional mathematical model was proposed for use in dam breach simulation, and a computer code was compiled. The model was calibrated using the field data mentioned above. Comparison of the erodibility parameters gained from the model showed reasonable agreement with the results of other authors.

Climate change and the causes of dam failures in Australia

International Nuclear Information System (INIS)

Lewis, B.

2007-01-01

As a result of poor dam construction methods in Australia and significant droughts occurring over the past 60 years, there is a danger that mistakes made during previous droughts will be repeated. Dams were often built in soils of very low moisture content to ensure a properly compacted bank. As a result of these poor construction methods, the drought years have produced an unusually high number of dam failures. This paper discussed the causes of dam failures such as dispersive clays and defects in associated structures. The discussion on dispersive clays included cracking, piping, tunneling, and slides. Dispersive clays occur in soils whose clay minerals separate into single grains when placed in contact with water and are associated with high soil erodability and their distribution often coincides with the occurrence of erosion gullying, rilling and piping. Dispersive clays in a dam embankment can result in the leaching out of material from the embankment with consequent erosion and failure. Defects in associated structures that were discussed included spillway blockage and outlet pipe blockage. It was concluded that dam failures are seldom due to one particular cause but rather due to one weakness triggering another. It was concluded that failures are difficult and expensive to remedy. 9 refs., 4 figs

Assessment of anomalous seepage conditions in the Opa dam ...

African Journals Online (AJOL)

, dipole-dipole electrical horizontal profiling, spontaneous potential (SP) profiling and magnetic profiling, was carried out along the embankment of the Opa dam located within the campus of the Obafemi Awolowo University, Ile-Ife, Nigeria.

Public safety around dams : Grand River Conservation Authority

Energy Technology Data Exchange (ETDEWEB)

Moore, N [Grand River Conservation Authority, Cambridge, ON (Canada)

2009-07-01

Ontario's Grand River Conservation Authority (GRCA) is a corporate body, through which municipalities, landowners and other organizations work cooperatively to manage the watershed and outdoor recreation. This involves reducing flood damage; improving water quality; providing adequate water supply; protecting natural areas; watershed planning; and environmental education. This presentation discussed public safety issues regarding a dam in the GRCA that is 5 minutes to downtown Brantford; 5 minutes to several elementary and secondary schools; and a popular area for anglers. The city of Brantford owns the east embankment and the Brant conservation area is located on the west embankment. The safeguards included measures to involve the municipality and local police; install better signage; install better fencing; and public education. Increasing public awareness of the dangers surrounding dams was an important point of the presentation. Results included reduced trespassing and greater community awareness. figs.

75 FR 49429 - Metal and Nonmetal Dams

Science.gov (United States)

2010-08-13

... internal water pressures. Pressures beyond a certain level would lead to structural instability. In the 18... foundation and embankment material strengths, and stability analyses to verify that the slopes of the dam..., rationales, benefits to miners, technological and economic feasibility, impact on small mines, and supporting...

Hydrologic design for riprap on embankment slopes

International Nuclear Information System (INIS)

Codell, R.B.

1988-09-01

Waste impoundments for uranium tailings and other hazardous substances are often protected by compacted earth and clay, covered with a layer of loose rock (riprap). The report outlines procedures that could be followed to design riprap to withstand forces caused by runoff resulting from extreme rainfall directly on the embankment. The Probable Maximum Precipitation for very small areas is developed from considerations of severe storms of short duration at mid-latitudes. A two-dimensional finite difference model is then used to calculate the runoff from severe rainfall events. The procedure takes into account flow both beneath and above the rock layer and approximates the concentration in flow which could be caused by a non-level or slumped embankment. The sensitivity to various assumptions, such as the shape and size of the rock, the thickness of the layer, and the shape of the embankment, suggests that peak runoff from an armored slope could be attenuated with proper design. Frictional relationships for complex flow regimes are developed on the basis of flow through rock-filled dams and in mountain streams. These relationships are tested against experimental data collected in laboratory flumes; the tests provide excellent results. The resulting runoff is then used in either the Stephenson or safety factor method to find the stable rock diameter. The rock sizes determined by this procedure for a given flow have been compared with data on the failure of rock layers in experimental flumes, again with excellent results. Computer programs are included for implementing the method. 15 refs., 21 figs., 9 tabs

Japan`s largest composition dam, aiming for harmony with nature. Chubetsu dam; Shizen tono chowa wo mezasu, Nippon ichi no fukugo dam. Chubetsu dam

Energy Technology Data Exchange (ETDEWEB)

Mizushima, T. [Hokkaido Development Bureau, Hokkaido Development Agency, Sapporo (Japan)

1994-08-15

This paper introduces Chubetsu Dam planned with a large-scale embankment having a river bed width of 600 m. Chubetsu Dam is being constructed with such objectives as flood control of Ishikari River, river flow rate maintenance, drinking water supply, irrigation water supply and power generation. The dam site is a gravel bed having a river bed width of 600 m and a maximum foundation rock thickness of 40 m, requiring evaluations as a dam foundation and discussions of water shielding methods. As a result of discussions at the Chubetsu Dam technical discussion committee, the dam type is decided to be a composition dam consisting of a gravity type concrete dam on the left river side and a central core type fill dam using a part of the gravel bed as the foundation on the right river side. A continuous underground wall system is planned to be used for shielding water in the gravel foundation. In discussing the anti-seismic properties, analyses for bank construction and water filling to derive stress and deformation conditions prior to an earthquake and a time-history response analysis to derive conditional changes during the earthquake are performed. According to the results thereof, evaluations are given on the safety by compounding the stress and the acceleration. In plans to improve the surrounding areas, an area will be provided upstream the reservoir where the water level is kept constant to serve as a bird sanctuary. 7 figs.

Dam-break studies for mine tailings impoundments

International Nuclear Information System (INIS)

Jeyapalan, J.K.

1982-01-01

This paper describes simple procedures for performing dam-break analyses. Tailings from dam failures usually liquefy and flow for substantial distances as a viscous fluid. The prediction of the possible extent of flow slide movement is illustrated using two case histories. Topics considered include the flow behavior of liquefied talings, dimensionsless numbers for mine tailings and associated flow regimes, laminar flow, and turbulent flow. The potential inundation regions downstream of mine tailings dams are assessed. It is concluded that instances of flow slides of mine waste embankments indicate that the failure of these structures has considerable potential for damage to life and property in many cases

Dams. Bulletin of the Technical Service of Electric Power and Big Dams; Barrages. Bulletin du Service Technique de l`Energie Electrique et des Grands Barrages

Energy Technology Data Exchange (ETDEWEB)

NONE

1996-12-31

Four papers were selected in this issue of the bulletin of the Technical Service of Electric Power and Big Dams. The first one concerns the `Catastrophe Medicine` congress which took place in Amiens (France) in December 5 to 7 1996 and during which the analysis of experience feedbacks and lessons gained after dam accidents and organisation of emergency plans was discussed. The second one is a report of the conclusions of the decennial and annual inspections of French dams. The third paper describes the reinforcement of the Lavaud-Gelade dam embankment and the last paper reports on the Control Services activities concerning the French dams in operation for the forth quarter of the year 1996. (J.S.)

Interpretation of self-potential data for dam seepage investigations

Energy Technology Data Exchange (ETDEWEB)

Corwin, R.F.; Sheffer, M.R.; Salmon, G. [BC Hydro, Burnaby, BC (Canada)

2007-04-15

This book represents one of a series on the subject of geophysical methods and their use in assessing seepage and internal erosion in embankment dams. This manual facilitates the interpretation of self-potential (SP) data generated by subsurface fluid flow, with an emphasis on dam seepage studies. It is intended for users with a background in geophysics or engineering having a general familiarity with both the SP and direct-current (DC) resistivity methods and their applications. It includes an extensive reference list covering all aspects of available SP interpretation techniques, including qualitative, analytical and numerical methods. Particular emphasis is placed on the use of geometric source analytical modeling methods to evaluate SP anomalies. These methods provide a simple yet efficient means of estimating the location and depth of current sources of observed SP data, which may be linked to fluid flow in the subsurface. The manual is primarily oriented toward embankment dams and earthen structures such as levees and dikes. SP methods have been used to investigate seepage through pervious zones and cracks in concrete and concrete-faced structures. The manual describes the nature of SP fields generated by both uniform and non-uniform dam seepage flow, as well as non-seepage sources of SP variations. These methods enable the study of more complex systems and require a more comprehensive analysis of a given field site. refs., tabs., figs.

Active and passive electrical and seismic time-lapse monitoring of earthen embankments

Science.gov (United States)

Rittgers, Justin Bradley

In this dissertation, I present research involving the application of active and passive geophysical data collection, data assimilation, and inverse modeling for the purpose of earthen embankment infrastructure assessment. Throughout the dissertation, I identify several data characteristics, and several challenges intrinsic to characterization and imaging of earthen embankments and anomalous seepage phenomena, from both a static and time-lapse geophysical monitoring perspective. I begin with the presentation of a field study conducted on a seeping earthen dam, involving static and independent inversions of active tomography data sets, and self-potential modeling of fluid flow within a confined aquifer. Additionally, I present results of active and passive time-lapse geophysical monitoring conducted during two meso-scale laboratory experiments involving the failure and self-healing of embankment filter materials via induced vertical cracking. Identified data signatures and trends, as well as 4D inversion results, are discussed as an underlying motivation for conducting subsequent research. Next, I present a new 4D acoustic emissions source localization algorithm that is applied to passive seismic monitoring data collected during a full-scale embankment failure test. Acoustic emissions localization results are then used to help spatially constrain 4D inversion of collocated self-potential monitoring data. I then turn to time-lapse joint inversion of active tomographic data sets applied to the characterization and monitoring of earthen embankments. Here, I develop a new technique for applying spatiotemporally varying structural joint inversion constraints. The new technique, referred to as Automatic Joint Constraints (AJC), is first demonstrated on a synthetic 2D joint model space, and is then applied to real geophysical monitoring data sets collected during a full-scale earthen embankment piping-failure test. Finally, I discuss some non-technical issues related to

Free flow spillways on loam dams; Deversoirs a ecoulement libre sur des digues en terre

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-12-31

The free flow spillways technique was developed abroad and has been used and developed in France by two research offices and foremen. Dams of this type can have heights of 8 to 20 m and both dams and spillways must fit with special technical characteristics which are described (drainage, joints, reinforcements, wall surface, embankment etc..). The experience of French foremen with this type of dams and spillways is reported. (J.S.)

Computational Aspects of Dam Risk Analysis: Findings and Challenges

Directory of Open Access Journals (Sweden)

Ignacio Escuder-Bueno

2016-09-01

Full Text Available In recent years, risk analysis techniques have proved to be a useful tool to inform dam safety management. This paper summarizes the outcomes of three themes related to dam risk analysis discussed in the Benchmark Workshops organized by the International Commission on Large Dams Technical Committee on “Computational Aspects of Analysis and Design of Dams.” In the 2011 Benchmark Workshop, estimation of the probability of failure of a gravity dam for the sliding failure mode was discussed. Next, in 2013, the discussion focused on the computational challenges of the estimation of consequences in dam risk analysis. Finally, in 2015, the probability of sliding and overtopping in an embankment was analyzed. These Benchmark Workshops have allowed a complete review of numerical aspects for dam risk analysis, showing that risk analysis methods are a very useful tool to analyze the risk of dam systems, including downstream consequence assessments and the uncertainty of structural models.

Numerical analysis of the construction of Odelouca Dam using a Subloading Surface Soil Model

OpenAIRE

Brito, A.; Maranha, J. R.; Caldeira, L.

2014-01-01

Odelouca dam is an embankment dam, with 76 m height, recently constructed in the south of Portugal. It is zoned with a core consisting of colluvial and residual schist soil, and with soil-rockfill mixtures making up the shells (weathered schist with a significant fraction of coarse sized particles). This paper presents a numerical analysis of Odelouca dam construction. In this analysis the explicit finite difference program FLAC is used. An unconventional elastoplastic soil model, a Subloadin...

Deformation performance of Waba Dam

Energy Technology Data Exchange (ETDEWEB)

Salloum, T.; Bhardwaj, V.; Hassan, P. [Ontario Power Generation, Niagara-on-the-Lake, ON (Canada); Cragg, C. [Cragg Consulting Services, Toronto, ON (Canada)

2009-07-01

This paper described the performance of the Waba Dam which is being monitored as part of Ontario Power Generation's Dam Safety Program. It described the deformations that have been observed in this 3600 ft long earthfill dam which lies on marine clay in eastern Ontario. An extensive instrumentation program, including foundation settlement gauges, surface monuments, slope inclinometers, load cells and piezometers has been in effect since the construction of the dam in 1975. Significant settlement has occurred at Waba Dam since its construction. Wide berms were provided upstream and downstream beyond the slopes of the main fill to ensure stability of the dyke on the soft clay foundation and the crest elevations were designed to allow for the expected settlement in the foundation which would be overstressed by the dam loading. Based on current settlements, future settlements are predicted based on Asaoka's method. Inclinometer measurements have shown a foundation lateral spreading of 12 in. The lateral versus vertical deformations were found to be comparable to well behaving embankments reported in the literature. These analyses indicate that Waba Dam is performing well and should continue to perform well into the future. 8 refs., 1 tab., 14 figs.

Internal erosion under spillway rested on an embankment dam

Directory of Open Access Journals (Sweden)

Mohammad Sedghi-Asl

2015-12-01

Full Text Available In this paper we investigate the mechanism of internal erosion caused in the right abutment of the Shahghasem dam’s spillway. Shahghasem dam is an earthen dam located in Yasouj, in southwest of Iran. A significant hole and pipe have been observed in the corner of the right abutment from upstream view. The foundation is Marlstone, which has low cohesion and susceptible for internal erosion and piping in some conditions. Going through details of the design maps has shown that Lane’s criteria for selecting safe dimensions of the seepage control measures have not been considered properly. A series of the supportive walls are designed to attach to the right part of the spillway in order to increase the length of seepage. The pipe route of the erosion should also be grouted with high quality concrete.

Sinkhole remediation at Swinging Bridge Dam

Energy Technology Data Exchange (ETDEWEB)

Jones, A. [Devine Tarbell and Associates, Portland, ME (United States)

2009-07-01

This case history summary described a piping-related sinkhole that occurred after a flood at the Swinging Bridge Dam. The earth-filled embankment dam was constructed using a hydraulic fill technique. A foundation drilling and grouting program was constructed in areas of the dam founded on jointed sandstone and shale. The storage volumes of the reservoir is 32,000 acre-feet. A sinkhole 25 to 300 feet in diameter was observed on May 5, 2005 along the edge of the dam crest. The sinkhole extended to within 10 feet of the reservoir and was separated by a shallow berm of soil and driftwood. Cracking of the crest extended across an area of 180 feet. Operations staff notified the appropriate agencies, implemented a monitoring program, and mobilized construction equipment and sands for use as emergency sinkhole filler. An increase in tailrace turbidity was observed. Historical records for the dam showed significant cracking during the initial filling of the reservoir. Failure modes included increased pore pressures and seepages resulting in the piping of soil along the outside of the dam conduit. Emergency repairs included chemical grouting and weld repairs in the penstocks. A Federal Emergency Management Agency (FEMA) is currently addressing safety issues associated with conduits through dams. 4 refs., 11 figs.

Isotope technique in JPS dam surveillance: its potential

International Nuclear Information System (INIS)

Sabri Hassan

2006-01-01

Controlling seepage is one of the most important requirements for safe dams. Any leakage at an earth embankment may be potentially dangerous since rapid internal erosion may quickly enlarge an initially minor defect. Thus dam owners need to have thorough surveillance programs that can forewarn of impending problems from seepage or other factors influencing the safety of dams. In carrying out dam surveillance works, all possible efforts should be considered and foreseeing the potential of isotope technique, JPS (Department of Irrigation and Drainage, Malaysia) and MINT (Malaysian Institute for Nuclear Technology Research) participated actively in the UNDP/RCA/IAEA program under RAS/8/093 project sponsored by the International Atomic Energy Agency (IAEA). Through these activities, it was noted that the technique demonstrated very promising potentials such as in assisting dam site selections, site investigations, watershed studies, dam and reservoir design, leakage investigations and sediments related issues, the two latter ones being relatively critical during the operational life of the dam. Establishment of baseline isotopic characteristics (or fingerprint), hydrochemistry, electrical conductivity and temperature profiles is underway for all JPS dams to be later utilized in diagnosing seepage related issues it is suggested that application of this technique be extended to other dam owners nationwide. (Author)

Monitoring report of groundwater quality around the Yotsugi mill-tailings dam, Ningyo-toge, Okayama, Japan

International Nuclear Information System (INIS)

Matsumura, Toshihiro; Takeuchi, Akira; Sato, Kazuhiko; Tsurudome, Koji; Tokizawa, Takayuki

1999-08-01

Monitoring of groundwater quality from boreholes around the Yotsugi mill-tailings dam, in the Ningyo-toge Environmental Engineering Center, JNC, have been carried out to estimate extent and quality of contaminated water plume from the mill-tailings pile. In this report, data collected from 1979 to 1998 fiscal year were listed and their spatial and time variation of physicochemical parameters, uranium and radium were also summarized. Additionally, groundwater sampler has been improved and analytical method has been modified. Some results from groundwater quality were; 1. Uranium and radium concentrations were low, although unexpected change was appeared in some borehole. 2. Water table and temperature from boreholes on the left bank of the dam showed drastically change. 3. Electric conductivity and concentrations or various dissolved ions tend to high from the embankment upward, whereas they tend to low from the embankment downward. (author)

Calculating earth dam seepage using HYDRUS software applications

Directory of Open Access Journals (Sweden)

Jakub Nieć

2017-06-01

Full Text Available This paper presents simulations of water seepage within and under the embankment dam of Lake Kowalskie reservoir. The aim of the study was to compare seepage calculation results obtained using analytical and numerical methods. In April 1985, after the first filling of the reservoir to normal storage levels, water leaks was observed at the base of the escarpment, on the air side of the dam. In order to control seepage flow, drainage was performed and additional piezometers installed. To explain the causes of increased pressure in the aquifer under the dam in May 1985 a simplified calculation of filtration was performed. Now, on the basis of archived data from the Department of Hydraulic and Sanitary Engineering using 3D HYDRUS STANDARD software, the conditions of seepage under the dam have been recreated and re-calculated. Piezometric pressure was investigated in three variants of drainage, including drainage before and after modernization.

National Dam Safety Program. Bayman Dam - No Name 381 (MO 20240), Missouri - Kansas City Basin, Jackson County, Missouri. Phase I Inspection Report.

Science.gov (United States)

1978-08-01

broad - crested weir equation and the sharp crested circular... weir equation. Broad - crested weir equation: Q = CLH 1 .5 (C = varies, L = varies, H is the head on weir ). Circular weir equation: Q = C0 2rR (H0 )5 (C0...the toe of the downstream embankment. The spillway inlet is about 25 feet upstream of the crest of the dam. (3) Pertinent physical data are given

Marine environmental intimidation to Sundarbans embankments

Digital Repository Service at National Institute of Oceanography (India)

Mandal, S.

stream_size 7 stream_content_type text/plain stream_name Workshop_Semin_Embank_Sundarban_Related_Issue_2005_105.pdf.txt stream_source_info Workshop_Semin_Embank_Sundarban_Related_Issue_2005_105.pdf.txt Content-Encoding ISO-8859...

Deformation Monitoring and Bathymetry Analyses in Rock-Fill Dams, a Case Study at Ataturk Dam

Science.gov (United States)

Kalkan, Y.; Bilgi, S.

2014-12-01

Turkey has 595 dams constructed between 1936 and 2013 for the purposes of irrigation, flood control, hydroelectric energy and drinking water. A major portion of the dam basins in Turkey are deprived of vegetation and have slope topography on near surrounding area. However, landscaping covered with forest around the dam basin is desirable for erosion control. In fact; the dams, have basins deprived of vegetation, fill up quickly due to sediment transport. Erosion control and forestation are important factors, reducing the sediment, to protect the water basins of the dams and increase the functioning life of the dams. The functioning life of dams is as important as the investment and construction. Nevertheless, in order to provide safety of human life living around, well planned monitoring is essential for dams. Dams are very large and critical structures and they demand the use or application of precise measuring systems. Some basic physical data are very important for assessing the safety and performance of dams. These are movement, water pressure, seepage, reservoir and tail-water elevations, local seismic activities, total pressure, stress and strain, internal concrete temperature, ambient temperature and precipitation. Monitoring is an essential component of the dam after construction and during operation and must en­able the timely detection of any behavior that could deteriorate the dam, potentially result in its shutdown or failure. Considering the time and labor consumed by long-term measurements, processing and analysis of measured data, importance of the small structural motions at regular intervals could be comprehended. This study provides some information, safety and the techniques about the deformation monitoring of the dams, dam safety and related analysis. The case study is the deformation measurements of Atatürk Dam in Turkey which is the 6th largest dam of world considering the filling volume of embankment. Brief information is given about the

4-D imaging of seepage in earthen embankments with time-lapse inversion of self-potential data constrained by acoustic emissions localization

Science.gov (United States)

Rittgers, J. B.; Revil, A.; Planes, T.; Mooney, M. A.; Koelewijn, A. R.

2015-02-01

New methods are required to combine the information contained in the passive electrical and seismic signals to detect, localize and monitor hydromechanical disturbances in porous media. We propose a field experiment showing how passive seismic and electrical data can be combined together to detect a preferential flow path associated with internal erosion in a Earth dam. Continuous passive seismic and electrical (self-potential) monitoring data were recorded during a 7-d full-scale levee (earthen embankment) failure test, conducted in Booneschans, Netherlands in 2012. Spatially coherent acoustic emissions events and the development of a self-potential anomaly, associated with induced concentrated seepage and internal erosion phenomena, were identified and imaged near the downstream toe of the embankment, in an area that subsequently developed a series of concentrated water flows and sand boils, and where liquefaction of the embankment toe eventually developed. We present a new 4-D grid-search algorithm for acoustic emissions localization in both time and space, and the application of the localization results to add spatially varying constraints to time-lapse 3-D modelling of self-potential data in the terms of source current localization. Seismic signal localization results are utilized to build a set of time-invariant yet spatially varying model weights used for the inversion of the self-potential data. Results from the combination of these two passive techniques show results that are more consistent in terms of focused ground water flow with respect to visual observation on the embankment. This approach to geophysical monitoring of earthen embankments provides an improved approach for early detection and imaging of the development of embankment defects associated with concentrated seepage and internal erosion phenomena. The same approach can be used to detect various types of hydromechanical disturbances at larger scales.

Investigation on the Causes of Cracking in Earth Dams (Case study: Mahmood-Abad Earth Dam

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H. Rahimi

2016-09-01

Full Text Available Introduction: Cracking of earth dams is a one of the main threat causes of stability of embankment dams. In this research by modeling of the behavior of an embankment dam and employing conditions of the earthquake, the reasons of cracking were inspected using by modeling of earth dam behavior. Based on the literature, one of the main causes of dam failures is sliding and cracking of the dam structure during earthquake. Localized liquefaction of foundation soils was one of the causes of the observed post-earthquake distress within these dams. Material and Methods: In order to study the causes and the results of crack on earth dams, Mahmoodabad earthen dam with a height of 19 m, is located in Zanjan province, northwest of Iran, which suffered a longitudinal crack on the crest and slight sliding of the upstream slope due to 2001 Avaj earthquake was studied. This dam has faced earthquake two times with an interval of two years. During the first earthquake with the magnitude about 6.6 in Richter scale small longitudinal cracks had created on the crest. The developed cracks had been repaired by injecting the cement and then has been hidden by passing the time. After the second earthquake with the magnitude about 6.5 in Richter scale the hidden cracks had been appeared again and the slight movement of the upper slopes of dam reported. Based on the site investigation and documented information about dam, including maps and parameter data, the behavior of the dam has modeled by using Plaxis as a finite element model. In order to check the accuracy of the design of dam, the stability analysis has been conducted using by Xslope as a limit equilibrium model. The foundation conditions and the Geotechnical properties of the layer beneath the dam has been inspected by open excavation. Results and Discussion: Underground investigation about Geotechnical properties of dam foundation has showed that there is a thin sandy layer confined in alluvium material of the

Technique and the scheme of engineering-seismometric supervision over seismic events on large dams

Energy Technology Data Exchange (ETDEWEB)

Karapetyan, S.; Babayan, T.; Mkrtchyan, G. [National Academy of Sciences of the Republic of Armenia (Armenia). Inst. of Geophysics and Engineering Seismology

2004-07-01

A network of engineering-seismometric monitoring stations have been installed at the Tavshout dam in a seismically active region of Armenia. The 37 meter high embankment dam consists of gravel-pebbles with a core of sandy clay. Recent earthquakes have presented a direct hazard for the dam and its water reservoir. In order to determine the degree of seismic hazard and prevention, it is necessary to study the interaction between the ground and the foundation of the dam. The seismometers were fixed at three points both on the foundation and the ground to obtain information on the whole route of seismic waves and to define the geology based amplification factors using empirical equations. The system of engineering-seismometric observations included a network of seismometric instruments, communications and a recording complex. 4 refs., 14 figs.

Dam safety investigations of the concrete structures of Hugh Keenleyside dam

International Nuclear Information System (INIS)

Hanna, A.W.; Nunn, J.O.H.; Cornish, L.; Northcott, P.

1993-01-01

The Hugh Keenleyside dam is located on the Columbia River in southeastern British Columbia, and impounds Arrow Lakes Reservoir which has a live storage of 8.8 km 3 and drains an area of 36,000 km 2 . It consists of a number of concrete structures, with a total length of 360 m and a maximum height of 58 m, and an earthfill embankment which spans across the original river channel. The 450 m long zoned earthfill dam is founded on pervious alluvium over 150 m deep. It has a sloping impervious core constructed from glacial till which extends 670 m upstream of the dam. This impervious blanket extends over the full width of the reservoir and is connected to the upstream face of the concrete structures. The results of a dam safety study, which was carried out due to the presence of high uplift pressures at some parts of the foundation, and stability concerns, are presented. The investigation concluded that the high uplift pressures were due to a localized defect in the upstream blanket and did not indicate any general deterioration of the blanket. Techniques that were found to be of particular use in the study for defining the source and nature of the foundation defects were: temperature surveys of flows from piezometers, cells and drains; air injection tests; and pressure response testing of cells, piezometers and drains to establish foundation interconnections. The concrete structures met the stability criteria for all load cases considered except for the navigation lock and the low level outlets. 3 refs., 6 figs

Dam-Breach hydrology of the Johnstown flood of 1889-challenging the findings of the 1891 investigation report.

Science.gov (United States)

Coleman, Neil M; Kaktins, Uldis; Wojno, Stephanie

2016-06-01

In 1891 a report was published by an ASCE committee to investigate the cause of the Johnstown flood of 1889. They concluded that changes made to the dam by the South Fork Fishing and Hunting Club did not cause the disaster because the embankment would have been overflowed and breached if the changes were not made. We dispute that conclusion based on hydraulic analyses of the dam as originally built, estimates of the time of concentration and time to peak for the South Fork drainage basin, and reported conditions at the dam and in the watershed. We present a LiDAR-based volume of Lake Conemaugh at the time of dam failure (1.455 × 10(7) m(3)) and hydrographs of flood discharge and lake stage decline. Our analytical approach incorporates the complex shape of this dam breach. More than 65 min would have been needed to drain most of the lake, not the 45 min cited by most sources. Peak flood discharges were likely in the range 7200 to 8970 m(3) s(-1). The original dam design, with a crest ∼0.9 m higher and the added capacity of an auxiliary spillway and five discharge pipes, had a discharge capacity at overtopping more than twice that of the reconstructed dam. A properly rebuilt dam would not have overtopped and would likely have survived the runoff event, thereby saving thousands of lives. We believe the ASCE report represented state-of-the-art for 1891. However, the report contains discrepancies and lapses in key observations, and relied on excessive reservoir inflow estimates. The confidence they expressed that dam failure was inevitable was inconsistent with information available to the committee. Hydrodynamic erosion was a likely culprit in the 1862 dam failure that seriously damaged the embankment. The Club's substandard repair of this earlier breach sowed the seeds of its eventual destruction.

Shear strength of clay and silt embankments.

Science.gov (United States)

2009-09-01

Highway embankment is one of the most common large-scale geotechnical facilities constructed in Ohio. In the past, the design of these embankments was largely based on soil shear strength properties that had been estimated from previously published e...

The use of soil-rock mixtures in dams in Portugal

OpenAIRE

Caldeira, L.; Brito, A.

2010-01-01

Soil-rock mixtures are being used in the construction of dam shells. The measured deformations associated to these materials have been larger than expected. This situation represents new challenges to compaction techniques and their control as well as to the determination of the characteristics of the embankment that results from the compaction method, as those characteristics suffer important changes according to the relative percentage of the existing fractions. For the execution control of...

Discussion on the Safety Factors of Slopes Recommended for Small Dams

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Jan Vrubel

2017-01-01

Full Text Available The design and assessment of the slope stability of small embankment dams is usually not carried out using slope stability calculations but rather by the comparison of proposed or existing dam slopes with those recommended by technical standards or guidelines. Practical experience shows that in many cases the slopes of small dams are steeper than those recommended. However, most of such steeper slopes at existing dams do not exhibit any visible signs of instability, defects or sliding. For the dam owner and also for dam stability engineers, the safety of the slope, expressed e.g. via a factor of safety, is crucial. The aim of this study is to evaluate the safety margin provided by recommended slopes. The factor of safety was evaluated for several dam shape and layout variants via the shear strength reduction method using PLAXIS software. The study covers various dam geometries, dam core and shoulder positions and parameter values of utilised soils. Three load cases were considered: one with a steady state seepage condition and two with different reservoir water level drawdown velocities – standard and critical. As numerous older small dams lack a drainage system, variants with and without a toe drain were assessed. Calculated factors of safety were compared with required values specified by national standards and guidelines.

Stability of embankments over cement deep soil mixing columns

International Nuclear Information System (INIS)

Morilla Moar, P.; Melentijevic, S.

2014-01-01

The deep soil mixing (DSM) is one of the ground improvement methods used for the construction of embankments over soft soils. DSM column-supported embankments are constructed over soft soils to accelerate its construction, improve embankment stability, increase bearing capacity and control of total and differential settlements. There are two traditional design methods, the Japanese (rigid columns) and the scandinavian (soft and semi-rigid columns). Based on Laboratory analysis and numerical analysis these traditional approaches have been questioned by several authors due to its overestimation of the embankment stability considering that the most common failures types are not assumed. This paper presents a brief review of traditional design methods for embankments on DSM columns constructed in soft soils, studies carried out determine the most likely failure types of DSM columns, methods to decrease the overestimation when using limit equilibrium methods and numerical analysis methods that permit detect appropriate failure modes in DSM columns. Finally a case study was assessed using both limited equilibrium and finite element methods which confirmed the overestimation in the factors of safety on embankment stability over DSM columns. (Author)

Langbjorn dam : adaptation for safe discharge of extreme floods

Energy Technology Data Exchange (ETDEWEB)

Yang, J. [Vattenfall Research and Development, Alvkarleby (Sweden); Ericsson, H.; Gustafsson, A. [SWECO, Stockholm (Sweden); Stenmark, M. [Vattenfall Power Consultant, Ludvika (Sweden); Mikaelsson, J. [Vattenfall Nordic Generation, Bispgarden (Sweden)

2007-07-01

The Langbjorn hydropower scheme, composed of an embankment dam with an impervious core of compacted moraine, a spillway section and a powerhouse, is located on the Angermanalven River in north Sweden. The scheme was commissioned in 1959 and is owned by Vattenfall. As part of its dam safety program, Vattenfall plans to adapt and refurbish many of its dams to the updated design-flood and dam-safety guidelines. Langbjorn is classified as a high hazard dam, as its updated design flood is 30 per cent higher than the existing spillway capacity. Safety evaluations were conducted for the Langbjorn dam, and, as required by the higher safety standard, there was a need to rebuild the dam, so that the design flood could be safely released without causing failure of the dam. This paper provided information on the Langbjorn hydropower scheme and discussed the planned rebuilding measures. For example, the design flood was accommodated by allowing a temporary raise of the water level by 1.3 metres above the legal retention reservoir level, which required heightening and reinforcement of the dam. Specifically, the paper discussed measures to increase the discharge capacity; handling and control of floating debris; improvement and heightening of impervious core in left and right connecting dam and abutment; measures to increase the stability of the left steep riverbank; and measures to increase stability of the spillway monoliths and the left guide wall. In addition, the paper discussed measures to ensure stability of the downstream stretch of the river bank and increase instrumentation. The paper also presented the results of hydraulic investigations to investigate the risk of erosion downstream of the dam. It was concluded that the dam could discharge the design flood and that the stability of the dam was improved and judged to be satisfactory during all foreseeable conditions. 2 refs., 8 figs.

Analisis Deformasi Vertikal Dan Horisontal Tanah Lunak Di Bawahpiled-Geogrid Supported Embankment

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Adhe Noor Patria

2010-02-01

Full Text Available Soft soil was easily founded in Indonesia. it was a low permeability soil. Constructing building such as embankment, roads on this kind of soil often faced problems. They were long term settlement, long term construction time and consolidation. Some method could be good alternative to overcome these problems such the usage of vertical drains, soil reinforcement, orsoil stabilization. This research carried out numerical simulation on piled-geogrid supported embankment. The simulation used Plaxis version 7.2 software to calculate some iterations. Used in this software as soil parameter input was Mohr-Coulomb Soil Model. Plane strain model was used for floating piles and geogrid. The results showed that the usage of floating piles and geogrid could reduce soil deformation. The reduction in horizontal deformation during contructing embankment were 60 to 68 % for rigid embankment and 80 to 60 % for interface embankment. Meanwhile the reduction in vertical deformation during contructing embankment were 60 to 65 % for rigid embankment and 80 to 65 % for interface embankment..

Characteristics of Wind Velocity and Temperature Change Near an Escarpment-Shaped Road Embankment

Directory of Open Access Journals (Sweden)

Young-Moon Kim

2014-01-01

Full Text Available Artificial structures such as embankments built during the construction of highways influence the surrounding airflow. Various types of damage can occur due to changes in the wind velocity and temperature around highway embankments. However, no study has accurately measured micrometeorological changes (wind velocity and temperature due to embankments. This study conducted a wind tunnel test and field measurement to identify changes in wind velocity and temperature before and after the construction of embankments around roads. Changes in wind velocity around an embankment after its construction were found to be influenced by the surrounding wind velocity, wind angle, and the level difference and distance from the embankment. When the level difference from the embankment was large and the distance was up to 3H, the degree of wind velocity declines was found to be large. In changes in reference wind velocities around the embankment, wind velocity increases were not proportional to the rate at which wind velocities declined. The construction of the embankment influenced surrounding temperatures. The degree of temperature change was large in locations with large level differences from the embankment at daybreak and during evening hours when wind velocity changes were small.

Stability of earth dam with a vertical core

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Orekhov Vyacheslav Valentinovich

2016-01-01

Full Text Available Earth dam with impervious element in the form of asphaltic concrete core is currently the most promising type of earth dams (due to simple construction technology and universal service properties of asphaltic concrete and is widely used in the world. However, experience in the construction and operation of high dams (above 160 m is not available, and their work is scarcely explored. In this regard, the paper discusses the results of computational prediction of the stress-strain state and stability of a high earth dam (256 m high with the core. The authors considered asphaltic concrete containing 7 % of bitumen as the material of the core. Gravel was considered as the material of resistant prisms. Design characteristics of the rolled asphaltic concrete and gravel were obtained from the processing of the results of triaxial tests. The calculations were performed using finite element method in elastoplastic formulation and basing on the phased construction of the dam and reservoir filling. The research shows, that the work of embankment dam with vertical core during filling of the reservoir is characterized by horizontal displacement of the lower resistant prism in the tailrace and the formation of a hard wedge prism descending along the core in the upper resistant prism. The key issue of the safety assessment is to determine the safety factor of the overall stability of the dam, for calculation of which the destruction of the earth dam is necessary, which can be done by reducing the strength properties of the dam materials. As a results of the calculations, the destruction of the dam occurs with a decrease in the strength characteristics of the materials of the dam by 2.5 times. The dam stability depends on the stability of the lower resistant prism. The destruction of its slope occurs on the classical circular-cylindrical surface. The presence of a potential collapse surface in the upper resistant prism (on the edges of the descending wedge does

Impact of Geotechnical Factors on the Safety of Low Embankment Dams From the Perspective of Technical and Safety Supervision

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Kasana Andrej

2015-03-01

Full Text Available Our research deals with a broad spectrum of problems concerning the variability of geotechnical factors and their influence on the safety of the biggest group of dam constructions in Slovakia, i.e., low earthfill dams. Its specific aim is the observation of their risk factors by using our experience and knowledge gained while working in the sector of technical and safety supervision. To achieve the aims of a research thesis, we analyzed 39 low earthfill dams. We performed observations and documented their conditions with the aim of clarifying the risk factors. After an analysis of the information materials that characterize dams and after a statistical analysis of the measurement results in situ, including measurements from technical and safety supervision databases, we performed an analysis by using mathematical modeling to evaluate the safety of the dam constructions. Out of the total number of 39 dam constructions, an analysis of the stability of the dam slopes was performed on 37 dams, and deformation problems were analyzed on 28 of the dams. Filtration problems were analyzed at 26 dams, and a complete evaluation of the intensity of filtration movements was performed on 19 of the constructions.

Cooling permafrost embankment by enhancing oriented heat conduction in asphalt pavement

International Nuclear Information System (INIS)

Yinfei, Du; Shengyue, Wang; Shuangjie, Wang; Jianbing, Chen

2016-01-01

Highlights: • Solar radiation heat was prevented from entering the embankment in summer. • The downward heat transfer efficiency in asphalt pavement and embankment reduced. • The net heat accumulation in the embankment decreased. - Abstract: In this paper, a new method was proposed to decrease the heat accumulation in permafrost embankment by controlling an oriented heat transfer in asphalt pavement. Two highly oriented heat-induced structures, named G-OHIS (only gradient thermal conductivity) and G+R-OHIS (combined gradient thermal conductivity and heat reflective layer), were designed by using two indexes of summertime daily heat absorption and annual net heat accumulation on the top of embankment. The results showed that the heat absorptions on the top of embankments of the G-OHIS and G+R-OHIS in summer decreased by 9.9% and 23.2% respectively. The annual net heat accumulation on the top of embankment decreased by 6.2% for the G-OHIS and 37.9% for the G+R-OHIS. Moreover, the summertime mean daily temperatures on the top of embankments of the G-OHIS and G+R-OHIS reduced by 0.74 °C and 1.66 °C respectively. The annual temperature difference on the top of embankment reduced by 1.07 °C for the G-OHIS and 1.96 °C for the G+R-OHIS. The effectiveness of the G-OHIS in reducing pavement temperature was validated by an indoor irradiation test. It is expected to reduce permafrost thawing and other pavement distresses caused by permafrost thawing by controlling an oriented heat transfer in asphalt pavement.

Railway embankments as new habitat for pollinators in an agricultural landscape.

Science.gov (United States)

Moroń, Dawid; Skórka, Piotr; Lenda, Magdalena; Rożej-Pabijan, Elżbieta; Wantuch, Marta; Kajzer-Bonk, Joanna; Celary, Waldemar; Mielczarek, Łukasz Emil; Tryjanowski, Piotr

2014-01-01

Pollinating insect populations, essential for maintaining wild plant diversity and agricultural productivity, rely on (semi)natural habitats. An increasing human population is encroaching upon and deteriorating pollinator habitats. Thus the population persistence of pollinating insects and their associated ecosystem services may depend upon on man-made novel habitats; however, their importance for ecosystem services is barely understood. We tested if man-made infrastructure (railway embankments) in an agricultural landscape establishes novel habitats that support large populations of pollinators (bees, butterflies, hoverflies) when compared to typical habitats for these insects, i.e., semi-natural grasslands. We also identified key environmental factors affecting the species richness and abundance of pollinators on embankments. Species richness and abundance of bees and butterflies were higher for railway embankments than for grasslands. The occurrence of bare (non-vegetated) ground on embankments positively affected bee species richness and abundance, but negatively affected butterfly populations. Species richness and abundance of butterflies positively depended on species richness of native plants on embankments, whereas bee species richness was positively affected by species richness of non-native flowering plants. The density of shrubs on embankments negatively affected the number of bee species and their abundance. Bee and hoverfly species richness were positively related to wood cover in a landscape surrounding embankments. This is the first study showing that railway embankments constitute valuable habitat for the conservation of pollinators in farmland. Specific conservation strategies involving embankments should focus on preventing habitat deterioration due to encroachment of dense shrubs and maintaining grassland vegetation with patches of bare ground.

Railway embankments as new habitat for pollinators in an agricultural landscape.

Directory of Open Access Journals (Sweden)

Dawid Moroń

Full Text Available Pollinating insect populations, essential for maintaining wild plant diversity and agricultural productivity, rely on (seminatural habitats. An increasing human population is encroaching upon and deteriorating pollinator habitats. Thus the population persistence of pollinating insects and their associated ecosystem services may depend upon on man-made novel habitats; however, their importance for ecosystem services is barely understood. We tested if man-made infrastructure (railway embankments in an agricultural landscape establishes novel habitats that support large populations of pollinators (bees, butterflies, hoverflies when compared to typical habitats for these insects, i.e., semi-natural grasslands. We also identified key environmental factors affecting the species richness and abundance of pollinators on embankments. Species richness and abundance of bees and butterflies were higher for railway embankments than for grasslands. The occurrence of bare (non-vegetated ground on embankments positively affected bee species richness and abundance, but negatively affected butterfly populations. Species richness and abundance of butterflies positively depended on species richness of native plants on embankments, whereas bee species richness was positively affected by species richness of non-native flowering plants. The density of shrubs on embankments negatively affected the number of bee species and their abundance. Bee and hoverfly species richness were positively related to wood cover in a landscape surrounding embankments. This is the first study showing that railway embankments constitute valuable habitat for the conservation of pollinators in farmland. Specific conservation strategies involving embankments should focus on preventing habitat deterioration due to encroachment of dense shrubs and maintaining grassland vegetation with patches of bare ground.

Deformation behavior and load limits of asphaltic concrete under the conditions of cores in embankment dams; Deformationsverhalten und Belastungsgrenzen des Asphaltbetons unter den Bedingungen von Staudammkerndichtungen

Energy Technology Data Exchange (ETDEWEB)

Mueller, U.

1998-12-31

Based on the analysis of existing dams with asphaltic diaphragm and investigations in the three-phase-system of asphaltic concrete a recipe for the composition of asphaltic cores is recommended. For the construction, rest and operating period of an embankment dam the load and the reaction of the asphaltic concrete cores as well as the appearing stress and deformations are described. Extensive material testings have been performed and at 41 asphaltic concrete specimens triaxial stress controlled pressure and creeping tests have been carried out. The evaluation of the triaxial tests led to proportions of the main stress and deformation limits as criteria of breaking. Under application of the standard equation for nonlinear viscoelastic element-laws a rheonom element formulation was developed from the experiment data and transformed into its differential form. With this approach the stress and deformation behavior of watertight asphaltic diaphragm can be precalculated for a period up to 10 years. The applicability of this approach, which can be also used within FE-calculations as well, is illustrated in four examples. (orig.) [Deutsch] Nach der Analyse bestehender Staudaemme mit Asphaltbetonkerndichtung und Untersuchungen zum Dreiphasensystem Asphaltbeton wird eine Rezepturempfehlung fuer den Asphaltkerndichtungsbau aufgestellt. Fuer die Bau-, Ruhe- und Betriebsphase eines Staudammes werden die Beanspruchungen und Reaktionen der Asphaltbetonkerndichtung sowie die auftretenden Spannungen und Verformungen beschrieben. Nach umfangreichen Materialpruefungen sind an 41 Asphaltbetonpruefkoerpern triaxiale spannungsgesteuerte Druck-Kriechversuche durchgefuehrt worden. Die Auswertung der Triaxialversuche ergab ein Grenzhauptspannungsverhaeltnis und Deformationsgrenzen als Bruchkriterien. Unter Verwendung der Standarformulierung fuer nichtlineare viskoelastische Stoffgesetze wurde aus den Versuchsdaten ein rheonomer Stoffansatz entwickelt und in seine differentielle Form

Effectiveness of distributed temperature measurements for early detection of piping in river embankments

Science.gov (United States)

Bersan, Silvia; Koelewijn, André R.; Simonini, Paolo

2018-02-01

Internal erosion is the cause of a significant percentage of failure and incidents involving both dams and river embankments in many countries. In the past 20 years the use of fibre-optic Distributed Temperature Sensing (DTS) in dams has proved to be an effective tool for the detection of leakages and internal erosion. This work investigates the effectiveness of DTS for dike monitoring, focusing on the early detection of backward erosion piping, a mechanism that affects the foundation layer of structures resting on permeable, sandy soils. The paper presents data from a piping test performed on a large-scale experimental dike equipped with a DTS system together with a large number of accompanying sensors. The effect of seepage and piping on the temperature field is analysed, eventually identifying the processes that cause the onset of thermal anomalies around piping channels and thus enable their early detection. Making use of dimensional analysis, the factors that influence this thermal response of a dike foundation are identified. Finally some tools are provided that can be helpful for the design of monitoring systems and for the interpretation of temperature data.

Reliability-based optimization design of geosynthetic reinforced road embankment.

Science.gov (United States)

2014-07-01

Road embankments are typically large earth structures, the construction of which requires for large amounts of competent fill soil. In order to limit costs, the utilization of geosynthetics in road embankments allows for construction of steep slopes ...

Assessment of metal retention in newly constructed highway embankments.

Science.gov (United States)

Werkenthin, Moritz; Kluge, Björn; Wessolek, Gerd

2016-12-01

Newly constructed embankments should provide both a specific bearing capacity to enable trafficability in emergency cases and a sufficient pollutant retention capacity to protect the groundwater. A number of lysimeters were installed along the A115 highway to determine total and dissolved metal concentrations in road runoff and in the soil solution of newly constructed embankments. Dissolved concentrations in soil solution of the embankments did not exceed the trigger values of the German legislation. Depending on the metal, total concentrations in soil solution were more than twice as high as dissolved concentrations. The high infiltration rates lead to increased groundwater recharge beneath the embankments (up to 4100 mm a -1 ). Although metal concentrations were not problematic from the legislators' point of view, the elevated infiltration rates beside the road facilitated the transfer of high metal loads into deeper soil layers and potentially into the groundwater as well.

Assessment of Susceptibility to Liquefaction of Saturated Road Embankment Subjected to Dynamic Loads

Science.gov (United States)

Borowiec, Anna; Maciejewski, Krzysztof

2014-03-01

Liquefaction has always been intensely studied in parts of the world where earthquakes occur. However, the seismic activity is not the only possible cause of this phenomenon. It may in fact be triggered by some human activities, such as constructing and mining or by rail and road transport. In the paper a road embankment built across a shallow water reservoir is analyzed in terms of susceptibility to liquefaction. Two types of dynamic loadings are considered: first corresponding to an operation of a vibratory roller and second to an earthquake. In order to evaluate a susceptibility of soil to liquefaction, a factor of safety against triggering of liquefaction is used (FSTriggering). It is defined as a ratio of vertical effective stresses to the shear stresses both varying with time. For the structure considered both stresses are obtained using finite element method program, here Plaxis 2D. The plastic behavior of the cohesionless soils is modeled by means of Hardening Soil (HS) constitutive relationship, implemented in Plaxis software. As the stress tensor varies with time during dynamic excitation, the FSTriggering has to be calculated for some particular moment of time when liquefaction is most likely to occur. For the purposes of this paper it is named a critical time and established for reference point at which the pore pressures were traced in time. As a result a factor of safety distribution throughout embankment is generated. For the modeled structure, cyclic point loads (i.e., vibrating roller) present higher risk than earthquake of magnitude 5.4. Explanation why considered structure is less susceptible to earthquake than typical dam could lay in stabilizing and damping influence of water, acting here on both sides of the slope. Analogical procedure is applied to assess liquefaction susceptibility of the road embankment considered but under earthquake excitation. Only the higher water table is considered as it is the most unfavorable. Additionally the

Shear strength of clay and silt embankments : executive summary report.

Science.gov (United States)

2009-11-01

Highway embankments constitute some of the most common geotechnical facilities being constructed by highway and transportation agencies. The design, construction, and field performance of these embankments are great importance to federal and state tr...

The air flow and heat transfer in gravel embankment in permafrost areas

Institute of Scientific and Technical Information of China (English)

JIANG Fan; LIU Shi; WANG Haigang; CHEN Huanzhuo

2004-01-01

A comparative numerical investigation of transient temperature profile and pore-air velocities in horizontal rock block embankments are conducted using the "gravels model", in which the embankment is composed of stones and air, and the "porous media model" respectively. As the velocities from the "gravels model" directly reflect the true flow of air and winter-time convection, in this paper it can be concluded that computational results from the "gravels model"are superior to the "porous media model". In addition, the "gravels model" has the advantages of reflecting the effect of the dimensions and collocation of gravels upon the temperature fields.Therefore, the computation of the gravels embankment is mainly based on the gravels model.Simulation results show that in summer, a clockwise circulation of the pore-air extends throughout most of the embankment. However its motion is very weak that results in relatively straight horizontal isotherm lines. And heat transfer is mainly maintained through conduction. But in winter, the pore-air velocities are higher and multiple vortexes are formed in the embankment.Natural convection then becomes the dominant influence on the isotherm shapes within the embankment. The isotherms are complex and alternative upward and downward flowing plumes exist. The winter-time convection can further reduce the temperature of the foundation soil beneath the gravel embankment. In addition, the effects of the gravel dimensions within the embankment have been analyzed and compared in the gravels model. It shows that in winter, large stones, e.g. 200 mm, lead to stronger vortexes than those of small stones, say 60 mm. Consequently, the zone of low-temperature beneath the large-stone embankment extends deeper into the ground.

Ecohydrology of an Embanked Lowland UK River Meadow and the Effects of Embankment Removal

Science.gov (United States)

Clilverd, H.; Thompson, J.; Sayer, C.; Heppell, K.; Axmacher, J.

2012-12-01

Pristine riparian and floodplain ecosystems are in a state of dynamic balance due to the regular floods that continuously reshape river channels and their banks, and transport water, sediment and nutrients onto the floodplain. However, the natural flow regime of many rivers has been altered by channelization and artificial embankments designed to protect agricultural and urban developments from flooding. This has had a lasting impact on the hydrological characteristics of floodplain ecosystems and the biological communities that inhabit them. Floodplain restoration, through embankment removal and the reconfiguration of river channels, is now being increasingly employed to re-establish river-floodplain connections and assist the recovery of lost or declining species. In order to manage a river restoration site for plant biodiversity, it is necessary to understand the physical and nutritional status of the root environment. We conducted fine scale (10 × 10 m) botanical and chemical sampling on a 3 ha embanked grassland meadow in Norfolk (Eastern England) and assessed the spatial pattern of plant communities in relation to soil physicochemical conditions. Continuous measurements of groundwater depth and river stage were collectively used to determine changes in the hydrological regime following embankment-removal. Prior to the restoration the meadow plant community was dominated by Holcus lanatus, Ranunculus repens and Agrostis stolonifera. Species richness was fairly low (mean: 8 spp. per m2), and indices of alpha-diversity suggest low heterogeneity of the plant assemblages (mean values for Shannon's Diversity and 1/Simpson's Diversity = 1.4 and 3.4, respectively). Top soils were moderately fertile, with mean respective Olsen P and plant available potassium concentrations of 9.1 mg P kg-1and 1.6 mg K+g-1. Plant available ammonium and nitrate concentrations were on average 31.7 mg NH4+-N kg-1 and 2.8 mg NO3--N kg-1, respectively. River water was enriched in nitrate

Study of a railway embankment reinforced with jute tassels

Indian Academy of Sciences (India)

Embankment; models (physical); soil reinforcement; jute tassel; slope ... Because of high tensile strength of vetiver grass roots, they act like soil .... All the joints are glued as well as reinforced with steel angles and .... slipping, it is nailed to the top of the embankment by several 25.4 mm iron ... The cables can yield in ten-.

Development of a Test Cell to Evaluate Embankment Infiltration

International Nuclear Information System (INIS)

Orton, T. L.

2002-01-01

Envirocare of Utah, Inc. (Envirocare) has developed and constructed a test pad to evaluate potential infiltration through the designed cover system over the low-level radioactive waste disposal embankments incorporated at the facility. The general design of the test pad follows the recommendations set forth in the Alternative Cover Assessment Program (ACAP) that is currently funded by the U.S. Environmental Protection Agency (EPA) to assess potential alternatives to conventional landfill cover designs. The bulk of the test pad is below grade with dimensions approximately 16 feet wide by 28 feet long. The base of the test pad is a lysimeter built to the same dimensions as compliance lysimeters within the disposal embankments at Envirocare. The lysimeter collects all liquids to a single low point and directs the liquids through monitoring instruments within a manhole outside the test pad. The lysimeter is constructed to simulate the ''top of waste'' condition in Envirocare's embankments; consequently, the top of the lysimeter is sloped at an angle of approximately 2.8 percent, the design top slope of the embankment. A replica of the embankment cover is constructed directly above the lysimeter. This cover is constructed exactly the same as final cover is constructed upon the waste disposal embankments, utilizing the same QA/QC measures. Permanent monitoring equipment has been placed during construction at specific intervals throughout the test pad. Monitoring equipment consists of water content reflectometers (WCRs), matric water potential sensors (heat dissipation units; HDUs), and temperature probes. The monitoring equipment provides cross-sectional data of the moisture content and temperatures throughout the constructed cover. Additionally, surface water runoff is collected through a drainage trough and measured in order to perform a water balance over the entire test pad. To aid in the assessment, data collected from the site meteorological stat ion will be used

Experimental study on rapid embankment construction methods

International Nuclear Information System (INIS)

Hirano, Hideaki; Egawa, Kikuji; Hyodo, Kazuya; Kannoto, Yasuo; Sekimoto, Tsuyoshi; Kobayashi, Kokichi.

1982-01-01

In the construction of a thermal or nuclear power plant in a coastal area, shorter embankment construction period has come to be called for recently. This tendency is remarkable where construction period is limited due to meteorological or sea conditions. To meet this requirement, the authors have been conducting basic experimental studies on two methods for the rapid execution of embankment construction, that is, Steel Plate Cellular Bulkhead Embedding Method and Ship Hull Caisson Method. This paper presents an outline of the results of the experimental study on these two methods. (author)

Tailings dams stability analysis using numerical modelling of geotechnical and geophysical data

Science.gov (United States)

Mihai, S.; Zlagnean, M.; Oancea, I.; Petrescu, A.

2009-04-01

Methods for monitoring seepage and detecting internal erosion are essential for the safety evaluation of embankment dams. Internal erosion is one of the major reasons for embankment dam failures, and there are thousands of large tailings dams and waste-rock dumps in the world that may pe considered as hotspots for environmental impact. In this research the geophysical survey works were performed on Cetatuia 2 tailings dam. Electrical resistivity imaging (ERI) method was able to detect spatially anomalous zones inside the embankment dam. These anomalies are the results of internal erosion phenomena which may progressing inside the dam and is difficult to detect by conventional methods. Data aquired by geophysical survey together with their interpretations were used in the numerical model for slope stability assessment. The final results show us the structural weakness induced by the presence of internal erosion elements especially for seismic loading case. This research methodology may be also available for tailings dam monitoring purposes. Electrical Rezistivity Imaging (ERI) was performed on Cetatuia 2 dam at the Uranium Milling Plant Feldioara, in order to map areas with lateral and vertical changes in resistivity. The electrodes are connected to an automated computer operated switch box that selects the 4 electrodes to be used. A computer controls the switch box and the measuring device, and runs a program that selects the electrodes, makes the measurement, and stores the measurement. For inversion processing procedures was used Res2Din software. The measured resistivity were plotted by the pseudo section contouring method. There are five resistivity pseudosections obtained from the Cetatuia 2 tailings dam during the october 2007 measurements. Four transversal profiles trans1 to trans4 are perpendicular to the berms and the longitudinal one long1 is placed along dam's crest. The high resistivities near the berms surfaces corresponds to unsaturated fill materials

The Impact of Vegetative Slope on Water Flow and Pollutant Transport through Embankments

Directory of Open Access Journals (Sweden)

Liting Sheng

2017-06-01

Full Text Available Embankments are common structures along rivers or lakes in riparian zones in plain areas. They should have natural slopes instead of slopes covered by concrete or other hard materials, in order to rebuild sustainable ecosystems for riparian zones. This study was conducted to evaluate the effects of vegetative slopes on water flow and pollutant transport through the embankments. Three embankments with different slope treatments (a bare slope, a slope covered in centipede grass, a slope covered in tall fescue were examined, and three inflow applications of pollute water with different concentration of total nitrogen (TN and total phosphorus (TP used to simulate different agricultural non-point pollution levels. The results showed that the water flux rates of the three embankments were relatively stable under all inflow events, and almost all values were higher than 80%. The embankments with vegetative slopes had better nitrogen removal than the bare slope under all events, and the one with tall fescue slope was best, but the benefits of vegetative slopes decreased with increasing inflow concentration. Moreover, there were no significant differences between the embankments on phosphorus removal, for which the reductions were all high (above 90% with most loads remaining in the front third of embankment bodies. Overall, the embankments with vegetative slopes had positive effects on water exchange and reducing non-point pollutant into lake or river water, which provides a quantitative scientific basis for the actual layout of lakeshores.

Thermal stability analysis under embankment with asphalt pavement and cement pavement in permafrost regions.

Science.gov (United States)

Junwei, Zhang; Jinping, Li; Xiaojuan, Quan

2013-01-01

The permafrost degradation is the fundamental cause generating embankment diseases and pavement diseases in permafrost region while the permafrost degradation is related with temperature. Based on the field monitoring results of ground temperature along G214 Highway in high temperature permafrost regions, both the ground temperatures in superficial layer and the annual average temperatures under the embankment were discussed, respectively, for concrete pavements and asphalt pavements. The maximum depth of temperature field under the embankment for concrete pavements and asphalt pavements was also studied by using the finite element method. The results of numerical analysis indicate that there were remarkable seasonal differences of the ground temperatures in superficial layer between asphalt pavement and concrete pavement. The maximum influencing depth of temperature field under the permafrost embankment for every pavement was under the depth of 8 m. The thawed cores under both embankments have close relation with the maximum thawed depth, the embankment height, and the service time. The effective measurements will be proposed to keep the thermal stabilities of highway embankment by the results.

Mechanical behavior of embankments overlying on loose subgrade stabilized by deep mixed columns

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Morteza Esmaeili

2016-10-01

Full Text Available Deep mixed column (DMC is known as one of the effective methods for stabilizing the natural earth beneath road or railway embankments to control stability and settlements under traffic loads. The load distribution mechanism of embankment overlying on loose subgrades stabilized with DMCs considerably depends on the columns' mechanical and geometrical specifications. The present study uses the laboratory investigation to understand the behavior of embankments lying on loose sandy subgrade in three different conditions: (1 subgrade without reinforcement, (2 subgrade reinforced with DMCs in a triangular pattern and horizontal plan, and (3 subgrade reinforced with DMCs in a square pattern and horizontal plan. For this purpose, by adopting the scale factor of 1:10, a reference embankment with 20 cm height, 250 cm length, and 93% maximum dry density achieved in standard Proctor compaction test was constructed over a 70 cm thick loose sandy bed with the relative density of 50% in a loading chamber, and its load-displacement behavior was evaluated until the failure occurred. In the next two tests, DMCs (with 10 cm diameter, 40 cm length, and 25 cm center-to-center spacing were placed in groups in two different patterns (square and triangular in the same sandy bed beneath the embankment and, consequently, the embankments were constructed over the reinforced subgrades and gradually loaded until the failure happened. In all the three tests, the load-displacement behaviors of the embankment and the selected DMCs were instrumented for monitoring purpose. The obtained results implied 64% increase in failure load and 40% decrease in embankment crest settlement when using the square pattern of DMCs compared with those of the reference embankment, while these values were 63% and 12%, respectively, for DMCs in triangular pattern. This confirmed generally better performance of DMCs with a triangular pattern.

Depuration of highway runoff water into grass-covered embankments.

Science.gov (United States)

Boivin, P; Saadé, M; Pfeiffer, H R; Hammecker, C; Degoumois, Y

2008-06-01

The management of polluted road runoff water is an important issue in environmental protection. A strategy could be to perform local depuration by infiltration into the soils of the embankment, but knowledge for designing such systems is lacking. This study aims at discussing the relevant soil properties, by estimating the long-term depuration of road runoff water infiltrating into the sandy soil embankment of the A9 highway in Wallis, Switzerland. This was done by estimating the heavy metals (HM) mass balance of two sites 23 and 12 years old, respectively. The accumulated HM were estimated by soil and GB analyses. The HM input was estimated by average water quality and traffic. The results were discussed using two-dimensional simulation of infiltration and a 14 months in situ monitoring of the runoff from the pavement to the embankment and at the bottom of the embankment. The soil properties were appropriate for both small particle adsorption and filtration. A good match between input and stored pollutant charges was found, and the HM profiles accorded well with infiltration simulation and monitoring results, which showed that 80-100% of the runoff water infiltrated into the embankment. Replacement of the cracked concrete gutters by an infiltration channel made of similar soil is recommended. These results oppose the Swiss guidelines for road-polluted water infiltration, as much more clayey soils are recommended. These later soils are difficult to find in Switzerland, and may allow for preferential flow through macro pores, in contrast to the studied site.

The impact of foundation conditions on the design and construction of the Snake Lake Reservoir dams

International Nuclear Information System (INIS)

Griffin, G. D.

1998-01-01

Unique aspects of the design and construction of two small dams for the Snake Lake Reservoir Project and some of the lessons learned in the process are described. The outstanding feature of this project was that although relatively close together and in the same post-glacial channel, the foundations of the two dams were quite different. The West Dam had permeable silt, sand and gravel with deep bedrock, while the East Dam had impermeable high plastic clay and shallow bedrock as foundation. The challenge to the design was to develop a cross section that would work for both foundation conditions. The final design turned out to be an impermeable fill with toe berms accommodating the variability in the foundations. Instrumentation was used to determine when the second construction stage should commence. At the end of the construction, the reservoir was partially filled relying on the instrumentation to suggest when that would be safe enough to proceed without impacting the overall embankment stability. In the event, the West Dam foundation soils proved to be several orders of magnitude higher than estimated from grain size analyses, requiring installation of a relief valve after construction was completed. Apart from that, dam construction proceeded smoothly and the instrumentation performed as expected.12 refs., 7 figs

Construction of a test embankment using a sand-tire shred mixture as fill material.

Science.gov (United States)

Yoon, Sungmin; Prezzi, Monica; Siddiki, Nayyar Zia; Kim, Bumjoo

2006-01-01

Use of tire shreds in construction projects, such as highway embankments, is becoming an accepted way of beneficially recycling scrap tires. However, in the last decade there was a decline in the use of pure tire shreds as fill materials in embankment construction, as they are susceptible to fire hazards due to the development of exothermic reactions. Tire shred-sand mixtures, on the other hand, were found to be effective in inhibiting exothermic reactions. When compared with pure tire shreds, tire shred-sand mixtures are less compressible and have higher shear strength. However, the literature contains limited information on the use of tire shred-soil mixtures as a fill material. The objectives of this paper are to discuss and evaluate the feasibility of using tire shred-sand mixtures as a fill material in embankment construction. A test embankment constructed using a 50/50 mixture, by volume, of tire shreds and sand was instrumented and monitored to: (a) determine total and differential settlements; (b) evaluate the environmental impact of the embankment construction on the groundwater quality due to leaching of fill material; and (c) study the temperature variation inside the embankment. The findings in this research indicate that mixtures of tire shreds and sand are viable materials for embankment construction.

Application of Electrical Resistivity Tomography Technique for Characterizing Leakage Problem in Abu Baara Earth Dam, Syria

Directory of Open Access Journals (Sweden)

Walid Al-Fares

2014-01-01

Full Text Available Electrical Resistivity Tomography (ERT survey was carried out at Abu Baara earth dam in northwestern Syria, in order to delineate potential pathways of leakage occurring through the subsurface structure close to the dam body. The survey was performed along two straight measuring profiles of 715 and 430 m length in up- and downstream sides of the dam’s embankment. The analysis of the inverted ERT sections revealed the presence of fractured and karstified limestone rocks which constitute the shallow bedrock of the dam reservoir. Several subsurface structural anomalies were identified within the fractured bedrock, most of which are associated with probable karstic cavities, voids, and discontinuity features developed within the carbonates rocks. Moreover, results also showed the occurrence of a distinguished subsiding structure coinciding with main valley course. Accordingly, it is believed that the bedrock and the other detected features are the main potential causes of water leakage from the dam’s reservoir.

Toru to Nukui dam construction carried out by Chugoku district construction department of Ministry of construction. Kensetsusho chugoku chiho kensetsukyoku Nukui dam koji kengakuki

Energy Technology Data Exchange (ETDEWEB)

Kitajima, E. (Chugoku Kayaku Co. Ltd. Hiroshima (Japan))

1993-08-31

This paper reports the summary of a tour to the Nukui dam being constructed on the Ota river system in Hiroshima Prefecture, as a study activity of the blasting expert working group. The Nukui dam has the second highest embankment in Japan (155 m). It adjusts flood at 1800 m[sup 3]/s from the planned high water discharge of 2900 m[sup 3]/s supplies water of 200,000 m[sup 3] daily at maximum, and generates electric power of 2300 kW as the maximum output. The blasting adopted a presplit system not to damage base rock beds, and was used with a bench height of 5 m, a hole diameter of 75 mm, a minimum shaft line of 2.5 m, and a hole distance of 2.8m. The main explosive used was the ANFO, No. 3 Kiri, Akatsuki dynamite. Slurry explosives were used for the presplit. Drilling machines with three-dimensional computers were used. The 'Nukui Dam Work Station' is the country's first site office/lodgings integrated facility offering as comfortable working environment as a city hotel. The facility is expected to wipe out the dirty, dangerous and hard image of construction work. 1 ref., 3 figs.

Preloaded Motorway Embankments

DEFF Research Database (Denmark)

Steenfelt, J. S.; Jørgensen, Mogens B.; Jørgensen, P. O.

1999-01-01

Road construction, particularly involving soft soil replacement, draws very heavily on the scarce resources of sand and gravel. One environmentally appealing alternative to complete soft soil replacement is preloading where the sand/gravel materials may be re-used along the road alignment....... The paper describes the first application of the method for motorways in connection with the completion of the Danish motorway infrastructure. To validate the feasibility of preloading an instrumented test embankment was constructed in the alignment. In the paper the extensive site characterisation...

Preloaded Motorway Embankments

DEFF Research Database (Denmark)

Steenfelt, Jørgen S.; Jørgensen, Mogens B.; Jørgensen, P.O.

Road construction, particularly involving soft soil replacement, draws very heavily on the scarce resources of sand and gravel. One environmentally appealing alternative to complete soft soil replacement is pre-loading where the sand/gravel materials may be re-used along the road alignment....... The paper describes the first application of the method for motorways in connection with the completion of the Danish motorway infrastructure. To validate the feasibility of pre-loading an instrumented test embankment was constructed in the alignment. In the paper the extensive site characterisation...

Estimating contaminant discharge rates from stabilized uranium tailings embankments

International Nuclear Information System (INIS)

Weber, M.F.

1986-01-01

Estimates of contaminant discharge rates from stabilized uranium tailings embankments are essential in evaluating long-term impacts of tailings disposal on groundwater resources. Contaminant discharge rates are a function of water flux through tailings covers, the mass and distribution of tailings, and the concentrations of contaminants in percolating pore fluids. Simple calculations, laboratory and field testing, and analytical and numerical modeling may be used to estimate water flux through variably-saturated tailings under steady-state conditions, which develop after consolidation and dewatering have essentially ceased. Contaminant concentrations in water discharging from the tailings depend on tailings composition, leachability and solubility of contaminants, geochemical conditions within the embankment, tailings-water interactions, and flux of water through the embankment. These concentrations may be estimated based on maximum reported concentrations, pore water concentrations, extrapolations of column leaching data, or geochemical equilibria and reaction pathway modeling. Attempts to estimate contaminant discharge rates should begin with simple, conservative calculations and progress to more-complicated approaches, as necessary

Numerical Analyses of Earthquake Induced Liquefaction and Deformation Behaviour of an Upstream Tailings Dam

Directory of Open Access Journals (Sweden)

Muhammad Auchar Zardari

2017-01-01

Full Text Available Much of the seismic activity of northern Sweden consists of micro-earthquakes occurring near postglacial faults. However, larger magnitude earthquakes do occur in Sweden, and earthquake statistics indicate that a magnitude 5 event is likely to occur once every century. This paper presents dynamic analyses of the effects of larger earthquakes on an upstream tailings dam at the Aitik copper mine in northern Sweden. The analyses were performed to evaluate the potential for liquefaction and to assess stability of the dam under two specific earthquakes: a commonly occurring magnitude 3.6 event and a more extreme earthquake of magnitude 5.8. The dynamic analyses were carried out with the finite element program PLAXIS using a recently implemented constitutive model called UBCSAND. The results indicate that the magnitude 5.8 earthquake would likely induce liquefaction in a limited zone located below the ground surface near the embankment dikes. It is interpreted that stability of the dam may not be affected due to the limited extent of the liquefied zone. Both types of earthquakes are predicted to induce tolerable magnitudes of displacements. The results of the postseismic slope stability analysis, performed for a state after a seismic event, suggest that the dam is stable during both the earthquakes.

Slope stability of rectify coal waste embankments on mining areas

International Nuclear Information System (INIS)

Klossek, C.

1999-01-01

The paper is of a theoretical and experimental character, focusing on the results of field tests on the load-bearing capacity and stability of high (> 20m.) transportation embankments rectified with coal waste. The embankments are located in industrial areas subjected to the intense impact of underground mining. Such phenomena are also accompanied by essential changes in the water conditions of the subsoil. The results of model tests by SIR geo-radar used to non-damaging estimation of the suffusion occurring in the embankment constructed on non-waste materials are discussed. The numerical assessment of the filtration process has been based on the MFE and MBE programs, which are extended calculation procedures enabling the overall estimation of the redistribution of all the stress-strain components in the structure, in consideration of any hypothesis of the boundary state

Preliminary laboratory assessments of a lightweight geocomposite material for embankment fill application

Directory of Open Access Journals (Sweden)

Felix Okonta

2015-03-01

Full Text Available The cost of retaining structures used for the lateral support of roadside embankments can be significantly reduced through the use of lightly cemented mixtures of expanded polystyrene (EPS beads and backfill soils as lightweight roadside embankment material. Four grades of residually derived sandy soils were mixed with EPS beads and the geocomposites were stabilised with 3% cement content, compacted and cured. The textural properties and shear strength parameters of dry and soaked specimens of the cemented geocomposites were determined by direct shear tests. The shear parameters and slope stability charts were used to simulate the slope of typical road embankments. The settlement potentials at different applied normal stresses were also determined. Inclusion of EPS reduced the dry density of the residual soils from an average value of 1790 kg/m3 to 1335 kg/m3. The maximum friction coefficient, tan ᴓ′, mobilised by the geocomposite specimens decreased with an increase in the soil fines content (>0.425 mm. The difference in tan ᴓ′ between the stabilised geocomposites and the natural soil was also dependent on the fines content. For an embankment height of 20 m, slope angles of 38° and 62° were determined for fine sand geocomposites in fully saturated drainage and drained conditions, respectively. Lower slope angles were determined for geocomposites made from silty, coarse and gravelly sands. A limiting embankment height of 50 m was determined for the four geocomposites. Rainfall-induced settlement of geocomposites was dependent on pre-inundation stiffness; for the range of applied stress up to 200 kPa, the settlement exhibited by the fine and silty sand geocomposites was lower than that for the coarse and gravelly sand geocomposites. Fine and silty sands make poor materials for slope embankments because of their poor hydraulic conductivity; however, fine and silty sand geocomposites have a good conductivity and friction angle to support

Horizon Dam design, construction, and quality management

Energy Technology Data Exchange (ETDEWEB)

Patrick, B. [EBA Engineering Consultants Ltd., Nanaimo, BC (Canada); Sisson, R. [Canadian Natural Resources Ltd., Fort McMurray, AB (Canada)

2010-07-01

This paper discussed the design and construction of the Tar River Diversion Dam and the quality management system (QMS) used during construction. The project was unusual in that the company constructed the project using its own workforce, without contractors, under challenging schedule and site conditions. The topography, geology and geotechnical aspects of the site were discussed along with the embankment design, seepage control measures and construction execution. The QMS was designed to fit the needs of the unique construction execution strategy and meet safety, reliability, performance, and operation requirements, comply with all regulations and approval conditions, and identify and communicate risk to the appropriate entity. Specifications and construction procedures had to be modified to accommodate equipment operators trained with the skills and techniques of mine operations, not those associated with conventional civil construction projects. Foundation movement identified during construction required mid-build design changes, construction rescheduling, and additional deformation analyses to determine long-term stability. The QMS allowed changes in the understanding of site conditions to be quickly addressed and risks to be identified and cost-effectively mitigated. Design consultants were used to modify designs and appropriately identify and mitigate risks. The approach to embankment construction was successful because the QMS included processes for change management, issue resolution, and risk-benefit assessment, and because experienced personnel had a regular presence on the construction site and worked collaboratively. The effective QMS was deemed to be integral to the success of the construction project. 1 tab., 7 figs.

Fuzzy stochastic generalized reliability studies on embankment systems based on first-order approximation theorem

Directory of Open Access Journals (Sweden)

Wang Yajun

2008-12-01

Full Text Available In order to address the complex uncertainties caused by interfacing between the fuzziness and randomness of the safety problem for embankment engineering projects, and to evaluate the safety of embankment engineering projects more scientifically and reasonably, this study presents the fuzzy logic modeling of the stochastic finite element method (SFEM based on the harmonious finite element (HFE technique using a first-order approximation theorem. Fuzzy mathematical models of safety repertories were introduced into the SFEM to analyze the stability of embankments and foundations in order to describe the fuzzy failure procedure for the random safety performance function. The fuzzy models were developed with membership functions with half depressed gamma distribution, half depressed normal distribution, and half depressed echelon distribution. The fuzzy stochastic mathematical algorithm was used to comprehensively study the local failure mechanism of the main embankment section near Jingnan in the Yangtze River in terms of numerical analysis for the probability integration of reliability on the random field affected by three fuzzy factors. The result shows that the middle region of the embankment is the principal zone of concentrated failure due to local fractures. There is also some local shear failure on the embankment crust. This study provides a referential method for solving complex multi-uncertainty problems in engineering safety analysis.

When air really matters: Flow depth relationships for stepped spillways

Science.gov (United States)

With changing demographics in the vicinity of aging embankment dams, hazard creep, a change in classification from low to significant or high, can become problematic and limit rehabilitation options. The most common deficiency for embankment dams due to hazard creep is inadequate spillway capacity....

Study of Various Techniques for Improving Weak and Compressible Clay Soil under a High Earth Embankment

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Zein A.K. M.

2014-04-01

Full Text Available This paper investigates the suitability of three soil improvement techniques for the construction of a high earth embankment on thick weak and highly compressible clay soil. The eastern approach embankment of Alhalfaya Bridge on the River Nile linking Khartoum North and Omdurman cities was chosen as a case study and a comprehensive site investigation program was carried out to determine the properties the subsurface soils. The study results showed that unless the subsurface soils have been improved they may fail or undergo excessively large settlements due to the embankment construction. Three ground improvement techniques based on the principles of the “staged construction method, SCM”, “vertical sand drain, VSD” and “sand compaction piles, SCP” of embankment foundation soil treatment are discussed and evaluated. Embankment design options based on applications of the above methods have been proposed for foundation treatment to adequately support embankment loads. A method performance evaluation based on the improvement of soil properties achieved; the time required for construction and compared estimated costs criteria was made to assess the effectiveness and expected overall performance. Adoption of any of the soil improvement techniques considered depends mainly on the most critical and decisive factor governing the embankment design. Based on the overall performance for the embankment case studied, the sand drains is considered as the most appropriate improvement method followed by the sand compaction piles technique whereas the staged construction method showed the poorest overall performance.

Earthquake Hazard for Aswan High Dam Area

Science.gov (United States)

Ismail, Awad

2016-04-01

analyzed with high priority and redesigned to increase the safety of the embankments and their appurtenant structures, if necessary. Key word Aswan High Dam, Earthquake hazard reduction

Characterisation of Beaver Habitat Parameters That Promote the Use of Culverts as Dam Construction Sites: Can We Limit the Damage to Forest Roads?

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Geneviève Tremblay

2017-12-01

Full Text Available The use of forest roads as foundations for dam construction by beavers is a recurrent problem in the management of forest road networks. In order to limit the damage to forest roads, our goal was to calculate the probability of beaver dam installation on culverts, according to surrounding habitat parameters, which could allow for improvement in the spatial design of new roads that minimise conflicts with beavers. Comparisons of culverts with (n = 77 and without (n = 51 dams in northwestern Quebec showed that catchment surface, cumulate length of all local streams within a 2-km radius, and road embankment height had a negative effect on the probability of dam construction on culverts, while flow level and culvert diameter ratio had a positive effect. Nevertheless, predicted probabilities of dam construction on culverts generally exceeded 50%, even on sites that were less favourable to beavers. We suggest that it would be more reasonable to take their probable subsequent presence into account at the earliest steps of road conception. Installing mitigation measures such as pre-dams during road construction would probably reduce the occurrence of conflicts with beavers and thus reduce the maintenance costs of forest roads.

Final Independent External Peer Review Report Supplemental Major Rehabilitation Evaluation Report for Center Hill Dam, Caney Fork River, DeKalb County, Tennessee

Science.gov (United States)

2013-09-25

and outlet structure and the penstock system for the Rocky Mountain Pumped Storage Facility under both pump and turbine modes. He also was the...level will not overtop the main embankment dam but will encroach into the 3.6-feet of freeboard allotted for wind and wave run-up. This encroachment...In particular, short-term impacts on noise, air quality, water quality, migratory birds , fisheries, and traffic during construction have not been

Improvement of the Assignment Methodology of the Approach Embankment Design to Highway Structures in Difficult Conditions

Science.gov (United States)

Chistyy, Y.; Kuzakhmetova, E.; Fazilova, Z.; Tsukanova, O.

2018-03-01

Design issues of junction of bridges and overhead road with approach embankment are studied. The reasons for the formation of deformations in the road structure are indicated. Activities to ensure sustainability and acceleration of the shrinkage of a weak subgrade approach embankment are listed. The necessity of taking into account the man-made impact of the approach embankment on the subgrade behavior is proved. Modern stabilizing agents to improve the properties of used soils in the embankment and the subgrade are suggested. Clarified methodology for determining an active zone of compression in the subgrade under load from the weight of the embankment is described. As an additional condition to the existing methodology for establishing the lower bound of the active zone of compression it is offered to accept the accuracy of evaluation of soil compressibility and determine shrinkage.

Thermal–moisture dynamics of embankments with asphalt pavement in permafrost regions of central Tibetan Plateau

Energy Technology Data Exchange (ETDEWEB)

Wen, Zhi; Zhang, Mingli; Ma, Wei; Wu, Qingbai; Niu, Fujun; Yu, Qihao; Fan, Zhaosheng; Sun, Zhizhong

2014-09-01

Subsurface moisture content is one of the critical factors that control the thermal dynamics of embankments. However, information on the subsurface moisture movement and distribution in embankments is still limited. To better understand the coupled water and heat transport within embankments, subsurface temperature and moisture of an asphalt pavement highway were extensively measured from 2009 to 2011. Collected data indicate that pure heat conduction is the overall main mechanism of heat transport in the embankment and heat convection plays a relatively unimportant role in heat transport. The results also indicate that subsurface moisture and temperature dynamics in the asphalt layer is strongly related to the rainfall events, while the subsurface moisture content below the road base course maintains relatively constant. Rainfall in summer leads to rapid cooling of the subsurface soil. Our results suggest that frequent and small rainfall events favour the thermal stability of the embankment due to the loss of latent heat of water evaporation. Moisture migration during freezing still occurred in the gravel fill and the water infiltrated into the active layer during thawing period. Freezing-induced water migration may result in the increase in water content of the embankment and the decrease in compactness of gravel fill.

Prediction of embankment settlement over soft soils.

Science.gov (United States)

2009-06-01

The objective of this project was to review and verify the current design procedures used by TxDOT : to estimate the total and rate of consolidation settlement in embankments constructed on soft soils. Methods : to improve the settlement predictions ...

Salt-marsh restoration : evaluating the success of de-embankments in north-west Europe

NARCIS (Netherlands)

Wolters, M; Garbutt, A; Bakker, JP

De-embankment of historically reclaimed salt marshes has become a widespread option for re-creating salt marshes, but to date little information exists on the success of de-embankments. One reason is the absence of pre-defined targets, impeding the measurement of success. In this review, success has

Putting Roman Dams in Context: a Virtual Approach

Science.gov (United States)

Decker, M. J.; Du Vernay, J. P.; Mcleod, J. B.

2017-08-01

Water resources and management have become a critical global issue. During the half-millennium of its existence, the Roman Empire developed numerous strategies to cope with water management, from large-scale urban aqueduct systems, to industrial-scale water mills designed to cope with feeding growing city populations. Roman engineers encountered, adopted, and adapted indigenous hydraulic systems, and left lasting imprints on the landscape of the Mediterranean and temperate Western Europe by employing a range of water technologies. A recent academic study has enabled the identification of remains of and references to seventy-two dams from the Roman era, constructed in Spain between the 1st and 4th century AD. Such unique heritage, without comparisons in the Mediterranean makes Spain an emblematic case study for the analysis of Roman hydraulic engineering and water management policies. Fifty dams have been located and detailed. The twenty-two outstanding, although identified on the ground, have not been able to be acceptably characterized, due in some cases to their being ruins in a highly degraded state, others due to their being masked by repairs and reconstructions subsequent to the Roman era. A good example of such neglected dams is the buttress dam of Consuegra , in Toledo province (Castilla-La Mancha). Dating to the 3rd - 4th century AD, the Dam of Consuegra, on the basin of the Guadiana, with its over 600 metres length and 4,80 metres height, is a remarkable case of Roman engineering mastery. It had a retaining wall upstream, numerous buttresses and perhaps an embankment downstream, of which no remains are left. The application of 3D digital imaging technique to create a high quality virtual model of such monuments has proved to be successful especially for the study of the technological aspects related its construction. The case study of the Roman dam of Muel (Zaragoza) has shown, in fact, as best practices in digital archaeology can provide an original and

Stability of embankments over cement deep soil mixing columns; Estabilidad de terraplenes sobre columnas de suelo-cemento

Energy Technology Data Exchange (ETDEWEB)

Morilla Moar, P.; Melentijevic, S.

2014-07-01

The deep soil mixing (DSM) is one of the ground improvement methods used for the construction of embankments over soft soils. DSM column-supported embankments are constructed over soft soils to accelerate its construction, improve embankment stability, increase bearing capacity and control of total and differential settlements. There are two traditional design methods, the Japanese (rigid columns) and the scandinavian (soft and semi-rigid columns). Based on Laboratory analysis and numerical analysis these traditional approaches have been questioned by several authors due to its overestimation of the embankment stability considering that the most common failures types are not assumed. This paper presents a brief review of traditional design methods for embankments on DSM columns constructed in soft soils, studies carried out determine the most likely failure types of DSM columns, methods to decrease the overestimation when using limit equilibrium methods and numerical analysis methods that permit detect appropriate failure modes in DSM columns. Finally a case study was assessed using both limited equilibrium and finite element methods which confirmed the overestimation in the factors of safety on embankment stability over DSM columns. (Author)

IoT-based flood embankments monitoring system

Science.gov (United States)

Michta, E.; Szulim, R.; Sojka-Piotrowska, A.; Piotrowski, K.

2017-08-01

In the paper a concept of flood embankments monitoring system based on using Internet of Things approach and Cloud Computing technologies will be presented. The proposed system consists of sensors, IoT nodes, Gateways and Cloud based services. Nodes communicates with the sensors measuring certain physical parameters describing the state of the embankments and communicates with the Gateways. Gateways are specialized active devices responsible for direct communication with the nodes, collecting sensor data, preprocess the data, applying local rules and communicate with the Cloud Services using communication API delivered by cloud services providers. Architecture of all of the system components will be proposed consisting IoT devices functionalities description, their communication model, software modules and services bases on using a public cloud computing platform like Microsoft Azure will be proposed. The most important aspects of maintaining the communication in a secure way will be shown.

An evaluation of the embankment project on the Pripyat river

International Nuclear Information System (INIS)

Lepicard, S.

2000-01-01

On considering only the economical and radiological criteria, and on the base of available information and adopted hypothesis, the benefits expected from the building project of an embankment on the Pripyat river lead to just compensate the building and maintenance costs estimated for this project. Nevertheless, taking into account the expected positive effects on different sectors of economy, the project of an embankment of Chernobyl, initiated more than twelve years after the accident, will be, in a long term perspective, an efficient mean to improve the radiations situation and the life conditions for the Ukraine populations. (N.C.)

Ground-penetrating radar profiling on embanked floodplains

NARCIS (Netherlands)

Bakker, M.A.J.; Maljers, D.; Weerts, H.J.T.

2007-01-01

Management of the Dutch embanked floodplains is of crucial interest in the light of a likely increase of extreme floods. One of the issues is a gradual decrease of floodwater accommodation space as a result of overbank deposition of mud and sand during floods. To address this issue, sediment

Ground-penetrating radar profiling on embanked floodplains

NARCIS (Netherlands)

Bakker, M.A.J.; Maljers, D.; Weerts, H.J.T.

Management of the Dutch embanked floodplains is of crucial interest in the light of a likely increase of extreme floods. One of the issues is a gradual decrease of floodwater accommodation space as a result of overbank deposition of mud and sand during floods. To address this issue, sediment

Inundation risk for embanked rivers

Directory of Open Access Journals (Sweden)

W. G. Strupczewski

2013-08-01

Full Text Available The Flood Frequency Analysis (FFA concentrates on probability distribution of peak flows of flood hydrographs. However, examination of floods that haunted and devastated the large parts of Poland lead us to revision of the views on the assessment of flood risk of Polish rivers. It turned out that flooding is caused not only by the overflow of the levee crest but also due to the prolonged exposure to high water on levees structure causing dangerous leaks and breaches that threaten their total destruction. This is because the levees are weakened by long-lasting water pressure and as a matter of fact their damage usually occurs after the culmination has passed the affected location. The probability of inundation is the total of probabilities of exceeding embankment crest by flood peak and the probability of washout of levees. Therefore, in addition to the maximum flow one should also consider the duration of high waters in a river channel. In the paper the new two-component model of flood dynamics: "Duration of high waters–Discharge Threshold–Probability of non-exceedance" (DqF, with the methodology of its parameter estimation was proposed as a completion to the classical FFA methods. Such a model can estimate the duration of stages (flows of an assumed magnitude with a given probability of exceedance. The model combined with the technical evaluation of the probability of levee breaches due to the duration (d of flow above alarm stage gives the annual probability of inundation caused by the embankment breaking. The results of theoretical investigation were illustrated by a practical example of the model implementation to the series of daily flow of the Vistula River at Szczucin. Regardless of promising results, the method of risk assessment due to prolonged exposure of levees to high water is still in its infancy despite its great cognitive potential and practical importance. Therefore, we would like to point out the need for and usefulness of

Geotechnical Materials Database for Embankment Design and Construction

Science.gov (United States)

2011-12-01

This project was focused on the assimilation of engineering properties of borrow soils across the state of : South Carolina. Extensive data on soils used for embankment construction were evaluated and compared : within Group A (Piedmont) and Group B ...

Dam! Dam! Dam!

International Nuclear Information System (INIS)

McCully, P.

1997-01-01

The author of ''Silenced Rivers'' a book questioning the desirability of dam building and hydroelectric power generation argues the main themes of his book in this paper. Despite being hailed by politicians as good solutions to power generation problems, and enthusiastically pursued in China, the U.S.A., the former Soviet Union, India and Japan, dams have far-reaching ecological and human consequences. The ecosystems lost to flooding, and the agricultural land use lost, the human cost in terms of homes and employment lost to reservoirs, disease from water-borne infections such as malaria, and the hazards of dams overflowing or breaking are all factors which are against the case for dam construction. The author argues the hydroelectric power may be renewable, but the social, agricultural and ecological costs are too high to justify it as a method of first choice. (UK)

SIMULATION OF SUBGRADE EMBANKMENT ON WEAK BASE

Directory of Open Access Journals (Sweden)

V. D. Petrenko

2015-08-01

Full Text Available Purpose. This article provides: the question of the sustainability of the subgrade on a weak base is considered in the paper. It is proposed to use the method of jet grouting. Investigation of the possibility of a weak base has an effect on the overall deformation of the subgrade; the identification and optimization of the parameters of subgrade based on studies using numerical simulation. Methodology. The theoretical studies of the stress-strain state of the base and subgrade embankment by modeling in the software package LIRA have been conducted to achieve this goal. Findings. After making the necessary calculations perform building fields of a subsidence, borders cramped thickness, bed’s coefficients of Pasternak and Winkler. The diagrams construction of vertical stress performs at any point of load application. Also, using the software system may perform peer review subsidence, rolls railroad tracks in natural and consolidated basis. Originality. For weak soils is the most appropriate nonlinear model of the base with the existing areas of both elastic and limit equilibrium, mixed problem of the theory of elasticity and plasticity. Practical value. By increasing the load on the weak base as a result of the second track construction, adds embankment or increasing axial load when changing the rolling stock process of sedimentation and consolidation may continue again. Therefore, one of the feasible and promising options for the design and reconstruction of embankments on weak bases is to strengthen the bases with the help of jet grouting. With the expansion of the railway infrastructure, increasing speed and weight of the rolling stock is necessary to ensure the stability of the subgrade on weak bases. LIRA software package allows you to perform all the necessary calculations for the selection of a proper way of strengthening weak bases.

Risk assessment and economic appraisal of protection methods for the Tarascon-Arles railway embankment

Directory of Open Access Journals (Sweden)

Cheetham Mark

2016-01-01

Full Text Available The coordination of flood management practices and the reduction of flood risk as proposed under the Plan Rhône project has led to a vast program of flood defence modernization and construction in the lower Rhône valley. One key element of the project involves the construction of a new 9km levee structure parallel to an existing railway line between the towns of Tarascon and Arles (Bouches-du-Rhône, France on the left bank of the Rhône, which has historically been an obstacle to the propagation of flood flows. The new levee is designed to protect the towns of Arles and Tarascon up to the 10−2 annual probability flood event, after which floodwater will flow over a 5km spillway which will be integrated into the structure. In case of overtopping of the spillway via a spillway structure, floodwater is collected in the space between the two embankments and will subsequently flow towards one of ten newly constructed flood discharge structures, spaced at regular intervals in the railway embankment. The levee will form part of a global system of defence which is designed against flooding on the Rhône with an annual probability of occurrence of 10−3. In the event of overtopping of the levee, the railway embankment will be subjected to hydraulic loading and is at risk of damage from flood flows. During the detailed design phase of the project, options were explored for optimizing the permanent protection for the railway embankment. Using results from 2D and 3D hydraulic numerical modelling, a detailed risk assessment of the railway embankment was undertaken to evaluate its vulnerability under different hydraulic loading conditions and for different failure mechanisms using various parameters including water depth, hydraulic load, the duration of flood exposure and flow velocity. A comprehensive understanding of the main mechanisms of embankment damage under hydraulic loading (internal/ external erosion, overtopping, rotational failure etc

Monitoring the ongoing deformation and seasonal behaviour affecting Mosul Dam through space-borne SAR data

Science.gov (United States)

Tessari, G.; Riccardi, P.; Pasquali, P.

2017-12-01

Monitoring of dam structural health is an important practice to control the structure itself and the water reservoir, to guarantee efficient operation and safety of surrounding areas. Ensuring the longevity of the structure requires the timely detection of any behaviour that could deteriorate the dam and potentially result in its shutdown or failure.The detection and monitoring of surface displacements is increasingly performed through the analysis of satellite Synthetic Aperture Radar (SAR) data, thanks to the non-invasiveness of their acquisition, the possibility to cover large areas in a short time and the new space missions equipped with high spatial resolution sensors. The availability of SAR satellite acquisitions from the early 1990s enables to reconstruct the historical evolution of dam behaviour, defining its key parameters, possibly from its construction to the present. Furthermore, the progress on SAR Interferometry (InSAR) techniques through the development of Differential InSAR (DInSAR) and Advanced stacking techniques (A-DInSAR) allows to obtain accurate velocity maps and displacement time-series.The importance of these techniques emerges when environmental or logistic conditions do not allow to monitor dams applying the traditional geodetic techniques. In such cases, A-DInSAR constitutes a reliable diagnostic tool of dam structural health to avoid any extraordinary failure that may lead to loss of lives.In this contest, an emblematic case will be analysed as test case: the Mosul Dam, the largest Iraqi dam, where monitoring and maintaining are impeded for political controversy, causing possible risks for the population security. In fact, it is considered one of the most dangerous dams in the world because of the erosion of the gypsum rock at the basement and the difficult interventions due to security problems. The dam consists of 113 m tall and 3.4 km long earth-fill embankment-type, with a clay core, and it was completed in 1984.The deformation

Deformasi Vertikal Dan Horisontal Pada Tanah Lunak Di Bawah Trial Embankment Di Kendal, Kaliwungu, Semarang

Directory of Open Access Journals (Sweden)

Adhe Noor Patria

2008-08-01

The analysis for vertical and horizontal deformation in soft soil carried out by comparing between the data resulted from field measurement and from numerical simulation. Numerical simulation carried out by using Plaxis version 7.0. In this simulation, soft soil and embankment soil were modelled in Mohr-Coulomb model material. The results of the analysis showed that there was an increasement in soft soil shear strength. This condition led to the decreasement in horizontal deformation. The extreme difference in horizontal deformation between field measurement and numerical simulaton caused by the difference assumption used in soil modeling. For instance modulus of elasticity assumption, soil homogeneity assumption, and fixed condition at the bottom edge of inclinometer. Maximum vertical deformation in soft soil occurred under the center of trial embankment. It happened because the highest compression occurred in this area when the maximum height of embankment reached. This condition led to highest burden supported by the soil under the center of trial embankment.

Linking experiments with the real world

Directory of Open Access Journals (Sweden)

José Couto Marques

2014-03-01

Full Text Available An interactive web application has been developed to provide a learning tool for soil mechanics students. Using digital video, html and javascript the interactive video provides some facts and figures about dams in general and embankment dams in particular, using a small scale experimental model and finite element numerical simulations to provide insight on groundwater flow phenomena in this type of works. The web application is able to supply further references through social networks in order to stimulate interest and promote deeper learning of embankment dam engineering and related phenomena.

Exploration of Drone and Remote Sensing Technologies in Highway Embankment Monitoring and Management (Phase I) : research project capsule.

Science.gov (United States)

2017-09-01

Over time, many Louisiana highway embankments have experienced surface sliding failures, a safety issue causing traffic disruptions. Since no advance-warning system is available for these highway embankment failures, the Louisiana Department of Trans...

EVALUATION ON THE SEISMIC RESPONSE CHARACTERISTICS OF A ROAD EMBANKMENT BASED ON THE MODERATE EARTHQUAKE OBSERVATION AND THE MICROTREMOR MEASUREMENT

Science.gov (United States)

Hata, Yoshiya; Ichii, Koji; Yamada, Masayuki; Tokida, Ken-Ichi; Takezawa, Koichiro; Shibao, Susumu; Mitsushita, Junji; Murata, Akira; Furukawa, Aiko; Koizumi, Keigo

Accurate evaluation on the seismic response characteristics of a road embankment is very important for the rational seismic assessment. However, in a lot of previous studies, the seismic response characteristics of an embankment were evaluated based on the results of shaking table test, centrifuge model test and dynamic FEM analysis. In this study, the transfer function and the shear wave velocity of a road embankment were evaluated based on the in-situ records of moderate earthquake observation and microtremor measurement. Test results show the possibility that the shear wave velocity of an embankment can be estimated by the earthquake observation or the microtremor measurement and the dynamic linear FEM analysis.

On 'Reinterpreting the famous train/embankment experiment of relativity'

International Nuclear Information System (INIS)

Mallinckrodt, A John

2004-01-01

Nelson contends that Einstein's train/embankment gedanken experiment is incomplete and inadequate to demonstrate the relativity of simultaneity. However, the contradictions he points to in support of this contention arise entirely from his attempt to perform an unnecessary reconciliation using a logically inconsistent framework. (letters and comments)

A simulation-optimization model for Stone column-supported embankment stability considering rainfall effect

International Nuclear Information System (INIS)

Deb, Kousik; Dhar, Anirban; Purohit, Sandip

2016-01-01

Landslide due to rainfall has been and continues to be one of the most important concerns of geotechnical engineering. The paper presents the variation of factor of safety of stone column-supported embankment constructed over soft soil due to change in water level for an incessant period of rainfall. A combined simulation-optimization based methodology has been proposed to predict the critical surface of failure of the embankment and to optimize the corresponding factor of safety under rainfall conditions using an evolutionary genetic algorithm NSGA-II (Non-Dominated Sorted Genetic Algorithm-II). It has been observed that the position of water table can be reliably estimated with varying periods of infiltration using developed numerical method. The parametric study is presented to study the optimum factor of safety of the embankment and its corresponding critical failure surface under the steady-state infiltration condition. Results show that in case of floating stone columns, period of infiltration has no effect on factor of safety. Even critical failure surfaces for a particular floating column length remain same irrespective of rainfall duration

A simulation-optimization model for Stone column-supported embankment stability considering rainfall effect

Energy Technology Data Exchange (ETDEWEB)

Deb, Kousik, E-mail: kousik@civil.iitkgp.ernet.in [Associate Professor, Department of Civil Engineering, IIT Kharagpur, Kharagpur-721302 (India); Dhar, Anirban, E-mail: anirban@civil.iitkgp.ernet.in [Assistant Professor, Department of Civil Engineering, IIT Kharagpur, Kharagpur-721302 (India); Purohit, Sandip, E-mail: sandip.purohit91@gmail.com [Former B.Tech Student, Department of Civil Engineering, NIT Rourkela, Rourkela (India)

2016-02-01

Landslide due to rainfall has been and continues to be one of the most important concerns of geotechnical engineering. The paper presents the variation of factor of safety of stone column-supported embankment constructed over soft soil due to change in water level for an incessant period of rainfall. A combined simulation-optimization based methodology has been proposed to predict the critical surface of failure of the embankment and to optimize the corresponding factor of safety under rainfall conditions using an evolutionary genetic algorithm NSGA-II (Non-Dominated Sorted Genetic Algorithm-II). It has been observed that the position of water table can be reliably estimated with varying periods of infiltration using developed numerical method. The parametric study is presented to study the optimum factor of safety of the embankment and its corresponding critical failure surface under the steady-state infiltration condition. Results show that in case of floating stone columns, period of infiltration has no effect on factor of safety. Even critical failure surfaces for a particular floating column length remain same irrespective of rainfall duration.

Fibre Bragg grating for flood embankment monitoring

Science.gov (United States)

Markowski, Konrad; Nevar, Stanislau; Dworzanski, Adam; Hackiewicz, Krzysztof; Jedrzejewski, Kazimierz

2014-11-01

In this article we present the preliminary studies for the flood embankment monitoring system based on the fibre Bragg gratings. The idea of the system is presented. The Bragg resonance shift is transformed to the change of the power detected by the standard InGaAs photodiode. The discrimination of the received power was executed by another fibre Bragg grating with different parameters. The project of the fully functional system is presented as well.

Transient Flow through an Unsaturated Levee Embankment during the 2011 Mississippi River Flood

Science.gov (United States)

Jafari, N.; Stark, T.; Vahedifard, F.; Cadigan, J.

2017-12-01

The Mississippi River and corresponding tributaries drain approximately 3.23 million km2 (1.25 million mi2) or the equivalent of 41% of the contiguous United States. Approximately 2,600 km ( 1,600 miles) of earthen levees presently protect major urban cities and agricultural land against the periodic Mississippi River floods within the Lower Mississippi River Valley. The 2011 flood also severely stressed the levees and highlighted the need to evaluate the behavior of levee embankments during high water levels. The performance of earthen levees is complex because of the uncertainties in construction materials, antecedent moisture contents, hydraulic properties, and lack of field monitoring. In particular, calibration of unsaturated and saturated soil properties of levee embankment and foundation layers along with the evaluation of phreatic surface during high river stage is lacking. Due to the formation of sand boils at the Duncan Point Levee in Baton Rouge, LA during the 2011 flood event, a reconnaissance survey was conducted to collect pore-water pressures in the sand foundation using piezometers and identifying the phreatic surface at the peak river level. Transient seepage analyses were performed to calibrate the foundation and levee embankment material properties using field data collected. With this calibrated levee model, numerical experiments were conducted to characterize the effects of rainfall intensity and duration, progression of phreatic surface, and seasonal climate variability prior to floods on the performance of the levee embankment. For example, elevated phreatic surface from river floods are maintained for several months and can be compounded with rainfall to lead to slope instability.

Hydrologic Analysis of Ungauged Catchments For The Supply of Water For Irrigation On Railway Embankment Batters

Science.gov (United States)

Gyasi-Agyei, Y.; Nissen, D.

Water has been identified as a key component to the success of grass establishment on railway embankment batters (side slope) within Central Queensland, Australia, to control erosion. However, the region under study being semi-arid experiences less than 600 mm average annual rainfall occurring on about 60 days of the year. Culverts and bridges are integral part of railway embankments. They are used to cross water courses, be it an ephemeral creek or just a surface runoff path. Surface runoff through an ungauged railway embankment culvert is diverted to a temporary excavated pond located at the downstream side of the hydraulic structure. The temporary excavated pond water is used to feed an automated drip irrigation system, with solar as a source of energy to drive a pump. Railway embankment batter erosion remediation is timed in the wet season when irrigation is used to supplement natural rainfall. Hydrologic analysis of ungauged catchments for sizing the temporary excavated pond is presented. It is based on scenarios of runoff coefficient and curve number, and mass curve (Rippl diagram). Three years of continuous rainfall data (1997/1998 -1999/2000) were used to design a pond. The performance of the designed pond was evaluated in a field experiment during the next wet season (2000/2001). It supplied adequate water for irrigation as predicted by the hydrologic analysis during the grass establishment. This helped to achieve 100% grass cover on the railway embankment batter within 12 weeks. The proposed irrigation system has been demonstrated t o be feasible and cost effective.

Soil erosion on road and railways embankments in the Canyoles river Basin. Eastern Spain.

Science.gov (United States)

Cerdà, Artemi; Antonio, Giménez-Morera; Félix Ángel, González-Peñaloza; María, Burguet; Paulo, Pereira; José Reyes, Ruiz

2013-04-01

Mediterranean landscapes are man-made. Its human ecosystems are characterized by a high population density, a long history of human settlement and an intense exchange of goods and people (Cerdà et al., 2010). This was possible due to a dense road network, most of it created during the Roman Empire. Modern roads and railways increased drastically during the last 30 years in the Mediterranean. Spain is a clear example of the acceleration of the road and railway infrastructures (Bel, 2005), especially during the 1960s as the tourism started to become a big issue in this part of the World. The increase in road and railways during the last 30 years resulted in a new transport system in Spain, which is based on high-speed railways and motorways. The characteristic of these infrastructures is that they were built by means of embankments, and little is now about the erosional response of those embankments to rainfall. The objective of this research is to assess the soil losses measured in road and railway embankments. The Canyoles River watershed was selected as an example of a region with a dense and recently developed modern network of roads, motorways and railway. The Canyoles river watershed is the natural path between the Mediterranean coast and Central Spain, the capital of the country and the touristic regions. Two motorways and two railways were built or re-built during the last two years and this paper assesses their impact on soil and water losses. As soil erosion rates are dependent on the high intensity - low frequency rainfall events, rainfall simulation experiments (40 experiments) were conducted (1 m2 plots; 60 minutes duration; 78 mm h-1 intensity) were carried out over plots on 2 railway (n=10 + 10) and motorway (n=10 + 10) research sites in August 2011, under very dry conditions. Soil moisture was below 5 % in the top 2 cm soil layer. The vegetation cover was very low in the two road and two railway embankments as the average cover was 4.2 % ranging from

Studying the effect of a variation in the main parameters on stability of homogeneous earth dams using design experiment

Directory of Open Access Journals (Sweden)

Lakehal Rida

2017-09-01

Full Text Available Deterministic approaches such as the limit equilibrium method (LEM especially Bishop modified method has been traditionally used to evaluate the stability of embankment dams. However, the uncertainty associated with the material properties necessitates the use of the probabilistic method to account the sensitivity of this uncertainty on the response of the deterministic approaches. In this study, the authors propose the application of design experiment, especially central composite design (CCD to determine the effects of independent uncertain parameters on the response of stability. A second-order polynomial model with cross terms is used to create an approximating function referred to as response surface for the implicit limit state surface, for which the input data were provided by stability analyses of different heights of homogeneous earth dams (10 m, 20 m, and 30 m with a depth ratio of DH = 1.5 and a circular slip surface using the Bishop modified limit equilibrium method. The proposed models obtained from this application represent higher prediction accuracy. The study of the effect of geotechnical parameters (material properties of embankment on safety factor show the importance of individual factors in level of linear effect with a positive effect of c’ or φ’ and a negative effect of H, γd, γsat and significant influence of two-factors interaction, the effect of c’ highly dependent on H, β, γd and φ’. Moreover, the effect of φ’ is dependent on the values of H and β. Lastly, the optimization of safety factor with respect to the range of values of material properties was made, and two failures modes are discussed which are (φ’, c’ reduction and γd increase.

Embankment quality and assessment of moisture control implementation : tech transfer summary.

Science.gov (United States)

2016-02-01

The motivation for this project was based on work by : Iowa State University (ISU) researchers at a few recent : grading projects that demonstrated embankments were : being constructed outside moisture control limits, even : though the contractor QC ...

Tailings dams from the perspective of conventional dam engineering

International Nuclear Information System (INIS)

Szymanski, M.B.

1999-01-01

A guideline intended for conventional dams such as hydroelectric, water supply, flood control, or irrigation is used sometimes for evaluating the safety of a tailings dam. Differences between tailings dams and conventional dams are often substantial and, as such, should not be overlooked when applying the techniques or safety requirements of conventional dam engineering to tailings dams. Having a dam safety evaluation program developed specifically for tailings dams is essential, if only to reduce the chance of potential errors or omissions that might occur when relying on conventional dam engineering practice. This is not to deny the merits of using the Canadian Dam Safety Association Guidelines (CDSA) and similar conventional dam guidelines for evaluating the safety of tailings dams. Rather it is intended as a warning, and as a rationale underlying basic requirement of tailings dam emgineering: specific experience in tailings dams is essential when applying conventional dam engineering practice. A discussion is included that focuses on the more remarkable tailings dam safety practics. It is not addressed to a technical publications intended for such dams, or significantly different so that the use of conventional dam engineering practice would not be appropriate. The CDSA Guidelines were recently revised to include tailings dams. But incorporating tailings dams into the 1999 revision of the CDSA Guidelines is a first step only - further revision is necessary with respect to tailings dams. 11 refs., 2 tabs

Computing Air Demand Using the Takagi–Sugeno Model for Dam Outlets

Directory of Open Access Journals (Sweden)

Mohammad Zounemat-Kermani

2013-09-01

Full Text Available An adaptive neuro-fuzzy inference system (ANFIS was developed using the subtractive clustering technique to study the air demand in low-level outlet works. The ANFIS model was employed to calculate vent air discharge in different gate openings for an embankment dam. A hybrid learning algorithm obtained from combining back-propagation and least square estimate was adopted to identify linear and non-linear parameters in the ANFIS model. Empirical relationships based on the experimental information obtained from physical models were applied to 108 experimental data points to obtain more reliable evaluations. The feed-forward Levenberg-Marquardt neural network (LMNN and multiple linear regression (MLR models were also built using the same data to compare model performances with each other. The results indicated that the fuzzy rule-based model performed better than the LMNN and MLR models, in terms of the simulation performance criteria established, as the root mean square error, the Nash–Sutcliffe efficiency, the correlation coefficient and the Bias.

Stability Analysis of the Embankment Model

Directory of Open Access Journals (Sweden)

G.S. Gopalakrishna

2009-01-01

Full Text Available In analysis of embankment model affected by dynamic force, employment of shaking table is a scientific way in assessment of earthquake behavior. This work focused on saturated loose sandy foundation and enbankment. The results generated through the pore pressure sensors indicated pore water pressure playing main role in creation of liquefaction and stability of the system, and also revealed deformation, settlement, liquefaction intensity and time stability of system in direct correlation with the strength and characteristics of soil. One of the economical methods in stabilization of soil foundation is improvement of some part soil foundation.

Numerical Simulation by using Soldiers Pile of the Embankment on Semarang-Solo Highway

Science.gov (United States)

Tumanduk, M. S. S. S.; Maki, T. S.; Pangkey, T. U. Y.; Pandeiroth, Y. C.

2018-02-01

Semarang-Solo highway works section II Gedawang-Penggaron constitutes a labile area. It is thought to be effect of the existence of coat clay shale which have moulded. For the purpose of anticipating the embankment mass movement it is placed line bored pile and stringed up (soldiers pile). The objective of this research is to know the efficient use of soldier’s pile of the embankment on Semarang-Solo highway section II Gedawang-Penggaron pursuant based upon numerical simulation. The result of analysis depicts that original slope in a stabil state with horizontal displacement which equal to 0.06 m and safety factor (SF) which equal to 1.31. The strengthened embankment with bored pile is not effective to give am SF improvement at slope so that, at this phase, the slope cannot be slid to be safe enough from landslide namely with horizontal displacement which equal to 0.20 m and SF which equal to 1.09. The effect of traffic load horizontal displacement is which equal to 0.21 m with SF which equal to 1.00. The earthquake simulation results horizontal displacement which equal to 0.75 m with SF which equal to 1.00. Long variation of bored pile of phase II by neglecting bored pile phase III at the depth 35 m yields horizontal displacement which equal to 0.03 m and SF optimum which equal to 2.17. The variation of pile location by placing bored pile under embankment slope foot with distance from the location of bored pile of phase II which equal to 20 m without changing the profile of the existing bored pile creates the horizontal displacement which equals to 0.02 m with SF which equal to 2.29. The result of the horizontal displacement and SF of the two alternative is safer compared to the existing condition (SF>1.5).

Impacts of Embankment System on Natural Wetlands and Sustainable Water Resources Development in the Northwest Region of Bangladesh

Science.gov (United States)

Pervin, M.; Rahman, M. A.

2012-12-01

In the Northwest region of Bangladesh, the Chalan Beel is one of the largest Beel ("Beel" refers to natural wetland) in Bangladesh. Polder C (an area surrounded by embankment) of Chalan Beel area consists of 50% natural wetland of the region. Historically, the area was rich with fish, flora and fauna, and agricultural resources. Both flood and drainage congestion have been identified as major problems existing in the project area. Farmers are badly affected by the sudden onrush of floodwater through the embankment breaches, public cuts and incomplete hydraulic structures during the rainy season. The floodwater damages B. Aman and late Boro paddy by 10% and washes away housing settlements. Sometimes water gets scarce in polder C in dry season that is unfavorable for the crop. Loss of crops and fishery affects the economy strongly. The polder was not according to master plan and with lack of operation and maintenance. Instead of improving the livelihood in the study area the embankment arises detrimental effect on the people. This paper focuses mainly the impact of the embankments on hydrology, fishery, agriculture and socio-economic condition in polder C at Chalan Beel area. Present conditions are compared with the natural conditions existed in the last decades. Finally, the paper gives some recommendations for further sustainable water resources management. It is estimated that the natural wetland loss is about 10%. The analysis shows that the river or channel cross-sections are reduced by ca. 2 m and water level is increasing with time in the rivers along the polder due to confinement effect and siltation. It appears from the study that due to this confinement effect and siltation effect, flood and drainage problems are increasing and consequently, the area is affected in every year to a great extent. At present, cross sections of natural canals are not working properly and back water flow from Hurasagar River creates drainage congestion. About 20% of fish

Performance-based seismic assessment of vulnerability of dam using time history analysis

Directory of Open Access Journals (Sweden)

Elmrabet Oumnia

2018-01-01

Full Text Available The current performance-based seismic assessment procedure can be computationally intensive as it requires many time history analyses (THA each requiring time intensive post-processing of results. Time history analysis is a part of structural analysis and is the calculation of the response of a structure to any earthquake. It is one of the main processes of structural design in regions where earthquakes are prevalent. The objective of this study is to evaluate the seismic performance of embankment dam located on the Oued RHISS in the Province of AL HOCEIMA using the THA method. To monitor structural behavior, the seismic vulnerability of structure is evaluated under real earthquake records with considering the soil-structure-fluide interaction. In this study, a simple assistant program is developed for implementing earthquake analyses of structure with ANSYS, ground acceleration–time history data are used for seismic analysis and dynamic numerical simulations were conducted to study and identify the total response of the soil-structure system.

Stability analysis of roadway embankments supported by stone columns with the presence of water table under short-term and long-term conditions

Directory of Open Access Journals (Sweden)

Kadhim Shaymaa Tareq

2018-01-01

Full Text Available Use of stone column technique to improve soft foundation soils under roadway embankments has proven to increase the bearing capacity and reduce the potential settlement. The potential contribution of stone columns to the stability of roadway embankments against general (i.e. deep-seated failure needs to be thoroughly investigated. Therefore, a two-dimensional finite difference model implemented by FLAC/SLOPE 7.0 software, was employed in this study to assess the stability of a roadway embankment fill built on a soft soil deposit improved by stone column technique. The stability factor of safety was obtained numerically under both short-term and long-term conditions with the presence of water table. Two methods were adopted to convert the three-dimensional model into plane strain condition: column wall and equivalent improved ground methods. The effect of various parameters was studied to evaluate their influence on the factor of safety against embankment instability. For instance, the column diameter, columns’ spacing, soft soil properties for short-term and long-term conditions, and the height and friction angle of the embankment fill. The results of this study are developed in several design charts.

Mapping seepage through the River Reservoir Dam near Eagar, Arizona

Energy Technology Data Exchange (ETDEWEB)

Rollins, P.

2005-06-30

This article describes the actions taken to address an unusual amount of water seepage from the left abutment weir-box of the River Reservoir dam built in 1896 near Eagar, Arizona. Upon noting the seepage in March 2004, the operator, Round Valley Water Users Association, contacted the State of Arizona who funded the investigation and subsequent remediation activities through an emergency fund. The dam was originally built with local materials and did not include a clay core. It was modified at least four times. The embankment sits on basalt bedrock and consists of clayey soils within a rock-fill shell. AquaTrack technology developed by Willowstick Technologies was used to assess the deteriorating situation. AquaTrack uses a low voltage, low amperage audio-frequency electrical current to energize the groundwater or seepage. This made it possible to follow the path of groundwater between the electrodes. A magnetic field was created which made it possible to locate and map the field measurements. The measured magnetic field data was processed, contoured and correlated to other hydrogeologic information. This identified the extent and preferential flow paths of the seepage. The survey pinpointed the area with the greatest leakage in both the horizontal and vertical directions. Fluorescent dyes were also used for tracer work to confirm previous findings that showed a serious seepage problem. The water of the reservoir was lowered to perform remedial measures to eliminate the risk of immediate failure. Funding for a more permanent repair is pending. 10 figs.

The House of Socialism in Literature. Trifonov's House on the Embankment

NARCIS (Netherlands)

van Baak, Joost; Brouwer, S

2008-01-01

The historic house described in Trifonov's novel, (sic) (The House on the Embankment; 1976) reflects an image of Soviet life in some of its crucial phases that has an enduring significance for later generations. It can be seen as a symbol of the Soviet era, in all its aspects. During the course of

Monitoring of railway embankment settlement with fiber-optic pulsed time-of-flight radar.

Science.gov (United States)

Kilpelä, Ari; Lyöri, Veijo; Duan, Guoyong

2012-12-01

This paper deals with a fiber-optic pulsed time-of-flight (PTOF) laser radar used for monitoring the settlement of a railway embankment. The operating principle is based on evaluating the changes in the lengths of the fiber-optic cables embedded in the embankment by measuring the time separation of the optical pulses reflected from both ends of the sensor fiber. The advantage of this method is that it integrates the elongation of the whole sensor, and many sensor fibers can be connected in series. In a field test, seven polyurethane-coated optical cables were installed in a railway embankment and used as 20-m long sensors. The optical timing pulses were created using specially polished optical connectors. The measured precision was 0.28 ps, which corresponds 1.8 μstrain elongation using a 20 m long sensor fiber, using an averaged value of 10,000 pulses for a single measurement value. The averaged elongation value of all sensors was used for cancelling out the effect of temperature variation on the elongation value of each individual sensor. The functionality of the method was tested by digging away a 7.5 m long and approximately 18 mm high section of sand below one sensor. It was measured as a +3 mm change in the length of the sensor fiber, which matched well with the theoretically calculated elongation value, 2.9 mm. The sensor type proved to be strong but flexible enough for this type of use.

Existing Resources, Standards, and Procedures for Precise Monitoring and Analysis of Structural Deformations. Volume 1

Science.gov (United States)

1992-09-01

commonplace, particularly in the monitoring of dams and hydro-electric power generating stations. Italy’s ENEL (Ente Nazionale per 1’ Energia Elettrica...State Commissions to enforce supervision and monitoring of dams by the new owners. Currently, dams owned by state organizations such as Agua y Energia ...Large Dams, Rio de Janeiro, Brazil May. Millmore, J.P. and J.A. Charles (1988). "A -survey of UK embankment dams." Proceedings of Reservoir Renovation 88

Mechanical Parameters of Rubber-Sand Mixtures for Numerical Analysis of a Road Embankment

Science.gov (United States)

Kowalska, Magdalena; Chmielewski, Maciej

2017-10-01

Waste production is one of the greatest problems of the modern world. It is inevitably related to the increase of industrialization. One of the most difficult, and growing in amounts, waste is scrap tyres. The most common method of utilization of end-of-life tyres by their incineration raises much concern in terms of air pollution. More sustainable seems to reuse the tyre derived products - rubber in particular - in civil engineering, where the interesting properties of this material may be effectively utilized. This paper presents results of direct shear strength tests on sand-rubber mixtures, which were next applied to a numerical FEM (finite element method) model of a road embankment built on soft ground. The laboratory tests, conducted for two types of scrap tyre rubber granulates (0.5 - 2 mm and 1 - 5 mm in size) mixed with medium fluvial sand in various proportions (5, 10, 30 and 50% by weight), proved that the unit weight of the mixtures is distinctly smaller that the unit weight of sand alone and at 50% rubber content it drops by half. The internal angle of friction stays almost unchanged for the mixtures with up to 10% of rubber (33 - 37°), but decreases by about 10° when the rubber content increases to 50%. In most of the cases analysed, the cohesion intercept is higher in case of sand-rubber mixtures when compared to sand alone. The numerical model simulated a 4.5 m high embankment with a 3 m thick layer made of sand-rubber mixtures, containing 0%, 10% or 30% of the waste product, founded on a weak subsoil (with a 3 m layer of organic soil). The results showed that stability factor of the structure built with the layer containing 30% of the coarser rubber granulate has increased from 1.60 - for sand only, to 2.15. The embankment was also able to carry load increased from 32 kPa to 45.5 kPa and its base showed much smaller settlement. The results prove that the use of tyre derived aggregates in embankment construction is not only an effective way of

NRC inventory of dams

International Nuclear Information System (INIS)

Lear, G.E.; Thompson, O.O.

1983-01-01

The NRC Inventory of Dams has been prepared as required by the charter of the NRC Dam Safety Officer. The inventory lists 51 dams associated with nuclear power plant sites and 14 uranium mill tailings dams (licensed by NRC) in the US as of February 1, 1982. Of the 85 listed nuclear power plants (148 units), 26 plants obtain cooling water from impoundments formed by dams. The 51 dams associated with the plants are: located on a plant site (29 dams at 15 plant sites); located off site but provide plant cooling water (18 dams at 11 additional plant sites); and located upstream from a plant (4 dams) - they have been identified as dams whose failure, and ensuing plant flooding, could result in a radiological risk to the public health and safety. The dams that might be considered NRC's responsibility in terms of the federal dam safety program are identified. This group of dams (20 on nuclear power plant sites and 14 uranium mill tailings dams) was obtained by eliminating dams that do not pose a flooding hazard (e.g., submerged dams) and dams that are regulated by another federal agency. The report includes the principal design features of all dams and related useful information

Spanish experiences with marginal and special materials on the construction of road embankments

International Nuclear Information System (INIS)

Cano Linares, H.; Perucho Martinez, A.

2015-01-01

The use of existing materials along the alignment of a road is an essential problem within the Sustainable Development policies, which is being promoting worldwide since a long time. In the Word road Association (PIARC-AIPCR) this subject has being investigated by different Technical Committees during last decades. Additionally, the review of the article 330 Embankment of PG-3 (FOM 1382/2002) has opened the door to new non-conventional materials, as wastes and artificial materials, to be used on embankments. This could come to adequate solutions, technically, and environmentally, contributing with national legislation on valorisation policies. In this sense, the use of marginal materials and wastes con represent and important save on natural resources and dumping sites. In Spain, some experiences with marginal materials and wastes have being carried out. The work presented has consisted in compiling and analysing the experiences executed with marginal materials and wastes on Spanish road embankments. Although there are many other cases, 24 cases published with adequate information have being analysed, summarising aspects as: materials problems arrangement solutions or treatments employed. Analysing these experiences and making them public can be a way to transmit confidence, help to improve knowledge, and progress on the preparation of recommendations. This work has being carried out on the frame of the Project Geotechnical Engineering, Materials and Structures and Impact of Infrastructure in Civil engineering (TTIGEM), within the frame Program Border Cooperation Spain-External Borders (POCTEFEX); particularly in the Activity 2 related to Technology Transfer of Construction Materials, including marginal materials and wastes. (Author)

An expression for the water-sediment moving layer in unsteady flows valid for open channels and embankments

Directory of Open Access Journals (Sweden)

A. M. Berta

2010-05-01

Full Text Available During the floods, the effects of sediment transport in river beds are particulary significant and can be studied through the evolution of the water-sediment layer which moves in the lower part of a flow, named "moving layer". Moving layer variations along rivers lead to depositions and erosions and are typically unsteady, but are often tackled with expressions developed for steady (equilibrium conditions. In this paper, we develop an expression for the moving layer in unsteady conditions and calibrate it with experimental data. During laboratory tests, we have in fact reproduced a rapidly changing unsteady flow by the erosion of a granular steep slope. Results have shown a clear tendency of the moving layer, for fixed discharges, toward equilibrium conditions. Knowing the equilibrium achievement has presented many difficulties, being influenced by the choice of the equilibrium expression and moreover by the estimation of the parameters involved (for example friction angle. Since we used only data relevant to hyper-concentrated mono-dimensional flows for the calibration – occurring for slope gradients in the range 0.03–0.20 – our model can be applied both on open channels and on embankments/dams, providing that the flows can be modelled as mono-dimensional, and that slopes and applied shear stress levels fall within the considered ranges.

Dams

Data.gov (United States)

Vermont Center for Geographic Information — This dataset �is generated from from the Vermont Dam Inventory (VDI). The VDI is managed by the VT DEC's Dam Safety and Hydrology Section and contains information...

A step in the right direction: new flow depth relationships for stepped spillway design

Science.gov (United States)

A common deficiency for embankment dams changing from a low hazard to a high hazard dam is inadequate spillway capacity. Roller compacted concrete (RCC) stepped spillways are a popular method to address this issue. Stepped spillway research has gained momentum in recent years due to the need for d...

Geophysical techniques in detection to river embankments - A case study: To locate sites of potential leaks using surface-wave and electrical methods

Science.gov (United States)

Chen, C.; Liu, J.; Xu, S.; Xia, J.; ,

2004-01-01

Geophysical technologies are very effective in environmental, engineering and groundwater applications. Parameters of delineating nature of near-surface materials such as compressional-wave velocity, shear-wave velocity can be obtained using shallow seismic methods. Electric methods are primary approaches for investigating groundwater and detecting leakage. Both of methods are applied to detect embankment in hope of obtaining evidences of the strength and moisture inside the body. A technological experiment has done for detecting and discovering the hidden troubles in the embankment of Yangtze River, Songzi, Hubei, China in 2003. Surface-wave and DC multi-channel array resistivity sounding techniques were used to detect hidden trouble inside and under dike like pipe-seeps. This paper discusses the exploration strategy and the effect of geological characteristics. A practical approach of combining seismic and electric resistivity measurements was applied to locate potential pipe-seeps in embankment in the experiment. The method presents a potential leak factor based on the shear-wave velocity and the resistivity of the medium to evaluate anomalies. An anomaly found in a segment of embankment detected was verified, where occurred a pipe-seep during the 98' flooding.

Safety Aspects of Sustainable Storage Dams and Earthquake Safety of Existing Dams

Directory of Open Access Journals (Sweden)

Martin Wieland

2016-09-01

Full Text Available The basic element in any sustainable dam project is safety, which includes the following safety elements: ① structural safety, ② dam safety monitoring, ③ operational safety and maintenance, and ④ emergency planning. Long-term safety primarily includes the analysis of all hazards affecting the project; that is, hazards from the natural environment, hazards from the man-made environment, and project-specific and site-specific hazards. The special features of the seismic safety of dams are discussed. Large dams were the first structures to be systematically designed against earthquakes, starting in the 1930s. However, the seismic safety of older dams is unknown, as most were designed using seismic design criteria and methods of dynamic analysis that are considered obsolete today. Therefore, we need to reevaluate the seismic safety of existing dams based on current state-of-the-art practices and rehabilitate deficient dams. For large dams, a site-specific seismic hazard analysis is usually recommended. Today, large dams and the safety-relevant elements used for controlling the reservoir after a strong earthquake must be able to withstand the ground motions of a safety evaluation earthquake. The ground motion parameters can be determined either by a probabilistic or a deterministic seismic hazard analysis. During strong earthquakes, inelastic deformations may occur in a dam; therefore, the seismic analysis has to be carried out in the time domain. Furthermore, earthquakes create multiple seismic hazards for dams such as ground shaking, fault movements, mass movements, and others. The ground motions needed by the dam engineer are not real earthquake ground motions but models of the ground motion, which allow the safe design of dams. It must also be kept in mind that dam safety evaluations must be carried out several times during the long life of large storage dams. These features are discussed in this paper.

Damming evidence : Canada and the World Commission on Dams

Energy Technology Data Exchange (ETDEWEB)

Vert, P.; Parkinson, B.

2003-06-01

Large hydroelectric projects have been met with strong resistance from affected communities, particularly indigenous groups who have been displaced from their flooded communities following the damming of a river. The World Commission on Dams (WCD) was formed in 1998 to review the effectiveness of large dams and develop internationally acceptable guidelines and standards for large dams or hydro energy projects. The Canadian government, through the Canadian International Development Agency, was one of many governments to fund the WCD. However, the authors argue that despite the financial support, the Canadian government was absent from any effort to follow-up on the recommendations of the WCD. The seven strategic priorities in the decision making process include: (1) gaining public acceptance, (2) comprehensive option assessment of water, energy, food and development needs, (3) addressing existing dams to improve the benefits that can be derived from them, (4) sustaining livelihoods, (5) recognizing the entitlements and sharing benefits, (6) ensuring compliance, and (7) sharing rivers for peace, development and security. This report offers a means to assess planned or existing dams and presents a set of guidelines for good practices linked to the seven strategic priorities. Ten case studies from around the world were presented, including the Three Gorges Dam in China. 154 refs., 3 figs., 3 appendices.

Proceedings of the Canadian Dam Association's 2006 annual conference: dams: past, present and future

International Nuclear Information System (INIS)

2006-01-01

This conference addressed particular technical challenges regarding the operation of dams with particular focus on best practices for improving dam management and safety. It featured 4 workshops and a technical program led by experts on dams and tailings facilities that addressed topics such as dam construction, design and rehabilitation; dam management in a hydrological uncertainty context; monitoring, instrumentation and maintenance; dam behaviour; dam safety, dam failure and practical approaches to emergency preparedness planning for dam owners; historical aspects and environmental issues and conflicting water use. Recent developments in dam construction were reviewed along with discharge and debris management, tailings dam issues, asset management, seismic issues, public safety, seepage monitoring, flow control, dam rehabilitation, concrete testing, hydrotechnical issues, risk assessment methodology, and dam safety guidelines for extreme flood analyses and their applications. All 80 presentations from this conference have been catalogued separately for inclusion in this database. refs., tabs., figs

Optimization in the use of Air Convection Embankments for Protection of Underlying Permafrost

DEFF Research Database (Denmark)

Jørgensen, Anders Stuhr; Ingeman-Nielsen, Thomas

2012-01-01

Since the beginning of the 1990s a significant increase in the mean annual air temperatures has been recorded all over the arctic regions. This has lead to a degrading of permafrost, which is now threatening the stability of airport and road embankments. To minimize the damages caused by thaw...

Proceedings of the 2010 Canadian Dam Association's public safety around dams workshop

Energy Technology Data Exchange (ETDEWEB)

NONE

2010-07-01

Nearly 30 people have drowned in dam-related incidents over the last 10 years in Canada. The Canadian public is now calling for improved safety guidelines. Public interaction with dams is increasing as a result of interest in extreme sports and perceived rights of access. However, many members of the public are not aware of the dangers posed by dams. This workshop provided a forum to discuss proposals for a draft publication of the Canadian Dam Association (CDA) guidelines for public safety and security around dams. Issues related to current legislation and liability were discussed. Methods of increasing public awareness of the hazards posed by dams included increased signage in dam locations, the use of audible and visual alert systems, and the use of booms and buoys. The responsibilities of dam owners in ensuring the safety of dams were also discussed. The conference featured 5 presentations, of which 2 have been catalogued separately for inclusion in this database. tabs., figs.

The Dams and Monitoring Systems and Case Study: Ataturk and Karakaya Dams

Science.gov (United States)

Kalkan, Y.; Bilgi, S.; Gülnerman, A. G.

2017-12-01

Dams are among the most important engineering structures used for flood controls, agricultural purposes as well as drinking and hydroelectric power. Especially after the Second World War, developments on the construction technology, increase the construction of larger capacity dams. There are more than 150.000 dams in the world and almost 1000 dams in Turkey, according to international criteria. Although dams provide benefits to humans, they possess structural risks too. To determine the performance of dams on structural safety, assessing the spatial data is very important. These are movement, water pressure, seepage, reservoir and tail-water elevations, local seismic activities, total pressure, stress and strain, internal concrete temperature, ambient temperature and precipitation. These physical data are measured and monitored by the instruments and equipment. Dams and their surroundings have to be monitored by using essential methods at periodic time intervals in order to determine the possible changes that may occur over the time. Monitoring programs typically consist of; surveillance or visual observation. These programs on dams provide information for evaluating the dam's performance related to the design intent and expected changes that could affect the safety performance of the dam. Additionally, these programs are used for investigating and evaluating the abnormal or degrading performance where any remedial action is necessary. Geodetic and non-geodetic methods are used for monitoring. Monitoring the performance of the dams is critical for producing and maintaining the safe dams. This study provides some general information on dams and their different monitoring systems by taking into account two different dams and their structural specifications with the required information. The case study in this paper depends on a comparison of the monitoring surveys on Atatürk Dam and Karakaya Dam, which are constructed on Firat River with two different structural

Stinking Foreshore to Tree Lined Avenue: Investigating the Riverine Lives Impacted by the Construction of the Thames Embankments in Victorian London

Directory of Open Access Journals (Sweden)

Hanna Louise Steyne

2013-09-01

Full Text Available Victorian London saw dramatic physical changes along the river Thames. Large enclosed Docks and Thames Embankments were constructed as the city struggled to cope with its ballooning population and prospering shipping industry. Whilst the Thames Embankments have been hailed as engineering triumphs, the fate of those whose livelihood relied on access to the river in central London (such as wharf workers, barge, ferry and lighter men, and others is unknown. In order to investigate the impact of the Embankment, a methodology has been developed which enables characterisation of a large swathe of urban riverside throughout the mid- to late 19th century, whilst also ensuring that the stories of individuals and communities are not lost. The approach combines and adapts established methodologies, such as Historic Landscape/Seascape Characterisation and Maritime Cultural Landscapes, to understand the nature and changes in the urban riverside landscape. This methodology forms the background for detailed research on smaller sites, such as a single street, housing block, or industrial site, in order to create ‘Ethnographies of Place’. These small-scale ‘Ethnographies’ have the potential to tell stories about how the social and economic circumstances of individuals and communities changed as a result of the landscape changes associated with the Embankment construction. This paper presents the initial work to establish the methodology and preliminary conclusions based on key sources.

Management of dams for the next Millennium: proceedings of the 1999 Canadian Dam Association

Energy Technology Data Exchange (ETDEWEB)

NONE

1999-07-01

The meeting featured seven sessions with 18 papers abstracted/indexed therein as follows: keynote address: tailings dams safety - implications for the dam safety community; 1 - design and performance: performance monitoring of dams: are we doing what we should be doing?; tailings dams from the perspective of conventional dam engineering; and design overview of Syncrude's Mildred Lake east toe berm; 2 - design and modelling: use of a 2D model for a dam break study on the ALCAN hydroelectric complex in Quebec; and spillway design implications resulting from changes in rainfall extremes; 3 - risk and dam safety I: closing the gaps in the dam safety guidelines; the reality of life safety consequence classification; and surveillance practices for the next millenium; 4 - risk and dam safety II: quantitative risk-assessment using the capacity-demand analysis; and new guidelines for dam safety classification; 5 - millenium issues: expectations of immortality, dam safety management into the next millenium; 6 - rehabilitation techniques: the unconventional application of conventional materials; nondestructive testing technology to characterize concrete dam/bedrock interface; method and instrument for detecting crack in concrete; and grouting of the cracks in the Arch 5-6 - Daniel Johnson Dam; and 7 - case studies: rehabilitation of an 80 year old Ambursen type dam; and debris booms for the protection of spillways.

Evaluating safety of concrete gravity dam on weak rock: Scott Dam

International Nuclear Information System (INIS)

Goodman, R.E.; Ahlgren, C.S.

2000-01-01

Scott Dam is owned and operated by Pacific Gas and Electric Co. (PG and E) as part of the Potter Valley Project. Although it is an unimpressive concrete gravity dam [233 m (765 ft) long with maximum water surface 33.4 m (110 ft) above tail water], the dam has unusually complex and weak foundation rocks; thick condition caused design changes during construction, numerous subsequent special investigations, and several corrections and additions. A main stumbling block to clarification of the dam safety issue for Scott Dam has always been difficulty in characterizing the foundation material. This paper discusses an approach to this problem as well s how the safety of the dam was subsequently confirmed. Following a comprehensive program of research, investigations, and analysis from 1991 to 1997

Comment on 'Reinterpreting the famous train/embankment experiment of relativity'

International Nuclear Information System (INIS)

Rowland, David R

2004-01-01

Nelson (2003 Eur. J. Phys. 24 379) recently claimed on logical grounds that Einstein's train and embankment thought experiment cannot be used to prove the relativity of simultaneity prior to knowledge of the Lorentz transformations as it is purported to do. It is argued in this comment that Nelson's claim is based on premises which are incorrect, thus invalidating his conclusions. It is also argued that Nelson's article furnishes a 'proof by contradiction' of the desired result, thus also invalidating his claim. (letters and comments)

Dam removal: Listening in

Science.gov (United States)

Foley, M. M.; Bellmore, J. R.; O'Connor, J. E.; Duda, J. J.; East, A. E.; Grant, G. E.; Anderson, C. W.; Bountry, J. A.; Collins, M. J.; Connolly, P. J.; Craig, L. S.; Evans, J. E.; Greene, S. L.; Magilligan, F. J.; Magirl, C. S.; Major, J. J.; Pess, G. R.; Randle, T. J.; Shafroth, P. B.; Torgersen, C. E.; Tullos, D.; Wilcox, A. C.

2017-07-01

Dam removal is widely used as an approach for river restoration in the United States. The increase in dam removals—particularly large dams—and associated dam-removal studies over the last few decades motivated a working group at the USGS John Wesley Powell Center for Analysis and Synthesis to review and synthesize available studies of dam removals and their findings. Based on dam removals thus far, some general conclusions have emerged: (1) physical responses are typically fast, with the rate of sediment erosion largely dependent on sediment characteristics and dam-removal strategy; (2) ecological responses to dam removal differ among the affected upstream, downstream, and reservoir reaches; (3) dam removal tends to quickly reestablish connectivity, restoring the movement of material and organisms between upstream and downstream river reaches; (4) geographic context, river history, and land use significantly influence river restoration trajectories and recovery potential because they control broader physical and ecological processes and conditions; and (5) quantitative modeling capability is improving, particularly for physical and broad-scale ecological effects, and gives managers information needed to understand and predict long-term effects of dam removal on riverine ecosystems. Although these studies collectively enhance our understanding of how riverine ecosystems respond to dam removal, knowledge gaps remain because most studies have been short (< 5 years) and do not adequately represent the diversity of dam types, watershed conditions, and dam-removal methods in the U.S.

Public safety around dams

Energy Technology Data Exchange (ETDEWEB)

Bourassa, H. [Centre d' expertise hydrique du Quebec, Quebec, PQ (Canada)

2009-07-01

Fourty public dams are managed on a real-time basis by the Centre d'expertise hydrique du Quebec (CEHQ). This presentation described the public dams owned by the CEHQ and discussed the public safety measures at the dams. The dams serve various purposes, including protection against floods; industrial or drinking water supply; resort or recreational activities; hydroelectric development; and wildlife conservation. Trigger events were also discussed, such as the complaint at Rapides-des-Cedres dam and deaths that occurred in 2004 when water from a dam was released without warning. Several photographs were presented to illustrate that people were unaware of the danger. Initiatives aimed at raising awareness and studying public safety issues were discussed. A pilot project was launched and a permanent committee was created to evaluate all aspects of public safety at the dams owned by CEHQ. The first tasks of the committee were to establish requirements for waterway safety barriers, both upstream and downstream, for all public dams; to establish requirements for safety signage for all public dams; and to develop criteria to decide on safety signage at each dam. figs.

Public safety around dams

Energy Technology Data Exchange (ETDEWEB)

Bourassa, H [Centre d' expertise hydrique du Quebec, Quebec, PQ (Canada)

2009-07-01

Fourty public dams are managed on a real-time basis by the Centre d'expertise hydrique du Quebec (CEHQ). This presentation described the public dams owned by the CEHQ and discussed the public safety measures at the dams. The dams serve various purposes, including protection against floods; industrial or drinking water supply; resort or recreational activities; hydroelectric development; and wildlife conservation. Trigger events were also discussed, such as the complaint at Rapides-des-Cedres dam and deaths that occurred in 2004 when water from a dam was released without warning. Several photographs were presented to illustrate that people were unaware of the danger. Initiatives aimed at raising awareness and studying public safety issues were discussed. A pilot project was launched and a permanent committee was created to evaluate all aspects of public safety at the dams owned by CEHQ. The first tasks of the committee were to establish requirements for waterway safety barriers, both upstream and downstream, for all public dams; to establish requirements for safety signage for all public dams; and to develop criteria to decide on safety signage at each dam. figs.

Assessing the effects of using compost-sludge mixtures to reduce erosion in road embankments.

Science.gov (United States)

De Oña, J; Osorio, F; Garcia, P A

2009-05-30

Recent research shows the benefits derived from applying compost and sludge to road embankments to enhance the cover crop and reduce soil loss due to erosion, particularly in arid environments. Following this line of research, the study described in this paper analyzes and compares the use of sludge and compost for the purposes mentioned. In the first phase of this study, compost or sludge was applied separately to road embankments, and in the second phase both were applied simultaneously. This paper discusses the results obtained in each case. Our study was conducted on a total of 32 plots, located along a road embankment. The 32 plots, each with an area of 20 m(2), were divided into two groups of 16. One group was placed on a 2:1 side slope, and the other was on a 3:2 side slope. Each group received four different compost dosages (0, 40, 60 and 80 t/ha) and four sludge dosages (0, 60, 80 and 100t/ha). Four plant species were selected to be planted in each plot. Our study analyzes the survival rate of the plants, their growth rate and germination, colonization of the plots by other species, cover crop per plot, and soil loss, all in relation to the compost and sludge dosage as well as the side slope type. The results obtained show that when only sludge or compost was applied to the plot, soil loss was reduced by an average of 35%, whereas when a mixture of sludge and compost was applied, soil erosion was reduced by 63% to as much as 90%.

Dam failure analysis for the Lago El Guineo Dam, Orocovis, Puerto Rico

Science.gov (United States)

Gómez-Fragoso, Julieta; Heriberto Torres-Sierra,

2016-08-09

The U.S. Geological Survey, in cooperation with the Puerto Rico Electric Power Authority, completed hydrologic and hydraulic analyses to assess the potential hazard to human life and property associated with the hypothetical failure of the Lago El Guineo Dam. The Lago El Guineo Dam is within the headwaters of the Río Grande de Manatí and impounds a drainage area of about 4.25 square kilometers.The hydrologic assessment was designed to determine the outflow hydrographs and peak discharges for Lago El Guineo and other subbasins in the Río Grande de Manatí hydrographic basin for three extreme rainfall events: (1) a 6-hour probable maximum precipitation event, (2) a 24-hour probable maximum precipitation event, and (3) a 24-hour, 100-year recurrence rainfall event. The hydraulic study simulated a dam failure of Lago El Guineo Dam using flood hydrographs generated from the hydrologic study. The simulated dam failure generated a hydrograph that was routed downstream from Lago El Guineo Dam through the lower reaches of the Río Toro Negro and the Río Grande de Manatí to determine water-surface profiles developed from the event-based hydrologic scenarios and “sunny day” conditions. The Hydrologic Engineering Center’s Hydrologic Modeling System (HEC–HMS) and Hydrologic Engineering Center’s River Analysis System (HEC–RAS) computer programs, developed by the U.S. Army Corps of Engineers, were used for the hydrologic and hydraulic modeling, respectively. The flow routing in the hydraulic analyses was completed using the unsteady flow module available in the HEC–RAS model.Above the Lago El Guineo Dam, the simulated inflow peak discharges from HEC–HMS resulted in about 550 and 414 cubic meters per second for the 6- and 24-hour probable maximum precipitation events, respectively. The 24-hour, 100-year recurrence storm simulation resulted in a peak discharge of about 216 cubic meters per second. For the hydrologic analysis, no dam failure conditions are

What factors determine restoration success of a salt marsh ten years after de-embankment?

NARCIS (Netherlands)

Chang, Esther R.; Veeneklaas, R.M.; Bakker, Jan P.; Daniels, Petra; Esselink, Peter

Questions How successful was the restoration of a salt marsh at a former summer polder on the mainland coast of the Dutch Wadden Sea 10 yr after de-embankment? What were the most important factors determining the level of restoration success? Location Noard-Fryslân Bûtendyks, northwest Netherlands.

Seismic evaluation and ranking of embankments for bridges on and over the parkways in Western Kentucky.

Science.gov (United States)

2008-06-01

This study represents one of the Seismic Evaluation of Bridges on and over the Parkways in Western Kentucky investigative series. The effort is focused on the seismic vulnerability of bridge embankments against slope instability and liquefaction pote...

Concrete lining of the core-foundation interface to prevent internal erosion: An efficiency assessment

OpenAIRE

Granados García, Alfredo; Garrote de Marcos, Luis; Granados García, Isabel; Remesal, José Antonio

2015-01-01

The core-foundation interface of the embankment dams requires particular attention during design and construction, and specific surveillance during operation. A deficient treatment of this area may facilitate seepage along the interface and erosion of the core-base which, in turn, could lead to a major internal erosion process. Several dam incidents and failures were initiated following this mechanism. For instance, an imperfect core-foundation treatment was one of the causes of the Teton Dam...

Mitigation measures for soil embankments against fault rupture using geosynthetics

DEFF Research Database (Denmark)

Zania, Varvara; Tsompanakis, Yiannis; Psarropoulos, Prodromos

2010-01-01

, the number of the reinforcements, the height of the soil layer and the applied fault displacement was examined. The results which were obtained from this investigation indicate that the proposed configurations of reinforced soil can be efficiently used in order to reduce the permanent deformations developed......In the current study the ability of geosynthetics to reduce the permanent deformations developed due to a fault rupture propagation in a soil embankment is investigated. For this purpose parametric numerical analyses were performed and the effect of the material properties of the geosynthetics...

CONSTRUCTION OF A NEW HIGHWAY EMBANKMENT ON THE SOFT CLAY SOIL TREATMENT BY STONE COLUMNS IN MALAYSIA

Directory of Open Access Journals (Sweden)

QASIM A. ALJANABI

2013-08-01

Full Text Available To continue of the second phase of the East Coast Expressway between Kuantan and Kula Terengganu in Malaysia system innovative solution are required. In this new phase there are embankment region has been subjected to extensive soft clay soil. These comprise typically of clayey silts of very high water content and undrained shear strengths in the range of 8 to 11 kPa to depths of up to 8m. To support an embankment height of up to 12 m, were filled and thereafter Vibro Replacement treatment was carried out to treat the very soft soil. Extensive instrumentation using rod settlement gauges, inclinometers and piezometers were installed to monitor the performance of the Vibro Replacement treatment. This paper reports on aspects of design, installation and the measured results from the instrumentation scheme.

Evaluating liquefaction potential. A case history

International Nuclear Information System (INIS)

Blystra, A.R.

1991-01-01

Several earthen hydropower embankment dams in the midwestern United States were constructed using hydraulic fill methods and are liable to liquefaction during an earthquake due to the use of very loose, saturated sand in the embankment or foundations. A case history is presented describing the methodology used in evaluating the liquefaction potential of the largest earthfill dam in Michigan. The methodology includes the use of standard penetration and cone penetration test data in the formulation of a simplified procedure. Field investigations, laboratory testing, and analyses used are described. In addition to the drilling program, field work included an extensive ground penetrating radar survey, acoustic emission testing, and an electrical resistivity survey. It was found that the lowest calculated factor of safety against liquefaction is 0.63 for a loose zone ca 140 feet below the top of the embankment, and the factor of safety against slope failure, should the zone liquefy, is 1.49. It was concluded that while liquefaction is possible, post earthquake stability is adequate. 6 refs., 3 figs., 1 tab

How big of an effect do small dams have? Using geomorphological footprints to quantify spatial impact of low-head dams and identify patterns of across-dam variation

Science.gov (United States)

Fencl, Jane S.; Mather, Martha E.; Costigan, Katie H.; Daniels, Melinda D.

2015-01-01

Longitudinal connectivity is a fundamental characteristic of rivers that can be disrupted by natural and anthropogenic processes. Dams are significant disruptions to streams. Over 2,000,000 low-head dams (research and conservation is impaired by not knowing the magnitude of low-head dam impacts. Based on the geomorphic literature, we refined a methodology that allowed us to quantify the spatial extent of low-head dam impacts (herein dam footprint), assessed variation in dam footprints across low-head dams within a river network, and identified select aspects of the context of this variation. Wetted width, depth, and substrate size distributions upstream and downstream of six low-head dams within the Upper Neosho River, Kansas, United States of America were measured. Total dam footprints averaged 7.9 km (3.0–15.3 km) or 287 wetted widths (136–437 wetted widths). Estimates included both upstream (mean: 6.7 km or 243 wetted widths) and downstream footprints (mean: 1.2 km or 44 wetted widths). Altogether the six low-head dams impacted 47.3 km (about 17%) of the mainstem in the river network. Despite differences in age, size, location, and primary function, the sizes of geomorphic footprints of individual low-head dams in the Upper Neosho river network were relatively similar. The number of upstream dams and distance to upstream dams, but not dam height, affected the spatial extent of dam footprints. In summary, ubiquitous low-head dams individually and cumulatively altered lotic ecosystems. Both characteristics of individual dams and the context of neighboring dams affected low-head dam impacts within the river network. For these reasons, low-head dams require a different, more integrative, approach for research and management than the individualistic approach that has been applied to larger dams.

Mechanics of slide dams

International Nuclear Information System (INIS)

Young, G.A.

1970-01-01

Studies which promote the use of nuclear energy for peaceful projects in engineering are sponsored by the Atomic Energy Commission under the Plowshare program. Specific projects being considered include the construction of harbors, canals, and dams. Of these projects, perhaps the most difficult to accomplish will be the latter. This paper which is in two parts considers the problems which are associated with the construction of slide dams with nuclear explosives. It examines first the characteristics of conventional earth and rock-fill dams which are based upon proven techniques developed after many years of experience. The characteristics of natural landslide dams are also briefly considered to identify potential problems that must be overcome by slide dam construction techniques. Second, the mechanics of slide dams as determined from small-scale laboratory studies are presented. It is concluded that slide dams can be constructed and that small-scale field tests and additional laboratory studies are justified. (author)

Mechanics of slide dams

Energy Technology Data Exchange (ETDEWEB)

Young, G A [Engineering, Agbabian-Jacobsen Associates, Los Angeles (United States)

1970-05-15

Studies which promote the use of nuclear energy for peaceful projects in engineering are sponsored by the Atomic Energy Commission under the Plowshare program. Specific projects being considered include the construction of harbors, canals, and dams. Of these projects, perhaps the most difficult to accomplish will be the latter. This paper which is in two parts considers the problems which are associated with the construction of slide dams with nuclear explosives. It examines first the characteristics of conventional earth and rock-fill dams which are based upon proven techniques developed after many years of experience. The characteristics of natural landslide dams are also briefly considered to identify potential problems that must be overcome by slide dam construction techniques. Second, the mechanics of slide dams as determined from small-scale laboratory studies are presented. It is concluded that slide dams can be constructed and that small-scale field tests and additional laboratory studies are justified. (author)

Dam break analysis and flood inundation map of Krisak dam for emergency action plan

Science.gov (United States)

Juliastuti, Setyandito, Oki

2017-11-01

The Indonesian Regulation which refers to the ICOLD Regulation (International Committee on Large Dam required have the Emergency Action Plan (EAP) guidelines because of the dams have potential failure. In EAP guidelines there is a management of evacuation where the determination of the inundation map based on flood modeling. The purpose of the EAP is to minimize the risk of loss of life and property in downstream which caused by dam failure. This paper will describe about develop flood modeling and inundation map in Krisak dam using numerical methods through dam break analysis (DBA) using hydraulic model Zhong Xing HY-21. The approaches of dam failure simulation are overtopping and piping. Overtopping simulation based on quadrangular, triangular and trapezium fracture. Piping simulation based on cracks of orifice. Using results of DBA, hazard classification of Krisak dam is very high. The nearest village affected dam failure is Singodutan village (distance is 1.45 kilometer from dam) with inundation depth is 1.85 meter. This result can be used by stakeholders such as emergency responders and the community at risk in formulating evacuation procedure.

Spruce Lake Dam reconstruction

Energy Technology Data Exchange (ETDEWEB)

Snyder, G. [SGE Acres Ltd., Fredericton, NB (Canada); Barnard, J. [SGE Acres Ltd., St. John' s, NF (Canada); Vriezen, C. [City of Saint John, NF (Canada); Stephenson, M. [Jacques Whitford Environment Ltd., Fredericton, NB (Canada)

2004-09-01

Spruce Lake Dam was constructed in 1898 as part of the water supply system for Saint John, New Brunswick. The original dam was a 6 meter high, 140 meter long concrete gravity dam with an intake structure at its mid point and an overflow spillway at the left abutment. A rehabilitation project was launched in 2001 to bring the deteriorated dam into conformance with the dam safety guidelines of the Canadian Dam Association. The project criteria included minimal disruption to normal operation of water supply facilities and no negative effect on water quality. The project involved installation of a new low level outlet, removal of a gate house and water intake pipes, replacement of an access road culvert in the spillway channel, and raising the earth dam section by 1.8 meters to allow for increased water storage. The new raised section has an impervious core. The project also involved site and geotechnical investigations as well as hydrotechnical and environmental studies. This presentation described the final design of the remedial work and the environmental permitting procedures. Raising the operating level of the system proved successful as demonstrated by the fewer number of pumping days required after dam rehabilitation. The dam safety assessment under the Canadian Environmental Assessment Act began in April 2001, and the rehabilitation was completed by the end of 2002. 1 tab., 8 figs.

Small dams need better management

Science.gov (United States)

Balcerak, Ernie

2012-03-01

Many small dams around the world are poorly maintained and represent a safety hazard, according to Pisaniello et al. Better oversight of small dams is needed, the authors argue. The researchers reviewed literature, conducted case studies in four states in Australia, and developed policy benchmarks and best practices for small-dam management. Small dams, often just several meters high and typically privately owned by individual farmers, have historically caused major damage when they fail. For instance, in China in 1975, 230,000 people died when two large dams failed because of the cumulative failure of 60 smaller upstream dams. In the United States, in 1977 the 8-meter-high Kelly Barnes Lake dam failed, killing 39 people. Many other small-dam failures around the world have resulted in casualties and severe ecological and economic damage.

The Impact of Dam-Reservoir-Foundation Interaction on Nonlinear Response of Concrete Gravity Dams

International Nuclear Information System (INIS)

Amini, Ali Reza; Motamedi, Mohammad Hossein; Ghaemian, Mohsen

2008-01-01

To study the impact of dam-reservoir-foundation interaction on nonlinear response of concrete gravity dams, a two-dimensional finite element model of a concrete gravity dam including the dam body, a part of its foundation and a part of the reservoir was made. In addition, the proper boundary conditions were used in both reservoir and foundation in order to absorb the energy of outgoing waves at the far end boundaries. Using the finite element method and smeared crack approach, some different seismic nonlinear analyses were done and finally, we came to a conclusion that the consideration of dam-reservoir-foundation interaction in nonlinear analysis of concrete dams is of great importance, because from the performance point of view, this interaction significantly improves the nonlinear response of concrete dams

Modeling of hydrologic conditions and solute movement in processed oil shale waste embankments under simulated climatic conditions

International Nuclear Information System (INIS)

Reeves, T.L.; Turner, J.P.; Hasfurther, V.R.; Skinner, Q.D.

1992-06-01

The scope of this program is to study interacting hydrologic, geotechnical, and chemical factors affecting the behavior and disposal of combusted processed oil shale. The research combines bench-scale testing with large scale research sufficient to describe commercial scale embankment behavior. The large scale approach was accomplished by establishing five lysimeters, each 7.3 x 3.0 x 3.0 m deep, filled with processed oil shale that has been retorted and combusted by the Lurgi-Ruhrgas (Lurgi) process. Approximately 400 tons of Lurgi processed oil shale waste was provided by RBOSC to carry out this study. Research objectives were designed to evaluate hydrologic, geotechnical, and chemical properties and conditions which would affect the design and performance of large-scale embankments. The objectives of this research are: assess the unsaturated movement and redistribution of water and the development of potential saturated zones and drainage in disposed processed oil shale under natural and simulated climatic conditions; assess the unsaturated movement of solubles and major chemical constituents in disposed processed oil shale under natural and simulated climatic conditions; assess the physical and constitutive properties of the processed oil shale and determine potential changes in these properties caused by disposal and weathering by natural and simulated climatic conditions; assess the use of previously developed computer model(s) to describe the infiltration, unsaturated movement, redistribution, and drainage of water in disposed processed oil shale; evaluate the stability of field scale processed oil shale solid waste embankments using computer models

Post flooding damage assessment of earth dams and historical reservoirs using non-invasive geophysical techniques

Science.gov (United States)

Sentenac, Philippe; Benes, Vojtech; Budinsky, Vladimir; Keenan, Helen; Baron, Ron

2017-11-01

This paper describes the use of four geophysical techniques to map the structural integrity of historical earth reservoir embankments which are susceptible to natural decay with time. The four techniques that were used to assess the post flood damage were 1. A fast scanning technique using a dipole electromagnetic profile apparatus (GEM2), 2. Electrical Resistivity Tomography (ERT) in order to obtain a high resolution image of the shape of the damaged/seepage zone, 3. Self-Potential surveys were carried out to relate the detected seepage evolution and change of the water displacement inside the embankment, 4. The washed zone in the areas with piping was characterised with microgravimetry. The four geophysical techniques used were evaluated against the case studies of two reservoirs in South Bohemia, Czech Republic. A risk approach based on the Geophysical results was undertaken for the reservoir embankments. The four techniques together enabled a comprehensive non-invasive assessment whereby remedial action could be recommended where required. Conclusions were also drawn on the efficiency of the techniques to be applied for embankments with wood structures.

Nanoclay Performance on Resistance of Clay under Freezing Cycles

African Journals Online (AJOL)

msi

Nanotechnology has created a new movement in food production systems. ... some additives to soil has been always considered as one of effective methods to ... including mud dams, road embankments, artificial slopes and landfill sites.

Perspectives on dam safety in Canada

International Nuclear Information System (INIS)

Halliday, R.

2004-01-01

Canadian dam safety issues were reviewed from the perspective of a water resources engineer who is not a dam safety practitioner. Several external factors affecting dam safety were identified along with perceived problems in dam safety administration. The author claims that the main weakness in safety practices can be attributed to provincial oversights and lack of federal engagement. Some additions to the Canadian Dam Safety Guidelines were proposed to address these weaknesses. Canada has hundreds of large dams and high hazard dams whose failure would result in severe downstream consequences. The safety of dams built on boundary waters shared with the United States have gained particular attention from the International Joint Commission. This paper also examined safety criteria for concerns such as aging dams, sabotage and global climate change that may compromise the safety of a dam. 26 refs

78 FR 53494 - Dam Safety Modifications at Cherokee, Fort Loudoun, Tellico, and Watts Bar Dams

Science.gov (United States)

2013-08-29

... Bar Dams AGENCY: Tennessee Valley Authority. ACTION: Issuance of Record of Decision. SUMMARY: This... the dam safety modifications at Cherokee, Fort Loudoun, Tellico, and Watts Bar Dams. The notice of... Loudoun, Tellico, and Watts Bar Dams was published in the Federal Register on May 31, 2013. This...

Distribution and abundance of bee forage flora across an agricultural landscape – railway embankments vs. road verges

Directory of Open Access Journals (Sweden)

Małgorzata Wrzesień

2016-09-01

Full Text Available In this study, we evaluated if railway embankments and road verges create refuge habitats for bee flora across agricultural landscape. The survey was conducted in 2009–2012, in the Lublin Province, SE Poland. Data on the bee forage flora were obtained while making floristic charts along 60 transect plots × 300 m, with a total length of 18 000 m, for each type of linear structure. Forage bee flora was compared with respect to species richness, diversity, and evenness indices. The canonical correspondence analysis (CCA was used to characterize relationship between species composition and environmental variables. The bee forage species richness and abundance were significantly greater on railway embankments than on road verges. The composition of species varied considerably; the number of bee forage species common to both habitats was only approximately 38% in entire data set. Most good-value bee forage species were recorded along the embankments of railways with an intermediate traffic volume. Bee forage species diversity benefits from the location of habitat elements (forests or meadows, primarily if the distance is <50 m. The lack of dense patches of valuable bee forage species in the road verges was related to the high density of non-nectariferous graminoids. Our results demonstrate how the value of man-made areas in an agricultural ecosystem can vary with respect to floral resources across the landscape, suggesting that it is inappropriate to generalize about agricultural systems as a whole without first addressing differences among habitats.

78 FR 2988 - New England Hydropower Company, LLC; Notice of Preliminary Permit Application Accepted for Filing...

Science.gov (United States)

2013-01-15

... following: (1) An existing 22-foot-high, 520-foot-long earth embankment dam with a 173- foot-long stone...-wide powerhouse containing a new gearbox and electrical controls; (7) a new above ground 215-foot-long...

Performance of Damaged Soil-Concrete Wraparound Dam Sections under Dynamic Loading

Energy Technology Data Exchange (ETDEWEB)

Kanarska, Y; Lomov, I; Glascoe, L; Morris, J; Antoun, T; Hall, R; Woodson, S; Fortune, J; Hynes, M E

2009-09-28

Predicting seismic or shock loading damage of the soil-concrete interface where an embankment wraparound dam provides support to the end monoliths in a concrete gravity dam is an inherently challenging three-dimensional coupled problem. We wish to predict formation and growth of a crack between the soil and concrete with a sustained flow of water. Further, we seek to better understand all critical phenomenology of this type of problem such as the potential mitigating and stabilizing role of upstream and downstream filter zone and shell materials. This collaborative research effort will ultimately determine whether advances in computational platforms, constitutive soil models (advances in representing particulates, tension, flow, and hydraulic erosion), and physical testing (advances in centrifuge and flume testing) can be applied successfully to solve this complex problem. Our focus is (1) to develop and validate high fidelity numerical models to investigate crack formation, soil erosion, transport of materials, and stability as part of the erosion process, and deposition within interface cracks; and (2) to investigate the performance of the filter zone materials if an extreme loading event such as an earthquake or shock damages the wraparound section. Our numerical tools include both continuum and discrete approaches. The continuum approach is based on the drift-flux multiphase model where a fluid and a solid are represented as interpenetrating continua and can account for turbulent flow characteristics, particle lift forces due to shear flow, particle collisions, and gravity settling. The discrete particle approach is also applied and is useful when deriving constitutive laws and parameterizations of soil behavior. Different experimental validation studies are under consideration for model validation and calibration. Several case studies for different crack sizes and orientations, particle sizes and environmental hydraulic conditions may be required to confirm

Dynamic decision making for dam-break emergency management - Part 2: Application to Tangjiashan landslide dam failure

Science.gov (United States)

Peng, M.; Zhang, L. M.

2013-02-01

Tangjiashan landslide dam, which was triggered by the Ms = 8.0 Wenchuan earthquake in 2008 in China, threatened 1.2 million people downstream of the dam. All people in Beichuan Town 3.5 km downstream of the dam and 197 thousand people in Mianyang City 85 km downstream of the dam were evacuated 10 days before the breaching of the dam. Making such an important decision under uncertainty was difficult. This paper applied a dynamic decision-making framework for dam-break emergency management (DYDEM) to help rational decision in the emergency management of the Tangjiashan landslide dam. Three stages are identified with different levels of hydrological, geological and social-economic information along the timeline of the landslide dam failure event. The probability of dam failure is taken as a time series. The dam breaching parameters are predicted with a set of empirical models in stage 1 when no soil property information is known, and a physical model in stages 2 and 3 when knowledge of soil properties has been obtained. The flood routing downstream of the dam in these three stages is analyzed to evaluate the population at risk (PAR). The flood consequences, including evacuation costs, flood damage and monetized loss of life, are evaluated as functions of warning time using a human risk analysis model based on Bayesian networks. Finally, dynamic decision analysis is conducted to find the optimal time to evacuate the population at risk with minimum total loss in each of these three stages.

Influences of geological parameters to probabilistic assessment of slope stability of embankment

Science.gov (United States)

Nguyen, Qui T.; Le, Tuan D.; Konečný, Petr

2018-04-01

This article considers influences of geological parameters to slope stability of the embankment in probabilistic analysis using SLOPE/W computational system. Stability of a simple slope is evaluated with and without pore–water pressure on the basis of variation of soil properties. Normal distributions of unit weight, cohesion and internal friction angle are assumed. Monte Carlo simulation technique is employed to perform analysis of critical slip surface. Sensitivity analysis is performed to observe the variation of the geological parameters and their effects on safety factors of the slope stability.

EVALUASI KEAMANAN DAM JATILUHUR BERBASIS INDEKS RESIKO

Directory of Open Access Journals (Sweden)

Avazbek Ishbaev

2014-12-01

Full Text Available The dams have very important roles to agricultural activities. Especially, West Java with 240,000 hectares of agricultural land, needs a good dam structure that can be used sustainably. Jatiluhur dam in Purwakarta, West Java is one of big dams in Indonesia which has important rules not only for Purwakarta but also for Jakarta, Karawang and Bekasi residents. A study and observation about safety and dam stability is needed to prevent any damage. The purpose of this research were to identify parameters that influenced dam safety and to evaluate dam reliability based on index tools. Analysis was done using risk index tools. The result showed that the condition of the dam of Jatiluhur is still satisfied with indicators, "Idam"-750. The total index risk was 127.22 and the safety factor was 83.04 out of 100. Therefore, Jatiluhur dam could be classified as safe and no need for particular treatments. Jatiluhur dam can be operated in normal condition or abnormal condition with periodic monitoring. Keywords: dam safety, evaluation, Jatiluhur Dam, risk index tools

Dam safety operating guidelines

International Nuclear Information System (INIS)

Elsayed, E.; Leung, T.; Kirkham, A.; Lum, D.

1990-01-01

As part of Ontario Hydro's dam structure assessment program, the hydraulic design review of several river systems has revealed that many existing dam sites, under current operating procedures, would not have sufficient discharge capacity to pass the Inflow Design Flood (IDF) without compromising the integrity of the associated structures. Typical mitigative measures usually considered in dealing with these dam sites include structural alterations, emergency action plans and/or special operating procedures designed for extreme floods. A pilot study was carried out for the Madawaska River system in eastern Ontario, which has seven Ontario Hydro dam sites in series, to develop and evaluate the effectiveness of the Dam Safety Operating Guidelines (DSOG). The DSOG consist of two components: the flood routing schedules and the minimum discharge schedules, the former of which would apply in the case of severe spring flood conditions when the maximum observed snowpack water content and the forecast rainfall depth exceed threshold values. The flood routing schedules would identify to the operator the optimal timing and/or extent of utilizing the discharge facilities at each dam site to minimize the potential for dam failures cased by overtopping anywhere in the system. It was found that the DSOG reduced the number of structures overtopped during probable maximum flood from thirteen to four, while the number of structures that could fail would be reduced from seven to two. 8 refs., 4 figs., 3 tabs

Dam risk reduction study for a number of large tailings dams in Ontario

Energy Technology Data Exchange (ETDEWEB)

Verma, N. [AMEC Earth and Environmental Ltd., Mississauga, ON (Canada); Small, A. [AMEC Earth and Environmental Ltd., Fredericton, NB (Canada); Martin, T. [AMEC Earth and Environmental, Burnaby, BC (Canada); Cacciotti, D. [AMEC Earth and Environmental Ltd., Sudbury, ON (Canada); Ross, T. [Vale Inco Ltd., Sudbury, ON (Canada)

2009-07-01

This paper discussed a risk reduction study conducted for 10 large tailings dams located at a central tailings facility in Ontario. Located near large industrial and urban developments, the tailings dams were built using an upstream method of construction that did not involve beach compaction or the provision of under-drainage. The study provided a historical background for the dam and presented results from investigations and instrumentation data. The methods used to develop the dam configurations were discussed, and remedial measures and risk assessment measures used on the dams were reviewed. The aim of the study was to address key sources of risk, which include the presence of high pore pressures and hydraulic gradients; the potential for liquefaction; slope instability; and the potential for overtopping. A borehole investigation was conducted and piezocone probes were used to obtain continuous data and determine soil and groundwater conditions. The study identified that the lower portion of the dam slopes were of concern. Erosion gullies could lead to larger scale failures, and elevated pore pressures could lead to the risk of seepage breakouts. It was concluded that remedial measures are now being conducted to ensure slope stability. 6 refs., 1 tab., 6 figs.

LETTERS AND COMMENTS: Comment on 'Reinterpreting the famous train/embankment experiment of relativity'

Science.gov (United States)

Rowland, David R.

2004-09-01

Nelson (2003 Eur. J. Phys. 24 379) recently claimed on logical grounds that Einstein's train and embankment thought experiment cannot be used to prove the relativity of simultaneity prior to knowledge of the Lorentz transformations as it is purported to do. It is argued in this comment that Nelson's claim is based on premises which are incorrect, thus invalidating his conclusions. It is also argued that Nelson's article furnishes a 'proof by contradiction' of the desired result, thus also invalidating his claim.

From lab to field: Geotechnical properties for predicting embankment settlement on Lake Bonneville deposits

International Nuclear Information System (INIS)

Hoagland, K.C.; Sampaco, C.L.; Anderson, L.R.; Caliendo, J.A.; Rausher, L.; Keane, E.

1994-01-01

The results of a laboratory analysis, to determine geotechnical properties of lacustrine Lake Bonneville deposits, within the I-15 corridor of Salt Lake City, Utah, is presented. Laboratory vertical and horizontal consolidation coefficients are compared with those back-calculated from observed, field settlement data and linear relationships established. The results are used to select vertical and horizontal field coefficients and predict settlement rate of an existing embankment, scheduled for enlargement. 27 refs., 9 figs

Impedance function study for cylindrical tanks surrounded by an earthen embankment

International Nuclear Information System (INIS)

Houston, T.W.; Mertz, G.E.

1995-01-01

The Department of Energy (DOE) operates many which are used to store radioactive waste material. The original design of the tanks was often based on criteria which did not meet current seismic codes. As a result DOE is undertaking a comprehensive review of the adequacy of these structures to meet current seismic standards. This comprehensive review includes an evaluation of soil-structure interaction. One method available for performing soil structure interaction analyses of structures couples a discrete model of the structure to a lumped parameter model of the soil. This method requires the knowledge of the expected dynamic stiffness and damping functions of the rigid, massless structure resting on the soil. These are commonly referred to as the impedance functions. Lumped parameter analysis is cost effective for the surface and embedded structure cases where impedance functions are available in the literature. For a complex case with the structure located on the surface surrounded by an embankment, the impedance functions must be established prior to using a lumped parameter model approach. The present paper describes the development of horizontal impedance functions for the structure surrounded by an embankment which are developed using a finite element approach as implemented by SASSI. Impedance functions for vertical, torsional, and rocking degrees of freedom can be developed in a similar manner. These functions are easily incorporated into simple models which provide conceptual and physical insight to the response of structures. These models provide both a check of more sophisticated methods, and, due to their simplicity, permit assessment of a wide range of site and structural parameters that my affect the dynamic response of structural systems

78 FR 28838 - New England Hydropower Company, LLC; Notice of Preliminary Permit Application Accepted for Filing...

Science.gov (United States)

2013-05-16

...-high, 433-foot-long earth embankment dam with a 154- foot-long stone masonry spillway and 3.5-foot-high...-foot-long, 30-foot-wide, and 4-foot-deep tailrace; (8) a new above-ground 365-foot-long, 35-kilovolt...

PRODUCTION HALIEUTIQUE DU LAC FAE (BASSIN DU SAN ...

African Journals Online (AJOL)

about 5.229 millions CFA for the shrimp production at the rate of 1500 Flkg. .... Figure 1 Lac Fae-Localisation geographique, zones de production, secteurs et ... embankment dam ; d : water intake for regulating the threshold level of water in the.

The Effects of Dams on Downstream Channel Characteristics in Pennsylvania and Maryland: Assessing the Potential Consequences of Dam Removal

Science.gov (United States)

Skalak, K. J.; Pizzuto, J. E.; Jenkins, P.

2003-12-01

The potential downstream effects of dam removal were assessed on fifteen sites of varying dam size and characteristics in Pennsylvania and Maryland. The dams ranged in size from a 30 cm high fish weir to a water supply dam 57 m high. Stream order ranged from 1 to 4. The dams are located in watersheds with varying degrees of human disturbance and urbanization. The dams are also operated differently, with significant consequences for hydraulic residence time and downstream flow variability. Most streams were alluvial, but 6 of the reaches were clearly bedrock channels. We hypothesize that the channel upstream, which is unaffected by the dam, will provide an accurate model for the channel downstream of the dam long after dam removal. Therefore, reaches upstream and downstream of the dam were compared to determine the effects of the dam as well as the condition of the stream that will ultimately develop decades after dam removal. Surprisingly, the dams had no consistent influence on channel morphology. However, the percentage of sand is significantly lower downstream than upstream: the mean % sand downstream is 11.47%, while the mean % sand upstream is 21.39%. The coarser fractions of the bed, as represented by the 84th percentile grain diameter, are unaffected by the presence of the dam. These results imply that decades after dam removal, the percentage of sand on the bed will increase, but the coarse fraction of the bed will remain relatively unchanged.

Public safety around dams guidelines

Energy Technology Data Exchange (ETDEWEB)

Bennett, T [Canadian Dam Association, Edmonton, AB (Canada)

2010-07-01

This presentation discussed Canadian and international initiatives for improving dam safety and described some of the drivers for the development of new Canadian Dam Association (CDA) public safety guidelines for dams. The CDA guidelines were divided into the following 3 principal sections: (1) managed system elements, (2) risk assessment and management, and (3) technical bulletins. Public and media responses to the drownings have called for improved safety guidelines. While the public remains unaware of the hazards of dams, public interaction with dams is increasing as a result of interest in extreme sports and perceived rights of access. Guidelines are needed for dam owners in order to provide due diligence. Various organizations in Canada are preparing technical and public safety dam guidelines. CDA guidelines have also been prepared for signage, booms and buoys, and audible and visual alerts bulletins. Working groups are also discussing recommended practices for spill procedures, spillways and the role of professional engineers in ensuring public safety. Methods of assessing risk were also reviewed. Managed system elements for risk assessment and public interactions were also discussed, and stepped control measures were presented. tabs., figs.

Effect of a dam on epilithic algal communities of a mountain stream: before-after dam construction comparison

Directory of Open Access Journals (Sweden)

Luciana Cibils Martina

2013-02-01

Full Text Available In this study we evaluated the effect of a dam on epilithic algal communities by analyzing community response after dam construction and by comparing community composition, structure and biomass upstream and downstream of the dam. Samples of epilithic algae and environmental data were collected at each site during high and low water periods before and after dam construction in Achiras Stream (Córdoba, Argentina. Ordinations showed modifications in algal assemblages after dam construction and downstream of the dam. Ordinations also suggested a loss of seasonality at the downstream site since the assemblages were similar between hydrological periods after dam construction. Indicator species, obtained by the Indicator Value method, showed that, after dam construction, there could have been an increase in nutrient concentration and a release of plankton from the impoundment. Abundance, richness and diversity were altered after dam construction as assessed by ANOVAs derived from a modified BACI Design. Proportion of early-successional species was higher at the upstream site while late-successional species were dominant at the downstream site, as predicted. Lower fluctuations in discharge downstream of the dam may have helped succession advance, whereas at the upstream site, mainly during the high water period, floods could have caused sloughing of life forms from the outer layers of the biofilm, resetting the algal community to early successional stages. It may be concluded that the dam affected algal community and favored succession advance mainly by reducing current velocity and flow fluctuations.

78 FR 77397 - Flood Control Regulations, Marshall Ford Dam (Mansfield Dam and Lake Travis), Colorado River, Texas

Science.gov (United States)

2013-12-23

... Regulations, Marshall Ford Dam (Mansfield Dam and Lake Travis), Colorado River, Texas AGENCY: U.S. Army Corps... Marshall Ford Dam (Mansfield Dam and Lake Travis), Colorado River, Texas. In 1997, the Lower Colorado River... regulations to reflect changes in ownership and responsibilities of flood control management of Marshall Ford...

7 CFR 1724.55 - Dam safety.

Science.gov (United States)

2010-01-01

... 7 Agriculture 11 2010-01-01 2010-01-01 false Dam safety. 1724.55 Section 1724.55 Agriculture... § 1724.55 Dam safety. (a) The provisions of this section apply only to RUS financed electric system... for Dam Safety,”(Guidelines), as applicable. A dam, as more fully defined in the Guidelines, is...

New guidelines for dam safety classification

International Nuclear Information System (INIS)

Dascal, O.

1999-01-01

Elements are outlined of recommended new guidelines for safety classification of dams. Arguments are provided for the view that dam classification systems should require more than one system as follows: (a) classification for selection of design criteria, operation procedures and emergency measures plans, based on potential consequences of a dam failure - the hazard classification of water retaining structures; (b) classification for establishment of surveillance activities and for safety evaluation of dams, based on the probability and consequences of failure - the risk classification of water retaining structures; and (c) classification for establishment of water management plans, for safety evaluation of the entire project, for preparation of emergency measures plans, for definition of the frequency and extent of maintenance operations, and for evaluation of changes and modifications required - the hazard classification of the project. The hazard classification of the dam considers, as consequence, mainly the loss of lives or persons in jeopardy and the property damages to third parties. Difficulties in determining the risk classification of the dam lie in the fact that no tool exists to evaluate the probability of the dam's failure. To overcome this, the probability of failure can be substituted for by a set of dam characteristics that express the failure potential of the dam and its foundation. The hazard classification of the entire project is based on the probable consequences of dam failure influencing: loss of life, persons in jeopardy, property and environmental damage. The classification scheme is illustrated for dam threatening events such as earthquakes and floods. 17 refs., 5 tabs

War damages and reconstruction of Peruca dam

International Nuclear Information System (INIS)

Nonveiller, E.; Sever, Z.

1999-01-01

The paper describes the heavy damages caused by blasting in the Peruca rockfill dam in Croatia in January 1993. Complete collapse of the dam by overtopping was prevented through quick action of the dam owner by dumping clayey gravel on the lowest sections of the dam crest and opening the bottom outlet of the reservoir, thus efficiently lowering the water level. After the damages were sufficiently established and alternatives for restoration of the dam were evaluated, it was decided to construct a diaphragm wall through the damaged core in the central dam part as the impermeable dam element and to rebuild the central clay core at the dam abutments. Reconstruction works are described

33 CFR 208.19 - Marshall Ford Dam and Reservoir (Mansfield Dam and Lake Travis), Colorado River, Tex.

Science.gov (United States)

2010-07-01

... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Marshall Ford Dam and Reservoir... Marshall Ford Dam and Reservoir (Mansfield Dam and Lake Travis), Colorado River, Tex. The Secretary of the Interior, through his agent, the Lower Colorado River Authority (LCRA) shall operate the Marshall Ford Dam...

Flood Risk and Asset Management

Science.gov (United States)

2012-09-01

or silty fluvial / estuarial dykes, or pre- damaged clay surface layer. Flows / pressures lead to internal erosion and piping (FLOODsite, 2007...or both data sets from the Teton Dam failure or the Huaccoto landslide in Peru . The docu- mented data for these two events is not very de- tailed...from that of homogeneous embankments, because of the existence of less erosive layers (such as a clay core) within the dam body. The erosion of the

Excavation of the Surikamigawa dam diversion tunnel. Surikamigawa dam karihaisui tunnel kantsu

Energy Technology Data Exchange (ETDEWEB)

Ikeda, T.; Konno, T. (Ministry of Construction, Tokyo (Japan))

1994-04-01

A bypass tunnel construction has been completed at the Surikamigawa dam (Japan). This paper describes the summary of the construction. The full-swing dam construction work is scheduled to begin in 1995. The soils distributed near the dam site consist of lapillus tuff containing andesite-based light stones and tuff-based conglomerates containing large gravels. Excavation of the dam diversion tunnel has used a blasting method, and the tunnel construction has adopted an automatic tunnel cross section marking system and a non-electric explosion method. This marking system is a system to irradiate a laser beam onto the facing to depict excavation lines that realizes labor saving and high-accuracy excavation. The error at the tunnel completion was found 20 mm. The non-electric explosion method ignites a coated explosive layer with an impact wave, which is electrostatically safe, and reduces blasting vibration. Electric detonators have also been used because of using ANFO explosives. The result obtained from measurements of inner space displacement necessary for the blasting process has indicated that the area near the dam site consists of stable mountains. 6 figs., 4 tabs.

Three Sisters Dam modifications and performance

Energy Technology Data Exchange (ETDEWEB)

Courage, L.J.R. [Monenco AGRA Inc., Calgary, AB (Canada)

1995-12-31

Recent modifications and maintenance carried out at the Three Sisters Dam, in the Alberta Rockies south of the town of Canmore, were described. A detailed account was given of the dam`s geological setting, its abnormally high leakage through the foundation and its sinkhole activity. Results of studies aimed at finding the cause of leakage and sinkhole occurrences were reviewed. Modifications made to the dam since 1951 were detailed, as were modifications to handle probable maximum flood levels. Three approaches for estimating failure probabilities after identification of failure modes were described. The overall conclusion was that based on constant leakage, no settlement in the dam, penstocks, or the powerhouse since construction, the Three Sisters Dam was stable. 1 ref.

Dams and Levees: Safety Risks

Science.gov (United States)

Carter, N. T.

2017-12-01

The nation's flood risk is increasing. The condition of U.S. dams and levees contributes to that risk. Dams and levee owners are responsible for the safety, maintenance, and rehabilitation of their facilities. Dams-Of the more than 90,000 dams in the United States, about 4% are federally owned and operated; 96% are owned by state and local governments, public utilities, or private companies. States regulate dams that are not federally owned. The number of high-hazard dams (i.e., dams whose failure would likely result in the loss of human life) has increased in the past decade. Roughly 1,780 state-regulated, high-hazard facilities with structural ratings of poor or unsatisfactory need rehabilitation. Levees-There are approximately 100,000 miles of levees in the nation; most levees are owned and maintained by municipalities and agricultural districts. Few states have levee safety programs. The U.S. Army Corps of Engineers (Corps) inspects 15,000 miles of levees, including levees that it owns and local levees participating in a federal program to assist with certain post-flood repairs. Information is limited on how regularly other levees are inspected. The consequence of a breach or failure is another aspect of risk. State and local governments have significant authority over land use and development, which can shape the social and economic impacts of a breach or failure; they also lead on emergency planning and related outreach. To date, federal dam and levee safety efforts have consisted primarily of (1) support for state dam safety standards and programs, (2) investments at federally owned dams and levees, and (3) since 2007, creation of a national levee database and enhanced efforts and procedures for Corps levee inspections and assessments. In Public Law 113-121, enacted in 2014, Congress (1) directed the Corps to develop voluntary guidelines for levee safety and an associated hazard potential classification system for levees, and (2) authorized support for the

Health impacts of large dams

International Nuclear Information System (INIS)

Lerer, L.B.

1999-01-01

Large dams have been criticized because of their negative environmental and social impacts. Public health interest largely has focused on vector-borne diseases, such as schistosomiasis, associated with reservoirs and irrigation projects. Large dams also influence health through changes in water and food security, increases in communicable diseases, and the social disruption caused by construction and involuntary resettlement. Communities living in close proximity to large dams often do not benefit from water transfer and electricity generation revenues. A comprehensive health component is required in environmental and social impact assessments for large dam projects

DAM-LAKEFRONT PLAZA: Revitalization of an Agriculture Reservoir Dam in Kashar-Tirana/Albania

Directory of Open Access Journals (Sweden)

Valbona Koçi

2014-12-01

Full Text Available The Dam-Lakefront Plaza in Kashar-Tirana/Albania is a research project that proposes not only the re-consideration and reinforcement of the artificial Reservoirs Dams built during Socialism in Albania, but envisions the maintenance of dams and revitalization of the lakeside area promoting the public-private collaboration. In addition, it envisions the generation of qualitative and lively public spaces in sub-urban areas as well. Admitting the artificial lakes as specific nodes of man-made infrastructure in the landscape, and consequently the dams (together with the drainage channels as important hydrotechnic elements of the flood protection infrastructure, this research intends to elaborate on one type of landscape infrastructure - the vertical screens, offering a mediation between the natural and built landscape.

Flood early warning system : Design, implementation and computational modules

NARCIS (Netherlands)

Krzhizhanovskaya, V.V.; Shirshov, G.S.; Melnikova, N.B.; Belleman, R.G.; Rusadi, F.I.; Broekhuijsen, B.J.; Gouldby, B.P.; Lhomme, J.; Balis, B.; Bubak, M.; Pyayt, A.L.; Mokhov, I.I.; Ozhigin, A.V.; Lang, B.; Meijer, R.J.

2011-01-01

We present a prototype of the flood early warning system (EWS) developed within the UrbanFlood FP7 project. The system monitors sensor networks installed in flood defenses (dikes, dams, embankments, etc.), detects sensor signal abnormalities, calculates dike failure probability, and simulates

Geometric and frequency EMI sounding of estuarine earthen flood defence embankments in Ireland using 1D inversion models

Science.gov (United States)

Viganotti, Matteo; Jackson, Ruth; Krahn, Hartmut; Dyer, Mark

2013-05-01

Earthen flood defence embankments are linear structures, raised above the flood plain, that are commonly used as flood defences in rural settings; these are often relatively old structures constructed using locally garnered material and of which little is known in terms of design and construction. Alarmingly, it is generally reported that a number of urban developments have expanded to previously rural areas; hence, acquiring knowledge about the flood defences protecting these areas has risen significantly in the agendas of basin and asset managers. This paper focusses, by reporting two case studies, on electromagnetic induction (EMI) methods that would efficiently complement routine visual inspections and would represent a first step to more detailed investigations. Evaluation of the results is presented by comparison with ERT profiles and intrusive investigation data. The EM data, acquired using a GEM-2 apparatus for frequency sounding and an EM-31 apparatus for geometrical sounding, has been handled using the prototype eGMS software tool, being developed by the eGMS international research consortium; the depth sounding data interpretation was assisted by 1D inversions obtained with the EM1DFM software developed by the University of British Columbia. Although both sounding methods showed some limitations, the models obtained were consistent with ERT models and the techniques were useful screening methods for the identification of areas of interest, such as material interfaces or potential seepage areas, within the embankment structure: 1D modelling improved the rapid assessment of earthen flood defence embankments in an estuarine environment; evidence that EMI sounding could play an important role as a monitoring tool or as a first step towards more detailed investigations.

Fragility Analysis of Concrete Gravity Dams

Science.gov (United States)

Tekie, Paulos B.; Ellingwood, Bruce R.

2002-09-01

Concrete gravity dams are an important part ofthe nation's infrastructure. Many dams have been in service for over 50 years, during which time important advances in the methodologies for evaluation of natural phenomena hazards have caused the design-basis events to be revised upwards, in some cases significantly. Many existing dams fail to meet these revised safety criteria and structural rehabilitation to meet newly revised criteria may be costly and difficult. A probabilistic safety analysis (PSA) provides a rational safety assessment and decision-making tool managing the various sources of uncertainty that may impact dam performance. Fragility analysis, which depicts fl%e uncertainty in the safety margin above specified hazard levels, is a fundamental tool in a PSA. This study presents a methodology for developing fragilities of concrete gravity dams to assess their performance against hydrologic and seismic hazards. Models of varying degree of complexity and sophistication were considered and compared. The methodology is illustrated using the Bluestone Dam on the New River in West Virginia, which was designed in the late 1930's. The hydrologic fragilities showed that the Eluestone Dam is unlikely to become unstable at the revised probable maximum flood (PMF), but it is likely that there will be significant cracking at the heel ofthe dam. On the other hand, the seismic fragility analysis indicated that sliding is likely, if the dam were to be subjected to a maximum credible earthquake (MCE). Moreover, there will likely be tensile cracking at the neck of the dam at this level of seismic excitation. Probabilities of relatively severe limit states appear to be only marginally affected by extremely rare events (e.g. the PMF and MCE). Moreover, the risks posed by the extreme floods and earthquakes were not balanced for the Bluestone Dam, with seismic hazard posing a relatively higher risk.

The role of dams in development

International Nuclear Information System (INIS)

Cakmak, C.

2001-01-01

Although the amounts of water resources are enough for the entire world, the distribution of them in time and space shows uneven pattern. The water need is increasing with heavy industrial and agricultural requirements, while available water in the world remains as a fixed source. Economic growth, socio-cultural, and environmental developments are being realized following these changes. In order to achieve sustainable management of water resources, these changes have to be taken into consideration in water-related development projects. Demand for water is steadily increasing through out the world, even though the fresh water resources are limited and unevenly distributed, during the past three centuries, the amount of water withdrawn from fresh water resources has increased by a factor of 35, whereas world population by a factor 8. The engineering of dams, which provides regular water from reservoirs of dams to be used in case of demand pattern, is a vital part of the civilization. Dams have played a key rote in the development since the third millennium B C when the first great civilizations evolved on major rivers, such as Tigris-Euphrates, the Nile and the Indus. From these early times dams were built for flood control, water supply, irrigation and navigation. Dams also had been built to produce motive power and electricity since the industrial revolution. Development priorities changed, experience accumulated with the construction and operation of dams. Although the importance of water is well known in the human life and civilization around the world, still various groups argue that expected economic benefits are not being produced and that major environmental, economic and social costs are not being taken into account. By the end of 20th century, there were 45000 large dams in over 150 countries. According to the same classification there are 625 large dams in Turkey. All over the world, 50 % of the large dams were built mainly for irrigation. It is estimated

Matahina Dam : lessons learned from an earthquake-related internal erosion incident at the Matahina Dam, New Zealand

Energy Technology Data Exchange (ETDEWEB)

Gillon, M. [Damwatch Services Ltd., Wellington (New Zealand)

2009-07-01

This case history discussed internal erosion damage and crest subsidence caused by an earthquake at the Matahina Dam in New Zealand. The study showed that cracking and internal erosion was initiated during the 1967 reservoir filling operation. Located in an area of active volcanism and faulting, the dam is located on a river with extensive erosion through an ignimbrite flow. The dam's core is founded on compact Tertiary age sediments overlain by sand and gravel deposits beneath the shoulders of the dam. The earthquake caused a rupture along an unidentified fault trace 12 km from the dam. The horizontal base acceleration recorded at the dam was 3.25 m/s. Transverse cracking was observed at each abutment, and deformations were observed in the rockfill. An investigation program was conducted to determine the dam's integrity. Piezometer measurements showed widespread fluctuations. It was concluded that the lack of an effective filter was a significant design omission. 12 refs., 12 figs.

Dam-breach analysis and flood-inundation mapping for selected dams in Oklahoma City, Oklahoma, and near Atoka, Oklahoma

Science.gov (United States)

Shivers, Molly J.; Smith, S. Jerrod; Grout, Trevor S.; Lewis, Jason M.

2015-01-01

Dams provide beneficial functions such as flood control, recreation, and storage of water supplies, but they also entail risk; dam breaches and resultant floods can cause substantial property damage and loss of life. The State of Oklahoma requires each owner of a high-hazard dam, which the Federal Emergency Management Agency defines as dams for which failure or improper operation probably will cause loss of human life, to develop an emergency action plan specific to that dam. Components of an emergency action plan are to simulate a flood resulting from a possible dam breach and map the resulting downstream flood-inundation areas. The resulting flood-inundation maps can provide valuable information to city officials, emergency managers, and local residents for planning an emergency response if a dam breach occurs.

Technical bulletin : structural considerations for dam safety

Energy Technology Data Exchange (ETDEWEB)

NONE

2007-07-01

This technical bulletin discussed issues related to the safety assessment of concrete water-retaining structures and timber dams. Structures reviewed in the paper included gravity dams; buttress dams; arch dams; spillway structures; intake structures; power plants; roller compacted concrete dams; and timber dams. A variety of issues related to the loss of cohesive bond and discontinuities in bedrock foundations were reviewed with reference to issues related to compressive strength, tensile strength, and shear strength. Static failure modes and failure mechanisms related to dam failures were also described. Visual indicators for potential failures include abutment and foundation movement, seepage, and structure movements. Loading combinations were discussed, and performance indicators for gravity dams were provided. Methods of analysis for considering load characteristics, structure types and geological conditions were also discussed. Modelling techniques for finite element analysis were also included. 16 refs., 3 tabs., 5 figs.

Off-site embankments to protect fields from the growth of peatlands in the Valli Grandi Veronesi Meridionali (Italy during Middle and Recent Bronze Age

Directory of Open Access Journals (Sweden)

Claudio Balista

2016-12-01

Full Text Available In the background of the late-Holocene landscape of the Southern Valli Grandi Veronesi (VGVM and nearby Bonifica Padana, an area that stretches between rivers Adige and Po and which is drained by the river Tartaro, was taken into consideration the position of a long embankment that ran through the territories of the two large moated sites of the middle and recent Bronze Age, Fondo Paviani (FP to east , and Castello del Tartaro (CdT to west. The location of this particular embankment called SAM (from italian southern embanked road, more than ten km long, and arranged parallel to the Tartaro old riparian belt, since long time attracted scholars as a witness of an old territorial organization, probably related to spatial distribution of cultivated or pasture by the communities who lived in the two large villages, bounded by massive ditch and bank systems. On the basis of recent acquisitions of new DEM and LIDAR sources and aimed field investigations, then merged into geo-chronological and chrono-typological analysis in the laboratory, was developed a research addressed the chrono-stratigraphic, cultural-evolutionary and functional scan of the SAM construct. For this purpose, the archaeological, stratigraphic and chronological record have been reviewed from a series of very significant off-sites, with stratigraphic columns documenting paleo-environmental and archaeological-functional reconstructions. They allowed to established the obvious links between the infrastructure of the ditches of the SAM embankment and the network of secondary rural ditches that seemed to drain and distribute waters in the parceled fields next to the large contemporary sites. In Ponte Moro off-site we captured the chrono-stratigraphic position of SAM embankment through the dating of two peat samples undertaken immediately before and after the stratigraphic position of the embankment. The datings have yielded an earliest date for the construction (MBA-RBA and a later date

Assessing Risks of Mine Tailing Dam Failures

Science.gov (United States)

Concha Larrauri, P.; Lall, U.

2017-12-01

The consequences of tailings dam failures can be catastrophic for communities and ecosystems in the vicinity of the dams. The failure of the Fundão tailings dam at the Samarco mine in 2015 killed 19 people with severe consequences for the environment. The financial and legal consequences of a tailings dam failure can also be significant for the mining companies. For the Fundão tailings dam, the company had to pay 6 billion dollars in fines and twenty-one executives were charged with qualified murder. There are tenths of thousands of active, inactive, and abandoned tailings dams in the world and there is a need to better understand the hazards posed by these structures to downstream populations and ecosystems. A challenge to assess the risks of tailings dams in a large scale is that many of them are not registered in publicly available databases and there is little information about their current physical state. Additionally, hazard classifications of tailings dams - common in many countries- tend to be subjective, include vague parameter definitions, and are not always updated over time. Here we present a simple methodology to assess and rank the exposure to tailings dams using ArcGIS that removes subjective interpretations. The method uses basic information such as current dam height, storage volume, topography, population, land use, and hydrological data. A hazard rating risk was developed to compare the potential extent of the damage across dams. This assessment provides a general overview of what in the vicinity of the tailings dams could be affected in case of a failure and a way to rank tailings dams that is directly linked to the exposure at any given time. One hundred tailings dams in Minas Gerais, Brazil were used for the test case. This ranking approach could inform the risk management strategy of the tailings dams within a company, and when disclosed, it could enable shareholders and the communities to make decisions on the risks they are taking.

The socio-economics dynamics of Dam on Rural Communities: A case study of Oyan Dam, Nigeria

Science.gov (United States)

Ayeni, Amidu; Ojifo, Lawrence

2018-06-01

Dams construction and operations have many benefits, nevertheless, they have also led to lots of negative social, health and human impacts. It is based on this that this study assesses the potential and socio-economics dynamics of Oyan dam between 1980 and 2016. The data used for this study include water level and discharge records of the dam between 2007 and 2016, Landsat imageries of 1984 and 2016 and socio-economic datasets for the period. Analysis of the dam potentials (water supply, agriculture and hydropower) and socio-economic impacts of the dam were carried out using basic statistical tools, land use change anaysis and field survey using questionnaire, structured interview with major stakeholders and personal observation. The results revealed that the water level and storage of the Oyan dam had a relative reduction of about 2 % as well as non-stationarity pattern of water abstraction and production for the period. The landuse classes show all classes decreased in extent except the cultivated landuse that acrued an increased of 19.9 % between 1984 and 2016. Furthermore, commercial water supply varied significantly between 2010 and 2016 while irrigation scheme is grossly under-utilized from the inception in 1983 to 2016. Finally, the result of socio-economic impacts revealed that majority of the selected communities' members are actually not benefiting from the dam and their livelihoods are not from the dam.

Sediment Transport Over Run-of-River Dams

Science.gov (United States)

O'Brien, M.; Magilligan, F. J.; Renshaw, C. E.

2016-12-01

Dams have numerous documented effects that can degrade river habitat downstream. One significant effect of large dams is their ability to trap sediment delivered from upstream. This trapping can alter sediment transport and grain size downstream - effects that often motivate dam removal decisions. However, recent indirect observations and modeling studies indicate that small, run-of-river (ROR) dams, which do not impede discharge, may actually leak sediment downstream. However, there are no direct measurements of sediment flux over ROR dams. This study investigates flow and sediment transport over four to six different New England ROR dams over a summer-fall field season. Sediment flux was measured using turbidity meters and tracer (RFID) cobbles. Sediment transport was also monitored through an undammed control site and through a river where two ROR dams were recently removed. These data were used to predict the conditions that contribute to sediment transport and trapping. Year 1 data show that tracer rocks of up to 61 mm were transported over a 3 m ROR dam in peak flows of 84% of bankfull stage. These tracer rocks were transported over and 10 m beyond the dam and continue to move downstream. During the same event, comparable suspended sediment fluxes of up to 81 g/s were recorded both upstream and downstream of the dam at near-synchronous timestamps. These results demonstrate the potential for sediment transport through dammed rivers, even in discharge events that do not exceed bankfull. This research elucidates the effects of ROR dams and the controls on sediment transport and trapping, contributions that may aid in dam management decisions.

Dam that social networking: connecting South Africa's major dams to social media

CSIR Research Space (South Africa)

Butgereit, L

2011-10-01

Full Text Available where four major South African dams are connected to Twitter and Facebook (and other social media such as MXit and Google Chat) in a mechanism which would be easy to replicate for additional dams or rivers. Data is supplied by the South African...

Flood early warning system: sensors and internet

NARCIS (Netherlands)

Pengel, B.E.; Krzhizhanovskaya, V.V.; Melnikova, N.B.; Shirshov, G.S.; Koelewijn, A.R.; Pyayt, A.L.; Mokhov, I.I.; Chavoshian, A.; Takeuchi, K.

2013-01-01

The UrbanFlood early warning system (EWS) is designed to monitor data from very large sensornetworks in flood defences such as embankments, dikes, levees, and dams. The EWS, based on the internet, uses real-time sensor information and Artificial Intelligence (AI) to immediately calculate the

30 CFR 779.25 - Cross sections, maps, and plans.

Science.gov (United States)

2010-07-01

... waste disposal, dams, embankments, other impoundments, and water treatment and air pollution control... locations of monitoring stations used to gather data for water quality and quantity, fish and wildlife, and... known workings of active, inactive, or abandoned underground mines, including mine openings to the...

TYPOLOGY OF LARGE DAMS. A REVIEW

Directory of Open Access Journals (Sweden)

Gheorghe ROMANESCU

2015-06-01

Full Text Available The dams represent hydrotechnical constructions meant to ensure a judicious use of water resources. The international literature is extremely rich in data regarding the large dams on Earth. In this context, a hierarchy of the main dams is attempted and the role they play in the economic development of the regions they were built in is underlined. The largest dams are built on the big rivers in Asia, North America, South America and Africa. The reservoirs have multiple roles: electricity production, drinking or industrial water supply, irrigations, recreation, etc. High costs and land fragility do not allow the construction of dams in the places most affected by drought or flood. This is why they are usually built in mountainous areas, at great distance from the populated centres. On the Romanian territory, there are 246 large dams, built in the hydrographical basins of Siret, Olt, Arges, Somes, etc. The largest rivers on Earth, by discharge, (Amazon and Zair do not also include the largest dams because the landform and the type of flow have not allowed such constructions.

Construction of anhydrite dams

Energy Technology Data Exchange (ETDEWEB)

Bortoluzzi, L; Francois, G

1977-05-01

To construct a ventilation dam, the road is closed with a fibreglass sheet onto which 3 or 4 cm of anhydrite paste is sprayed. The equipment necessary is described, and the cost is compared with that of an aggregate dam.

Dams, Hydrology and Risk in Future River Management

Science.gov (United States)

Wegner, D. L.

2017-12-01

Across America there are over 80,000 large to medium dams and globally the number is in excess of 800,000. Currently there are over 1,400 dams and diversion structures being planned or under construction globally. In addition to these documented dams there are thousands of small dams populating watersheds. Governments, agencies, native tribes, private owners and regulators all have a common interest in safe dams. Often dam safety is characterized as reducing structural risk while providing for maximum operational flexibility. In the 1970's there were a number of large and small dam failures in the United States. These failures prompted the federal government to issue voluntary dam safety guidelines. These guidelines were based on historic information incorporated into a risk assessment process to analyze, evaluate and manage risk with the goal to improve the quality of and support of dam management and safety decisions. We conclude that historic and new risks need to be integrated into dam management to insure adequate safety and operational flexibility. A recent assessment of the future role of dams in the United States premises that future costs such as maintenance or removal beyond the economic design life have not been factored into the long-term operations or relicensing of dams. The converging risks associated with aging water storage infrastructure, multiple dams within watersheds and uncertainty in demands policy revisions and an updated strategic approach to dam safety. Decisions regarding the future of dams in the United States may, in turn, influence regional water planning and management. Leaders in Congress and in the states need to implement a comprehensive national water assessment and a formal analysis of the role dams play in our water future. A research and national policy agenda is proposed to assess future impacts and the design, operation, and management of watersheds and dams.

Mitigating Dam Impacts Using Environmental Flow Releases

Science.gov (United States)

Richter, B. D.

2017-12-01

One of the most ecologically disruptive impacts of dams is their alteration of natural river flow variability. Opportunities exist for modifying the operations of existing dams to recover many of the environmental and social benefits of healthy ecosystems that have been compromised by present modes of dam operation. The potential benefits of dam "re-operation" include recovery of fish, shellfish, and other wildlife populations valued both commercially and recreationally, including estuarine species; reactivation of the flood storage and water purification benefits that occur when floods are allowed to flow into floodplain forests and wetlands; regaining some semblance of the naturally dynamic balance between river erosion and sedimentation that shapes physical habitat complexity, and arresting problems associated with geomorphic imbalances; cultural and spiritual uses of rivers; and many other socially valued products and services. Assessing the potential benefits of dam re-operation begins by characterizing the dam's effects on the river flow regime, and formulating hypotheses about the ecological and social benefits that might be restored by releasing water from the dam in a manner that more closely resembles natural flow patterns. These hypotheses can be tested by implementing a re-operation plan, tracking the response of the ecosystem, and continually refining dam operations through adaptive management. This presentation will highlight a number of land and water management strategies useful in implementing a dam re-operation plan, with reference to a variety of management contexts ranging from individual dams to cascades of dams along a river to regional energy grids. Because many of the suggested strategies for dam re-operation are predicated on changes in the end-use of the water, such as reductions in urban or agricultural water use during droughts, a systemic perspective of entire water management systems will be required to attain the fullest possible

Simulation of Breach Outflow for Earthfill Dam

International Nuclear Information System (INIS)

Razad, Azwin Zailti Abdul; Muda, Rahsidi Sabri; Sidek, Lariyah Mohd; Azia, Intan Shafilah Abdul; Mansor, Faezah Hanum; Yalit, Ruzaimei

2013-01-01

Dams have been built for many reasons such as irrigation, hydropower, flood mitigation, and water supply to support development for the benefit of human. However, the huge amount of water stored behind the dam can seriously pose adverse impacts to the downstream community should it be released due to unwanted dam break event. To minimise the potential loss of lives and property damages, a workable Emergency Response Plan is required to be developed. As part of a responsible dam owner and operator, TNB initiated a study on dam breach modelling for Cameron Highlands Hydroelectric Scheme to simulate the potential dam breach for Jor Dam. Prediction of dam breach parameters using the empirical equations of Froehlich and Macdonal-Langridge-Monopolis formed the basis of the modelling, coupled with MIKE 11 software to obtain the breach outflow due to Probable Maximum Flood (PMF). This paper will therefore discuss the model setup, simulation procedure and comparison of the prediction with existing equations.

Restoring Environmental Flows by Modifying Dam Operations

Directory of Open Access Journals (Sweden)

Brian D. Richter

2007-06-01

Full Text Available The construction of new dams has become one of the most controversial issues in global efforts to alleviate poverty, improve human health, and strengthen regional economies. Unfortunately, this controversy has overshadowed the tremendous opportunity that exists for modifying the operations of existing dams to recover many of the environmental and social benefits of healthy ecosystems that have been compromised by present modes of dam operation. The potential benefits of dam "re-operation" include recovery of fish, shellfish, and other wildlife populations valued both commercially and recreationally, including estuarine species; reactivation of the flood storage and water purification benefits that occur when floods are allowed to flow into floodplain forests and wetlands; regaining some semblance of the naturally dynamic balance between river erosion and sedimentation that shapes physical habitat complexity, and arresting problems associated with geomorphic imbalances; cultural and spiritual uses of rivers; and many other socially valued products and services. This paper describes an assessment framework that can be used to evaluate the benefits that might be restored through dam re-operation. Assessing the potential benefits of dam re-operation begins by characterizing the dam's effects on the river flow regime, and formulating hypotheses about the ecological and social benefits that might be restored by releasing water from the dam in a manner that more closely resembles natural flow patterns. These hypotheses can be tested by implementing a re-operation plan, tracking the response of the ecosystem, and continually refining dam operations through adaptive management. The paper highlights a number of land and water management strategies useful in implementing a dam re-operation plan, with reference to a variety of management contexts ranging from individual dams to cascades of dams along a river to regional energy grids. Because many of the

Sustainability of dams-an evaluation approach

Science.gov (United States)

Petersson, E.

2003-04-01

Situated in the stream bed of a river, dams and reservoirs interrupt the natural hydrological cycle. They are very sensitive to all kinds of changes in the catchment, among others global impacts on land use, climate, settlement structures or living standards. Vice versa dams strongly affect the spatially distributed, complex system of ecology, economy and society in the catchment both up- and downstream of the reservoir. The occurrence of negative impacts due to large dams led to serious conflicts about future dams. Nevertheless, water shortages due to climatic conditions and their changes, that are faced by enormous water and energy demands due to rising living standards of a growing world population, seem to require further dam construction, even if both supply and demand management are optimised. Although environmental impact assessments are compulsory for dams financed by any of the international funding agencies, it has to be assumed that the projects lack sustainability. Starting from an inventory of today's environmental impact assessments as an integral part of a feasibility study the presentation will identify their inadequacies with regard to the sustainability of dams. To improve the sustainability of future dams and avoid the mistakes of the past, the planning procedures for dams have to be adapted. The highly complex and dynamical system of interrelated physical and non-physical processes, that involves many different groups of stakeholders, constitutes the need for a model-oriented decision support system. In line with the report of the World Commission of Dams an integrated analysis and structure of the complex interrelations between dams, ecology, economy and society will be presented. Thus the system, that a respective tool will be based on, is analysed. Furthermore an outlook will be given on the needs of the potential users of a DSS and how it has to be embedded in the overall planning process. The limits of computer-based decision-support in the

33 CFR 100.1102 - Marine Events on the Colorado River, between Davis Dam (Bullhead City, Arizona) and Headgate Dam...

Science.gov (United States)

2010-07-01

... River, between Davis Dam (Bullhead City, Arizona) and Headgate Dam (Parker, Arizona). 100.1102 Section... MARINE PARADES SAFETY OF LIFE ON NAVIGABLE WATERS § 100.1102 Marine Events on the Colorado River, between Davis Dam (Bullhead City, Arizona) and Headgate Dam (Parker, Arizona). (a) General. Sponsors are...

Brazil's Amazonian dams: Ecological and socioeconomic impacts

Science.gov (United States)

Fearnside, P. M.

2016-12-01

Brazil's 2015-2024 Energy Expansion Plan calls for 11 hydroelectric dams with installed capacity ≥ 30 MW in the country's Amazon region. Dozens of other large dams are planned beyond this time horizon, and dams with environmental and socioeconomic impacts. Loss of forest to flooding is one, the Balbina and Tucuruí Dams being examples (each 3000 km2). If the Babaquara/Altamira Dam is built it will flood as much forest as both of these combined. Some planned dams imply loss of forest in protected areas, for example on the Tapajós River. Aquatic and riparian ecosystems are lost, including unique biodiversity. Endemic fish species in rapids on the Xingu and Tapajós Rivers are examples. Fish migrations are blocked, such as the commercially important "giant catfish" of the Madeira River. Dams emit greenhouse gases, including CO2 from the trees killed and CH4 from decay under anoxic conditions at the bottom of reservoirs. Emissions can exceed those from fossil-fuel generation, particularly over the 20-year period during which global emissions must be greatly reduced to meet 1.5-2°C limit agreed in Paris. Carbon credit for dams under the Climate Convention causes further net emission because the dams are not truly "additional." Anoxic environments in stratified reservoirs cause methylation of mercury present in Amazonian soils, which concentrates in fish, posing a health risk to human consumers. Population displacement is a major impact; for example, the Marabá Dam would displace 40,000 people, mostly traditional riverside dwellers (ribeirinhos). Various dams impact indigenous peoples, such as the Xingu River dams (beginning with Belo Monte) and the São Luiz do Tapajós and Chacorão Dams on the Tapajós River. Brazil has many energy options other than dams. Much energy use has little benefit for the country, such as exporting aluminum. Electric showerheads use 5% of the country's power. Losses in transmission lines (20%) are far above global averages and can be

Behavior and dam passage of juvenile Chinook salmon at Cougar Reservoir and Dam, Oregon, March 2011 - February 2012

Science.gov (United States)

Beeman, John W.; Hansel, Hal C.; Hansen, Amy C.; Haner, Philip V.; Sprando, Jamie M.; Smith, Collin D.; Evans, Scott D.; Hatton, Tyson W.

2013-01-01

The movements and dam passage of juvenile Chinook salmon implanted with acoustic transmitters and passive integrated transponder tags were studied at Cougar Reservoir and Dam, near Springfield, Oregon. The purpose of the study was to provide information to aid with decisions about potential alternatives for improving downstream passage conditions for juvenile salmonids in this flood-control reservoir. In 2011, a total of 411 hatchery fish and 26 wild fish were tagged and released during a 3-month period in the spring, and another 356 hatchery fish and 117 wild fish were released during a 3-month period in the fall. A series of 16 autonomous hydrophones throughout the reservoir and 12 hydrophones in a collective system near the dam outlet were used to determine general movements and dam passage of the fish over the life of the acoustic transmitter, which was expected to be about 3 months. Movements within the reservoir were directional, and it was common for fish to migrate repeatedly from the head of the reservoir downstream to the dam outlet and back to the head of the reservoir. Most fish were detected near the temperature control tower at least once. The median time from release near the head of the reservoir to detection within about 100 meters of the dam outlet at the temperature control tower was between 5.7 and 10.8 days, depending on season and fish origin. Dam passage events occurred over a wider range of dates in the spring and summer than in the fall and winter, but dam passage numbers were greatest during the fall and winter. A total of 10.5 percent (43 of 411) of the hatchery fish and 15.4 percent (4 of 26) of the wild fish released in the spring are assumed to have passed the dam, whereas a total of 25.3 percent (90 of 356) of the hatchery fish and 16.9 percent (30 of 117) of the wild fish released in the fall are assumed to have passed the dam. A small number of fish passed the dam after their transmitters had stopped working and were detected at

Dams and Intergovernmental Transfers

Science.gov (United States)

Bao, X.

2012-12-01

Gainers and Losers are always associated with large scale hydrological infrastructure construction, such as dams, canals and water treatment facilities. Since most of these projects are public services and public goods, Some of these uneven impacts cannot fully be solved by markets. This paper tried to explore whether the governments are paying any effort to balance the uneven distributional impacts caused by dam construction or not. It showed that dam construction brought an average 2% decrease in per capita tax revenue in the upstream counties, a 30% increase in the dam-location counties and an insignificant increase in downstream counties. Similar distributional impacts were observed for other outcome variables. like rural income and agricultural crop yields, though the impacts differ across different crops. The paper also found some balancing efforts from inter-governmental transfers to reduce the unevenly distributed impacts caused by dam construction. However, overall the inter-governmental fiscal transfer efforts were not large enough to fully correct those uneven distributions, reflected from a 2% decrease of per capita GDP in upstream counties and increase of per capita GDP in local and downstream counties. This paper may shed some lights on the governmental considerations in the decision making process for large hydrological infrastructures.

Uncertainty Analysis and Overtopping Risk Evaluation of Maroon Dam withMonte Carlo and Latin Hypercube Methods

Directory of Open Access Journals (Sweden)

J. M. Vali Samani

2016-02-01

Full Text Available Introduction: The greatest part of constructed dams belongs to embankment dams and there are many examples of their failures throughout history. About one-third of the world’s dam failures have been caused by flood overtopping, which indicates that flood overtopping is an important factor affecting reservoir projects’ safety. Moreover, because of a poor understanding of the randomness of floods, reservoir water levels during flood seasons are often lowered artificially in order to avoid overtopping and protect the lives and property of downstream residents. So, estimation of dam overtopping risk with regard to uncertainties is more important than achieving the dam’s safety. This study presents the procedure for risk evaluation of dam overtopping due to various uncertaintiess in inflows and reservoir initial condition. Materials and Methods: This study aims to present a practical approach and compare the different uncertainty analysis methods in the evaluation of dam overtopping risk due to flood. For this purpose, Monte Carlo simulation and Latin hypercube sampling methods were used to calculate the overtopping risk, evaluate the uncertainty, and calculate the highest water level during different flood events. To assess these methods from a practical point of view, the Maroon dam was chosen for the case study. Figure. 1 indicates the work procedure, including three parts: 1 Identification and evaluation of effective factors on flood routing and dam overtopping, 2 Data collection and analysis for reservoir routing and uncertainty analysis, 3 Uncertainty and risk analysis. Figure 1- Diagram of dam overtopping risk evaluation Results and Discussion: Figure 2 shows the results of the computed overtopping risks for the Maroon Dam without considering the wind effect, for the initial water level of 504 m as an example. As it is shown in Figure. 2, the trends of the risk curves computed by the different uncertainty analysis methods are similar

GIS inundation mapping and dam breach analysis of Woolwich Dam using HEC-geoRAS

Energy Technology Data Exchange (ETDEWEB)

Mocan, N. [Crozier and Associates Inc., Collingwood, ON (Canada); Joy, D.M. [Guelph Univ., ON (Canada); Rungis, G. [Grand River Conservation Authority, Cambridge, ON (Canada)

2006-07-01

A study was conducted to determine the extent of flood inundation given a hypothetical dam breach scenario of the Woolwich Dam located in the Grand River Watershed, 2.5 km north of the Town of Elmira, Ontario. The dam is operated by the Grand River Conservation Authority and was constructed to provide low-flow augmentation to Canagagigue Creek. Advances in the computational capabilities of numerical models along with the availability of fine resolution geospatial data has lead to significant advances in the evaluation of catastrophic consequences due to the ensuing flood waters when dams fail. The hydraulic models HEC-RAS and HEC-GeoRAS were used in this study along with GIS to produce high resolution spatial and temporal flood inundation mapping. Given the proximity to the Town of Elmira, the dam is classified as having a high hazard potential. The large size and high hazard potential of the dam suggests that the Inflow Design Flood (IDF) is the Probable Maximum Flood (PMF) event. The outlet structure of the spillway consists of 4 ogee-type concrete spillways equipped with radial gates. A low-level concrete pipe located within the spillway structure provides spillage for maintenance purposes. The full flow capacity of the spillway structure is 297 cubic metres per second at the full supply level of 364.8 metres. In addition to GIS flood inundation maps, this paper included the results of flood hydrographs, water surface profiles and peak flow data. It was concluded that techniques used in this analysis should be considered for use in the development of emergency management planning and dam safety assessments across Canada. 6 refs., 3 tabs., 4 figs.

Research on shape optimization of CSG dams

Directory of Open Access Journals (Sweden)

Xin Cai

2011-12-01

Full Text Available The multi-objective optimization method was used for shape optimization of cement sand and gravel (CSG dams in this study. The economic efficiency, the sensitivities of maximum horizontal displacement and maximum settlement of the dam to water level changes, the overall stability, and the overall strength security were taken into account during the optimization process. Three weight coefficient selection schemes were adopted to conduct shape optimization of a dam, and the case studies lead to the conclusion that both the upstream and downstream dam slope ratios for the optimal cross-section equal 1:0.7, which is consistent with the empirically observed range of 1:0.6 to 1:0.8 for the upstream and downstream dam slope ratios of CSG dams. Therefore, the present study is of certain reference value for designing CSG dams.

The World Commission on Dams + 10: Revisiting the Large Dam Controversy

Directory of Open Access Journals (Sweden)

Deborah Moore

2010-06-01

Full Text Available The World Commission on Dams (WCD was an experiment in multi-stakeholder dialogue and global governance concerned with a subject area – large dams – that was fraught with conflict and controversy. The WCD Report, Dams and Development: A New Framework for Decision-Making, was published in 2000 and accompanied by hopes that broad-based agreements would be forged on how to better manage water and energy development. Ten years later, this special issue of Water Alternatives revisits the WCD and its impacts, exploring the question: Is the WCD still relevant? The editorial team and the Guest Editors of this special issue of Water Alternatives have selected a range of 20 papers, 6 viewpoints, and 4 book reviews that help to illustrate the evolution in the dams debate. The goal of this special issue is to examine the influence and the impacts of the WCD on the dam enterprise, in general, and on the policies and practices of key stakeholders and institutions, and on the development outcomes for affected communities and environments, in particular. In this introduction, the Guest Editors provide an overview of the special issue, exploring the new drivers of dam development that have emerged during the last decade, including climate change and new financiers of dams, and describing the themes emerging from this diverse set of papers and viewpoints. This special issue demonstrates the need for a renewed multi-stakeholder dialogue at multiple levels. This would not be a redo of the WCD, but rather a rekindling and redesigning of processes and forums where mutual understanding, information-sharing, and norm-setting can occur. One of the most promising developments of the last decade is the further demonstration, in case studies described here, that true partnership amongst key stakeholders can produce transformative resource-sharing agreements, showing that many of the WCD recommendations around negotiated decision making are working in practice. We hope

Research progress on dam-break floods

KAUST Repository

Wu, Jiansong; Bao, Kai; Zhang, Hui

2011-01-01

Because of the catastrophic effects downstream of dam-break failure, more and more researchers around the world have been working on the study of dam-break flows to accurately forecast the downstream inundation mapping. With the rapid development of computer hardware and computing techniques, numerical study on dam-break flows has been a popular research subject. In the paper, the numerical methodologies used to solve the governing partial differential equations of dam-break flows are classified and summarized, and their characteristics and applications are discussed respectively. Furthermore, the fully-developed mathematical models developed in recent decades are reviewed, and also introduced the authors' on-going work. Finally, some possible future developments on modeling the dam-break flows and some solutions are presented and discussed. © 2011 IEEE.

Research progress on dam-break floods

KAUST Repository

Wu, Jiansong

2011-08-01

Because of the catastrophic effects downstream of dam-break failure, more and more researchers around the world have been working on the study of dam-break flows to accurately forecast the downstream inundation mapping. With the rapid development of computer hardware and computing techniques, numerical study on dam-break flows has been a popular research subject. In the paper, the numerical methodologies used to solve the governing partial differential equations of dam-break flows are classified and summarized, and their characteristics and applications are discussed respectively. Furthermore, the fully-developed mathematical models developed in recent decades are reviewed, and also introduced the authors\\' on-going work. Finally, some possible future developments on modeling the dam-break flows and some solutions are presented and discussed. © 2011 IEEE.

A model for predicting embankment slope failures in clay-rich soils; A Louisiana example

Science.gov (United States)

Burns, S. F.

2015-12-01

A model for predicting embankment slope failures in clay-rich soils; A Louisiana example It is well known that smectite-rich soils significantly reduce the stability of slopes. The question is how much smectite in the soil causes slope failures. A study of over 100 sites in north and south Louisiana, USA, compared slopes that failed during a major El Nino winter (heavy rainfall) in 1982-1983 to similar slopes that did not fail. Soils in the slopes were tested for per cent clay, liquid limits, plasticity indices and semi-quantitative clay mineralogy. Slopes with the High Risk for failure (85-90% chance of failure in 8-15 years after construction) contained soils with a liquid limit > 54%, a plasticity index over 29%, and clay contents > 47%. Slopes with an Intermediate Risk (55-50% chance of failure in 8-15 years) contained soils with a liquid limit between 36-54%, plasticity index between 16-19%, and clay content between 32-47%. Slopes with a Low Risk chance of failure (soils with a liquid limit plasticity index soil characteristics before construction. If the soils fall into the Low Risk classification, construct the embankment normally. If the soils fall into the High Risk classification, one will need to use lime stabilization or heat treatments to prevent failures. Soils in the Intermediate Risk class will have to be evaluated on a case by case basis.

Tenaga Nasional Berhad dam safety and surveillance program

International Nuclear Information System (INIS)

Jansen Luis; Zulkhairi Abd Talib

2006-01-01

This paper discusses the current practice of dam surveillance, which includes dam monitoring which is a process of visual inspections, measuring, processing, compiling and analyzing dam instrumentation data to determine the performance of a dam. The prime objective of the dam surveillance system is to ensure that any occurrence and development of safety deficiencies and problems are quickly detected, identified, analyzed and the required remedial actions are determined and consequently carried out in due time. In brief, the section is responsible to ensure that the dam monitoring and surveillance works are implemented as per scheduled and in accordance with the requirement and guidelines prepared by the dam designers and in accordance with international commission on large dams, ICOLD. The paper also illustrates and recommends an alternative approach for dam surveillance program using risk management approach, which is currently being actively adopted by some countries like USA, Canada, Australia and etc, towards improving the dam safety management and the decision making process. The approach provides a wider area of opportunity, improvements and benefits particular in the evaluation and modifications to the dam performance and safety. The process provides an effective and efficient tool for the decision makers and engineers through a comprehensive evaluation and a good understanding of the hazards, risks and consequences in relation to dam safety investigations. (Author)

Proceedings of the Canadian Dam Association's 2005 annual conference : 100 years of dam experience : balancing tradition and innovation. CD-ROM ed.

International Nuclear Information System (INIS)

2004-09-01

This conference provided a forum to promote discussion on improving the management and safety of dams. It featured 8 technical sessions as well as workshops to discuss dam safety guidelines and guidelines for extreme flood analyses and their applications. It also featured workshops on instrumentation and performance monitoring of dams; tailing dam closures and reclamation; and, practical approaches to emergency preparedness for dam owners. The discussions provided details on large hydropower development projects, their innovations in environmental impact assessment, mitigation, and monitoring. The conference included a technical component led by experts on dams and tailings facilities. Recent developments in dam construction were reviewed along with discharge and debris management, tailings dam issues, asset management, seismic issues, public safety, seepage monitoring, flow control, dam rehabilitation, concrete testing, hydrotechnical issues, risk assessment methodology, and safety guidelines. All 24 presentations at this conference have been catalogued separately for inclusion in this database

National Dam Safety Program. Lake Caroline Dam (Inventory Number VA 03324), Mattaponi River Basin, Caroline County, Virginia. Phase I Inspection Report.

Science.gov (United States)

1981-04-01

embankment being founded on overburden with a cutoff trench extending to the top of fresh or non- rippable rock. The trench was planned to have a 20 ft...n : I). The subgrade was to be cleared of all loose ard oL -ct onabl e material. The cutoff was to extend to fresh or non- rippable rock. ,jo mention

Dynamic tests at the Outardes 3 dam

International Nuclear Information System (INIS)

Proulx, J.; Paultre, P.; Duron, Z.; Tai Mai Phat; Im, O.

1992-01-01

At the Outardes 3 gravity dam, part of the Manicouagan-Outardes hydroelectric complex in northeastern Quebec, forced vibration tests were carried out using an eccentric mass shaker attached to the dam crest at three different locations. Accelerations were measured along the crest and in the inspection galleries, and hydrodynamic pressures were measured along the upstream dam face and at various locations in the reservoir. The tests were designed to analyze the effects of gravity dam-reservoir interactions and to generate a data base for calibrating finite element models used in studying the dynamic behavior of gravity dams. Experimental results are presented in order to demonstrate the quality of the data obtained and the effectiveness of the experimental procedures. Modes of vibration were observed which corresponded to those obtained by finite element analysis. It is shown that techniques recently developed for dynamic tests on large dams can be successfully used on gravity dams. 3 refs., 6 figs

Modeling the capacity of riverscapes to support beaver dams

Science.gov (United States)

Macfarlane, William W.; Wheaton, Joseph M.; Bouwes, Nicolaas; Jensen, Martha L.; Gilbert, Jordan T.; Hough-Snee, Nate; Shivik, John A.

2017-01-01

The construction of beaver dams facilitates a suite of hydrologic, hydraulic, geomorphic, and ecological feedbacks that increase stream complexity and channel-floodplain connectivity that benefit aquatic and terrestrial biota. Depending on where beaver build dams within a drainage network, they impact lateral and longitudinal connectivity by introducing roughness elements that fundamentally change the timing, delivery, and storage of water, sediment, nutrients, and organic matter. While the local effects of beaver dams on streams are well understood, broader coverage network models that predict where beaver dams can be built and highlight their impacts on connectivity across diverse drainage networks are lacking. Here we present a capacity model to assess the limits of riverscapes to support dam-building activities by beaver across physiographically diverse landscapes. We estimated dam capacity with freely and nationally-available inputs to evaluate seven lines of evidence: (1) reliable water source, (2) riparian vegetation conducive to foraging and dam building, (3) vegetation within 100 m of edge of stream to support expansion of dam complexes and maintain large colonies, (4) likelihood that channel-spanning dams could be built during low flows, (5) the likelihood that a beaver dam is likely to withstand typical floods, (6) a suitable stream gradient that is neither too low to limit dam density nor too high to preclude the building or persistence of dams, and (7) a suitable river that is not too large to restrict dam building or persistence. Fuzzy inference systems were used to combine these controlling factors in a framework that explicitly also accounts for model uncertainty. The model was run for 40,561 km of streams in Utah, USA, and portions of surrounding states, predicting an overall network capacity of 356,294 dams at an average capacity of 8.8 dams/km. We validated model performance using 2852 observed dams across 1947 km of streams. The model showed

Towards a diversification of Flood Risk Management in Europe: a reflection on meta-governance challenges

NARCIS (Netherlands)

Dieperink, C.; Hegger, D.L.T.; Bakker, M.H.N.; Driessen, P.P.J.

2014-01-01

Because of climate change, extreme weather events and urban sprawl, urban areas have to deal with increasing flood risks. It is argued, both in literature and in practice that these risks can no longer be dealt with by focusing solely on flood defences (building dikes, dams, embankments etc.).

National dam inventory provides data for analysis

International Nuclear Information System (INIS)

Spragens, L.

1992-01-01

The Association of State Dam Safety Officials completed a dam inventory this fall. Information on approximately 90,000 state-regulated dams in the US collected during the four-year inventory is being used to build a database managed by the Federal Emergency Management Agency. In addition to ASDSO's work, the federal government conducted an inventory of federal dams. This data will be added to the state information to form one national database. The database will feature 35 data fields for each entry, including the name of the dam, its size, the name of the nearest downstream community, maximum discharge and storage volume, the date of the last inspection, and details about the emergency action plan. The program is an update of the nation's first dam inventory, required by the Dam Safety Act of 1972. The US Army Corps of Engineers completed the original inventory in 1981. The Water Resources Development Act of 1986 authorized appropriations of $2.5 million for the Corps to update the inventory. FEMA and the Corps entered into an agreement for FEMA to undertake the task for the Corps and to coordinate work on both the federal and state inventories. ASDSO compiles existing information on state-regulated dams into a common format for the database, added missing information, and established a process for continually updating data. ASDSO plans to analyze the information collected for the database. It will look at statistics for the number of dams regulated, communities that could be affected, and the number of high-hazard dams. FEMA is preparing reports for Congress on the project. The reports, which are expected to be ready by May 1993, will include information on the methodology used and facts about regulated dams under state jurisdiction

Seismic failure modes and seismic safety of Hardfill dam

Directory of Open Access Journals (Sweden)

Kun Xiong

2013-04-01

Full Text Available Based on microscopic damage theory and the finite element method, and using the Weibull distribution to characterize the random distribution of the mechanical properties of materials, the seismic response of a typical Hardfill dam was analyzed through numerical simulation during the earthquakes with intensities of 8 degrees and even greater. The seismic failure modes and failure mechanism of the dam were explored as well. Numerical results show that the Hardfill dam remains at a low stress level and undamaged or slightly damaged during an earthquake with an intensity of 8 degrees. During overload earthquakes, tensile cracks occur at the dam surfaces and extend to inside the dam body, and the upstream dam body experiences more serious damage than the downstream dam body. Therefore, under the seismic conditions, the failure pattern of the Hardfill dam is the tensile fracture of the upstream regions and the dam toe. Compared with traditional gravity dams, Hardfill dams have better seismic performance and greater seismic safety.

Qu'Appelle River Dam, dam break analysis using advanced GIS tools for rapid modelling and inundation mapping

Energy Technology Data Exchange (ETDEWEB)

Bonin, D. [Hatch Energy, Winnipeg, MB (Canada); Campbell, C. [Saskatchewan Watershed Authority, Moose Jaw, SK (Canada); Groeneveld, J. [Hatch Energy, Calgary, AB (Canada)

2008-07-01

The South Saskatchewan River Project (SSRP) comprises a multi-purpose reservoir that provides water for conservation and irrigation, flood control, power generation, recreation, and municipal and industrial water supply. In addition to the 64 m high Gardiner Dam, the 27 m high Qu'Appelle River Dam and the 22 km long Lake Diefenbaker Reservoir, the SSRP also includes ancillary works. The Qu'Appelle River valley extends for 458 km before connecting to the Assiniboine River. The valley is incised up to 90 m in depth and is a popular cottaging and recreational area with several major communities located in the flood plain. In the event of a breach of the Qu'Appelle Dam, the discharge will increase from a normal maximum discharge of under 60 m{sup 3} per second to over 50,000 m{sup 3} per second. The Saskatchewan Watershed Authority (SWA) is responsible for ensuring safe development of the Province's water resources, without affecting reservoir or lake operations, and preventing damage from flooding, erosion or land slides. It is in the process of developing Hazard Assessments and emergency preparedness plans for each of their dams in accordance with the Canadian Dam Safety Guidelines. Studies using GIS technology and the hydrodynamic routing model HEC-RAS have been completed to evaluate the potential inundation that may result in the event of failure of the Qu'Appelle River Dam. These studies involved the development of a breach parameter model using a breach data set revised to better reflect the Qu'Appelle River Dam; the development of a dam break model for the Qu'Appelle River Dam and downstream river and flood plain; and, the use of this model to simulate two potential dam failure scenarios for the Qu'Appelle River Dam, notably failure during passage of the PMF and failure during fair weather conditions. Inundation maps have been prepared for the downstream Qu'Appelle River valley for each of the above events. 3 refs., 4

Dam Design can Impede Adaptive Management of Environmental Flows: A Case Study from the Opuha Dam, New Zealand

Science.gov (United States)

Lessard, JoAnna; Murray Hicks, D.; Snelder, Ton H.; Arscott, David B.; Larned, Scott T.; Booker, Doug; Suren, Alastair M.

2013-02-01

The Opuha Dam was designed for water storage, hydropower, and to augment summer low flows. Following its commissioning in 1999, algal blooms (dominated first by Phormidium and later Didymosphenia geminata) downstream of the dam were attributed to the reduced frequency and magnitude of high-flow events. In this study, we used a 20-year monitoring dataset to quantify changes associated with the dam. We also studied the effectiveness of flushing flows to remove periphyton from the river bed. Following the completion of the dam, daily maximum flows downstream have exceeded 100 m3 s-1 only three times; two of these floods exceeded the pre-dam mean annual flood of 203 m3 s-1 (compared to 19 times >100 m3 s-1 and 6 times >203 m3 s-1 in the 8 years of record before the dam). Other changes downstream included increases in water temperature, bed armoring, frequency of algal blooms, and changes to the aquatic invertebrate community. Seven experimental flushing flows resulted in limited periphyton reductions. Flood wave attenuation, bed armoring, and a shortage of surface sand and gravel, likely limited the effectiveness of these moderate floods. Floods similar to pre-dam levels may be effective for control of periphyton downstream; however, flushing flows of that magnitude are not possible with the existing dam infrastructure. These results highlight the need for dams to be planned and built with the capacity to provide the natural range of flows for adaptive management, particularly high flows.

The interplay of activists and dam developers : the case of Myanmar’s mega-dams

NARCIS (Netherlands)

Kirchherr, Julian|info:eu-repo/dai/nl/411261487; J. Charles, Katrina; Walton, Matthew J.

2017-01-01

Scholars investigating activism against large dam developments in Asia usually focus on those campaigning, but not on those the campaigns are aimed at–the dam developers. Yet the developers’ perspective is crucial to comprehensively understand the dynamics of social and environmental activism in

Seismic response monitoring of the Arno river masonry embankment during the conservation works after the Lungarno Torrigiani riverbank landslide (Florence - May 25, 2016)

Science.gov (United States)

Lotti, Alessia; Pazzi, Veronica; Chiara, Paolo; Lombardi, Luca; Nocentini, Massimiliano; Casagli, Nicola

2017-04-01

Geohazards are the most relevant processes that can damage or increase the risk of human beings, properties, critical and transport infrastructures, and environment itself. They also could involve the interruption of human activities. The concepts of disaster risk reduction and disaster risk management involve the development, improvement, and application of policies, strategies, and practices to minimize disaster risks throughout society. Since 1972 (UNESCO Convention) the identification, protection, and preservation of cultural and natural heritage has been recognized to be of outstanding value to humanity, and a key resource to build resilient societies. Nevertheless, world architectural wealth is accumulating damages and heavy losses because of both materials deterioration and exceptional natural or man-made events. The "health" of buildings/structures/infrastructures may be evaluate by its deterioration or damage level. Thus, structure dynamic characterization and microtremor analysis are considered powerful techniques, even thought seismic noise techniques in densely populated area are hardly to carry out because of the background noise due to the human activities. A wide bibliography about buildings/structures/infrastructures seismic dynamic characterization is counterposed to a missing one about their seismic response during conservation/safety works, even thought the seismic vibration monitoring (SVM) is widely used. On May 25, 2016 a riverbank landslide seriously damaged a portion roughly 100 m long of the Lungarno Torrigiani historical masonry embankment wall (left river bank of the Florence urban stretch of the Arno river, between Ponte alle Grazie e Ponte Vecchio). The street next to the embankment wall collapsed, and the earth fill material was fully retained by the embankment wall that did not collapse but seriously deformed towards the Arno river, fracturing itself in three main areas (a cusp roughly in the middle of the damaged wall, where is also

Factors influencing hysteresis characteristics of concrete dam deformation

Directory of Open Access Journals (Sweden)

Jia-he Zhang

2017-04-01

Full Text Available Thermal deformation of a concrete dam changes periodically, and its variation lags behind the air temperature variation. The lag, known as the hysteresis time, is generally attributed to the low velocity of heat conduction in concrete, but this explanation is not entirely sufficient. In this paper, analytical solutions of displacement hysteresis time for a cantilever beam and an arch ring are derived. The influence of different factors on the displacement hysteresis time was examined. A finite element model was used to verify the reliability of the theoretical analytical solutions. The following conclusions are reached: (1 the hysteresis time of the mean temperature is longer than that of the linearly distributed temperature difference; (2 the dam type has a large impact on the displacement hysteresis time, and the hysteresis time of the horizontal displacement of an arch dam is longer than that of a gravity dam; (3 the reservoir water temperature variation lags behind of the air temperature variation, which intensifies the differences in the horizontal displacement hysteresis time between the gravity dam and the arch dam; (4 with a decrease in elevation, the horizontal displacement hysteresis time of a gravity dam tends to increase, whereas the horizontal displacement hysteresis time of an arch dam is likely to increase initially, and then decrease; and (5 along the width of the dam, the horizontal displacement hysteresis time of a gravity dam decreases as a whole, while the horizontal displacement hysteresis time of an arch dam is shorter near the center and longer near dam surfaces.

Energetic use of embankment biogas as an option for reducing the emission of greenhouse effect gases - case study at Campinas - SP - Brazil; Uso energetico do biogas de aterro como opcao para reducao da emissao de gases de efeito estufa. Estudo de caso em Campinas, SP

Energy Technology Data Exchange (ETDEWEB)

Ensinas, Adriano Viana; Bizzo, Waldir Antonio; Sanchez, Caio Glauco [Universidade Estadual de Campinas, SP (Brazil). Faculdade de Engenharia Mecanica]. E-mails: adrianov@fem.unicamp.br; bizzo@fem.unicamp.br; caio@fem.unicamp.br

2004-07-01

This paper evaluates the electric power generation potential of an embankment from the generated bio gas, therefore reducing the aggravation of the greenhouse. For that purpose data from a case study on the Delta de Campinas - Sao Paulo, BR - embankment had been used, by adopting a theoretical methodology from the literature for future emissions forecasting. Also, a scheme have been proposed of a possible project for the embankment aiming electric power generation with the objective of greenhouse effect reduction.

Dams life; La vie des barrages

Energy Technology Data Exchange (ETDEWEB)

NONE

1996-12-31

The paper reports on the conclusions of decennial and annual inspections of French dams. Dams surveillance is performed by the operators and consists in visual examinations and measurements. Concrete dams, in particular, always have more or less developed fissures with water sweating threw the concrete mass or the foundations. Old concrete often show low swelling phenomena which are measured too. (J.S.)

Dam safety management in Victoria (Australia)

International Nuclear Information System (INIS)

Adem, J.

1996-01-01

The Victoria state government's decision to make dam owners accountable for safety and upkeep of their dams was reported. To give effect to this decision a series of guidelines have been developed which outline the required activities and skills to ensure that dams are properly managed within a framework of 'light-handed' regulation. The guidelines are also intended to ensure that dam management becomes an integral part of the business decision making process, not just a set of prescribed technical procedures. Details of the direction being taken and the proposed controls to ensure compliance with national and international standards were described. 4 refs., 2 figs

Large Dam Effects on Flow Regime and Hydraulic Parameters of river (Case study: Karkheh River, Downstream of Reservoir Dam

Directory of Open Access Journals (Sweden)

Farhang Azarang

2017-06-01

Full Text Available Introduction: The critical role of the rivers in supplying water for various needs of life has led to engineering identification of the hydraulic regime and flow condition of the rivers. Hydraulic structures such dams have inevitable effects on their downstream that should be well investigated. The reservoir dams are the most important hydraulic structures which are the cause of great changes in river flow conditions. Materials and Methods: In this research, an accurate assessment was performed to study the flow regime of Karkheh river at downstream of Karkheh Reservoir Dam as the largest dam in Middle East. Karkheh River is the third waterful river of Iran after Karun and Dez and the third longest river after the Karun and Sefidrud. The Karkheh Dam is a large reservoir dam built in Iran on the Karkheh River in 2000. The Karkheh Reservoir Dam is on the Karkheh River in the Northwestern Khouzestan Province, the closest city being Andimeshk to the east. The part of Karkheh River, which was studied in this research is located at downstream of Karkheh Reservoir Dam. This interval is approximately 94 km, which is located between PayePol and Abdolkhan hydrometric stations. In this research, 138 cross sections were used along Karkheh River. Distance of cross sections from each other was 680m in average. The efficient model of HEC-RAS has been utilized to simulate the Karkheh flow conditions before and after the reservoir dam construction using of hydrometric stations data included annually and monthly mean discharges, instantaneous maximum discharges, water surface profiles and etc. Three defined discharges had been chosen to simulate the Karkheh River flow; maximum defined discharge, mean defined discharge and minimum defined discharge. For each of these discharges values, HEC-RAS model was implemented as a steady flow of the Karkheh River at river reach of study. Water surface profiles of flow, hydraulic parameters and other results of flow regime in

Exporting dams: China's hydropower industry goes global.

Science.gov (United States)

McDonald, Kristen; Bosshard, Peter; Brewer, Nicole

2009-07-01

In line with China's "going out" strategy, China's dam industry has in recent years significantly expanded its involvement in overseas markets. The Chinese Export-Import Bank and other Chinese financial institutions, state-owned enterprises, and private firms are now involved in at least 93 major dam projects overseas. The Chinese government sees the new global role played by China's dam industry as a "win-win" situation for China and host countries involved. But evidence from project sites such as the Merowe Dam in Sudan demonstrates that these dams have unrecognized social and environmental costs for host communities. Chinese dam builders have yet to adopt internationally accepted social and environmental standards for large infrastructure development that can assure these costs are adequately taken into account. But the Chinese government is becoming increasingly aware of the challenge and the necessity of promoting environmentally and socially sound investments overseas.

Measuring and managing safety at Wahleach Dam

International Nuclear Information System (INIS)

Salmon, G. M.; Cattanach, J. D.; Hartford, D. N. D.

1996-01-01

Safety improvements recently implemented at the Wahleach Dam were described as one of the first instances in international dam safety practice where risk concepts have been used in conjunction with acceptable risk criteria to evaluate safety of a dam relative to required level of safety. Erosion was identified as the greatest threat to the safety of the dam. In addressing the deficiencies B.C. Hydro formulated a process which advocates a balanced level of safety,i.e. the probability of failure multiplied by the consequences of failure, integrated over a range of initiators. If the risk posed by the dam is lower than a 'tolerable' risk, the dam is considered to be safe enough. In the case of the Wahleach Dam, the inflow design flood (IDF) was selected to be about one half of the probable maximum flow (PMF), hence it was more likely than not that the spillway could pass floods up to and including the PMF. By accepting the determined level of risk, expenditures of several million dollars for design and construction of dam safety improvements were made redundant. Another byproduct of this new concept of risk assessment was the establishment of improved life safety protection by means of an early warning system for severe floods through the downstream community and emergency authorities. 3 refs., 5 tabs

Procedure for recovering embanked bases of oil wells in Carmopolis - state of Sergipe - Brazil

International Nuclear Information System (INIS)

Alves, Mara R.F.V.

2000-01-01

This present work objective was to elaborate a procedure to deal with degraded areas due to petroleum mining, seeking the recovery of embanked bases of razed oil wells, in Carmopolis/SE. This procedure was a result from studies upon soil recovery and several works performed by Mining Companies, adapted to local conditions. Once defined the objectives and the future soil use, this procedure will take place in four phases: landscape re composition; soil preparation for revegetation; revegetation and management of the area. The suggested procedure application can prove its effectiveness on recovering previous soil uses (farming or local Atlantic Rain Forest). (author)

Study of the behavior of a reinforced embankment supported on alluvial soft soil - doi: 10.4025/actascitechnol.v35i4.16046

Directory of Open Access Journals (Sweden)

João Alexandre Paschoalin Filho

2013-10-01

Full Text Available This paper presented a study on the behavior of an embankment, 5.0 m high, reinforced with geogrids, and constructed over a soft soil 7.0 m thick. In order to determine the design strength (Td of the reinforcement, it was carried out a limit equilibrium analysis using the following methods: Simplified Bishop (1955 and Corrected Janbu (1954, for the hypothesis of circular and non circular slip surfaces respectively. In order to verify the behavior of the reinforced embankment, finite element analyses were performed using the software Phase2. Therefore, this work presented the determination of the reinforcement load design, verification of the magnitude of reinforcement strains, determination of the plastification zones in the foundation soil due to the elevation of the compacted soil, and values of distortion and horizontal displacement of the soft soil and mechanism of mobilization of reinforcement load.   

Large dams and alluvial rivers in the Anthropocene: The impacts of the Garrison and Oahe Dams on the Upper Missouri River

Science.gov (United States)

Skalak, Katherine; Benthem, Adam J.; Schenk, Edward R.; Hupp, Cliff R.; Galloway, Joel M.; Nustad, Rochelle A.; Wiche, Gregg J.

2013-01-01

The Missouri River has had a long history of anthropogenic modification with considerable impacts on river and riparian ecology, form, and function. During the 20th century, several large dam-building efforts in the basin served the needs for irrigation, flood control, navigation, and the generation of hydroelectric power. The managed flow provided a range of uses, including recreation, fisheries, and habitat. Fifteen dams impound the main stem of the river, with hundreds more on tributaries. Though the effects of dams and reservoirs are well-documented, their impacts have been studied individually, with relatively little attention paid to their interaction along a river corridor. We examine the morphological and sedimentological changes in the Upper Missouri River between the Garrison Dam in ND (operational in 1953) and Oahe Dam in SD (operational in 1959). Through historical aerial photography, stream gage data, and cross sectional surveys, we demonstrate that the influence of the upstream dam is still a major control of river dynamics when the backwater effects of the downstream reservoir begin. In the “Anthropocene”, dams are ubiquitous on large rivers and often occur in series, similar to the Garrison Dam Segment. We propose a conceptual model of how interacting dams might affect river geomorphology, resulting in distinct and recognizable morphologic sequences that we term “Inter-Dam sequence” characteristic of major rivers in the US.

The changing hydrology of a dammed Amazon

Science.gov (United States)

Timpe, Kelsie; Kaplan, David

2017-01-01

Developing countries around the world are expanding hydropower to meet growing energy demand. In the Brazilian Amazon, >200 dams are planned over the next 30 years, and questions about the impacts of current and future hydropower in this globally important watershed remain unanswered. In this context, we applied a hydrologic indicator method to quantify how existing Amazon dams have altered the natural flow regime and to identify predictors of alteration. The type and magnitude of hydrologic alteration varied widely by dam, but the largest changes were to critical characteristics of the flood pulse. Impacts were largest for low-elevation, large-reservoir dams; however, small dams had enormous impacts relative to electricity production. Finally, the “cumulative” effect of multiple dams was significant but only for some aspects of the flow regime. This analysis is a first step toward the development of environmental flows plans and policies relevant to the Amazon and other megadiverse river basins. PMID:29109972

Water-quality data from an earthen dam site in southern Westchester County, New York, 2015

Science.gov (United States)

Chu, Anthony; Noll, Michael L.

2017-10-11

The U.S. Geological Survey, in cooperation with the New York City Department of Environmental Protection, sampled 37 sites in the reservoir area for nutrients, major ions, metals, pesticides and their degradates, volatile organic compounds, temperature, pH, and specific conductance during fall 2015. Data collection was done to characterize the local groundwater-flow system and identify potential sources of seeps from the southern embankment at the Hillview Reservoir. Water-quality samples were collected in accordance with standard U.S. Geological Survey methods at 37 sites in and adjacent to Hillview Reservoir. These 37 sites were sampled to determine (1) baseline water-quality conditions of the saturated, low-permeability sediments that compose the earthen embankment that surrounds the reservoir, (2) water-quality conditions in the southwestern part of the study area in relation to the seeps on the embankment, and (3) temporal variation of water-quality conditions between 2006 and 2015 (not included in this report). The physical parameters and the results of the water-quality analysis from the 37 sites are included in this report and can be downloaded from the U.S. Geological Survey National Water Information System website.

Self-Assembling of Tetradecylammonium Chain on Swelling High Charge Micas (Na-Mica-3 and Na-Mica-2): Effect of Alkylammonium Concentration and Mica Layer Charge.

Science.gov (United States)

Pazos, M Carolina; Cota, Agustín; Osuna, Francisco J; Pavón, Esperanza; Alba, María D

2015-04-21

A family of tetradecylammonium micas is synthesized using synthetic swelling micas with high layer charge (Na(n)Si(8-n)Al(n)Mg6F4O20·XH2O, where n = 2 and 3) exchanged with tetradecylammonium cations. The molecular arrangement of the surfactant is elucidated on the basis of XRD patterns and DTA. The ordering conformation of the surfactant molecules into the interlayer space of micas is investigated by IR/FT, (13)C, (27)Al, and (29)Si MAS NMR. The structural arrangement of the tetradecylammonium cation in the interlayer space of high-charge micas is more sensitive to the effect of the mica layer charge at high concentration. The surfactant arrangement is found to follow the bilayer-paraffin model for all values of layer charge and surfactant concentration. However, at initial concentration below the mica CEC, a lateral monolayer is also observed. The amount of ordered conformation all-trans is directly proportional to the layer charge and surfactant concentration.

Three-dimensional modelling of an embankment built on a soft soil improved with prefabricated vertical drains

OpenAIRE

Venda Oliveira, P.J.; Cruz, R.F.P.M.L.; Lemos, L.J.L.; Almeida e Sousa, J.N.V.

2015-01-01

This work compares the field measurements of a non-symmetric embankment built on a Portuguese soft soil improved with prefabricated vertical drains (PVDs), with the numerical predictions of a 3D modelling where the PVDs are simulated according to the field flow conditions. The change in the permeability with the void ratio and the effect of the smear zone are also included in the numerical analysis. The numerical predictions are compared with the field data in terms of settlement, horizontal ...

Dams and transnational advocacy: Political opportunities in transnational collective action

Science.gov (United States)

Fu, Teng

Possible arguments to explain the gradual decline in big dam development and its site transferring from developed to developing countries include technical, economic, and political factors. This study focuses on the political argument---the rise of transnational anti-dam advocacy and its impact on state policy-making. Under what conditions does transnational anti-dam advocacy matter? Under what conditions does transnational advocacy change state dam policies (delay, scale down, or cancel)? It examines the role of transnational anti-dam actors in big dam building in a comparative context in Asia. Applying the social movement theory of political opportunity structure (POS) and using the qualitative case-study method, the study provides both within-case and cross-case analyses. Within-case analysis is utilized to explain the changing dynamics of big dam building in China (Three Gorges Dam and proposed Nu/Salween River dam projects), and to a lesser extent, Sardar Sarovar Project in India and Nam Theun 2 Dam in Laos. Different domestic and international POS (DPOS and IPOS) impact the strategies and outcomes of anti-dam advocacies in these countries. The degree of openness of the POS directly affects the capacity of transnational efforts in influencing state dam policies. The degree of openness or closure is measured by specific laws, institutions, discourse, or elite allies (or the absence of these) for the participation of non-state actors on big dam issues at a particular moment. This degree of openness is relative, varying over time, across countries and regions. This study finds that the impact of transnational anti-dam activism is most effective when both DPOS and IPOS are relatively open. Transnational anti-dam advocacy is least effective in influencing state dam policies when both DPOS and IPOS are relatively closed. Under a relatively open DPOS and closed IPOS, transnational anti-dam advocacy is more likely to successfully change state dam policies and even

Environmental impacts of small dams on agriculture and ground water development: a case study of Khan pur Dam, Pakistan

International Nuclear Information System (INIS)

Ejaz, N.; Shahmim, M.A.; Elahi, A.; Khan, N.M.

2012-01-01

The water scarcity issues are increasing through out the world. Pakistan is also facing water crises and its water demands are increasing every day. During this research it is investigated that small dams are playing an important role for the sustainability of groundwater and agriculture. The main objective of this study was to assess the environmental impacts of small dam on agricultural and ground water. Proper planning and management of small dams may improve the sustainable agriculture in Pakistan. It is also concluded that small dams are significantly contributing towards economy, environment, local climate, recreational activities and crop production. Small dams can also be utilized for the production of electricity at local level. On the other hand, water management issues can be resolved by the involvement of local farmer's associations. Water losses through seepage, unlined channels and old irrigation methods are most critical in developing world. Considering the overall positive environmental impacts, construction of small dams must be promoted. (author)

Large dams and risk management

International Nuclear Information System (INIS)

Cazelais, N.

2003-01-01

In July 1996, Quebec's Saguenay region was subjected to intensive rainfall which caused severe floods and uncontrolled release of several reservoirs, resulting in extensive damage to dam structures and reservoirs. The probability of occurrence for that disaster was 1:10,000. Following the disaster, the Quebec government established a dam management body entitled the Commission scientifique et technique sur la gestion des barrages, which pointed out several safety shortcomings of existing dams. Many were either very old or had undergone significant function change without being subsequently re-evaluated. A report by the Commission stated that damage following the floods could have been limited if the design and operating standards of the dams had been more stringent. A Dam Safety Act was adopted by the Quebec National Assembly on May 30, 2000 following recommendations to retain safer structures. The Act demands regular reporting of operating procedures. Seismic activity was noted as being a topic that requires in-depth examination since Quebec's St. Lawrence Valley, particularly the Charlevoix region, is one of Canada's largest seismic zones. The other is on the west coast in British Columbia. Earthquakes in Quebec are less intense than the ones in British Columbia, but they have higher frequency content which exerts a quasi-resonance wave effect which impacts roads, bridges, buildings and hydroelectric generating facilities. Hydro-Quebec is a public utility which owns 563 retaining structures, of which 228 are ranked as large dams that measure more than 15 metres high, 400 metres long and with a reservoir capacity of more than 1 million cubic metres of water. Hydro-Quebec addresses hydrological, seismic, technological and human risks through a dam safety procedure that includes structured plans for choosing best alternatives through staged exercises. Hazard levels are minimized through the adoption of emergency, prevention and alleviation measures. The utility

78 FR 62627 - Sam Rayburn Dam Rate

Science.gov (United States)

2013-10-22

..., Wholesale Rates for Hydro Power and Energy Sold to Sam Rayburn Dam Electric Cooperative, Inc. (Contract No... Schedule SRD-08, Wholesale Rates for Hydro Power and Energy Sold to Sam Rayburn Dam Electric Cooperative... ADMINISTRATION RATE SCHEDULE SRD-13 \\1\\ WHOLESALE RATES FOR HYDRO POWER AND ENERGY SOLD TO SAM RAYBURN DAM...

Evaluatie Dam tot Damloop 2014

NARCIS (Netherlands)

Deutekom-Baart de la Faille, Marije

In het weekend van 20 en 21 september 2014 vond de 30ste editie van de Dam tot Damloop plaats. Onderzoekers van de Hogeschool van Amsterdam en Hogeschool Inholland hebben bij de Dam tot Damloop een evaluatieonderzoek uitgevoerd met als doel het vinden van aanknopingspunten voor het structureel

The Total Risk Analysis of Large Dams under Flood Hazards

Directory of Open Access Journals (Sweden)

Yu Chen

2018-02-01

Full Text Available Dams and reservoirs are useful systems in water conservancy projects; however, they also pose a high-risk potential for large downstream areas. Flood, as the driving force of dam overtopping, is the main cause of dam failure. Dam floods and their risks are of interest to researchers and managers. In hydraulic engineering, there is a growing tendency to evaluate dam flood risk based on statistical and probabilistic methods that are unsuitable for the situations with rare historical data or low flood probability, so a more reasonable dam flood risk analysis method with fewer application restrictions is needed. Therefore, different from previous studies, this study develops a flood risk analysis method for large dams based on the concept of total risk factor (TRF used initially in dam seismic risk analysis. The proposed method is not affected by the adequacy of historical data or the low probability of flood and is capable of analyzing the dam structure influence, the flood vulnerability of the dam site, and downstream risk as well as estimating the TRF of each dam and assigning corresponding risk classes to each dam. Application to large dams in the Dadu River Basin, Southwestern China, demonstrates that the proposed method provides quick risk estimation and comparison, which can help local management officials perform more detailed dam safety evaluations for useful risk management information.

Analysis the dynamic response of earth dam in free vibration and forced by introducing the effect of the interaction dam foundation

Directory of Open Access Journals (Sweden)

Malika Boumaiza

2018-01-01

Full Text Available The present study concerns the analysis of the dynamic response of earth dam, in free and forced vibration (under the effect of earthquake using the finite element method. The analysis is carried out at the end of dam construction without filling. The behavior of the dam materials and the foundation is linear elastic. In free vibration, to better understand the effect of the dam foundation interaction, we will take into account different site conditions and see their influence on the free vibration characteristics of the dam. In forced vibration, to study the seismic response of the dam, the system is subjected to the acceleration of the Boumerdes earthquake of May 21, 2003 recorded at the station n ° 2 of the dam of Kaddara in the base, with a parametric study taking into account the influence of the main parameters such as the mechanical properties of the soil: rigidity, density.

Ice interactions at a dam face

Energy Technology Data Exchange (ETDEWEB)

Morse, B.; Morse, J.; Beaulieu, P.; Pratt, Y. [Laval Univ., Quebec City, PQ (Canada). Dept. of Civil Engineering; Stander, E. [State Univ. of New York, Cobleskill College, Cobleskill, NY (United States). Dept. of Natural Sciences; Cote, A.; Tarras, A.; Noel, P. [Hydro-Quebec, Varennes, PQ (Canada). IREQ

2009-07-01

This paper reported on a joint research project between Laval University and Hydro-Quebec to study ice forces on dams in an effort to harmonize design criteria and develop mitigation strategies. This paper introduced the project and explored some of the preliminary results of the 2007-2008 field season. Ice displacement, ice stresses and ice forces on the LaGabelle dam were measured at several locations. The paper identified and discussed the complex relationships between data sets and discussed the spatial-temporal variability of the ice forces and its impact on design criteria. The project objective was to develop design criteria for ice forces on dams and to provide a scientific basis for interpreting and harmonizing existing recommended criteria. The methodology and site description were presented. It was concluded that the ice processes in a reservoir near a dam face subject to water fluctuations are quite complex. Therefore, in order to know the real average pressure on the dam, a significant amount of panels are required, having important implications for determining safe design values. 9 refs., 10 figs.

On the non-linear pressure distribution in embankment dams

Energy Technology Data Exchange (ETDEWEB)

Svensson, Urban [Computer-aided Fluid Engineering AB, Norrkoeping (Sweden)

1999-12-01

The main objective of this study is to evaluate if a mathematical/numerical model of the air-theory can be formulated. It is the author's view that this has been demonstrated. The model is based on relevant physical laws and principles and produces results which are in qualitative agreement with observations. However, it should be emphasised that it is a feasibility study where some empirical relations have been tuned without considering possible experimental data or findings. If a more well-founded model is to be developed it is suggested that the following points are considered: (1) Compile relevant information on permeabilities for the type of two-phase flow considered. (2) Evaluate relevant laws and coefficients for the phase exchange. (3) Verify simulations by comparisons with laboratory experiments, if available. (4) Consider the two-dimensional situation.

Modeling of the solid-solution partitioning of heavy metals and arsenic in embanked flood plain soils of the rivers Rhine and Meuse

NARCIS (Netherlands)

Schröder, T.J.; Hiemstra, T.; Vink, J.P.M.

2005-01-01

The aim of this study is to predict the solid-solution partitioning of heavy metals in river flood plain soils. We compared mechanistic geochemical modeling with a statistical approach. To characterize the heavy metal contamination of embanked river flood plain soils in The Netherlands, we collected

Thermal effects of dams in the Willamette River basin, Oregon

Science.gov (United States)

Rounds, Stewart A.

2010-01-01

Methods were developed to assess the effects of dams on streamflow and water temperature in the Willamette River and its major tributaries. These methods were used to estimate the flows and temperatures that would occur at 14 dam sites in the absence of upstream dams, and river models were applied to simulate downstream flows and temperatures under a no-dams scenario. The dams selected for this study include 13 dams built and operated by the U.S. Army Corps of Engineers (USACE) as part of the Willamette Project, and 1 dam on the Clackamas River owned and operated by Portland General Electric (PGE). Streamflows in the absence of upstream dams for 2001-02 were estimated for USACE sites on the basis of measured releases, changes in reservoir storage, a correction for evaporative losses, and an accounting of flow effects from upstream dams. For the PGE dam, no-project streamflows were derived from a previous modeling effort that was part of a dam-relicensing process. Without-dam streamflows were characterized by higher peak flows in winter and spring and much lower flows in late summer, as compared to with-dam measured flows. Without-dam water temperatures were estimated from measured temperatures upstream of the reservoirs (the USACE sites) or derived from no-project model results (the PGE site). When using upstream data to estimate without-dam temperatures at dam sites, a typical downstream warming rate based on historical data and downstream river models was applied over the distance from the measurement point to the dam site, but only for conditions when the temperature data indicated that warming might be expected. Regressions with measured temperatures from nearby or similar sites were used to extend the without-dam temperature estimates to the entire 2001-02 time period. Without-dam temperature estimates were characterized by a more natural seasonal pattern, with a maximum in July or August, in contrast to the measured patterns at many of the tall dam sites

The Political Ecology of Chinese Large Dams in Cambodia: Implications, Challenges and Lessons Learnt from the Kamchay Dam

Directory of Open Access Journals (Sweden)

Giuseppina Siciliano

2016-09-01

Full Text Available Given the opportunities offered by foreign investment in energy infrastructure mostly by Chinese firms, the Government of Cambodia is giving high priority to developing hydropower resources for reducing energy poverty and powering economic growth. Using a “Political ecology of the Asian drivers” framework, this paper assesses China’s involvement in the development of large dams’ in Cambodia and its impacts on the access of natural resources such as water and energy by dam builders, local communities and the government. This analysis is based on 61 interviews and 10 focus group discussions with affected communities, institutional actors, Chinese dam builders and financiers in relation to the first large Chinese dam built in Cambodia: the Kamchay dam. Based on the results of the analysis this paper makes recommendations on how to improve the planning, implementation and governance of future large dams in Cambodia.

Douglas County Dam Breach Inundation Areas

Data.gov (United States)

Kansas Data Access and Support Center — Dam breach analysis provides a prediction of the extent and timing of flooding from a catastrophic breach of the dams. These results are sufficient for developing...

Expectations of immortality: dam safety management into the next millennium

Energy Technology Data Exchange (ETDEWEB)

Palmer, M.D. [Tonkin and Taylor International Ltd., Auckland, (New Zealand)

1999-07-01

Topics concerning the problems associated with older and aging dams are considered including: what can be done to extent the lifetime of an old dam, the decision to decommission a dam based on a value judgment that the risk of maintaining the dam is too great for society's acceptance, the possibility of change in the level of risk tolerance with time in a technological environment, traditional surveillance methods used by dam owners in the Y2K situation, and the unreality of dam immortality. Trends and means for preserving older dams for their owner's purposes are outlined, as well as their lifetime compared to that of the downstream systems they serve. Despite the fact that we live in a throwaway society, dam owners cannot just leave their dam asset when they are through with using it. Someone has to maintain the dam, or ensure that it is safely decommissioned when the owner is finished with it. On a worldwide scale the available pool of experienced dam engineers is shrinking. This problem needs to be addressed by a shift towards operating and dam safety management skills based on a firm awareness of dam design principles. A shift in society's expectations has occurred such that dam designers and owners must now recognize the impact a dam can have both on its natural and social environments. Because of the increasing emphasis on paying attention to the impacts of people's activities on the planet, engineers more than anyone else must have a significant influence in that direction. 9 refs.

Expectations of immortality: dam safety management into the next millennium

International Nuclear Information System (INIS)

Palmer, M.D.

1999-01-01

Topics concerning the problems associated with older and aging dams are considered including: what can be done to extent the lifetime of an old dam, the decision to decommission a dam based on a value judgment that the risk of maintaining the dam is too great for society's acceptance, the possibility of change in the level of risk tolerance with time in a technological environment, traditional surveillance methods used by dam owners in the Y2K situation, and the unreality of dam immortality. Trends and means for preserving older dams for their owner's purposes are outlined, as well as their lifetime compared to that of the downstream systems they serve. Despite the fact that we live in a throwaway society, dam owners cannot just leave their dam asset when they are through with using it. Someone has to maintain the dam, or ensure that it is safely decommissioned when the owner is finished with it. On a worldwide scale the available pool of experienced dam engineers is shrinking. This problem needs to be addressed by a shift towards operating and dam safety management skills based on a firm awareness of dam design principles. A shift in society's expectations has occurred such that dam designers and owners must now recognize the impact a dam can have both on its natural and social environments. Because of the increasing emphasis on paying attention to the impacts of people's activities on the planet, engineers more than anyone else must have a significant influence in that direction. 9 refs

The mathematics of dam safety

Energy Technology Data Exchange (ETDEWEB)

Widmann, R. [Osterreichische Gesellschaft fuer Geomechanik, Salzburg (Austria)

1997-05-01

The safety of a dam is determined by its design, construction and supervision during operation. High arch dam failures have dropped dramatically since the early part of this century. An essential part of the success story relates to improved measurement techniques that can detect earlier unexpected behaviour that may lead to failure. (UK)

Automatic dam concrete placing system; Dam concrete dasetsu sagyo no jidoka system

Energy Technology Data Exchange (ETDEWEB)

Yoneda, Y; Hori, Y; Nakayama, T; Yoshihara, K; Hironaka, T [Okumura Corp., Osaka (Japan)

1994-11-15

An automatic concrete placing system was developed for concrete dam construction. This system consists of the following five subsystems: a wireless data transmission system, an automatic dam concrete mixing system, a consistency determination system, an automatic dam concrete loading and transporting system, and a remote concrete bucket opening and closing system. The system includes the following features: mixing amount by mixing ratio and mixing intervals can be instructed from a concrete placing site by using a wireless handy terminal; concrete is mixed automatically in a batcher plant; a transfer car is started, and concrete is charged into a bucket automatically; the mixed concrete is determined of its properties automatically; labor cost can be reduced, the work efficiency improved, and the safety enhanced; and the system introduction has resulted in unattended operation from the aggregate draw-out to a bunker line, manpower saving of five persons, and reduction in cycle time by 10%. 11 figs., 2 tabs.

On the response of large dams to incoherent seismic excitation

International Nuclear Information System (INIS)

Ramadan, O.; Novak, M.

1993-01-01

An intensive parametric study was conducted to investigate the response of concrete gravity dams to horizontal, spatially variable seismic ground motions. Both segmented dams consisting of separate blocks, or monoliths, and continuous monolithic dams are considered. The study includes the effects of various parameters on system natural frequencies, vibration modes, modal displacement ratios, as well as dam displacements and internal stresses due to spatially variable ground motions. The dam analytical model, and dam response to incoherent ground motions are described. The results show that the dam vibrates almost as a rigid body under the fully correlated waves, but bends and twists significantly under the spatially correlated motions. Dam-foundation interaction magnifies the low frequency components of the dam response, more so for a full reservoir, but decreases the high frequency components. For long dams, the effects of spatially incoherent ground motions are qualitatively different and can be much greater than those due to surface travelling waves. 3 refs., 3 figs

the effect of age of dam on weaning mass for ftve dam breed types

African Journals Online (AJOL)

SUMMARY: The effect of age of dam on adjusted 210 day calf weaning mass was estimated by the Least Squares method for 5 dam types on 2 farms. ... the later maturing breeds would have a low level of productivity because these cows would be eliminated in their potentially prime .... time at 28 (2A) or 3l (28) months old.

Proceeding of the public safety around dams conference

Energy Technology Data Exchange (ETDEWEB)

NONE

2011-07-01

The Canadian Dam Association hosted the Public Safety Around Dams workshop in which presentations were given in the morning to describe the different measures and methods implemented by the Ontario Ministry of Natural Resources, Ontario Power Generation and others to improve safety around dams. In the afternoon, the participants toured the Auburn and Lakefield dams and facilities to view the infrastructures and equipment. A roundtable discussion concluded the day. Following this workshop, a Public Safety Around Dams group was created on the social network site, LinkedIn. This conference featured 6 presentations, 3 of which have been catalogued separately for inclusion in this database.

Major dams of the United States, Geographic NAD83, USGS (2006) [dams00x020_USGS_2006

Data.gov (United States)

Louisiana Geographic Information Center — This map layer portrays major dams of the United States, including Puerto Rico and the U.S. Virgin Islands. The map layer was created by extracting dams 50 feet or...

Geodetic deformation monitoring at Pendidikan Diponegoro Dam

Science.gov (United States)

Yuwono, Bambang Darmo; Awaluddin, Moehammad; Yusuf, M. A.; Fadillah, Rizki

2017-07-01

Deformation monitoring is one indicator to assess the feasibility of Dam. In order to get the correct result of the deformation, it is necessary to determine appropriate deformation monitoring network and the observation data should be analyse and evaluated carefully. Measurement and analysis of deformation requires relatively accurate data and the precision is high enough, one of the observation method that used is GPS (Global Positioning System). The research was conducted at Pendidikan Undip Dams is Dam which is located in Tembang. Diponegoro Dam was built in 2013 and a volume of 50.86 m3 of water, inundation normal width of up to 13,500 m2. The main purpose of these building is not only for drainage but also for education and micro hydro power plant etc. The main goal of this reasearch was to monitor and analyze the deformation at Pendidikan Undip Dam and to determaine whether GPS measurement could meet accuracy requirement for dam deformation measurements. Measurements were made 2 times over 2 years, 2015 and 2016 using dual frequency GPS receivers with static methods and processed by Scientific Software GAMIT 10.6

Use of soil-rock mixtures in dam construction

OpenAIRE

Caldeira, L.; Brito, A.

2014-01-01

The employment of non-traditional materials such as soil–rock mixtures, for economic and environmental reasons, in the construction of earthworks poses some new challenges for compaction techniques and their control as well as for the determination of the characteristics of the embankment that result from the compaction method. Those characteristics experience important changes according to the relative percentages of the existing fractions. Usually, this kind of material results from bulky r...

Investigating leaks in dams and reservoirs

International Nuclear Information System (INIS)

2003-01-01

Millions of people throughout the world depend on dams and reservoirs for electricity, water and flood protection. Dams require significant investment to build and maintain, and yet their usefulness and integrity are constantly threatened by leakage and sedimentation. Isotope hydrology techniques, combined with conventional analytical methods, are a cost-effective tool to reduce such threats. The International Atomic Energy Agency is promoting their use to protect these investments and improve management, particularly by supporting specialized teams of scientists and engineers to investigate dam leakage in African countries on request. (IAEA)

A study on the effect of a broken large sabo dam on the sediment transportation in channel - an example of Baling-sabo-dam

Science.gov (United States)

Tseng, W. H.; Shieh, C. L.; Lee, S. P.; Tsang, Y. C.

2009-04-01

To retard the sediment transportation and its effect on the reservoir, large sabo dams are built in the main channel of the reservoir watershed in Taiwan. Therefore, these large sabo dams affect upstream, downstream, and the reservoir significantly if the dam breaks. There was about 450 mm of rain fell in the reservoir watershed during typhoon Wipha that struck Taiwan on 17-19, September, 2007. This heavy rainfall caused the Baling-sabo-dam broken about 60 m of the upper Dahan Creek in the Shimen Reservoir watershed. The dam, built in 1977, is 38 m in height, 80 m in width, and is designed to reserve sediment materials about 10 million m3. The upper river bed was diminished maximum to 20 m in a month; the deposited and affected areas are unable to estimate and still required to be observed. The main purpose of this paper is to analyze the topographic characteristic of the channel after the dam broke according to the topographic and surveyed data before and after the dam broke. The longitudinal profile and the cross section data show the effects to the channel after the dam break and the channel is able to classify in several sections. A simple comparison of the sediment discharge estimated from the hydrologic data with the topographic survey data is also analyzed. Keywords:dam break, sabo dam, sediment discharge

The Grand Ethiopian Renaissance Dam and Ethiopia's Succession ...

African Journals Online (AJOL)

Tadesse Kassa Woldetsadik

2013-06-01

Jun 1, 2013 ... Dam concessions engendered detrimental impacts on Ethiopia's riparian rights ... control works on the Aswan High and the Roseires dams. Disturbed by the ... hegemonic control that would inevitably ensue from construction of the Dam ...... Projects Implementation Division AAAID, Sudan, p.1. 39 Ibid.

Dam failure analysis/calibration using NWS models on dam failure in Alton, New Hampshire

International Nuclear Information System (INIS)

Capone, E.J.

1998-01-01

The State of New Hampshire Water Resources Board, the United States Geological Service, and private concerns have compiled data on the cause of a catastrophic failure of the Bergeron Dam in Alton, New Hampshire in March of 1996. Data collected related to the cause of the breach, the breach parameters, the soil characteristics of the failed section, and the limits of downstream flooding. Dam break modeling software was used to calibrate and verify the simulated flood-wave caused by the Bergeron Dam breach. Several scenarios were modeled, using different degrees of detail concerning the topography/channel-geometry of the affected areas. A sensitivity analysis of the important output parameters was completed. The relative importance of model parameters on the results was assessed against the background of observed historical events

STABILITAS CHECK DAM DI ARBORETUM DESA SUMBER BRANTAS

Directory of Open Access Journals (Sweden)

Endang Purwati

2012-09-01

Full Text Available Abstract: The stability of check-dam in arboretum of Sumber Brantas village. Sumber Brantas water sources area is arboretum territory which has to be maintained as conservation either for technical or vegetation (plants cover by sustainable development. Arboretum territory is made as asylum in irrigation system district of Brantas River. This research discusses technical conservation activity to build the check dam in conserving the area. Check dam is built dimensionally by using HEC-RAS Program to get safe and stable dimension for rolling, shifting and piping of Sf > 1.5, and based on hydrologic analysis to get maximum flood discharge of 48.01 m3second-1. Hydraulic analysis is used to get water level profile and pressure for the dam body. Stability of the structure will be controlled by construction load (weight of check dam and its fully sediment storage condition. The result of this research shows that the safe and stable dimension for check dam are as follows: 28 meter of width; 3 meter of main height; 1.5 meter of sub-height; 10 meter of stilling basin length (Main Dam–Sub Dam.

The blind men meet the elephant at the dam: Alternative spatial and taxonomic components reveal different insights about how low-head dams impact fish biodiversity

Science.gov (United States)

Fencl, Jane S.; Mather, Martha E.; Smith, Joseph M.; Hitchman, Sean M.

2017-01-01

Dams are ubiquitous environmental impacts that threaten aquatic ecosystems. The ability to compare across research studies is essential to conserve the native biodiversity that is impacted by the millions of low‐head dams that currently fragment streams and rivers. Here, we identify a previously unaddressed obstacle that impedes this generalization. Specifically, divergent spatial and taxonomic approaches that result from different conceptualizations of the dam‐biodiversity problem can produce conflicting science‐based conclusions about the same dam impact. In this research, using the same dammed and undammed sites, we evaluated the scientific generality of different conceptualizations of the dam‐biodiversity problem. We compared two different but commonly used spatial approaches—(1) above dam–below dam vs. (2) undammed–dammed comparisons—and 11 different, commonly used taxonomic approaches (three assemblage summaries, eight guilds). Sites above the dam structure had less diverse fish assemblages than sites below dams, whereas sites below the dam structure were similar to undammed sites. Thus, spatial approach 1 detected a large dam effect and spatial approach 2 detected a small dam effect. Similarly, some taxonomic responses (species richness, diversity, abundance, and number of guilds) detected large dam effects; other responses detected small (riffle specialist guild) or no dam effects (pool generalists). In summary, our results showed that how the problem was framed altered scientific conclusions and created different dam realities. The metaphor of how individual blind men disagree about the structure of an elephant, based on examinations of different body parts, reinforces the need for a coordinated, holistic perspective on dam research. Although no single approach is adequate for all problems, identifying the form, consequences of, and relationships among different research conceptualizations will set the stage for future syntheses of dam�

Seismic response of uplifting concrete gravity dams

International Nuclear Information System (INIS)

Leger, P.; Sauve, G.; Bhattacharjee, S.

1992-01-01

The foundation interaction effects on the seismic response of dam-foundation systems have generally been studied using the linear elastic finite element models. In reality, the foundation can not develop effective tensile stresses to a significant degree along the interface. A two-dimensional finite element model, in which nonlinear gap elements are used at the dam-foundation interface to determine the uplift response of concrete gravity dams subjected to seismic loads, is presented. Time domain analyses were performed for a wide range of modelling assumptions such as dam height, interface uplift pressure, interface mesh density, and earthquake input motions, that were systematically varied to find their influence on the seismic response. The nonlinear interface behavior generally reduces the seismic response of dam-foundation systems acting as a seismic isolation mechanism, and may increase the safety against sliding by reducing the base shear transmitted to the foundation. 4 refs., 5 figs., 6 tabs

Seismic performance assessment of latyan concrete buttress dam ...

African Journals Online (AJOL)

In order to design earthquake resistant dams and evaluate the safety of existing dams that will be exposed to future earthquakes, it is essential to have accurate and reliable analysis procedures to predict the stresses and deformations in dams subjected to earthquake ground motion. For a damwater- foundation system, the ...

Walden North Dam overtopping : emergency response and rehabilitation

Energy Technology Data Exchange (ETDEWEB)

Dyer, S. [FortisBC Inc., South Slocan, BC (Canada); McCreanor, J. [Acres International Ltd., Calgary, AB (Canada); Cronin, D.L.R.; Daw, D. [Acres International Ltd., Vancouver, BC (Canada)

2004-09-01

This paper described the events that led to the overtopping of the Walden North Dam during a heavy rainfall in June 2002, resulting in a breach around an abutment wall. The dam is part of a run-of-river hydro development on Cayoosh Creek near Lillooet, British Columbia. The Walden North Dam was a low, 46 meter wide concrete dam with a single radial gate. The dam overtopping was attributed to failure of the radial gate hoist. Prior to this event, the dam had been classified by the British Columbia Dam Safety Authorities as a high and then a low consequence category of failure. As facility managers, Aquila Networks Canada Ltd. established an immediate action plan to stabilize the situation and resume normal power production by applying the following priorities: (1) ensure safety of workers and the public, (2) limit further damage to the dam and other facilities, (3) ensure environmental protection, and (4) continue to operate the generation units. Local authorities were informed to evacuate a downstream campsite and environmental agencies were contacted along with safety regulators. Repairs included demolition of the damaged portion of the structure and construction a new two-bay gate/stoplog spillway and bridge. Construction was completed by September 2003 according to the requirements of the Department of Fisheries and Oceans for minimum flow, accurate control of fish flows and environmental monitoring of the stream area. 10 figs.

Developing an integrated dam safety program

International Nuclear Information System (INIS)

Nielsen, N. M.; Lampa, J.

1996-01-01

An effort has been made to demonstrate that dam safety is an integral part of asset management which, when properly done, ensures that all objectives relating to safety and compliance, profitability, stakeholders' expectations and customer satisfaction, are achieved. The means to achieving this integration of the dam safety program and the level of effort required for each core function have been identified using the risk management approach to pinpoint vulnerabilities, and subsequently to focus priorities. The process is considered appropriate for any combination of numbers, sizes and uses of dams, and is designed to prevent exposure to unacceptable risks. 5 refs., 1 tab

Grouting Applications in Cindere Dam

Directory of Open Access Journals (Sweden)

Devrim ALKAYA

2011-01-01

Full Text Available Grouting is one of the most popular method to control the water leakage in fill dam constructions. With this regard this method is widely used in all the world. Geological and geotechnical properties of rock are important parameters affect the design of grouting. In this study, geotechnical properties of Cindere Dam's base rock and the grouting prosedure have been investigated with grouting pressure.

Sinkhole investigated at B.C. Hydro's Bennett Dam

International Nuclear Information System (INIS)

Anon.

1996-01-01

The cause of a sinkhole which appeared in a roadway crossing an earth filled dam in B. C., was discussed. The hole measured 6 ft. across and 20 ft. deep, and occurred in B.C. Hydro's W.A.C. Bennett Dam which measures 600 ft. high, 2,600 ft. wide at the base and 35 ft. wide at the crest. The cause of the sinkhole is not known, but it is believed that a weakness in the dam may have found its way to the surface via a pipe connected to a bedrock settlement gauge buried within the dam. Sonar and ground penetrating radar were used to examine the area. The hole has been filled with gravel and monitoring continues. Experts do not anticipate immediate risk of dam failure. 1 fig

Plugs or flood-makers? the unstable landslide dams of eastern Oregon

Science.gov (United States)

Safran, Elizabeth B.; O'Connor, Jim E.; Ely, Lisa L.; House, P. Kyle; Grant, Gordon E.; Harrity, Kelsey; Croall, Kelsey; Jones, Emily

2015-01-01

Landslides into valley bottoms can affect longitudinal profiles of rivers, thereby influencing landscape evolution through base-level changes. Large landslides can hinder river incision by temporarily damming rivers, but catastrophic failure of landslide dams may generate large floods that could promote incision. Dam stability therefore strongly modulates the effects of landslide dams and might be expected to vary among geologic settings. Here, we investigate the morphometry, stability, and effects on adjacent channel profiles of 17 former and current landslide dams in eastern Oregon. Data on landslide dam dimensions, former impoundment size, and longitudinal profile form were obtained from digital elevation data constrained by field observations and aerial imagery; while evidence for catastrophic dam breaching was assessed in the field. The dry, primarily extensional terrain of low-gradient volcanic tablelands and basins contrasts with the tectonically active, mountainous landscapes more commonly associated with large landslides. All but one of the eastern Oregon landslide dams are ancient (likely of order 103 to 104 years old), and all but one has been breached. The portions of the Oregon landslide dams blocking channels are small relative to the area of their source landslide complexes (0.4–33.6 km2). The multipronged landslides in eastern Oregon produce marginally smaller volume dams but affect much larger channels and impound more water than do landslide dams in mountainous settings. As a result, at least 14 of the 17 (82%) large landslide dams in our study area appear to have failed cataclysmically, producing large downstream floods now marked by boulder outwash, compared to a 40–70% failure rate for landslide dams in steep mountain environments. Morphometric indices of landslide dam stability calibrated in other environments were applied to the Oregon dams. Threshold values of the Blockage and Dimensionless Blockage Indices calibrated to worldwide

The geomorphic legacy of small dams — An Austrian study

NARCIS (Netherlands)

Poeppl, R.E.; Keesstra, S.D.; Hein, T.

2015-01-01

Dams represent one of the most dominant forms of human impact upon fluvial systems during the Anthropocene, as they disrupt the downstream transfer of water and sediments. Removing dams restores river continuity and channel morphology. Both dam construction and dam removal induce geomorphic channel

Macroinvertebrados bentônicos como indicadores de qualidade de água na Barragem Santa Bárbara, Pelotas, RS, Brasil Zoobenthics as indicators of the water quality in the Santa Bárbara Dam, Pelotas, RS, Brazil

Directory of Open Access Journals (Sweden)

Sérgio Renato Noguez Piedras

2006-04-01

Full Text Available O objetivo deste trabalho foi estudar o impacto de dois afluentes da barragem Santa Bárbara sobre o ambiente da mesma, utilizando a ocorrência de invertebrados bentônicos e características químicas da água. Durante nove meses foram realizadas coletas e análises da água e de invertebrados bentônicos nos afluentes Sanga da Barbuda e Sanga do Passo do Cunha e também no interior da bacia de acumulação da barragem. Os resultados mostram que, embora a Sanga da Barbuda e a Sanga do Passo do Cunha apresentem características químicas abaixo do recomendável, no limite aceitável pela legislação que determina os padrões de qualidade da água para abastecimento público, estes afluentes estão, ainda, sendo diluídos de forma satisfatória na bacia de acumulação da barragem. O estudo das relações entre variáveis químicas e invertebrados bentônicos mostra haver correlação significativa entre os baixos níveis de oxigênio dissolvido e a presença de Oligochaeta, sendo que o aumento do número de Oligochaeta indica uma situação de anoxia na barragem Santa Bárbara.The objective of this work was to study the impact of two tributaries from the Santa Bárbara Dam on this environment using the occurrence of zoobenthics and some water chemical characteristics. Monthly gathering and analysis from the water and zoobenthics were done during nine months in the tributaries Sanga da Barbuda and Sanga Passo do Cunha as well as in the inner part of the accumulation basin in the Santa Barbara dam. The results demonstrate that, though Sanga da Barbuda and Sanga Passo do Cunha present chemical characteristics lower than the recommended but still in the limits acceptable by the law that regulates the water quality standards for the supply, these tributaries are being diluted in a satisfactory way in the accumulation basin in the Santa Barbara dam. The study of the relations between chemical variables and zoobenthics show a significant correlation

Estimating flood inundation caused by dam failures

Energy Technology Data Exchange (ETDEWEB)

Mocan, N. [Crozier and Associates Inc., Collingwood, ON (Canada); Joy, D.M. [Guelph Univ., ON (Canada). School of Engineering; Rungis, G. [Grand River Conservation Authority, Cambridge, ON (Canada)

2006-01-15

Recent advancements in modelling inundation due to dam failures have allowed easier and more illustrative analyses of potential outcomes. This paper described new model and mapping capabilities available using the HEC-RAS hydraulic model in concert with geographic information systems (GIS). The study area was the upper reaches of Canagagigue Creek and the Woolwich Dam near Elmira, Ontario. A hydraulic analysis of a hypothetical dam failure was developed based on the summer probable maximum flood (PMF) event. Limits extended from Woolwich Dam to downstream of the Town of Elmira. An incoming summer PMF hydrograph was set as the upstream boundary condition in the upstream model. Simulation parameters include simulation time-step; implicit weighting factor; water surface calculation tolerance; and output calculation interval. Peak flows were presented, as well as corresponding flood inundation results through the Town of Elmira. The hydraulic model results were exported to a GIS in order to develop inundation maps for emergency management planning. Results from post-processing included inundation maps for each of the simulated time-steps as well as an inundation animation for the duration of the dam breach. It was concluded that the modelling tools presented in the study can be applied to other dam safety assessment projects in order to develop effective and efficient emergency preparedness plans through public consultation and the establishment of impact zones. 1 tab., 2 figs.

Hydrogeophysical investigations at Hidden Dam, Raymond, California

Science.gov (United States)

Minsley, Burke J.; Burton, Bethany L.; Ikard, Scott; Powers, Michael H.

2011-01-01

Self-potential and direct current resistivity surveys are carried out at the Hidden Dam site in Raymond, California to assess present-day seepage patterns and better understand the hydrogeologic mechanisms that likely influence seepage. Numerical modeling is utilized in conjunction with the geophysical measurements to predict variably-saturated flow through typical two-dimensional dam cross-sections as a function of reservoir elevation. Several different flow scenarios are investigated based on the known hydrogeology, as well as information about typical subsurface structures gained from the resistivity survey. The flow models are also used to simulate the bulk electrical resistivity in the subsurface under varying saturation conditions, as well as the self-potential response using petrophysical relationships and electrokinetic coupling equations.The self-potential survey consists of 512 measurements on the downstream area of the dam, and corroborates known seepage areas on the northwest side of the dam. Two direct-current resistivity profiles, each approximately 2,500 ft (762 m) long, indicate a broad sediment channel under the northwest side of the dam, which may be a significant seepage pathway through the foundation. A focusing of seepage in low-topography areas downstream of the dam is confirmed from the numerical flow simulations, which is also consistent with past observations. Little evidence of seepage is identified from the self-potential data on the southeast side of the dam, also consistent with historical records, though one possible area of focused seepage is identified near the outlet works. Integration of the geophysical surveys, numerical modeling, and observation well data provides a framework for better understanding seepage at the site through a combined hydrogeophysical approach.

Seepage problem in Papan dam and the treatment

Energy Technology Data Exchange (ETDEWEB)

Sharghi, A. [JTMA Co., Tehran (Iran, Islamic Republic of); Palassi, M. [Tehran Univ. (Iran, Islamic Republic of). Dept. of Civil Engineering

2003-07-01

The Papan dam in the Krygyz Republic is 97 metres high. It is located in the Osh Oblast, within a narrow and steep sided gorge on the Ak-Bura River, approximately 20 kilometres south of the City of Osh. The impoundment of the dam revealed large inflows of water to the downstream dam through the upper half of the dam and through the joints in the right abutment. A number of options were considered before a treatment method was selected. The causes of the leakage were poor grouting, and joints and fissures in the abutment. The remedial process involved the use of a plastic concrete cutoff wall extended from the crest of the dam to a depth of approximately 70 metres, in addition to the use of a grouting curtain in the right abutment. 2 figs.

Design and Construction of Dams, Reservoirs, and Balancing Lakes

International Nuclear Information System (INIS)

Lemperiere, F.

2003-01-01

The general data presented in sections two and three gives an idea of the extreme diversity of the millions of very large or very small dams worldwide. Dam design and construction methods for the most usual types of large dams are presented and justified in section four. The possibility and usefulness of building as many dams in the 21. century as have been built in the 20. is analyzed in section six. (author)

Estimates o the risks associated with dam failure

Energy Technology Data Exchange (ETDEWEB)

Ayyaswamy, P.; Hauss, B.; Hseih, T.; Moscati, A.; Hicks, T.E.; Okrent, D.

1974-03-01

The probabilities and potential consequences of dam failure in California, primarily due to large earthquakes, was estimated, taking as examples eleven dams having a relatively large population downstream. Mortalities in the event of dam failure range from 11,000 to 260,000, while damage to property may be as high as $720 million. It was assumed that an intensity IX or X earthquake (on the Modified Mercalli Scale) would be sufficient to completely fail earthen dams. Predictions of dam failure were based on the recurrence times of such earthquakes. For the dams studied, the recurrence intervals for an intensity IX earthquake varied between 20 and 800 years; for an intensity X between 50 and 30,000 years. For the Lake Chabot and San Pablo dams (respectively 20, 30 years recurrent earthquake times for a intensity X) the associated consequences are: 34,000 (Lake Chabot) and 30,000 (San Pablo) people killed; damage $140 million and $77 million. Evaculation was found to ameliorate the consequences slightly in most cases because of the short time available. Calculations are based on demography, and assume 10 foot floodwaters will drown all in their path and destroy all one-unit homes in the flood area. Damage estimates reflect losses incurred by structural damage to buildings and do not include loss of income. Hence the economic impact is probably understated.

Dam spills and fishes

International Nuclear Information System (INIS)

1996-01-01

This short paper reports the main topics discussed during the two days of the annual colloquium of the Hydro-ecology Committee of EdF. The first day was devoted to the presentation of the joint works carried out by EdF, the Paul-Sabatier University (Toulouse), the Provence St-Charles University (Marseille), the ENSAT (Toulouse) and the CEMAGREF (Lyon and Aix-en-Provence) about the environmental impact of dam spills on the aquatic flora and fauna downstream. A synthesis and recommendations were presented for the selection and characterization of future sites. The second day was devoted to the hydro-ecology study of the dam reservoir of Petit-Saut (French Guyana): water reoxygenation, quality evolution, organic matter, plankton, invertebrates and fishes. The 134 French dams concerned by water spills have been classified according to the frequency of spills, the variations of flow rates created, and their impacts on fishing, walking, irrigation, industry, drinking water, navigation, bathing. Particular studies on different sites have demonstrated the complexity of the phenomena involved concerning the impact on the ecosystems and the water quality. (J.S.)

Grouting of karstic arch dam foundation

Energy Technology Data Exchange (ETDEWEB)

Young, J.; Rigbey, S. [Acres International, Niagara Falls, ON (Canada)

2002-07-01

A 200 m high arch dam and a 2000 MW underground power house complex is under development in the Middle East. The project is located in a highly seismic area in rugged, mountainous terrain. The arch dam is constructed on good quality limestone and dolomitic limestone rock mass, but it contains several zones of disturbed or sheared rock. The basement rock is slightly karstic with hydraulic conductivities in the order of 100 Lugeons. In order to get a satisfactory foundation surface for the dam, it will be necessary to excavate extensively and backfill with concrete. Because of the presence of many clay infilled cavities and fractures, geotechnicians are considering the installation of a multiple row grout curtain to a depth of 150 m below the dam foundation to ensure adequate seepage and uplift parameters when the reservoir is impounded. Initial grouting water pressure test results suggested that the grouting and drainage curtain should be extended to the left abutment beyond the current design. However, when horizontal slide models of the dam abutment were developed using the finite element program SEEPW, it was shown that there is no benefit to extending the length of grout curtains unless they are tied to an area of much lower hydraulic conductivity much deeper in the abutment. 1 tab., 5 figs.

Predictions of total deformations in Jebba main dam by finite ...

African Journals Online (AJOL)

This paper examined the deformations of the Jebba Main Dam, Jebba Nigeria using the finite element method. The study also evaluated the predicted deformations and compared them with the actual deformations in the dam to identify possible causes of the observed longitudinal crack at the dam crest. The Jebba dam is a ...

Assessment of check-dam groundwater recharge with water-balance calculations

Science.gov (United States)

Djuma, Hakan; Bruggeman, Adriana; Camera, Corrado; Eliades, Marinos

2017-04-01

Studies on the enhancement of groundwater recharge by check-dams in arid and semi-arid environments mainly focus on deriving water infiltration rates from the check-dam ponding areas. This is usually achieved by applying simple water balance models, more advanced models (e.g., two dimensional groundwater models) and field tests (e.g., infiltrometer test or soil pit tests). Recharge behind the check-dam can be affected by the built-up of sediment as a result of erosion in the upstream watershed area. This natural process can increase the uncertainty in the estimates of the recharged water volume, especially for water balance calculations. Few water balance field studies of individual check-dams have been presented in the literature and none of them presented associated uncertainties of their estimates. The objectives of this study are i) to assess the effect of a check-dam on groundwater recharge from an ephemeral river; and ii) to assess annual sedimentation at the check-dam during a 4-year period. The study was conducted on a check-dam in the semi-arid island of Cyprus. Field campaigns were carried out to measure water flow, water depth and check-dam topography in order to establish check-dam water height, volume, evaporation, outflow and recharge relations. Topographic surveys were repeated at the end of consecutive hydrological years to estimate the sediment built up in the reservoir area of the check dam. Also, sediment samples were collected from the check-dam reservoir area for bulk-density analyses. To quantify the groundwater recharge, a water balance model was applied at two locations: at the check-dam and corresponding reservoir area, and at a 4-km stretch of the river bed without check-dam. Results showed that a check-dam with a storage capacity of 25,000 m3 was able to recharge to the aquifer, in four years, a total of 12 million m3 out of the 42 million m3 of measured (or modelled) streamflow. Recharge from the analyzed 4-km long river section without

Earthquake induced liquefaction analysis of Tendaho earth-fill dam ...

African Journals Online (AJOL)

fill dam, which is part of Tendaho Dam and Irrigation Project; the largest irrigation project in Ethiopia to date. The dam is located in the most seismic part of Ethiopia and was originally designed to be founded on potentially liquefiable alluvium ...

Dams and Obstructions along Iowa's Canoe Routes

Data.gov (United States)

Iowa State University GIS Support and Research Facility — This dataset represents obstruction to canoe and boat users of the canoe routes of Iowa. This may represent actual dams, rock dams (natural or man made), large...

Ririe Dam Release Test Assessment

Science.gov (United States)

2013-06-01

Notes HEC - RAS Location Station (ft) Observation Notes 1420 Ririe Dam Ririe Dam 119,880 Gates opened and initial release started. 1455 115th St...16°F air temperature. Table A2. Observations made on 11 February 2013. Time Location Notes HEC - RAS Location Station (ft) Observation Notes...ERDC/CRREL TR-13-10 52 Time Location Notes HEC - RAS Location Station (ft) Observation Notes Travel Time* (sec) Vel.** (fps) 1224 5th

Non uniform nature of recorded ground accelerations at dam foundation interface

Energy Technology Data Exchange (ETDEWEB)

Ghaemian, Mohsen; Gilani, Morteza Sohrabi [Sharif University of Technology, Tehran, (Iran, Islamic Republic of); Noorzad, Ali [Power and Water University of Technology, Tehran, (Iran, Islamic Republic of)

2010-07-01

The Karun III is a double curved concrete arch dam located in Iran which was used to investigate earthquake motions and dam responses. This paper presented the study of the Karun III dam foundation interface. Using an array of 15 accelerometers, two major events that occurred on 2007.11.20 and 2007.11.21 were recorded during dam operation with a PGA at crest of 0.312 g and 0.109.g respectively. A finite element model of Karun III dam was performed. The response of the Karun III dam during the 2007 earthquake was investigated using the NSAD-DRI program. It was found that the motion of the dam foundation interface is non-uniform. There is a time shift and amplification at the abutment compared to those at the base of the dam. The results showed that the spatially varying earthquake assumption is in good agreement with the recorded displacement of the dam.

Verifying Pressure of Water on Dams, a Case Study

Directory of Open Access Journals (Sweden)

Temel Bayrak

2008-09-01

Full Text Available Sensing and monitoring deformation pattern of dams is often one of the most effective ways to understand their safety status. The main objective of the present study is to find the extent to which rising reservoir level affects the mechanism of deformation of the Yamula dam under certain changes in the reservoir level conditions during the first filling period. A new dynamic deformation analysis technique was developed to analyze four geodetic monitoring records consisting of vertical and horizontal displacements of nine object points established on the dam and six reference points surrounding it, to see whether the rising reservoir level is responsible for the vertical and horizontal deformations during the first filling period. The largest displacements were determined in the middle points of the dam construction. There is an apparent linear relationship between the dam subsidence and the reservoir level. The dynamic deformation model was developed to model this situation. The model infers a causative relationship between the reservoir level and the dam deformations. The analysis of the results determines the degree of the correlation between the change in the reservoir level and the observed structural deformation of the dam.

Detection of water leaks in the dam Joumine and study of sedimentation in the dam Ghezela by nuclear method

International Nuclear Information System (INIS)

Sari Souha

2013-01-01

The objective of this study is to determinate the paths of leaks observed in the dam Joumine and to identify the origin of salinity in the drain D2. In addition, the evaluation of the sedimentation measurement of suspended elements in the dam Ghezela is our second objective. The Joumine dam located in the North-east of Tunisia (governorate of Bizerte), was built in 1983 has an upstream watershed area of 418 km 2 . The reservoir capacity is 130 Mm 3 . This dam observed a water leakage from its implementation at the two drains D1 and D2 with a emerging flow rate reached a value close to 500 l/s, about 16 pour cent of its capacity. The injection of an insulating material in Karsts networks reduces the leakage rate to a value of 120 l / s in 1993 and 88 l / s in 2013, but this decrease was accompanied by an increase in salinity level in D2. The results from a multidisciplinary approach showed that the leakage path from the left bank of the reservoir where the leak was first detected, heading both D1 and D2 drains and the salinity in drain D2 due to the dissolution of the gypsum layer downstream of the dam and the contribution of brackish water from the left bank. The Ghezela dam located in the same area, was built in 1984 has an upstream watershed area of 48 km 2 . This dam has been an increase in sedimentation of 0.3 million m3 in 1994 to 1.7 million m 3 in 2010. In this study, the suspended elements were measured with a nuclear probe composed by a radioactive source of americium 241 and a NaI detector trained by a boat at different depth in the reservoir.

Pearl Harbor: lessons for the dam safety community

Energy Technology Data Exchange (ETDEWEB)

Martin, T.E. [AMEC Earth and Environmental Ltd., Burnaby, BC (Canada)

2001-10-01

Every good dam safety program must be based on surveillance and emergency response planning. The same principles apply to the gathering of information for military intelligence and the planning of defence tactics. Lessons learned from failure have spurred the advancement of dam engineering. Dam safety experts can benefit from the inadequacies encountered by the military community, with the most famous occurring on December 7, 1941 in Pearl Harbor. Both intelligence gathering and contingency response planning failed miserably. The data was not properly disseminated, interpreted, analysed. The proper response to the situation was not initiated. Human error and failure to communicate are the two main reasons that explain the debacle. The inquiries into the tragedy at Pearl Harbor provided valuable lessons, related to individual and organizational failures, which the authors shared in this presentation. The relevance to dam safety was made. All Federal Bureau of Investigation (FBI) agents must read the lessons drawn from Pearl Harbor, as they have responsibility for dam safety. 4 refs.

Towards a dams safety management system for Angola

OpenAIRE

Camilo, V.; Silva, A.; Costa, R.; Barateiro, J.; Portela, E. A.; Fonseca, J.

2015-01-01

Dams have contributed to the human development and have brought many benefits, such as delivering hydropower, irrigating agricultural fields, supplying drinking water, or just for navigational and recreational purposes. Nevertheless, dams are critical structures that raise multiple concerns and risks associated with the ecological, social and economic impact. Angola has a rich and complex network of water basins and dams that serves different strategic purposes as defined in it...

Analysis of disposal of uranium mill tailings in a mined out open pit

International Nuclear Information System (INIS)

Staub, W.P.; Triegel, E.K.

1978-01-01

Mined out open pits are presently under consideration as disposal sites for uranium mill tailings. In this method of tailings management, the escape of contaminated liquid into an adjacent aquifer is the principal environmental concern. The modified Bishop Method was used to analyze the structural stability of a clay liner along the highwall and fluid flow models were used to analyze the effect of tailings solutions on ground water under several operating conditions. Results of the slope stability analysis showed that it would be necessary to construct the clay liner as a modified form of engineered embankment. This embankment would be similar in construction to that of an earthfill dam. It could be constructed on a 1:1 slope provided the tailings slurry were managed properly. It would be necessary to maintain the freeboard height between the embankment and tailings at less than 4 m. A partially dewatered sand beach would have to be located adjacent to the embankment. Potential leakage and aquifer contamination was modeled for lined and unlined pits of various designs. Sulfate, and possibly U and Th, are the most likely contaminants. Results from the model showed the clay and soil cement lined pit to be most effective in containing the pollutants

Remote Sensing of Deformation of a High Concrete-Faced Rockfill Dam Using InSAR: A Study of the Shuibuya Dam, China

Directory of Open Access Journals (Sweden)

Wei Zhou

2016-03-01

Full Text Available Settlement is one of the most important deformation characteristics of high concrete faced rockfill dams (CFRDs, >100 m. High CFRDs safety would pose a great threat to the security of people’s lives and property downstream if this kind of deformation were not to be measured correctly, as traditional monitoring approaches have limitations in terms of durability, coverage, and efficiency. It has become urgent to develop new monitoring techniques to complement or replace traditional monitoring approaches for monitoring the safety and operation status of high CFRDs. This study examines the Shuibuya Dam (up to 233.5 m in height in China, which is currently the highest CFRD in the world. We used space-borne Interferometric Synthetic Aperture Radar (InSAR time series to monitor the surface deformation of the Shuibuya Dam. Twenty-one ALOS PALSAR images that span the period from 28 February 2007 to 11 March 2011 were used to map the spatial and temporal deformation of the dam. A high correlation of 0.93 between the InSAR and the in-situ monitoring results confirmed the reliability of the InSAR method; the deformation history derived from InSAR is also consistent with the in-situ settlement monitoring system. In addition, the InSAR results allow continuous investigation of dam deformation over a wide area that includes the entire dam surface as well as the surrounding area, offering a clear picture continuously of the dam deformation.

Measurement of Dam Deformations: Case Study of Obruk Dam (Turkey)

Science.gov (United States)

Gulal, V. Engin; Alkan, R. Metin; Alkan, M. Nurullah; İlci, Veli; Ozulu, I. Murat; Tombus, F. Engin; Kose, Zafer; Aladogan, Kayhan; Sahin, Murat; Yavasoglu, Hakan; Oku, Guldane

2016-04-01

In the literature, there is information regarding the first deformation and displacement measurements in dams that were conducted in 1920s Switzerland. Todays, deformation measurements in the dams have gained very different functions with improvements in both measurement equipment and evaluation of measurements. Deformation measurements and analysis are among the main topics studied by scientists who take interest in the engineering measurement sciences. The Working group of Deformation Measurements and Analysis, which was established under the International Federation of Surveyors (FIG), carries out its studies and activities with regard to this subject. At the end of the 1970s, the subject of the determination of fixed points in the deformation monitoring network was one of the main subjects extensively studied. Many theories arose from this inquiry, as different institutes came to differing conclusions. In 1978, a special commission with representatives of universities has been established within the FIG 6.1 working group; this commission worked on the issue of determining a general approach to geometric deformation analysis. The results gleaned from the commission were discussed at symposiums organized by the FIG. In accordance with these studies, scientists interested in the subject have begun to work on models that investigate cause and effect relations between the effects that cause deformation and deformation. As of the scientist who interest with the issue focused on different deformation methods, another special commission was established within the FIG engineering measurements commission in order to classify deformation models and study terminology. After studying this material for a long time, the official commission report was published in 2001. In this prepared report, studies have been carried out by considering the FIG Engineering Surveying Commission's report entitled, 'MODELS AND TERMINOLOGY FOR THE ANALYSIS OF GEODETIC MONITORING OBSERVATIONS

1D and 2D urban dam-break flood modelling in Istanbul, Turkey

Science.gov (United States)

Ozdemir, Hasan; Neal, Jeffrey; Bates, Paul; Döker, Fatih

2014-05-01

and its breaching such as depth, wide, length, volume and breaching shape and daily total rainfall data were used in the models. The simulated flooding in the both models were compared with the real flood extent which gathered from photos taken after the flood event, high satellite images acquired after 20 days from the flood event, and field works. The results show that LISFLOOD-Roe hydraulic model gives more than 80% fit to the extent of real flood event. Also both modelling results show that the embankment breaching of the Ata Pond directly affected the flood magnitude and intensity on the area. This study reveals that modelling of the probable flooding in urban areas is necessary and very important in urban planning. References Gallegos, H. A., Schubert, J. E., and Sanders, B. F.: Two dimensional, high-resolution modeling of urban dam-break flooding: A case study of Baldwin Hills California, Adv. Water Resour., 32, 1323-1335, 2009. Neal, J., Villanueva, I., Wright, N., Willis, T., Fewtrell, T. and Bates, P.: How mush physical complexity is needed to model flood inundation? Hydrological Processes, DOI: 10.1002/hyp.8339. Ozdemir H., Sampson C., De Almeida G., Bates P.D.: Evaluating scale and roughness effects in urban flood modelling using terrestrial LiDAR data, Hydrology and Earth System Sciences, vol.17, pp.4015-4030, 2013. Roe P.: Approximate Riemann solvers, parameter vectors, and difference-schemes. Journal of Computational Physics 43(2): 357-372, 1981. Villanueva I, Wright NG.: Linking Riemann and storage cell models for flood prediction. Proceedings of the Institution of Civil Engineers, Journal of Water Management 159: 27-33, 2006.

National Program for Inspection of Non-Federal Dams. Miller Pond Dam (CT 00154), Thames River Basin, Waterford, Connecticut. Phase I Inspection Report.

Science.gov (United States)

1980-08-01

Road and adjacent to the Brook are likely to be impacted by dam failure. Because a breach of Miller Pond Dam would cause severe economic loss and the...TO THE ASSUMED SPILL CREST ELEVATION 3 WATER %. WACE ELEATCRS. SHOREI I NE AND 7AI NGTER COGRATIONS ARE APPROXIMATE, AS OBTAINED Dl"F I -t DAM INSECTION

Seismic Analysis of Concrete Dam by Using Finite Element Method

Directory of Open Access Journals (Sweden)

Rozaina Ismail

2017-01-01

Full Text Available This paper reports a brief study on linear seismic analysis of Sg. Kinta Concrete Dam. The analysis was conducted in order to determine the performance and behaviour of the dam under seismic excitation. The dam was modelled as two-dimensional and developed based on the design drawing that is obtained from Angkasa Consulting Services Sdn. Bhd. The seismic analysis of the dam is conducted using finite element analysis software package LUSAS 14.3 and the dam has been analyse as a plain stress problem with a linear consideration. A set of historic data, with E1 Centro earthquake acceleration of about 0.50g is used as an earthquake excitation. The natural frequency and mode shape up to fifth mode of the dam has been obtained from the analysis to show the differences of the stress and deformation between each mode. The maximum horizontal and vertical stress of Sg. Kinta dam was found and the distribution of them was discussed in form of contours. The deformation of the dam were also been discussed by comparing the maximum displacement for each mode shaped.

Alteration of stream temperature by natural and artificial beaver dams.

Science.gov (United States)

Weber, Nicholas; Bouwes, Nicolaas; Pollock, Michael M; Volk, Carol; Wheaton, Joseph M; Wathen, Gus; Wirtz, Jacob; Jordan, Chris E

2017-01-01

Beaver are an integral component of hydrologic, geomorphic, and biotic processes within North American stream systems, and their propensity to build dams alters stream and riparian structure and function to the benefit of many aquatic and terrestrial species. Recognizing this, beaver relocation efforts and/or application of structures designed to mimic the function of beaver dams are increasingly being utilized as effective and cost-efficient stream and riparian restoration approaches. Despite these verities, the notion that beaver dams negatively impact stream habitat remains common, specifically the assumption that beaver dams increase stream temperatures during summer to the detriment of sensitive biota such as salmonids. In this study, we tracked beaver dam distributions and monitored water temperature throughout 34 km of stream for an eight-year period between 2007 and 2014. During this time the number of natural beaver dams within the study area increased by an order of magnitude, and an additional 4 km of stream were subject to a restoration manipulation that included installing a high-density of Beaver Dam Analog (BDA) structures designed to mimic the function of natural beaver dams. Our observations reveal several mechanisms by which beaver dam development may influence stream temperature regimes; including longitudinal buffering of diel summer temperature extrema at the reach scale due to increased surface water storage, and creation of cool-water channel scale temperature refugia through enhanced groundwater-surface water connectivity. Our results suggest that creation of natural and/or artificial beaver dams could be used to mitigate the impact of human induced thermal degradation that may threaten sensitive species.

National Program for Inspection of Non-Federal Dams. Tihonet Pond Number 2 Dam (MA 00030), Massachusetts Coastal Basin, Wareham, Massachusetts. Phase I Inspection Report.

Science.gov (United States)

1981-07-01

drainage area above the dam is 8.1 square miles. The watershed is characterized by irregular topography: cranberry bogs, small ponds and depressions ...and recreational purposes. Water from this pond is used in the U irrigation of cranberry bogs downstream. The maximum storage capacity of the dam is...295-1000 g. PURPOSE OF DAM The dam impounds Tihonet Pond which is a storage reservoir 4_- 4 4: . * used principally for irrigating cranberry bogs which

National Program for Inspection of Non-Federal Dams. Paper Mill Pond Dam (CT 00621), Connecticut River Basin, Vernon, Connecticut. Phase I Inspection Report.

Science.gov (United States)

1981-03-01

HYDROLOGIC AND HYDRAULIC COMPUTATIONS E INFORMATION AS CONTAINED IN THE NATIONAL INVENTORY OF DAMS ,v ’walL.it, AM I OVERVIEV \\ PHOTO Iv 390 L-( ibb~ ~5~4 N...AS-A144 539 NATIONAL PROGRAM FOR INSPEGTION 0F NON-FEDERAL DAMS / PAPER MIL POND DAM (.(U CORPS OF ENGINEERS WALTHAM A S MA NEW ENGLANA DIV MAR...CATALOG NUMBER CT 00621A 4 TITLE (amdSubtile) S. TYPE OF REPORT & PERIOD’COVERED Paper Mill Pond Dam INSPECTION REPORT NATIONAL PROGRAM FOR INSPECTION

Hydraulic fracture considerations in oil sand overburden dams

Energy Technology Data Exchange (ETDEWEB)

Cameron, R.; Madden, B.; Danku, M. [Syncrude Canada Ltd., Fort McMurray, AB (Canada)

2008-07-01

This paper discussed hydraulic fracture potential in the dry-filled temporary dams used in the oil sands industry. Hydraulic fractures can occur when reservoir fluid pressures are greater than the minimum stresses in a dam. Stress and strain conditions are influenced by pore pressures, levels of compaction in adjacent fills as well as by underlying pit floor and abutment conditions. Propagation pressure and crack initiation pressures must also be considered in order to provide improved hydraulic fracture protection to dams. Hydraulic fractures typically result in piping failures. Three cases of hydraulic fracture at oil sands operations in Alberta were presented. The study showed that hydraulic fracture failure modes must be considered in dam designs, particularly when thin compacted lift of dry fill are used to replace wetted clay cores. The risk of hydraulic fractures can be reduced by eliminating in situ bedrock irregularities and abutments. Overpressure heights, abutment sloping, and the sloping of fills above abutments, as well as the dam's width and base conditions must also be considered in relation to potential hydraulic fractures. It was concluded that upstream sand beaches and internal filters can help to prevent hydraulic fractures in dams in compacted control zones. 5 refs., 16 figs.

Characterization of landslide dams in the San Juan province (Argentina)

Science.gov (United States)

Penna, Ivanna; Longchamp, Celine; Derron, Marc-Henri; Jaboyedoff, Michel

2013-04-01

River blockages caused by landslide deposition are common phenomena in active mountain chains, influencing erosion-sedimentation patterns and acting as primary and secondary hazards. Regional scale analyses regarding their spatial distribution and morphometry allow establishing boundary conditions for their occurrence and stability, and determine differences among regions with different landscape and climatic conditions. Owing to the combination of endogenous and exogenous factors, landslide dams are frequent phenomena in the Andes. In the Argentinean NW and the Patagonian Andes, previous studies showed that stability of landslide dams determined by morphometric parameters generally matched satisfactorily with dam behavior, with some exceptions in which climatic component played an important role in dam longevity. Aiming to expand the knowledge of landslide dams in the Argentinean Andes, in this work we analyzed the stability of rock avalanche dams in the Pampeam flat slab subduction zone. In the study area, mountain dynamics creates suitable conditions for the occurrence of 34 rock avalanches with volumes up to 0.3 km3. They developed in deeply carved valleys (Cordillera) and Inter-thrust valleys (Precordillera). 22 impoundments of rivers resulted from channelized rock avalanches with long runouts (4-10 km) that blocked tributaries rivers, but most of them by rock avalanches that filled the valley bottom, with run up in the opposite slope and limited movement parallel to the valley axis. Most of the dams breached in unknown times, except for the last event that occurred on November 12th 2005. The quantification of morphometric parameters and contributing areas indicates the existence of dams with dimensionless blockage index above 2.75 (stable domain) and below 3.08 (instable domain). The Los Erizos dam in our study area and the Barrancas dam in the Patagonian Andes show that besides morphometric parameters, climatic conditions are decisive. Stable landslide dams

Engineers find climbing techniques work well for dam inspections

Energy Technology Data Exchange (ETDEWEB)

O`Shea, M.; Graves, A. [Bureau of Reclamation, Denver, CO (United States)

1996-10-01

Climbing techniques adopted by the Bureau of Reclamation to inspect previously inaccessible or difficult to reach features at dams are described. Following the failure of the steel radial-arm gate at Folsom Dam, engineers mounted an effort to reach and inspect the dam`s seven other spillway gates. This close-up examination was performed to: (1) determine the condition of these gates; and (2) gather clues about the failure of the one gate. The access techniques described involved mountaineering techniques, as opposed to high scaling techniques, performed with dynamic and static nylon kermantle ropes.

Spanish experiences with marginal and special materials on the construction of road embankments; Experiencias de utilizacion de materiales marginales y especiales en terraplenes viarios en Espana

Energy Technology Data Exchange (ETDEWEB)

Cano Linares, H.; Perucho Martinez, A.

2015-07-01

The use of existing materials along the alignment of a road is an essential problem within the Sustainable Development policies, which is being promoting worldwide since a long time. In the Word road Association (PIARC-AIPCR) this subject has being investigated by different Technical Committees during last decades. Additionally, the review of the article 330 Embankment of PG-3 (FOM 1382/2002) has opened the door to new non-conventional materials, as wastes and artificial materials, to be used on embankments. This could come to adequate solutions, technically, and environmentally, contributing with national legislation on valorisation policies. In this sense, the use of marginal materials and wastes con represent and important save on natural resources and dumping sites. In Spain, some experiences with marginal materials and wastes have being carried out. The work presented has consisted in compiling and analysing the experiences executed with marginal materials and wastes on Spanish road embankments. Although there are many other cases, 24 cases published with adequate information have being analysed, summarising aspects as: materials problems arrangement solutions or treatments employed. Analysing these experiences and making them public can be a way to transmit confidence, help to improve knowledge, and progress on the preparation of recommendations. This work has being carried out on the frame of the Project Geotechnical Engineering, Materials and Structures and Impact of Infrastructure in Civil engineering (TTIGEM), within the frame Program Border Cooperation Spain-External Borders (POCTEFEX); particularly in the Activity 2 related to Technology Transfer of Construction Materials, including marginal materials and wastes. (Author)

Responses of riparian reptile communities to damming and urbanization

Science.gov (United States)

Hunt, Stephanie D.; Guzy, Jacquelyn C.; Price, Steven J.; Halstead, Brian J.; Eskew, Evan A.; Dorcas, Michael E.

2013-01-01

Various anthropogenic pressures, including habitat loss, threaten reptile populations worldwide. Riparian zones are critical habitat for many reptile species, but these habitats are also frequently modified by anthropogenic activities. Our study investigated the effects of two riparian habitat modifications-damming and urbanization-on overall and species-specific reptile occupancy patterns. We used time-constrained search techniques to compile encounter histories for 28 reptile species at 21 different sites along the Broad and Pacolet Rivers of South Carolina. Using a hierarchical Bayesian analysis, we modeled reptile occupancy responses to a site's distance upstream from dam, distance downstream from dam, and percent urban land use. The mean occupancy response by the reptile community indicated that reptile occupancy and species richness were maximized when sites were farther upstream from dams. Species-specific occupancy estimates showed a similar trend of lower occupancy immediately upstream from dams. Although the mean occupancy response of the reptile community was positively related to distance downstream from dams, the occupancy response to distance downstream varied among species. Percent urban land use had little effect on the occupancy response of the reptile community or individual species. Our results indicate that the conditions of impoundments and subsequent degradation of the riparian zones upstream from dams may not provide suitable habitat for a number of reptile species.

Sinkhole investigated at B.C. Hydro`s Bennett Dam

Energy Technology Data Exchange (ETDEWEB)

Anon.

1996-07-01

The cause of a sinkhole which appeared in a roadway crossing an earth filled dam in B. C., was discussed. The hole measured 6 ft. across and 20 ft. deep, and occurred in B.C. Hydro`s W.A.C. Bennett Dam which measures 600 ft. high, 2,600 ft. wide at the base and 35 ft. wide at the crest. The cause of the sinkhole is not known, but it is believed that a weakness in the dam may have found its way to the surface via a pipe connected to a bedrock settlement gauge buried within the dam. Sonar and ground penetrating radar were used to examine the area. The hole has been filled with gravel and monitoring continues. Experts do not anticipate immediate risk of dam failure. 1 fig.

Analytical Solution and Application for One-Dimensional Consolidation of Tailings Dam

Directory of Open Access Journals (Sweden)

Hai-ming Liu

2018-01-01

Full Text Available The pore water pressure of tailings dam has a very great influence on the stability of tailings dam. Based on the assumption of one-dimensional consolidation and small strain, the partial differential equation of pore water pressure is deduced. The obtained differential equation can be simplified based on the parameters which are constants. According to the characteristics of the tailings dam, the pore water pressure of the tailings dam can be divided into the slope dam segment, dry beach segment, and artificial lake segment. The pore water pressure is obtained through solving the partial differential equation by separation variable method. On this basis, the dissipation and accumulation of pore water pressure of the upstream tailings dam are analyzed. The example of typical tailings is introduced to elaborate the applicability of the analytic solution. What is more, the application of pore water pressure in tailings dam is discussed. The research results have important scientific and engineering application value for the stability of tailings dam.

Geophysics Methods in Electrometric Assessment of Dams

Energy Technology Data Exchange (ETDEWEB)

Davydov, V. A., E-mail: davydov-va@yandex.ru; Baidikov, S. V., E-mail: badikek@mail.ru; Gorshkov, V. Yu., E-mail: vitalaa@yandex.ru; Malikov, A. V., E-mail: alex.mal.1986@mail.ru [Russian Academy of Sciences, Geophysical Institute, Ural Branch (Russian Federation)

2016-07-15

The safety assessment of hydraulic structures is proposed to be conducted via geoelectric measurements, which are capable of assessing the health of earth dams in their natural bedding without intervention in their structure. Geoelectric measurements are shown as being capable of pinpointing hazardous parts of a dam, including areas of elevated seepage. Applications of such methods are shown for a number of mini-dams in the Sverdlovsk region. Aparameter (effective longitudinal conductivity) that may be used to monitor the safety of hydraulic structures is proposed. Quantitative estimates of this parameter are given in terms of the degree of safely.

Mica fission detectors

International Nuclear Information System (INIS)

Wong, C.; Anderson, J.D.; Hansen, L.; Lehn, A.V.; Williamson, M.A.

1977-01-01

The present development status of the mica fission detectors is summarized. It is concluded that the techniques have been refined and developed to a state such that the mica fission counters are a reliable and reproducible detector for fission events

National Dam Safety Program. Lakeview Estates Dam (MO 11004), Mississippi - Kaskaskia - St. Louis Basin, Warren County, Missouri. Phase I Inspection Report.

Science.gov (United States)

1979-09-01

ificatiozh Distributon/ Availabilit oe LAKEVIEW ESTATES DAM WARREN COUNTY, MISSOURI MISSOURI INVENTORY NO. 11004 PHASE I INSPECTION REPORT NATIONAL DAM SAFETY...and *impounds less than 1,000 acre-feet of water . Our inspection and evaluation indicates that the spill- way of Lakeview Estates Dam does not meet...not be measured because of high reservoir level, scalloping near the crest and a berm just under the water surface. Limestone riprap in sizes from sand

Seismic Fortification Analysis of the Guoduo Gravity Dam in Tibet, China

Directory of Open Access Journals (Sweden)

Peng Lin

2015-01-01

Full Text Available The primary aim of this research was to analyze the seismic performance of the Guoduo gravity dam. A nonlinear FEM method was implemented to study the deformation, stress, and overall stability of dam under both static and dynamic loading conditions, including both normal and overloading conditions. A dam seismic failure risk control method is proposed based on the cracking mechanism induced by the dynamic load to ensure dam safety and stability. Numerical simulation revealed that (1 under normal static and dynamic loading the symmetry of the displacement distributions is good, showing that the dam abutments and riverbed foundation have good overall stiffness. The stress distribution is a safe one for operation under both normal water loading and seismic loading. (2 Attention should be paid to the reinforcement design of outlets of the diversion dam monoliths, and enhance the capability of sustaining that tensile stress of dam monoliths. (3 The shape of the dam profile has a significant effect on the dynamic response of the dam. (4 By employing the “overload safety factor method,” the overall seismic fortification is as follows: K1=1.5, K2= 2~3, and K3= 3~4.

In the Land of the Dammed: Assessing Governance in Resettlement of Ghana’s Bui Dam Project

Directory of Open Access Journals (Sweden)

Kwabena Asiama

2017-11-01

Full Text Available Resettlement resulting from dam construction has raised several concerns due to the negative aftermath impacts. In Ghana, the construction of three hydroelectric dams resulted in large-scale resettlements. Given the little experience that Ghana has in resettlements, it is necessary for a robust monitoring structure for resettlements. However, this was not available in the last resettlement undertaken for the Bui Dam Project. This paper aims at developing an assessment framework for monitoring resettlement activities on customary lands from a good governance perspective. Based on four good governance principles, transparency, public participation and inclusiveness, equity and rule of law and accountability, a good governance assessment framework is built and applied to the Bui Dam Project using a case study approach. Data were collected through interviews and focus group discussion with the key actors of the resettlement project. It was first found that the planning stage of the resettlement came out with a robust plan that was to prevent the impoverishment of the affected persons. However, in the implementation of the resettlement, not all good governance principles were adhered to. In conclusion, it was found that by deconstructing the resettlement process with a good governance framework, the problematic areas of the resettlement can be effectively differentiated between the planning and implementation phases.

National Inventory of Dams Coastal California Extract 2010

Data.gov (United States)

California Department of Resources — The National Inventory of Dams (NID) is a congressionally authorized database, which documents dams in the U.S. and its territories. The NID was most recently...

National Inventory of Dams Coastal California Extract 2010

Data.gov (United States)

California Natural Resource Agency — The National Inventory of Dams (NID) is a congressionally authorized database, which documents dams in the U.S. and its territories. The NID was most recently...

Seismic risks at Elsie Lake Main Dam

International Nuclear Information System (INIS)

McCammon, N.R.; Momenzadeh, M.; Hawson, H.H.; Nielsen, N.M.

1991-01-01

The Elsie Lake dams are located on Vancouver Island in an area of high seismic risk. A safety review in 1986 indicated potential deficiencies in the earthfill main dam with respect to modern earthquake design standards. A detailed field investigation program comprising drilling and penetration tests was carried out and the results used in an assessment of seismic stability. A 0.8 m thick less dense layer in the granular shell of the dam, possibly caused by wet construction conditions, would likely liquefy in a major earthquake but sufficient residual strength would likely remain to prevent catastrophic failure. The dam shell might undergo some distortion, and an assessment was initiated to determine the requirements for reservoir drawdown following an extreme earthquake to ensure the timely lowering of the reservoir for inspection and repair. It was suggested that an adequate evacuation capability would be 25% and 50% drawdown in not more than 30 and 50 days, respectively. 9 refs., 11 figs., 1 tab

The environmental impact of large dams

International Nuclear Information System (INIS)

Razvan, E.

1992-01-01

The campaigns of conservationist groups against dams are generally based on rather emotional issues. This paper puts the situation in a more rational perspective, by analysing the various claims which tend to be put forward concerning the impacts of large dams, examining the validity of the arguments, looking at ways in which any adverse effects can be mitigated, and presenting the complexity of the problems. (author)

Numerical analysis of stone columns in mitigating liquefaction effects in embankment fills

Energy Technology Data Exchange (ETDEWEB)

Borghei, Z.; Soroush, A. [Amirkabir University of Technology, Tehran, (Iran, Islamic Republic of); Noorzad, A. [Power and Water University of Technology, Tehran, (Iran, Islamic Republic of)

2010-07-01

The traditional approach to liquefaction in embankment fills is to use in-situ densification. The use of stone columns offers the possibility of preventing liquefaction and associated settlements while reducing the cost and time required for treatment. This paper investigated the behaviour of stone columns using a numerical method. The study focused on a case study, a sand layer beneath two wall tanks, butane and propane NGL, located on Siri Island, Persian Gulf, Iran. Numerical analyses were carried out to evaluate the rate of excess pore pressure build-up in the improved ground. The numerical model results were compared to the simulation results from a centrifuge test for a uniform 19m-thick liquefiable sand layer. The numerical methodology was verified. The results showed that the stone columns can significantly increase the rate of pore pressure dissipation and reduce the settlement. It was found that the installation process densifies the surrounding soil, decreasing the liquefaction potential.

Owyhee River intracanyon lava flows: does the river give a dam?

Science.gov (United States)

Ely, Lisa L.; Brossy, Cooper C.; House, P. Kyle; Safran, Elizabeth B.; O'Connor, Jim E.; Champion, Duane E.; Fenton, Cassandra R.; Bondre, Ninad R.; Orem, Caitlin A.; Grant, Gordon E.; Henry, Christopher D.; Turrin, Brent D.

2013-01-01

Rivers carved into uplifted plateaus are commonly disrupted by discrete events from the surrounding landscape, such as lava flows or large mass movements. These disruptions are independent of slope, basin area, or channel discharge, and can dominate aspects of valley morphology and channel behavior for many kilometers. We document and assess the effects of one type of disruptive event, lava dams, on river valley morphology and incision rates at a variety of time scales, using examples from the Owyhee River in southeastern Oregon. Six sets of basaltic lava flows entered and dammed the river canyon during two periods in the late Cenozoic ca. 2 Ma–780 ka and 250–70 ka. The dams are strongly asymmetric, with steep, blunt escarpments facing up valley and long, low slopes down valley. None of the dams shows evidence of catastrophic failure; all blocked the river and diverted water over or around the dam crest. The net effect of the dams was therefore to inhibit rather than promote incision. Once incision resumed, most of the intracanyon flows were incised relatively rapidly and therefore did not exert a lasting impact on the river valley profile over time scales >106 yr. The net long-term incision rate from the time of the oldest documented lava dam, the Bogus Rim lava dam (≤1.7 Ma), to present was 0.18 mm/yr, but incision rates through or around individual lava dams were up to an order of magnitude greater. At least three lava dams (Bogus Rim, Saddle Butte, and West Crater) show evidence that incision initiated only after the impounded lakes filled completely with sediment and there was gravel transport across the dams. The most recent lava dam, formed by the West Crater lava flow around 70 ka, persisted for at least 25 k.y. before incision began, and the dam was largely removed within another 35 k.y. The time scale over which the lava dams inhibit incision is therefore directly affected by both the volume of lava forming the dam and the time required for sediment

Some aspects in the legal regulation of the dams

International Nuclear Information System (INIS)

Tancev, Ljubomir

1996-01-01

In order to ensure high quality and low cost design and building of dams and appurtenant structures, as well as safe exploitation, it is obvious to have appropriate legislation. Keeping in mind that the dams are unique structures, for the design stage the legislation should be less strong. For the next phases - building, maintenance and exploitation - detail and rigorous legislation is recommended. It is emphasised that the engineers should have more freedom designing the dams, but they should be obvious to apply the most recent achievement in the field of the dam design and construction. For illustration, some aspects of three important questions are discussed - 1) the choice of maximum flood discharge, 2) the application of new materials and construction methods and 3) the application of modern methods for static and dynamic analysis of dams. (Author)

Analytical Solution and Application for One-Dimensional Consolidation of Tailings Dam

OpenAIRE

Liu, Hai-ming; Nan, Gan; Guo, Wei; Yang, Chun-he; Zhang, Chao

2018-01-01

The pore water pressure of tailings dam has a very great influence on the stability of tailings dam. Based on the assumption of one-dimensional consolidation and small strain, the partial differential equation of pore water pressure is deduced. The obtained differential equation can be simplified based on the parameters which are constants. According to the characteristics of the tailings dam, the pore water pressure of the tailings dam can be divided into the slope dam segment, dry beach seg...

2005 Tri-Service Infrastructure Systems Conference and Exhibition. Volume 7, Tracks 7 and 8

Science.gov (United States)

2005-08-04

Performance Measures for Prefabricated Submerged Concrete Breakwaters: Section 227 Cape May Point, New Jersey Demonstration Project, by Donald K Stauble...Slope Stability Evaluation of the Baldhill Dam Right Abutment , by Neil T. Schwanz Design and Construction of Anchored Bulkheads with Synthetic Sheet...Sinkholes near Switchyard + right d/s abutment wet areas D/S of embankment, muddy flows 1968-72 Emergency exploration / grouting 1975-79 Diaphragm walls

Biotermodin?mica en animales

OpenAIRE

Granados Moreno, Jairo Enrique

2014-01-01

El documento presenta como la termodin?mica es la ciencia que estudia las relaciones entre calor y las dem?s formas de transferencias de energ?a. Se explica que toda transformaci?n biofisicoqu?mica implica, generalmente, un cambio energ?tico. Se tratan los conceptos de temperatura, escalas de temperatura, calor, calor de combusti?n, postulados de la termodin?mica, entrop?a y energ?a libre metab?lica

33 CFR 117.705 - Beaver Dam Creek.

Science.gov (United States)

2010-07-01

... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Beaver Dam Creek. 117.705 Section 117.705 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements New Jersey § 117.705 Beaver Dam Creek. The draw of the...

Dams. Bulletin of the technical service of electric power and big dams; Barrages. Bulletin du service technique de l`energie electrique et des grands barrages

Energy Technology Data Exchange (ETDEWEB)

Davard, J.

1997-12-31

The Dams bulletin reports on technical news concerning big French dams in operation. This issue comprises 5 papers. Two of them are examples of granting problems which led to the dismantling of the dams of Kernansquillec (Cotes d`Armor, France) and Maisons-Rouges (Indre-et-Loire, France) for economical and environmental reasons. The 3 other papers concern the life of French dams (technical control reports of the French dams in operation), the activities of the control service (annual inspections, preparation of draining operations, renewing of granting), and some general information (organisation of competent authorities, colloquium reports, hydro-power production during the first quarter of 1997). (J.S.)

Fosfortab fra det dyrkede areal til Stevning Dam, Hindemaj og Haderslev Dam

DEFF Research Database (Denmark)

Andersen, Hans Estrup; Heckrath, Goswin; Thodsen, Hans

Størrelsen af dyrkningsbidraget til søerne i Haderslev Dam-systemet er vurderet med to forskellige metoder til at udgøre ca. 42 % af den samlede tilførsel. En risikokortlægning med det nye, danske P-indeks viser, at i alt 15 % af det dyrkede areal er i højrisiko mht. fosfortab. P-indeks-kortlægni......Størrelsen af dyrkningsbidraget til søerne i Haderslev Dam-systemet er vurderet med to forskellige metoder til at udgøre ca. 42 % af den samlede tilførsel. En risikokortlægning med det nye, danske P-indeks viser, at i alt 15 % af det dyrkede areal er i højrisiko mht. fosfortab. P...

Dams and river dolphins: Can they co-exist?

International Nuclear Information System (INIS)

Reeves, R.R.; Leatherwood, S.

1994-01-01

Dam construction is one of many ways that humans have modified river-dolphin habitats. It is suggested that physiographic and hydrologic complexity plays an important role in making rivers suitable for dolphins. If this hypothesis is true, then it can be assumed that dams and other artificial obstructions degrade dolphin habitat insofar as they reduce such complexity. This paper identifies some of the impacts that dams, barrages, and dikes might have on dolphins. Research is needed at project sites, both before and after construction, to document impacts. Specially designed ''swimways'' may allow upstream and downstream passage by dolphins and thus mitigate at least one of the adverse effects of dam projects, namely population fragmentation, but such measures aimed at benefiting single species are no substitute for protecting ecosystems. 30 refs

Dynamic probability evaluation of safety levels of earth-rockfill dams using Bayesian approach

Directory of Open Access Journals (Sweden)

Zi-wu Fan

2009-06-01

Full Text Available In order to accurately predict and control the aging process of dams, new information should be collected continuously to renew the quantitative evaluation of dam safety levels. Owing to the complex structural characteristics of dams, it is quite difficult to predict the time-varying factors affecting their safety levels. It is not feasible to employ dynamic reliability indices to evaluate the actual safety levels of dams. Based on the relevant regulations for dam safety classification in China, a dynamic probability description of dam safety levels was developed. Using the Bayesian approach and effective information mining, as well as real-time information, this study achieved more rational evaluation and prediction of dam safety levels. With the Bayesian expression of discrete stochastic variables, the a priori probabilities of the dam safety levels determined by experts were combined with the likelihood probability of the real-time check information, and the probability information for the evaluation of dam safety levels was renewed. The probability index was then applied to dam rehabilitation decision-making. This method helps reduce the difficulty and uncertainty of the evaluation of dam safety levels and complies with the current safe decision-making regulations for dams in China. It also enhances the application of current risk analysis methods for dam safety levels.

Mechanism Research of Arch Dam Abutment Forces during Overload

Directory of Open Access Journals (Sweden)

Yu Xia

2015-01-01

Full Text Available This paper presents research on the abutment forces of a double-curvature arch dam during overload based on numerical calculation results obtained through finite element method by Ansys. Results show that, with an increase in elevation, the abutment forces and bending moment of the arch dam increase first and then decrease from the bottom to the top of the dam. Abutment forces and bending moment reach their maximum at the middle or middle-down portion of the dam. The distributions of abutment forces and moment do not change during overload. The magnitude of each arch layer’s forces and moment increases linearly during overload. This result indicates that each arch layer transmits bearing loads to the rocks of the left and right banks steadily. This research explains the operating mechanism of an arch dam under normal and overload conditions. It provides a simple method to calculate the distribution of forces Fx and Fy and a new method to calculate the overload factor of an arch dam through the estimation of arch layers based on the redistribution characteristic of arch abutment forces.

Determining The Water Quality of Maruf Dam (Boyabat–Sinop

Directory of Open Access Journals (Sweden)

Ekrem MUTLU

2017-06-01

Full Text Available In this study, the preliminary findings obtained from 3 sampling points, which represent the whole, on Maruf Irrigation Dam, which is located in Boyabat district of Sinop province, for 12 months between September 2015 and August 2016 were examined. The parameters monitored are temperature, dissolved oxygen, pH, electrical conductivity, total hardness, total alkalinity, chemical oxygen demand, biological oxygen demand, and dissolved anions and cations (sodium, potassium, calcium, magnesium, ammonium, nitrate, phosphate, chloride, sulfate, and sulfite. Because of its low dissolved ionic matter content, Maruf Dam was characterized as an alkali dam with mid-hard water and low electrical conductivity. In terms of parameters A and B of Surface Water Quality Management Regulation, the dam is considered “high-quality” and “unpolluted”. Besides the irrigation purposes, for which the barrage was constructed, the dam can also be used for aquaculture, animal breeding, and farming needs.

MNR's role in public safety around dams

Energy Technology Data Exchange (ETDEWEB)

Keyes, Jennifer [Ministry of Natural Resources, Peterborough, ON (Canada)

2011-07-01

The Ministry of Natural Resources (MNR) is the largest dam owner in Ontario with around 400 dams located all across the province. MNR works to exercise stewardship of Ontario's water resources in a context of public safety, employee safety and environmental awarenes. This presentation shows the different measures MNR implemented to reduce risks. Warning signs, safety booms, barrel buoys and pedestrian fencing have been installed around dams to alert the public to possible dangers. In addition, MNR employees receive training in how to inspect dams for safety concerns, how to identify problems which could result in hazards to the public and how to work safely.

Detection of Water Leaks in Beni-Haroun Dam (Algeria)

International Nuclear Information System (INIS)

Hocini, N.; Mami, M.

2011-01-01

The main objective of this work was to detect water leakage origin combining conventional, tracing and isotope techniques. The investigation was performed by a research team from the 'Algiers Nuclear Research Centre' in collaboration with engineers from the 'National Agency for Dams'. The chemical and isotopic results have shown no influence of dam water on the water sampled at the piezometers and drains that are present in the close neighbourhood of the dam. However, the water flowing at drain D15 has exhibited the nearest quality to that dam. Dye tracing has shown a water circulation through complex pathways for the left bank. (author)

Inventory of Dams in the State of Iowa

Data.gov (United States)

Iowa State University GIS Support and Research Facility — Permitted dams in Iowa and associated attributes, as recorded by the Floodplain Section of the DNR. The dams regulated are those with the parameters listed below: a....

User's Guide: Arch Dam Stress Analysis System (ADSAS)

National Research Council Canada - National Science Library

1997-01-01

.... ADSAS assumes linear elastic behavior for the entire dam, i.e. the dam is assumed to support the computed tensile stresses within the concrete mass and across the monolith joints without cracking or opening the joints...

Avoiding the Water-Climate-Poverty Trap: Adaptive Risk Management for Bangladesh's Coastal Embankments

Science.gov (United States)

Hall, J. W.

2015-12-01

Our recent research on water security (Sadoff et al., 2015, Dadson et al., 2015) has revealed the dynamic relationship between water security and human well-being. A version of this dynamic is materialising in the coastal polder areas of Khulna, Bangladesh. Repeated coastal floods increase salinity, wipe out agricultural yields for several years and increase out-migration. As a tool to help inform and target future cycles of investment in improvements to the coastal embankments, in this paper we propose a dynamical model of biophysical processes and human well-being, which downscales our previous research to the Khulna region. State variables in the model include agricultural production, population, life expectancy and child mortality. Possible infrastructure interventions include embankment improvements, groundwater wells and drainage infrastructure. Hazard factors include flooding, salinization and drinking water pollution. Our system model can be used to inform adaptation decision making by testing the dynamical response of the system to a range of possible policy interventions, under uncertain future conditions. The analysis is intended to target investment and enable adaptive resource reallocation based on learning about the system response to interventions over the seven years of our research programme. The methodology and paper will demonstrate the complex interplay of factors that determine system vulnerability to climate change. The role of climate change uncertainties (in terms of mean sea level rise and storm surge frequency) will be evaluated alongside multiple other uncertain factors that determine system response. Adaptive management in a 'learning system' will be promoted as a mechanism for coping with climate uncertainties. References:Dadson, S., Hall, J.W., Garrick, D., Sadoff, C. and Grey, D. Water security, risk and economic growth: lessons from a dynamical systems model, Global Environmental Change, in review.Sadoff, C.W., Hall, J.W., Grey, D

Risk Perception Analysis Related To Existing Dams In Italy

Science.gov (United States)

Solimene, Pellegrino

2013-04-01

In the first part of this work, the progress of Italian National Rules about dams design, construction and operation are presented to highlight the strong connection existing between the promulgation of new decrees, as a consequence of a dam accidents, and the necessity to prevent further loss of lives and goods downstream. Following the Gleno Dam failure (1923), a special Ministerial Committee wrote out the first Regulations and made the proposal to establish, within the High Council of Public Works, a special department that become soon the "Dam Service", with the tasks of control and supervision about construction and operation phases of the dams and their reservoirs. A different definition of tasks and the structure of Dam Service were provided in accordance with law n° 183/1989, which transferred all the technical services to the Office of the Prime Minister; the aim was to join the Dam Office with the Department for National Technical Services, with the objective of increasing the knowledge of the territory and promoting the study on flood propagation downstream in case of operations on bottom outlet or hypothetical dam-break. In fact, population living downstream is not ready to accept any amount of risk because has not a good knowledge of the efforts of experts involved in dam safety, both from the operators and from the safety Authority. So it's important to optimize all the activities usually performed in a dam safety program and improve the emergency planning as a response to people's primary needs and feeling about safety from Civil Protection Authority. In the second part of the work, a definition of risk is provided as the relationship existing between probability of occurrence and loss, setting out the range within to plan for prevention (risk mitigation), thanks to the qualitative assessment of the minimum safety level that is suited to assign funds to plan for Civil Protection (loss mitigation). The basic meaning of the reliability of a zoned

Dam safety review using non-destructive methods for reinforced concrete structure

Energy Technology Data Exchange (ETDEWEB)

Philibert, Alain; Saint-Pierre, Francois; Turcotte, Bernard [Le Groupe S.M. International Inc., Sherbrooke, (Canada)

2010-07-01

Dams built at the beginning of the twentieth century include concrete structures that were put in under rehabilitation works. In some cases, the details of the structures are not well documented. In other cases, concrete damage can be hidden under new layers of undamaged material. This requires that the dam safety review in a real investigation gather the information necessary for carrying out the hydraulic and stability studies required by the Dam Safety Act. This paper presented the process of dam safety review using non-destructive methods for reinforced concrete structures. Two reinforced concrete dams built in the 1900's, the Eustic dam on the Coaticook River and the Frontenac dam on the Magog River near Sherbrooke, were evaluated by S.M. International using non-destructive methods such as sonic and ground penetrating radar methods. The studies allowed mapping of concrete damage and provided geometric information on some non visible structure elements that were part of previous reinforcement operations.

How to manage the cumulative flood safety of catchment dams ...

African Journals Online (AJOL)

Dam safety is a significant issue being taken seriously worldwide. However, in Australia, although much attention is being devoted to the medium- to large-scale dams, minimal attention is being paid to the serious potential problems associated with smaller dams, particularly the potential cumulative safety threats they pose ...

Cleveland Dam East Abutment : seepage control project

Energy Technology Data Exchange (ETDEWEB)

Huber, F.; Siu, D. [Greater Vancouver Regional District, Burnaby, BC (Canada); Ahlfield, S.; Singh, N. [Klohn Crippen Consultants Ltd., Vancouver, BC (Canada)

2004-09-01

North Vancouver's 91 meter high Cleveland Dam was built in the 1950s in a deep bedrock canyon to provide a reservoir for potable water to 18 municipalities. Flow in the concrete gravity dam is controlled by a gated spillway, 2 mid-level outlets and intakes and 2 low-level outlets. This paper describes the seepage control measures that were taken at the time of construction as well as the additional measures that were taken post construction to control piezometric levels, seepage and piping and slope instability in the East Abutment. At the time of construction, a till blanket was used to cover the upstream reservoir slope for 200 meters upstream of the dam. A single line grout curtain was used through the overburden from ground surface to bedrock for a distance of 166 meters from the dam to the East Abutment. Since construction, the safety of the dam has been compromised through changes in piezometric pressure, seepage and soil loss. Klohn Crippen Consultants designed a unique seepage control measure to address the instability risk. The project involved excavating 300,000 cubic meters of soil to form a stable slope and construction bench. A vertical wall was constructed to block seepage. The existing seepage control blanket was also extended by 260 meters. The social, environmental and technical issues that were encountered during the rehabilitation project are also discussed. The blanket extension construction has met design requirements and the abutment materials that are most susceptible to internal erosion have been covered by non-erodible blanket materials such as plastic and roller-compacted concrete (RCC). The project was completed on schedule and within budget and has greatly improved the long-term stability of the dam and public safety. 2 refs., 8 figs.

Descriptive characteristics of the large Italian dams

International Nuclear Information System (INIS)

Dello Vicario, E.; Petaccia, A.; Savanella, V.

1999-01-01

In the present note the characteristics of the Italian dams are examined, underlining, in a statistical view, story, geographical location, types and use of the most important works. Such a review can be useful for a more detailed analysis, both for the dams characterization and for further studies relevant to water resources utilization [it

Primary Productivity of the Cengklik Dam Boyolali

Directory of Open Access Journals (Sweden)

WIRYANTO

2002-01-01

Full Text Available Primary productivity dynamic of the water ecosystem was conducted faster in the last decades. This study was intended to find out the primary productivity of Cengklik dam Boyolali, Central Java to explain the ecosystem dynamic and to lead the maintenance of dam. This study used quantitative methods in completely randomized group design (CRD, and the data was analized by Analysis of Variance (ANAVA. Samples were taken horizontally in four sampling point, respectively in the riparian zone, around of the floating net (“karamba”, in the center of dam water and around of the ex-paddy fields. There were taken vertically in three-depth point in each of the sampling point, respectively 0.5 meter, 1.5 meter, and 2.5 meter. The results showed that the gross primary productivity of the dam was 11.122.500-22.545.600 mgC/m3/days, and the primary productivity differences in each of the point sampling caused by light intensity, nutrient supply, and abundance of the chlorophyll organisms.

Management of agro-pastoral dams in Benin: stakeholders, institutions and rehabilitation research

NARCIS (Netherlands)

Kpéra, G.N.; Aarts, N.; Saïdou, A.; Tossou, R.C.; Eilers, C.H.A.M.; Mensah, G.A.; Sinsin, B.A.; Kossou, D.K.; van der Zijpp, A.J.

2012-01-01

Agro-pastoral dams are waterholes constructed to provide water for livestock and for agricultural development. In Benin, agro-pastoral dams are managed by dam management committees. This study seeks to (1) characterize the stakeholders involved in agro-pastoral dam use and management, (2) identify

Fragmentation of Andes-to-Amazon connectivity by hydropower dams.

Science.gov (United States)

Anderson, Elizabeth P; Jenkins, Clinton N; Heilpern, Sebastian; Maldonado-Ocampo, Javier A; Carvajal-Vallejos, Fernando M; Encalada, Andrea C; Rivadeneira, Juan Francisco; Hidalgo, Max; Cañas, Carlos M; Ortega, Hernan; Salcedo, Norma; Maldonado, Mabel; Tedesco, Pablo A

2018-01-01

Andes-to-Amazon river connectivity controls numerous natural and human systems in the greater Amazon. However, it is being rapidly altered by a wave of new hydropower development, the impacts of which have been previously underestimated. We document 142 dams existing or under construction and 160 proposed dams for rivers draining the Andean headwaters of the Amazon. Existing dams have fragmented the tributary networks of six of eight major Andean Amazon river basins. Proposed dams could result in significant losses in river connectivity in river mainstems of five of eight major systems-the Napo, Marañón, Ucayali, Beni, and Mamoré. With a newly reported 671 freshwater fish species inhabiting the Andean headwaters of the Amazon (>500 m), dams threaten previously unrecognized biodiversity, particularly among endemic and migratory species. Because Andean rivers contribute most of the sediment in the mainstem Amazon, losses in river connectivity translate to drastic alteration of river channel and floodplain geomorphology and associated ecosystem services.

SCENARIO OF AN ACCIDENT OF SOIL DAMS IN CASE OF WATER SPILL OVER A DAM CREST BY USING FAULT TREE ANALYSIS

Directory of Open Access Journals (Sweden)

Kuznetsov Dmitriy Viktorovich

2016-04-01

Full Text Available The scenario of a hydrodynamic accident of water flow over a crest of a soil dam is considered by the method of fault tree analysis, for which the basic reasons and controlled diagnostic indicators of an accident have been defined. Logical operators “AND”/”OR” were used for creation of a sequence of logically connected events, leading to an undesired event in the scenario of accident. The scenario of the accident was plotted in case of three basic reasons - an excessive settling of a dam crest, an excess flood, an inoperable spillway, taking into account the sequence of the events’ development and with observance of the necessary conditions leading to an accident. “Technical” reasons were observed in the present scenario, force majeure events were not considered. The provided scenario of the accident consists of two branches of events’ development: the left one that depends on an upstream level, and the right one that depends on settling of a dam crest. In each of the considered events an accident “the water spill over a crest of a soil dam” is possible only in case of execution of two different conditions at the same time, i.e. in case of an appropriate upstream level and the appropriate mark of a crest of a soil dam. The conditions of the accident are defined by diagnostic indices - the upstream level and settling of a dam crest, which at the same time are safety criteria of the hydraulic structure for soil dams. They allow defining the technical condition of the construction. Four possible technical conditions are suggested for the definition of technical statuses - normative, operable, limited operable, abnormal. Criteria of safety are the boundaries of the state: for loading and impact - it is the upstream level, for geometrical compliance of the construction - it is a dam crest mark.

National Dam Safety Program. Clove Lake Dam (NJ 00259) Delaware River Basin, Shimers Brook, Sussex County, New Jersey. Phase I Inspection Report.

Science.gov (United States)

1981-08-01

it be reclassified as low hazard. The spillway will pass the 100-year flood and is considered adequate. e. Ownership. The dam is owned by Clubhouse ...Associates. For information, contact Mr. Gerald Roby, Clubhouse Associates, RD 4, Box 108, Montague, New Jersey 07827. f. Purpose. The Clove Lake Dam...into what appears to be a man-made lake downstream of Clove Lake Dam about 0.5 mile. Although no homes are presently constructed around this downstream

Incremental Dynamic Analysis of Koyna Dam under Repeated Ground Motions

Science.gov (United States)

Zainab Nik Azizan, Nik; Majid, Taksiah A.; Nazri, Fadzli Mohamed; Maity, Damodar; Abdullah, Junaidah

2018-03-01

This paper discovers the incremental dynamic analysis (IDA) of concrete gravity dam under single and repeated earthquake loadings to identify the limit state of the dam. Seven ground motions with horizontal and vertical direction as seismic input considered in the nonlinear dynamic analysis based on the real repeated earthquake in the worldwide. All the ground motions convert to respond spectrum and scaled according to the developed elastic respond spectrum in order to match the characteristic of the ground motion to the soil type. The scaled was depends on the fundamental period, T1 of the dam. The Koyna dam has been selected as a case study for the purpose of the analysis by assuming that no sliding and rigid foundation, has been estimated. IDA curves for Koyna dam developed for single and repeated ground motions and the performance level of the dam identifies. The IDA curve of repeated ground motion shown stiffer rather than single ground motion. The ultimate state displacement for a single event is 45.59mm and decreased to 39.33mm under repeated events which are decreased about 14%. This showed that the performance level of the dam based on seismic loadings depend on ground motion pattern.

COMPREHENSIVE ANALYSIS ON SEEPAGE AND STRUCTURAL STABILITY OF EARTH-ROCK DAM: A CASE STUDY OF XIQUANYAN DAM IN CHINA

Directory of Open Access Journals (Sweden)

Qingqing GUO

2016-07-01

Full Text Available Earth-rock dam is commonly used in the high-dam engineering around the world. It has been widely accepted that the analysis on structural and seepage stability plays a very important role, and it is necessary to take into account while designing the earth-rock dam. In performing the analysis of structural and seepage stability, many remarkable methods are available at current stage. However, there are still some important issues remaining unsolved, including: (1 Finite element methods (FEMs is a means of solutions to analysis seepage process, but it is often a difficult task to determine the so-called seepage coefficient, because the common-used water injection test is limited in the practical work due to the high cost and complex procedure. (2 It has long been discussed that the key parameters for structural stability analysis show a significant spatial and temporal variations. It may be partly explained by the inhomogeneous dam-filling during construction work and the developing seepage process. The consequence is that one constant value of the parameter cannot represent the above variations. In this context, we solve the above issues and introduce the solution with a practical earth-rock dam project. For determining the seepage coefficient, the data from the piezo metric tube is used to calculate the potential value, based on which the seepage coefficient can be back-analysed. Then the seepage field, as well as the seepage stability are numerically analysed using the FEM-based SEEP/W program. As to the structural safety, we take into account the spatial and temporal variations of the key parameters, and incorporate the Monte-Carlo simulation method into the commonly used M-P method to calculate the frequency distribution of the obtained structural safety factor. In this way, the structural and seepage safety can be well analysed. This study is also beneficial to provide a mature method and a theoretical insight into the earth-rock dam design

FULCRUM - A dam safety management and alert system

Energy Technology Data Exchange (ETDEWEB)

Butt, Cameron; Greenaway, Graham [Knight Piesold Ltd., Vancouver, (Canada)

2010-07-01

Efficient management of instrumentation, monitoring and inspection data are the keys to safe performance and dam structure stability. This paper presented a data management system, FULCRUM, developed for dam safety management. FULCRUM is a secure web-based data management system which simplifies the process of data collection, processing and analysis of the information. The system was designed to organize and coordinate dam safety management requirements. Geotechnical instrumentation such as piezometers or inclinometers and operating data can be added to the database. Data from routine surveillance and engineering inspection can also be incorporated into the database. The system provides users with immediate access to historical and recent data. The integration of a GIS system allows for rapid assessment of the project site. Customisable alerting protocols can be set to identify and respond quickly to significant changes in operating conditions and potential impacts on dam safety.

The behaviour of a large dam at severe frost

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M. C. SPADEA

1972-06-01

Full Text Available Synthesizing the problem, the action of the thrusts in the
behaviour of t h e dam of Pieve di Cadore, makes itself conspicuous expecially
during three periods of the year:
1. - About the end of June, the air temperature, 011 t h e average, overcomes
the water one in the watershed upstream the dam: the bending of
t h e dam upstream increases from the bottom to the top.
2. - About the end of October, the thermal conditions change; the
mean air temperature grows lower than the mean water temperature; the
dam begins her bending dowstream.
3. - When the air temperature is distinctly below 0 °C, the action of
t h e t h r u s t s grows more complexe; t h e rocky waterlogged system downstream
of t h e dam, while cooling, swells and pushes t h e bottom of t h e dam upstream;
at t h e higher quote, on the contrary, the t h r u s t downstream continues.
When the strenght limit of the medium is surpassed, arises a contrast
between the rocky system and the concrete structure: this contrast can origin
a t e very small fractures, revealed from seismic station installed into the
central ashlar (XIV a t 660 metres height of t h e dam, under t h e form of microshocks
which energy is of about 10I0-10U erg.

The potential for dams to impact lowland meandering river floodplain geomorphology.

Science.gov (United States)

Marren, Philip M; Grove, James R; Webb, J Angus; Stewardson, Michael J

2014-01-01

The majority of the world's floodplains are dammed. Although some implications of dams for riverine ecology and for river channel morphology are well understood, there is less research on the impacts of dams on floodplain geomorphology. We review studies from dammed and undammed rivers and include influences on vertical and lateral accretion, meander migration and cutoff formation, avulsion, and interactions with floodplain vegetation. The results are synthesized into a conceptual model of the effects of dams on the major geomorphic influences on floodplain development. This model is used to assess the likely consequences of eight dam and flow regulation scenarios for floodplain geomorphology. Sediment starvation downstream of dams has perhaps the greatest potential to impact on floodplain development. Such effects will persist further downstream where tributary sediment inputs are relatively low and there is minimal buffering by alluvial sediment stores. We can identify several ways in which floodplains might potentially be affected by dams, with varying degrees of confidence, including a distinction between passive impacts (floodplain disconnection) and active impacts (changes in geomorphological processes and functioning). These active processes are likely to have more serious implications for floodplain function and emphasize both the need for future research and the need for an "environmental sediment regime" to operate alongside environmental flows.

The Potential for Dams to Impact Lowland Meandering River Floodplain Geomorphology

Directory of Open Access Journals (Sweden)

Philip M. Marren

2014-01-01

Full Text Available The majority of the world's floodplains are dammed. Although some implications of dams for riverine ecology and for river channel morphology are well understood, there is less research on the impacts of dams on floodplain geomorphology. We review studies from dammed and undammed rivers and include influences on vertical and lateral accretion, meander migration and cutoff formation, avulsion, and interactions with floodplain vegetation. The results are synthesized into a conceptual model of the effects of dams on the major geomorphic influences on floodplain development. This model is used to assess the likely consequences of eight dam and flow regulation scenarios for floodplain geomorphology. Sediment starvation downstream of dams has perhaps the greatest potential to impact on floodplain development. Such effects will persist further downstream where tributary sediment inputs are relatively low and there is minimal buffering by alluvial sediment stores. We can identify several ways in which floodplains might potentially be affected by dams, with varying degrees of confidence, including a distinction between passive impacts (floodplain disconnection and active impacts (changes in geomorphological processes and functioning. These active processes are likely to have more serious implications for floodplain function and emphasize both the need for future research and the need for an “environmental sediment regime” to operate alongside environmental flows.

National Dam Safety Program. Potake Lake Dam (Inventory Number N.Y. 970), Passaic River Basin, Lower Hudson River Area, Rockland County, New York. Phase I Inspection Report,

Science.gov (United States)

1981-08-14

facilitate thedischarge of storm flows. 2. The animal burrows, depressions , and tire ruts onthe crest of the dam should be filled, compacted and seeded. 3...storm flows. 2. The animal burrows, depressions , and tire ruts on the crest of the dam should be filled, compacted, and seeded...defined by the Recommended Guidelines for Safety Inspection of Dams (Reference 13, Appendix D). d. Hazard Classifications - Cranberry Lake Dam is one mile

Dam failure analysis for the Lago de Matrullas Dam, Orocovis, Puerto Rico

Science.gov (United States)

Torres-Sierra, Heriberto; Gómez-Fragoso, Julieta

2015-01-01

The U.S. Geological Survey, in cooperation with the Puerto Rico Electric Power Authority, completed a hydrologic and hydraulic study to assess the potential hazard to human life and property associated with the hypothetical failure of the Lago de Matrullas Dam, located within the headwaters of the Río Grande de Manatí. The hydrologic study yielded outflow hydrographs and peak discharges for Lago de Matrullas and other subbasins in the Río Grande de Manatí hydrographic basin for three extreme rainfall events: (1) a 6-hour probable maximum precipitation (PMP) event, (2) a 24-hour PMP event, and (3) a 100-year-recurrence, 24-hour rainfall event. The hydraulic study simulated the hypothetical dam failure of Lago de Matrullas using hypothetical flood hydrographs generated from the hydrologic study and selected dam breach parameters. The flood wave resulting from the failure was downstream-routed through the lower reaches of the Río Matrullas, the Río Toro Negro, and the Río Grande de Manatí for determination of water-surface profiles developed from the event-based hydrologic scenarios and “sunny day” (no precipitation) conditions. The Hydrologic Modeling System (HEC–HMS) and the River Analysis System (HEC–RAS) computer programs, developed by the Hydrologic Engineering Center (HEC) of the U.S. Army Corps of Engineers, were used for the hydrologic and hydraulic modeling, respectively. The flow routing in the hydraulic analyses was performed using the unsteady-state flow module available in the HEC–RAS model.

Impact of dam-building on marine life

Science.gov (United States)

Pandian, T. J.

1980-03-01

Dam-building across naturally flowing rivers tends to decrease discharge of surplus water into the sea, reduce nutrient concentration in estuaries and coastal waters, and diminish plankton blooms as well as fish landings. Depletion of nutrients and organic matter along with reduced mud and silt deposition affect benthic life on the continental shelf. Reduced mud and silt deposition leads to coastal retreat. Dams, especially those constructed for hydro-electric purposes, hinder migration of fishes and decapods. Discharge from dams can create barriers at high or low flows, cause delays, disrupt normal behavioural routine and change the travel speed of migratory animals. Where all spawners of a given population are frequently kept away from the breeding site, the population faces extinction.

DESIGN OF SLIT DAMS FOR CONTROLLING STONY DEBRIS FLOWS

Institute of Scientific and Technical Information of China (English)

Hui-Pang LIEN

2003-01-01

A new method to a slit dam for controlling the stony debris flow has been derived based on the mass conservation law of the stony debris flow passing through a slit dam and the laboratory experiment results.This new method is then combined with three primary efficiency expressions: the dimensionless sediment outflow ratio,the sediment concentration ratio,and the sediment storage rate to develop a simple module,with which the height and the spacing of the posts,as well as the total spacing of slit dam are determined.Furthermore,these expressions can also be applied to check those slit dams that have already been constructed with their effectiveness against various magnitudes of the debris flow. The comparison between these expressions and laboratory data is in reasonable agreement.

Utilisation of Sepidrud dam basin sediments in fired clay bricks: laboratory scale experiment

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Jamshidi-Chenari, R.

2015-12-01

Full Text Available The prevailing disposal methods for dam basin sediments are not free from the environmental pollution and the ecological imbalance. At present, a new way to treat the dredged sediments to manufacture bricks is being investigated, prioritizing waste recovery over its deposition in landfills. However, construction materials such as clay bricks must comply with the international and local standards. Considering the perpetual availability of the sediments, particle sizing and their chemical composition and the results of physical and qualification tests on Sepidrud Dam basin sediments it can be concluded that the utilization of basin sediments as a full or partial replacement in clay brick production will lead to the production of quality bricks that meet all the regulatory limits in the standards. This research is novel in view of both increasing the reservoir effective volume capacity and preventing the use of alternative land quarries which are mainly covered by green land.Los métodos actuales de eliminación de los sedimentos de las cuencas de las presas no están exentos de problemas de contaminación ambiental y ecológicos. En la actualidad, se está investigando la posibilidad de utilizar los sedimentos dragados para la fabricación de ladrillos, dando prioridad a su valoración como residuos frente a su depósito en vertederos. Sin embargo, los ladrillos, como otros materiales de construcción, deben de cumplir con las correspondientes normas nacionales e internacionales. Teniendo en cuenta la disponibilidad permanente de los sedimentos, el tamaño de sus partículas y su composición química y los resultados físicos de las pruebas de calificación de los sedimentos de la cuenca Sepidrud Dam, en este estudio se ha concluido su viabilidad como materiales de reemplazo total o parcial de las materias primas convencionales, para la producción de ladrillos. Estos ladrillos cumplen además con las normas vigentes. Este es un estudio novedoso

River Restoration by Dam Removal: Assessing Riverine Re-Connectivity Across New England

Science.gov (United States)

Magilligan, F. J.; Nislow, K. H.; Graber, B.; Sneddon, C.; Fox, C.; Martin, E.

2014-12-01

The impacts of dams in New England are especially acute as it possesses one of the highest densities of dams in the US, with the NID documenting more than 4,000 dams, and state agency records indicating that >14,000 dams are peppered throughout the landscape. This large number of dams contributes to pervasive watershed fragmentation, threatening the ecological integrity of rivers and streams, and in the case of old, poorly maintained structures, posing a risk to lives and property. These concerns have generated active dam removal efforts throughout New England. To best capture the geomorphic, hydrologic, and potential ecological effects of dam removal at a regional level, we have compiled a dataset of 127 removed dams in New England, which includes information about structural characteristics, georectified locations, and key watershed attributes (including basin size, distance to next upstream obstacle, and number of free-flowing river kms opened up). Our specific research questions address (1) what is the spatial distribution of removed dams and how does this pattern relate to stated management goals of restoring critical habitat for native resident freshwater and diadromous fish, (2) what are the structural or management commonalities in dam types that have been removed, and (3) what has been the incremental addition of free-flowing river length? Rather than reflecting an overall management prioritization strategy, results indicate that dam removals are characterized more by opportunistic removals. For example, despite a regional emphasis on diadromous fish protection and restoration, most removals are inland rather than coastal settings. Most of the removed dams were small (~ 45% 2,300 river kms over the past several decades, with implication for both resident and diadromous fish, and with many removals located in mid-sized rivers that are a key link between upstream and downstream/coastal aquatic ecosystems.

Safety management of the Karapiro dam, New Zealand

International Nuclear Information System (INIS)

Everitt, S.C.

1995-01-01

The dam safety program for 36 hydraulic structures in New Zealand were presented, with special emphasis on the application of this program to the Karapiro dam. The management of the hazard presented by the dam was detailed, and the proposed solutions for its remediation were presented. Dynamic analysis was employed using an elastic 3-D finite element model, using actual earthquake time history records as an input, scaled to the required Maximum Credibility Earthquake (MCE). The results confirmed that the arch section of the Karapiro dam was satisfactory, as was the spillway block, provided that drainage was preserved, however, the left abutment and thrust block were considered unstable. Four options were proposed for strengthening the abutment: (1) lowering the groundwater, (2) installation of stresses anchors, (3) mass concrete buttressing upstream and/or downstream, and (4) installation of reinforced concrete shear keys. However, prior to undertaking any remediation work, rock mass properties and groundwater conditions should be re-investigated. 1 ref., 7 figs

Mapping the social impacts of small dams: The case of Thailand's Ing River basin.

Science.gov (United States)

Fung, Zali; Pomun, Teerapong; Charles, Katrina J; Kirchherr, Julian

2018-05-24

The social impacts of large dams have been studied extensively. However, small dams' social impacts have been largely neglected by the academic community. Our paper addresses this gap. We examine the social impacts of multiple small dams in one upstream and one downstream village in Thailand's Ing River basin. Our research is based on semi-structured interviews with beneficiaries, government and NGOs. We argue that small dams' social impacts are multi-faceted and unequal. The dams were perceived to reduce fish abundance and provide flood mitigation benefits. Furthermore, the dams enabled increased access to irrigation water for upstream farmers, who re-appropriated water via the dams at the expense of those downstream. The small dams thus engendered water allocation conflicts. Many scholars, practitioners and environmentalists argue that small dams are a benign alternative to large dams. However, the results of our research mandate caution regarding this claim.

Feasibility of groundwater recharge dam projects in arid environments

Science.gov (United States)

Jaafar, H. H.

2014-05-01

A new method for determining feasibility and prioritizing investments for agricultural and domestic recharge dams in arid regions is developed and presented. The method is based on identifying the factors affecting the decision making process and evaluating these factors, followed by determining the indices in a GIS-aided environment. Evaluated parameters include results from field surveys and site visits, land cover and soils data, precipitation data, runoff data and modeling, number of beneficiaries, domestic irrigation demand, reservoir objectives, demography, reservoirs yield and reliability, dam structures, construction costs, and operation and maintenance costs. Results of a case study on more than eighty proposed dams indicate that assessment of reliability, annualized cost/demand satisfied and yield is crucial prior to investment decision making in arid areas. Irrigation demand is the major influencing parameter on yield and reliability of recharge dams, even when only 3 months of the demand were included. Reliability of the proposed reservoirs as related to their standardized size and net inflow was found to increase with increasing yield. High priority dams were less than 4% of the total, and less priority dams amounted to 23%, with the remaining found to be not feasible. The results of this methodology and its application has proved effective in guiding stakeholders for defining most favorable sites for preliminary and detailed design studies and commissioning.

Study on seismic stability of seawall in man-made island. Pt. 3. Development of evaluation method for seismic stability of seawall considering dynamic interaction of armour embankment and caisson

International Nuclear Information System (INIS)

Tochigi, Hitoshi; Kanatani, Mamoru; Kawai, Tadashi

1999-01-01

In the development of siting technology for off-shore nuclear power plants on man-made island, assessing the stability of seawall which ensure the safety of backfill ground against ocean waves and earthquakes is indispensable. Concerning the seismic stability of seawall, it is indicated that the evaluation of the influence of lateral pressure of armour embankment acting on the caisson wall is an important factor. We proposed modeling method of discontinuity such as armour unit by distinct element method (DEM) and combined them with caisson type seawall model idealized by FEM. To show the validity of this DEM-FEM hybrid analysis method, the numerical simulation for the shaking table tests was conducted. For the two kinds of seawall model with armour embankment and without the one, the lateral displacement of the seawall induced by sliding of caisson is successfully reproduced and accuracy of above mentioned numerical procedure is confirmed. (author)

Birecik: a role model for private companies

Energy Technology Data Exchange (ETDEWEB)

Holzmann, P. [Corporate Communications, Frankfurt am Main (Germany)

2001-04-01

The Birecik hydroelectric power project in Turkey is highlighted as a good example of the effectiveness of a private sector company in planning, financing and constructing a hydro power plant on a build, operate and transfer (BOT) basis. Birecik AS has built the 672 MW plant and dam on the River Euphrates near the border with Syria as part of a Turkish government plan to develop southeast Anatolia. The dam, which was built on schedule and within budget, has embankments on the left and right hand sides and a gravity dam in the centre containing the power house, intake and spillway. The power house contains six Francis turbines, three of which are already operational. The plant's specifications and other vital statistics are summarised in a table. Its location is shown in a map of Turkey.

Examining the economic impacts of hydropower dams on property values using GIS.

Science.gov (United States)

Bohlen, Curtis; Lewis, Lynne Y

2009-07-01

While the era of dam building is largely over in the United States, globally dams are still being proposed and constructed. The articles in this special issue consider many aspects and impacts of dams around the world. This paper examines dam removal and the measurement of the impacts of dams on local community property values. Valuable lessons may be found. In the United States, hundreds of small hydropower dams will come up for relicensing in the coming decade. Whether or not the licenses are renewed and what happens to the dams if the licenses expires is a subject of great debate. Dams are beginning to be removed for river restoration and fisheries restoration and these "end-of-life" decisions may offer lessons for countries proposing or currently building small (and large) hydropower dams. What can these restoration stories tell us? In this paper, we examine the effects of dams along the Penobscot River in Maine (USA) on residential property values. We compare the results to findings from a similar (but ex post dam removal) data set for properties along the Kennebec river in Maine, where the Edwards Dam was removed in 1999. The Penobscot River Restoration Project, an ambitious basin-wide restoration effort, includes plans to remove two dams and decommission a third along the Penobscot River. Dam removal has significant effects on the local environment, and it is reasonable to anticipate that environmental changes will themselves be reflected in changes in property values. Here we examine historical real estate transaction data to examine whether landowners pay a premium or penalty to live near the Penobscot River or near a hydropower generating dam. We find that waterfront landowners on the Penobscot or other water bodies in our study area pay approximately a 16% premium for the privilege of living on the water. Nevertheless, landowners pay LESS to live near the Penobscot River than they do to live further away, contrary to the expectation that bodies of water

Strategies of Successful Anti-Dam Movements: Evidence from Myanmar and Thailand

NARCIS (Netherlands)

Kirchherr, J.W.|info:eu-repo/dai/nl/411261487

2018-01-01

Scholars are rarely able to examine anti-dam movements that result in project suspensions or cancellations since these cases are rare empirically. Yet, they are central to understanding how anti-dam movements can succeed. This paper analyzes the movements against Myanmar’s Myitsone Dam and

Evaluating temporal changes in hydraulic conductivities near karst-terrain dams: Dokan Dam (Kurdistan-Iraq)

Science.gov (United States)

Dafny, Elad; Tawfeeq, Kochar Jamal; Ghabraie, Kazem

2015-10-01

Dam sites provide an outstanding opportunity to explore dynamic changes in the groundwater flow regime because of the high hydraulic gradient rapidly induced in their surroundings. This paper investigates the temporal changes of the hydraulic conductivities of the rocks and engineered structures via a thorough analysis of hydrological data collected at the Dokam Dam, Iraq, and a numerical model that simulates the Darcian component of the seepage. Analysis of the data indicates increased seepage with time and suggests that the hydraulic conductivity of the rocks increased as the conductivity of the grout curtain decreased. Conductivity changes on the order of 10-8 m/s, in a 20-yr period were quantified using the numerical analysis. It is postulated that the changes in hydraulic properties in the vicinity of Dokan Dam are due to suspension of fine materials, interbedded in small fissures in the rocks, and re-settlement of these materials along the curtain. Consequently, the importance of the grout curtain to minimize the downstream seepage, not only as a result of the conductivity contrast with the rocks, but also as a barrier to suspended clay sediments, is demonstrated. The numerical analysis also helped us to estimate the proportion of the disconnected karstic conduit flow to the overall flow.

Endocrine-disruptor molecular responses, occurrence of intersex and gonado-histopathological changes in tilapia species from a tropical freshwater dam (Awba Dam) in Ibadan, Nigeria

International Nuclear Information System (INIS)

Adeogun, Aina O.; Onibonoje, Kolawole; Ibor, Oju R.; Omiwole, Roseline A.; Chukwuka, Azubuike V.; Ugwumba, Alex O.; Ugwumba, Adiaha A.A.; Arukwe, Augustine

2016-01-01

Highlights: • Occurrence and severity of intersex in Nigerian aquatic environment. • Estrogenic and reproductive developmental effects of effluents from a University community. • Biomarker of endocrine disruption in fish from a developing country. • Relationship between estrogenic responses and sediment contaminants burden in a dam used for University domestic water supply and for fisheries. • Possible health consequences of environmental contamination - Abstract: In the present study, the occurrence of endocrine disruptive responses in Tilapia species from Awba Dam has been investigated, and compared to a reference site (Modete Dam). The Awba Dam is a recipient of effluents from University of Ibadan (Nigeria) and several other anthropogenic sources. A total of 132 Tilapia species (Sarotherodon malenotheron (n = 57 and 32, males and females, respectively) and Tilapia guineensis (n = 23 and 20, males and females, respectively)) were collected from June to September 2014. At the reference site, samples of adult male and female S. melanotheron (48 males and 47 females) and T. guineensis (84 males and 27 females) were collected. Gonads were morphologically and histologically examined and gonadosomatic index (GSI) was calculated. Hepatic mRNA transcriptions of vitellogenin (Vtg) and zona radiata protein (Zrp) genes were analyzed using validated RT-qPCR. Significant increase in Vtg and Zrp transcripts were observed in male tilapias from Awba Dam, compared to males from the reference site. In addition, male tilapias from Awba Dam produced significantly higher Vtg and Zrp mRNA, compared to females in June and July. However, at the natural peak spawning period in August and September, females produced, significantly higher Vtg and Zrp mRNA, compared to males. Fish gonads revealed varying incidence of intersex with a striking presence of two (2) pairs of testes and a pair of ovary in S. melanotheron from Awba Dam. The entire fish population examined at Awba Dam

Endocrine-disruptor molecular responses, occurrence of intersex and gonado-histopathological changes in tilapia species from a tropical freshwater dam (Awba Dam) in Ibadan, Nigeria

Energy Technology Data Exchange (ETDEWEB)

Adeogun, Aina O.; Onibonoje, Kolawole; Ibor, Oju R.; Omiwole, Roseline A.; Chukwuka, Azubuike V.; Ugwumba, Alex O.; Ugwumba, Adiaha A.A. [Department of Zoology, University of Ibadan, Ibadan (Nigeria); Arukwe, Augustine, E-mail: arukwe@bio.ntnu.no [Department of Biology, Norwegian University of Science and Technology (NTNU), 7491 Trondheim (Norway)

2016-05-15

Highlights: • Occurrence and severity of intersex in Nigerian aquatic environment. • Estrogenic and reproductive developmental effects of effluents from a University community. • Biomarker of endocrine disruption in fish from a developing country. • Relationship between estrogenic responses and sediment contaminants burden in a dam used for University domestic water supply and for fisheries. • Possible health consequences of environmental contamination - Abstract: In the present study, the occurrence of endocrine disruptive responses in Tilapia species from Awba Dam has been investigated, and compared to a reference site (Modete Dam). The Awba Dam is a recipient of effluents from University of Ibadan (Nigeria) and several other anthropogenic sources. A total of 132 Tilapia species (Sarotherodon malenotheron (n = 57 and 32, males and females, respectively) and Tilapia guineensis (n = 23 and 20, males and females, respectively)) were collected from June to September 2014. At the reference site, samples of adult male and female S. melanotheron (48 males and 47 females) and T. guineensis (84 males and 27 females) were collected. Gonads were morphologically and histologically examined and gonadosomatic index (GSI) was calculated. Hepatic mRNA transcriptions of vitellogenin (Vtg) and zona radiata protein (Zrp) genes were analyzed using validated RT-qPCR. Significant increase in Vtg and Zrp transcripts were observed in male tilapias from Awba Dam, compared to males from the reference site. In addition, male tilapias from Awba Dam produced significantly higher Vtg and Zrp mRNA, compared to females in June and July. However, at the natural peak spawning period in August and September, females produced, significantly higher Vtg and Zrp mRNA, compared to males. Fish gonads revealed varying incidence of intersex with a striking presence of two (2) pairs of testes and a pair of ovary in S. melanotheron from Awba Dam. The entire fish population examined at Awba Dam

Application of the Periodic Average System Model in Dam Deformation Analysis

Directory of Open Access Journals (Sweden)

Yueqian Shen

2015-01-01

Full Text Available Dams are among the most important hydraulic engineering facilities used for water supply, flood control, and hydroelectric power. Monitoring of dams is crucial since deformation might have occurred. How to obtain the deformation information and then judge the safe conditions is the key and difficult problem in dam deformation monitoring field. This paper proposes the periodic average system model and creates the concept of “settlement activity” based on the dam deformation issue. Long-term deformation monitoring data is carried out in a pumped-storage power station, this model combined with settlement activity is used to make the single point deformation analysis, and then the whole settlement activity profile is drawn by clustering analysis. Considering the cumulative settlement value of every point, the dam deformation trend is analyzed in an intuitive effect way. The analysis mode of combined single point with multipoints is realized. The results show that the key deformation information of the dam can be easily grasped by the application of the periodic average system model combined with the distribution diagram of settlement activity. And, above all, the ideas of this research provide an effective method for dam deformation analysis.

Optimization design of foundation excavation for Xiluodu super-high arch dam in China

Directory of Open Access Journals (Sweden)

Qixiang Fan

2015-04-01

Full Text Available With better understanding of the quality and physico-mechanical properties of rocks of dam foundation, and the physico-mechanical properties and structure design of arch dam in association with the foundation excavation of Xiluodu arch dam, the excavation optimization design was proposed for the foundation surface on the basis of feasibility study. Common analysis and numerical analysis results demonstrated the feasibility of using the weakly weathered rocks III1 and III2 as the foundation surface of super-high arch dam. In view of changes in the geological conditions at the dam foundation along the riverbed direction, the design of extending foundation surface excavation area and using consolidating grouting and optimizing structure of dam bottom was introduced, allowing for harmonization of the arch dam and foundation. Three-dimensional (3D geomechanics model test and finite element analysis results indicated that the dam body and foundation have good overload stability and high bearing capacity. The monitoring data showed that the behaviors of dam and foundation correspond with the designed patterns in the construction period and the initial operation period.

A progressive methodology for seismic safety evaluation of gravity dams

International Nuclear Information System (INIS)

Ghrib, F.; Leger, P.; Tinawi, R.; Lupien, R.; Veilleux, M.

1995-01-01

A progressive methodology for the seismic safety evaluation of existing concrete gravity dams was described. The methodology was based on five structural analysis levels with increasing complexity to represent inertia forces, dam-foundation and dam-interaction mechanisms, as well as concrete cracking. The five levels were (1) preliminary screening, (2) pseudo-static method, (3) pseudo-dynamic method, (4) linear time history analysis, and (5) non-linear history analysis. The first four levels of analysis were applied for the seismic safety evaluation of Paugan gravity dam (Quebec). Results showed that internal forces from pseudo-dynamic, response spectra and transient finite element analyses could be used to interpret the dynamic stability of dams from familiar strength-based criteria. However, as soon as the base was cracked, the seismically induced forces were modified, and level IV analyses proved more suitable to handle rationally these complexities. 8 refs., 7 figs., 1 tab

Hydro-electric power project on the Toulnustouc River

International Nuclear Information System (INIS)

Rochon, Y.; Morneau, J.; Lefebvre, G.

2001-01-01

Hydro-Quebec has proposed the development of a hydro-electric power project on the Toulnustouc River, located between Saint-Anne Lake and Manic Reservoir. The work would involve the construction of a power generation plant of 526 MW, construction of a 77 m dam on the Toulnustouc River, 14 km downstream from the existing Lac-Saint-Anne dam, the creation of a new water expanse covering 22 square kilometers, the construction of an embankment, the strengthening of the existing Saint-Anne embankment, digging a 9.8 km gallery, and the construction of a flood spillway. This work would have consequences for three different sectors of the river: between the existing and the proposed dam, between the dam and the projected power plant, and between the power plant and the limit of the influence of the reservoir Manic-2. Hydro-Quebec would like the work to begin in July 2001, with the aim of having the plant in operation in 2005. The overall cost of the project is estimated at 600 million dollars. It is expected that the economic benefits for the region would be in the 211 million dollar range. An environmental assessment of the entire project was performed by Quebec Ministere de l'Environnement. The authors determined that the project was recognized as justified by the Ministere des Ressources Naturelles (Natural Resources Ministry) and concluded that the project was acceptable from an environmental point of view as long as six conditions were met. They touched on the construction of a flood spillway capable of evacuating 19 cubic meters per second at any time during the year, that water be evacuated downstream following a pre-determined debit that varies according to the time of year, monitoring of the brook trout population and its habitat, and environmental monitoring. 46 refs., 7 tabs., 2 figs., 1 annex

Dam-Break Flood Analysis Upper Hurricane Reservoir, Hartford, Vermont

National Research Council Canada - National Science Library

Acone, Scott

1995-01-01

.... Various dam break flood conditions were modeled and inundation maps developed. Based on this analysis the dam is rated a Class 2 or significant hazard category in terms of its potential to cause downstream damage...

Review Article: Numerical analysis of the seismic behaviour of earth dam

Directory of Open Access Journals (Sweden)

Y. Parish

2009-03-01

Full Text Available The present study concerns analysis of the seismic response of earth dams. The behaviour of both the shell and core of the dam is described using the simple and popular non associated Mohr-Coulomb criterion. The use of this constitutive model is justified by the difficulty to obtain constitutive parameters for more advanced constitutive relations including isotropic and kinematic hardening. Analyses with real earthquake records show that the seismic loading induces plasticity in a large part of the shell and in the lower part of the core. Analysis shows that plasticity should be considered in the analysis of the seismic response of the dam, because it leads to a decrease in the natural frequencies of the dam together to energy dissipation, which could significantly affect the seismic response of the dam. Plastic analysis constitutes also a good tool for the verification of the stability of the dam under seismic loading.

Potential Risk Analysis of Tailings Dam under Preloading Condition and Its Countermeasures

Directory of Open Access Journals (Sweden)

Shuren Wang

2015-01-01

Full Text Available It is very important for mine production safety to ensure the stability of the tailings dam. Taking a flatland tailings pond as the background, a threedimensional computational model was built based on a tailings dam under mullock heap preloading condition. Considering the current operating water level conditions, a liquid-solid coupling analysis of the model was conducted.The deformation characteristics of the tailings dam were revealed during successive preloading at the front of the dam. The safety factor and the potential slide face of the tailings dam were calculated under different conditions using the strength reduction method. The results show that the tailings dam in its current condition is basically stable, but if the mullock heap continues to be heightened, the tailings dam will become unstable. Therefore, in order to limit the height of the mullock heap, establishing a monitor and early warning mechanism are put forward to ensure mine production safety.

Seismic rehabilitation and analysis of Chaohe earth dam

Science.gov (United States)

Fu, Lei; Zeng, Xiangwu

2005-12-01

Stability of earth dams during earthquakes has been a major concern for geotechnical engineers in seismic active regions. Liquefaction induced slope failure occurred at the upstream slope of a major earth dam in the suburb of Beijing, China, during the 1976 Tangshan Earthquake. The gravelly soil with loose initial condition liquefied under relatively small ground vibration. In recent years, a major seismic rehabilitation project was carried out on a similar earth dam nearby using dumped quarry stone. Seismic stability analysis was carried out using model test, finite element simulation, and pseudo-static slope stability program after taking into account the influence of excess pore pressure.

Allegheny County Dam Locations

Data.gov (United States)

Allegheny County / City of Pittsburgh / Western PA Regional Data Center — This dataset shows the point locations of dams in Allegheny County. If viewing this description on the Western Pennsylvania Regional Data Center’s open data portal...

Endocrine-disruptor molecular responses, occurrence of intersex and gonado-histopathological changes in tilapia species from a tropical freshwater dam (Awba Dam) in Ibadan, Nigeria.

Science.gov (United States)

Adeogun, Aina O; Onibonoje, Kolawole; Ibor, Oju R; Omiwole, Roseline A; Chukwuka, Azubuike V; Ugwumba, Alex O; Ugwumba, Adiaha A A; Arukwe, Augustine

2016-05-01

In the present study, the occurrence of endocrine disruptive responses in Tilapia species from Awba Dam has been investigated, and compared to a reference site (Modete Dam). The Awba Dam is a recipient of effluents from University of Ibadan (Nigeria) and several other anthropogenic sources. A total of 132 Tilapia species (Sarotherodon malenotheron (n=57 and 32, males and females, respectively) and Tilapia guineensis (n=23 and 20, males and females, respectively)) were collected from June to September 2014. At the reference site, samples of adult male and female S. melanotheron (48 males and 47 females) and T. guineensis (84 males and 27 females) were collected. Gonads were morphologically and histologically examined and gonadosomatic index (GSI) was calculated. Hepatic mRNA transcriptions of vitellogenin (Vtg) and zona radiata protein (Zrp) genes were analyzed using validated RT-qPCR. Significant increase in Vtg and Zrp transcripts were observed in male tilapias from Awba Dam, compared to males from the reference site. In addition, male tilapias from Awba Dam produced significantly higher Vtg and Zrp mRNA, compared to females in June and July. However, at the natural peak spawning period in August and September, females produced, significantly higher Vtg and Zrp mRNA, compared to males. Fish gonads revealed varying incidence of intersex with a striking presence of two (2) pairs of testes and a pair of ovary in S. melanotheron from Awba Dam. The entire fish population examined at Awba Dam showed a high prevalence of intersex (34.8%), involving phenotypic males and females of both species. Analysis of sediment contaminant levels revealed that As, Cd, Pb, Hg and Ni (heavy metals), monobutyltin cation, 4-iso-nonyphenol and PCB congeners (138, 153 and 180) were significantly higher in Awba Dam, compared to the reference site. Principal component analysis (PCA) showed that fish variables were positively correlated with sediment contaminant burden at Awba Dam, indicating

Watershed restoration: planning and implementing small dam removals to maximize ecosystem services

Science.gov (United States)

Tonitto, C.; Riha, S. J.

2016-12-01

River restoration and enhancing watershed connectivity is of growing concern in industrialized nations. The past two decades have seen a number of small dam removals, though many removals remain unstudied and poorly documented. We summarize socio-economic and biophysical lessons learned during the past two decades of accelerated activity regarding small dam removals throughout the United States. We present frameworks for planning and implementing removals developed by interdisciplinary engagement. Toward the goal of achieving thorough dam removal planning, we present outcomes from well-documented small dam removals covering ecological, chemical, and physical change in rivers post-dam removal, including field observation and modeling methodologies. Guiding principles of a dam removal process should include: 1) stakeholder engagement to navigate the complexity of watershed landuse, 2) an impacts assessment to inform the planning process, 3) pre- and post-dam removal observations of ecological, chemical and physical properties, 4) the expectation that there are short- and long-term ecological dynamics with population recovery depending on whether dam impacts were largely related to dispersion or to habitat destruction, 5) an expectation that changes in watershed chemistry are dependent on sediment type, sediment transport and watershed landuse, and 6) rigorous assessment of physical changes resulting from dam removal, understanding that alteration in hydrologic flows, sediment transport, and channel evolution will shape ecological and chemical dynamics, and shape how stakeholders engage with the watershed.

Multiple-Purpose Project: Platte River Basin, Little Platte River, Missouri, Smithville Lake; Operation and Maintenance Manual. Appendix 5. Embankment Criteria and Performance Report. Supplement 1.

Science.gov (United States)

1987-03-01

13-inch diameter rockbits and self-destroying organic polymer drilling fluid through the Raytovn Limestone. Installation details are shov on plate A...c I CtY~rso’~’f A~y/ew7 ~Es~pAm- .1,ENA~ -kPAE O TOP OF BEOPOCK CORITOUMS aRJC SU8 L FT ABEUTMENT SCALE 1󈧶 /A\\/ ~lQ. 10 _ _ _ __ 1 EMBANKMENT TOE

PRODUCTIVITY COMPARISON BETWEEN BOER AND KACANG GOAT DAM

Directory of Open Access Journals (Sweden)

S. Elieser

2014-10-01

Full Text Available A study to evaluate the productivity of Boer and Kacang goats dam was carried out for 2 years atResearch Institute for Goat Production, Sungei Putih-North Sumatera. The materials used were goatsowned by the institute. The parameters observed were total birth and weaning weights of kid, litter size,parity of dam, pre-weaning mortality and kidding interval. The rate of reproduction and productivity ofthe dam were estimated using Amir and Knipscheer methods and were statistically analyzed usingGeneral Linear Model. The results showed that the total birth and weaning weight of Boer goats werehigher (P<0.05 than that of Kacang goats, while litter size of Boer goats were higher (P<0.05 than thatof Kacang goats. The pre-weaning mortality of Boer goat 15.1 ± 6.02% was lower than that ofKacang. The kidding interval of Boer goats was higher (P<0.05 than that of Kacang. Parity of dam hadsignificant effect on all production traits (P<0.05 except for pre-weaning mortality. Dam reproductionrate of Boer (1.81 was higher than that of Kacang (1.78, while productivity of Boer goat (37.12kg/head/year was higher than that of Kacang (18.12. It can be concluded that the reproductivity ofBoer and Kacang goats were similar, however the productivity of Boer goat had better than Kacang.

Dams. Bulletin of the Technical Service of Electric Power and Big Dams; Barrages. Bulletin du Service Technique de l`Energie Electrique et des Grands Barrages

Energy Technology Data Exchange (ETDEWEB)

NONE

1996-12-31

Three papers were selected in this issue of the bulletin of the Technical Service of Electric Power and Big Dams. The first one concerns the experience feedback gained from the accident of the Drac river near Grenoble (France) due to a spillover at the Notre-Dame-de-Commiers` dam and which led to the death of 6 children and their teacher. The second one is a report of the conclusions of decennial and annual safety inspections of French dams, while the third one is a report of the Control Services activities for the third quarter of the year 1996 concerning the French dams in operation. (J.S.)

Linking Three Gorges Dam and downstream hydrological regimes along the Yangtze River, China

NARCIS (Netherlands)

Mei, X.; Dai, Z.; Van Gelder, P.H.A.J.M.; Gao, J.

2015-01-01

The magnitude of anthropogenic influence, especially dam regulation, on hydrological system is of scientific and practical value for large river management. As the largest dam in the world by far, Three Gorges Dam (TGD) is expected to be a strong evidence on dam impacts on downstream hydrological

Freshwater mussel survey for the Columbia Dam removal, Paulins Kill, New Jersey

Science.gov (United States)

Galbraith, Heather S.; Blakeslee, Carrie J.; Cole, Jeffrey C.; Silldorff, Erik L.

2018-06-04

Semi-quantitative mussel surveys, conducted by the U.S. Geological Survey and the Delaware Riverkeeper Network in cooperation with The Nature Conservancy, were completed in the vicinity of the Columbia Dam, on the Paulins Kill, New Jersey, in August 2017 in order to document the mussel species composition and relative abundance prior to removal of the dam. Surveys were conducted from the Brugler Road Bridge downriver approximately 2,000 meters (m) to the Columbia Dam and downriver from the dam about 300 m to 75 m upriver from the confluence of the Paulins Kill with the Delaware River. Sixteen sections (average length=175 m) were surveyed by personnel snorkeling or SCUBA diving; 13 sections were upriver from the dam, and 3 were downriver from the dam. Mussels, as they were encountered by surveyors, were removed from the sediment, immediately identified to species, and replaced in their original collection locations. Habitat data were collected for each surveyed section. Upriver and downriver from the dam, river margins with dense vegetation were examined for mussels by personnel using snorkels in transects (approximately 25 meters) perpendicular to river flow every 50 m on both sides of the river. Only two species were found upriver from the dam, and those were present in relatively low numbers. Catch per unit effort is reported here within parentheses as the average across upriver sections in number of mussels per person hour of survey time: 42 Elliptio complanata (2.6) and 1 Pyganodon cataracta (0.1) were found upriver from the dam. No mussels were found in the dense vegetation either upriver or downriver of the dam by surveyors using snorkels. Significantly higher species richness and mussel catch per unit effort were found downriver from the dam than upriver, including 106 E. complanta (32.5), 27 Utterbackiana implicata (8.2), 1 Alasmidonta undulata (0.4), 2 Lampsilis cariosa (0.5), 6 Lampsilis radiata (2.1), 4 P. cataracta (1.1), and 1 Strophitus undulatus (0

Variability of Ecosystem State in Rivers Containing Natural Dams: A Chemical Analysis

Science.gov (United States)

Reynolds, Z. A.

2015-12-01

Flooding, and the resulting economic damage to roads and property, is associated with natural dams such as beaver dams or log jams. For this reason, humans often remove natural dams; however, river reaches with natural dams provide very different ecosystem services in comparison with free-flowing river reaches. Therefore, the goal of this project is to assess the differences in ecosystem state between these different river reach types in the northeastern United States. We focused on differences in basic chemistry (e.g., dissolved oxygen, pH, temperature, and organic carbon) to assess the impact of natural dams on river ecosystem state. Study sites include rivers in the White Mountains and southeastern New Hampshire at locations with beaver dams, beaver ponds, beaver meadows, log jams, and free-flowing reaches. Dissolved oxygen, ORP, pH, temperature, and conductivity were measured in the field with a YSI Professional Plus meter. Water samples were collected for subsequent laboratory analysis of total organic carbon with a Shimadzu TOC-L. Preliminary results show that the chemistry of river water varies with feature type. Most significantly, dissolved oxygen concentrations are highest in free-flowing reaches and lowest in beaver ponds. Although beaver ponds are often associated with lower pH, due the increased concentration of organic acids, some beaver ponds can increase pH when compared to free-flowing reaches on the same river. Early results also show that water chemistry returns quickly to the chemistry typical of the free-flowing river reaches after being altered by a natural dam. Overall, natural dams create a river system that has more heterogeneity, and therefore has opportunities to provide more ecosystem functions, than a purely free-flowing river; this can increase the number of supported instream and riparian species. By increasing the understanding of how natural dams affect the chemistry of river water, river engineers can improve their decisions on how

Risk assessment of tailings facility dam failure

OpenAIRE

Hadzi-Nikolova, Marija; Mirakovski, Dejan; Stefanova, Violeta

2011-01-01

This paper presents the consequences of tailings facility dam failure and therefore the needs for its risk assessment. Tailings are fine-grained wastes of the mining industry, output as slurries, due to mixing with water during mineral processing. Tailings dams vary a lot as it is affected by: tailings characteristics and mill output, site characteristics as: topography, hydrology, geology, groundwater, seismicity and available material and disposal methods. The talings which accumulat...

Geoelectrical Methods and Monitoring for Dam Safety Assessment, Republic of Korea

Science.gov (United States)

Lim, S. K.; Oldenburg, D.; Kang, S.; Song, S. H.

2016-12-01

Geoelectrical methods and monitoring to detect the seepage and internal erosion are essential for the safety assessment of earth dams. This work aims to develop improved methodologies to analyze the observed data and to monitor changes in seepage flow using direct current (DC) and self-potential (SP) methods. The seasonal variation of water level at dams causes a change in seepage and water saturation and hence alters the resistivity of the dam material. DC data are sensitive to water saturation and hence changes in saturation can be obtained by repeatedly measuring DC data. However, a more diagnostic parameter for safety assessment is fluid flow, and resistivity is only weakly coupled to that. Fortunately SP signals are directly related to fluid flow, and thus an SP survey has the potential to characterize fluid flow through the earth matrix. In Korea, the safety assessment of earth fill dams has been dealt by Korea Rural Community Corporation (KRC). Most of the dams are relatively old ( >50 years), hence assessing deterioration and corresponding seepage of those dams are crucial. In order to evaluate the engineering geological properties of the soil at earth dams in Korea, two boreholes in each dam were drilled to a bedrock depth that exceeds the height of the dam. A large set of field tests, including standard penetration tests (SPT) and in-situ permeability tests, were carried out along the boreholes. However, seepage paths in the dam is complex hence those limited measurements at a few points is not sufficient to delineate the zone of preferential seepage flow. For this, KRC developed permanent DC monitoring systems at a number of agricultural dams in Korea. The data were automatically collected every 6 hours. During the monitoring, the measurements of the water level at two boreholes were gathered at the same time. In this presentation we select an agricultural dam and delineate an anomalous leakage zone by inverting and interpreting time-lapse DC resistivity

Evaluating the Mosul Dam's Instability after Resumption of Maintenance

Science.gov (United States)

Al-husseinawi, Y.; Li, Z.; Clarke, P. J.; Edwards, S.

2017-12-01

There is serious concern about the safety of Mosul dam in the north of Iraq. Millions of people in the downstream area are exposed to risk of catastrophic collapse of this dam due to its soluble foundation. Recent study (Milillo et al., 2016, Scientific Report/10.1038/srep37408) reported that the dam deformation has accelerated since August 2014, when grouting operations were interrupted due to the conflict in the region. In this study, we investigate the health of Mosul dam since Jun 2016 using three independent datasets: Sentinel-1A/B SAR images, levelling, and GPS measurement. The latter are based on three epochs of terrestrial observation for levelling and GPS data: March 2016, December 2016 and July 2017. During this period, maintenance operations are being recovered to keep the dam stable. The monitoring network, on which the levelling and GPS observations are based, consists of eighty-seven pillars distributed on the dam surface. The results from InSAR and leveling data show that the dam crest is settling by 9 mm/yr. In contrast to previous studies, our results show a deceleration in the settlement. This may be due to the maintenance operations performed in the last few months. InSAR time series analysis was performed using the in-house tool TM-SBAS. When using the small baseline Sentinel-1 constellation, all possibilities of image choice are taken into consideration and the SRTM DEM accuracy is sufficient to generate the differential interferograms. Data from both Sentinel-1A and -1B images are used, and these results can be compared with multi-platform (Envisat, Sentinel-1, Cosmo-SkyMed, and TerraSar-X) data collected during the period between March 2003 and September 2016.

5. decennial inspection of Tignes dam. Draining of the higher french dam; 5. inspection decennale du barrage de Tignes. Vidange du plus haut barrage de France

Energy Technology Data Exchange (ETDEWEB)

NONE

2000-03-01

This document deals with the 5. decennial inspection of the Tignes dam. The Tignes dam has been drained to allow EDF and the public authorities to verify the dam wall, of 180 m high, in order to validate the next decade. The four steps of the drainage are described as the maintenance policy of such building. (A.L.B.)

Expansion at Olympic Dam

International Nuclear Information System (INIS)

Lewis, C.

1997-01-01

The Olympic Dam orebody is the 6th largest copper and the single largest uranium orebody in the world. Mine production commenced in June 1988, at an annual production rate of around 45,000 tonnes of copper and 1,000 tonnes of uranium. Western Mining Corporation announced in 1996 a proposed $1.25 billion expansion of the Olympic Dam operation to raise the annual production capacity of the mine to 200,000 tonnes of copper, approximately 3,700 tonnes of uranium, 75,000 ounces of gold and 950,000 ounces of silver by 2001. Further optimisation work has identified a faster track expansion route, with an increase in the capital cost to $1.487 billion but improved investment outcome, a new target completion date of end 1999, and a new uranium output of 4,600 tonnes per annum from that date

WAC Bennett Dam - the characterization of a crest sinkhole

Energy Technology Data Exchange (ETDEWEB)

Stewart, R.A.; Gaffran, P.C. [British Columbia Hydro, Burnaby, BC (Canada); Watts, B.D. [Klohn-Crippen Consultants Ltd., Richmond, BC (Canada); Sobkowicz, J.C. [Thurber Engineering Ltd., Vancouver, BC (Canada); Kupper, A.G. [AGRA Earth and Environmental, Edmonton, AB (Canada)

1998-11-01

In June, 1996, a small hole was discovered in the asphaltic concrete road on the crest of the 183 m high WAC Bennett Dam on the Peace River in northeastern British Columbia. Examination of the hole resulted in a sinkhole on the dam crest. The sinkhole was 2.5 m in diameter and 7 m deep. Speculation was that the cavity was likely associated in some way with a buried survey benchmark tube. An investigation was immediately planned and executed to characterize the sinkhole, to determine the extent of damage and the safety status of this very large dam. British Columbia`s Dam Safety Regulator made the decision to lower the reservoir level. During the reservoir drawdown, various surface geophysical techniques were used to investigate the condition of the dam beyond the sinkholes. Intrusive investigations of the sinkhole were also planned. This involved trial drilling and downhole geophysical surveys in intact portions of the core at locations far from the sinkhole. The objectives and criteria developed for the investigation program are summarized. Scope of key activities at the sinkhole and important lessons learned during the investigation are also described. 9 refs., 15 figs.

Characteristics of transplacental lead transfer in rat dams and fetuses

International Nuclear Information System (INIS)

Kopfler, F.C.; Miller, R.G.; Kowal, N.E.; Kelty, K.C.; Doerger, J.U.; Mills, T.

1987-01-01

This study was designed to quantitate the dose resulting from lead exposure during the critical periods of brain development during gestation by determining: (1) if blood lead concentration in rat dams is affected by pregnancy status or duration of lead exposure, (2) if lead concentration in fetuses is associated with the duration of dam exposure, (3) the rates of lead absorption and elimination in pregnant and nonpregnant dams; and (4) the effect that prebreeding exposure on lead kinetics in the dam and upon fetus blood lead concentrations. The results of experiments in which the dams' drinking water contained 50 mg/L lead indicate blood lead levels (after normalizing by water consumption on a body weight basis) of pregnant rats are significantly higher than blood lead levels of non-pregnant rats. Statistical differences in blood lead levels were observed by day 15 of gestation and continue through day 20 of gestation. These blood lead differences are not due to lead treatment prior to breeding as seen when comparing Figure 1 and Figure 2. The blood lead levels of the fetuses at day 20 of gestation were 50-60% higher than that of the corresponding dams. The results from the latter two phases were ambiguous, due to large variability in individual animal absorption and elimination rates. However, the following observations can be made. Preexposure to lead does not affect the percent of lead transferred from the dams' blood to the fetuses. The rate of elimination of lead from the dams' blood does not appear to be affected by prebreeding exposure to lead or by the status of pregnancy. The fraction of the 203 Pb dose transferred to the fetus increases dramatically toward the end of gestation. The data suggest that lead absorption from the gut of pregnant rats is higher than that for nonpregnant rats

Influence of check dams on debris-flow run-out intensity

Directory of Open Access Journals (Sweden)

A. Remaître

2008-12-01

Full Text Available Debris flows are very dangerous phenomena claiming thousands of lives and millions of Euros each year over the world. Disaster mitigation includes non-structural (hazard mapping, insurance policies, active structural (drainage systems and passive structural (check dams, stilling basins countermeasures. Since over twenty years, many efforts are devoted by the scientific and engineering communities to the design of proper devices able to capture the debris-flow volume and/or break down the energy. If considerable theoretical and numerical work has been performed on the size, the shape and structure of check dams, allowing the definition of general design criteria, it is worth noting that less research has focused on the optimal location of these dams along the debris-flow pathway.

In this paper, a methodological framework is proposed to evaluate the influence of the number and the location of the check dams on the reduction of the debris-flow intensity (in term of flow thickness, flow velocity and volume. A debris-flow model is used to simulate the run-out of the debris flow. The model uses the Janbu force diagram to resolve the force equilibrium equations; a bingham fluid rheology is introduced and represents the resistance term. The model has been calibrated on two muddy debris-flow events that occurred in 1996 and 2003 at the Faucon watershed (South French Alps.

Influence of the check dams on the debris-flow intensity is quantified taking into account several check dams configurations (number and location as input geometrical parameters. Results indicate that debris-flow intensity is decreasing with the distance between the source area and the first check dams. The study demonstrates that a small number of check dams located near the source area may decrease substantially the debris-flow intensity on the alluvial fans.

Intergarted geophysical investigations by GPR and ERT on the largest rock fill dam in Europe: Monte Cotugno dam (Southern Italy)

Science.gov (United States)

Loperte, A.; Bavusi, M.; Cerverizzo, G.; Lapenna, V.; Soldovieri, F.

2012-04-01

This work is concerned with the first results of a survey based on the integration of geophysical techniques for the inspection of the Monte Cotugno dam, the largest rock fill dam in Europe. The Monte Cotugno dam, managed by National Irrigation Development and Agrarian Transformation in Puglia, Basilicata and Irpinia is located on the Sinni river (Basilicata District, South Italy) and represents the nodal point in the whole hydraulic system on the Ionic side of Italy; in fact, the dam allows harnessing of the Sinni river water for agricultural, industrial, drinking and domestic purposes. The dam is of the zoned type and consists of a central core in sandy silt and of gravelly-sandy shoulders; its water tightness is ensured by a bituminous conglomerate facing on the upstream side, welded at the bottom to the foundation sealing system. The latter is about 1,900m long and consist of a massive concrete cut-off wall based on the marly-clay formation, 300m long on the right and 600 m long on the left side. On the valley bottom it is made up of a reinforced concrete cut-off wall that is inserted in the marly-clay formation and is surmounted by an inspection and percolation water collection tunnel. The watertight face consists of a bottom levelling layer 7-8 cm thick in semi open-graded bituminous concrete, a 5 cm separation layer in dense-graded bituminous concrete, a drainage layer in very open-graded concrete varying in thickness from 10 to 16 cm from the top of the dam down, two 4-cm top layers in dense-graded bituminous concrete with stepped joints, a finishing sealing coat containing 1.5 kg/cm2 of asphalt. The shallowest part of this layering is started to show incipient small detachments due to thermal solicitations; these detachments represent a possible way for water infiltration in the dam. In this framework, it was decided to perform the identification, characterization and evaluation of the potential loss of water through small cracks in the bituminous concrete

Investigation of seepage under the Wenxiakou dam using radiotracer

International Nuclear Information System (INIS)

Li Zhangsu

1988-01-01

This paper describes the result of seepage observation on the dam foundation of Wenxiakou Reservoir using radioactive NaI (I-131) as a tracer. The main feature of the observing technique is to ascertain the seepages between the dam foundation and the clay core wall and around the abutment by measuring vertical flow. The results obtained from the observation have provided some important information for planning the engineering project of anti-seepage and reinforcement of the dam foundation and its right abutment. (author). 2 refs, 4 figs, 1 tab

Skyscraper dams in Yunnan : China's new electricity generator should step in

Energy Technology Data Exchange (ETDEWEB)

Ryder, G.

2006-05-12

The construction of a series of high-head hydroelectric power dams in China's earthquake-prone Yunnan province has raised concerns in China's scientific and environmental communities. The series of skyscraper-high dams are being built to meet Beijing's power production targets without the benefit of market discipline or effective regulatory oversight. Dam building is central to Beijing's plan for tripling the country's hydropower production by 2020. To meet that target, the State Council granted exclusive development rights to Hydrolancang, the Yunnan Huadian Nu River Hydropower Development Company and the Three Gorges Corporation. The Hydrolancang company is building 2 of the world's tallest and most controversial hydro dams on the Lancang River. When completed in 2012, Xiaowan will be the world's tallest arch dam at 292 metres high. Another dam, the 254 metre high Nuozhadu dam is expected to start generating power in 2017. In addition, there are plans for 13 other high dams along the Nu River, one of only 2 major rivers in China that remains free-flowing. This document expressed that China's new electricity regulator should initiate a full-cost review of state dam-building in the earthquake-prone province. It was argued that as state-owned power companies, the dam builders are not market-driven and are shielded from many of the financial risks and environmental liabilities associated with large dams. The author argued that China's electricity regulator should examine the dam builders' projects costs and profits and review the economic implications of the hydro policy for China's power consumers. It was also suggested that the country's modernization goals for the power industry should be reviewed. The immediate concerns are ecological damage and the frequency with which Yunnan province is hit by earthquakes, rock falls and landslides. Experts caution that the extra weight of the high dams and reservoirs

The Influence of Dams on Malaria Transmission in Sub-Saharan Africa.

Science.gov (United States)

Kibret, Solomon; Wilson, G Glenn; Ryder, Darren; Tekie, Habte; Petros, Beyene

2017-06-01

The construction of dams in sub-Saharan Africa is pivotal for food security and alleviating poverty in the region. However, the unintended adverse public health implications of extending the spatial distribution of water infrastructure are poorly documented and may minimize the intended benefits of securing water supplies. This paper reviews existing studies on the influence of dams on the spatial distribution of malaria parasites and vectors in sub-Saharan Africa. Common themes emerging from the literature were that dams intensified malaria transmission in semi-arid and highland areas with unstable malaria transmission but had little or no impact in areas with perennial transmission. Differences in the impacts of dams resulted from the types and characteristics of malaria vectors and their breeding habitats in different settings of sub-Saharan Africa. A higher abundance of a less anthropophilic Anopheles arabiensis than a highly efficient vector A. gambiae explains why dams did not increase malaria in stable areas. In unstable areas where transmission is limited by availability of water bodies for vector breeding, dams generally increase malaria by providing breeding habitats for prominent malaria vector species. Integrated vector control measures that include reservoir management, coupled with conventional malaria control strategies, could optimize a reduction of the risk of malaria transmission around dams in the region.

Surveillance of medium-size dams; Surveillance des barrages de taille moyenne

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-12-31

French hydro-power buildings belong to the government and are retroceded by the licence holder when the granting delay comes to an end. Experience has shown that less care is given by licence holders to the maintenance of medium-size dams that to big dams. For this reason, the French Ministry of Industry decided to harmonize and standardize the surveillance practices of medium-size dams. A circular was signed on May 23, 1997 which concerns the 10 to 20 m height dams with water reservoir volumes lower than the H{sup 2} x V{sup 0.5} criterion which is an evaluation of the potential risk of the dam. The surveillance modalities concern: the construction, the licence holder file, the first filling up, the operation, and the periodical safety inspections. (J.S.)

National Dam Inspection Program. Bentleyville Dam (NDI ID Number PA- 1096, DER ID Number 63-49), Ohio River Basin, Tributary North Branch Pigeon Creek, Washington County, Pennsylvania. Phase I Inspection Report

Science.gov (United States)

1981-06-01

controlled manner.V The Bentleyville Dam is a significant hazard-small size dam. TK2 recommended spillway design flood (SDF) for a dam of this size and...the dam was completed in 1938. 9. Evaluation. No major deficiencies were observed during the inspection which were considered as having an immediate

Will river erosion below the Three Gorges Dam stop in the middle Yangtze?

Science.gov (United States)

Lai, X.; Yin, D.; Finlayson, B. L.; Wei, T.; Li, M.; Yuan, W.; Yang, S.; Dai, Z.; Gao, S.; Chen, Z.

2017-11-01

The environmental impact of the Three Gorges Dam has been a subject of vigorous academic, political and social debate since its inception. This includes the key issue of post-dam river channel erosion, which was predicted by the feasibility study to extend to the river mouth. In this paper we examine the geomorphic response of the channel of the middle Yangtze for 660 km downstream of the dam. Using data on channel characteristics, bed material and sediment transport, we show that in the decade following the dam closure, pre-dam seasonal erosion has been replaced by year-round erosion, a pattern most marked at the upstream end of the study area. The sediment carrying capacity of the river channel has been largely reduced below the dam. The locus of bed scour has moved progressively downstream, ceasing as the bed material became too coarse to be transported (e.g. D50: 0.29 mm pre-dam coarsened to 20 mm below the dam by 2008). About 400 km below the dam there is a reduction in channel slope that changes the sediment carrying capacity from 0.25 kg m-3 to only about 0.05 kg m-3, which is insufficient to move bed sediment. The new long-term hydro-morphological equilibrium that will be established in this section of the middle Yangtze will prevent the further incision downstream initiated by the Three Gorges Dam. The results suggest that the full extent of adverse environmental impact predicted by the pre-dam studies will not eventuate.

Comparison of HEC-RAS with FLDWAV and DAMBRK models for dam break analysis

Energy Technology Data Exchange (ETDEWEB)

Zhou, R.D.; Judge, D.G.; Donnelly, C.R. [Acres International Ltd., Niagara Falls, ON (Canada)

2004-09-01

Dam break analysis is conducted as a routine dam safety assessment in determining the incremental hazard potential (IHP) that would occur in the event of a dam failure. Dam safety analysis also provides the information needed to make flood inundation maps and emergency preparedness plans (EPP) for dams that present a risk to human safety. For several years, the standard programs that have been used by the national weather service (NWS) for dam break flood simulation were the FLDWAV and DAMBRK models. However, another popular hydraulic model has been introduced. The HEC-RAS is an upgraded version of the former HEC-2 model used for the assessment of river floodplain inundation. A dam break analysis module has been added to HEC-2 and renamed the HEC-RAS which offers similar modeling capabilities to the DAMBRK and FLDWAV models for simulating flood hydrographs and flood wave propagation in river channels located downstream of a breached dam. The use of the alternative HEC-RAS could save time and resources. As such, it has the potential to replace the FLDWAV and DAMBRK. This paper compares the HEC-RAS dam break module with the FLDWAV and DAMBRK to determine if the new module accurately represents the dam break flood process. The comparison focuses on the theoretical background of the models, numerical solution techniques, ease of use of the module, modeling accuracy, practical aspects in performing dam break simulations, and capability for coupling the models with GIS for inundation mapping. The advantages and disadvantages of each model were summarized. 19 refs., 5 figs.

Temporary Restoration of Bull Trout Passage at Albeni Falls Dam

Energy Technology Data Exchange (ETDEWEB)

Paluch, Mark; Scholz, Allan; McLellan, Holly [Eastern Washington University Department of Biology; Olson, Jason [Kalispel Tribe of Indians Natural Resources Department

2009-07-13

This study was designed to monitor movements of bull trout that were provided passage above Albeni Falls Dam, Pend Oreille River. Electrofishing and angling were used to collect bull trout below the dam. Tissue samples were collected from each bull trout and sent to the U. S. Fish and Wildlife Service Abernathy Fish Technology Center Conservation Genetics Lab, Washington. The DNA extracted from tissue samples were compared to a catalog of bull trout population DNA from the Priest River drainage, Lake Pend Oreille tributaries, and the Clark Fork drainage to determine the most probable tributary of origin. A combined acoustic radio or radio tag was implanted in each fish prior to being transported and released above the dam. Bull trout relocated above the dam were able to volitionally migrate into their natal tributary, drop back downstream, or migrate upstream to the next dam. A combination of stationary radio receiving stations and tracking via aircraft, boat, and vehicle were used to monitor the movement of tagged fish to determine if the spawning tributary it selected matched the tributary assigned from the genetic analysis. Seven bull trout were captured during electrofishing surveys in 2008. Of these seven, four were tagged and relocated above the dam. Two were tagged and left below the dam as part of a study monitoring movements below the dam. One was immature and too small at the time of capture to implant a tracking tag. All four fish released above the dam passed by stationary receivers stations leading into Lake Pend Oreille and no fish dropped back below the dam. One of the radio tags was recovered in the tributary corresponding with the results of the genetic test. Another fish was located in the vicinity of its assigned tributary, which was impassable due to low water discharge at its mouth. Two fish have not been located since entering the lake. Of these fish, one was immature and not expected to enter its natal tributary in the fall of 2008. The other

Information collection and processing of dam distortion in digital reservoir system

Science.gov (United States)

Liang, Yong; Zhang, Chengming; Li, Yanling; Wu, Qiulan; Ge, Pingju

2007-06-01

The "digital reservoir" is usually understood as describing the whole reservoir with digital information technology to make it serve the human existence and development furthest. Strictly speaking, the "digital reservoir" is referred to describing vast information of the reservoir in different dimension and space-time by RS, GPS, GIS, telemetry, remote-control and virtual reality technology based on computer, multi-media, large-scale memory and wide-band networks technology for the human existence, development and daily work, life and entertainment. The core of "digital reservoir" is to realize the intelligence and visibility of vast information of the reservoir through computers and networks. The dam is main building of reservoir, whose safety concerns reservoir and people's safety. Safety monitoring is important way guaranteeing the dam's safety, which controls the dam's running through collecting the dam's information concerned and developing trend. Safety monitoring of the dam is the process from collection and processing of initial safety information to forming safety concept in the brain. The paper mainly researches information collection and processing of the dam by digital means.

MacDonald Dam reconstruction : using roller-compacted concrete

Energy Technology Data Exchange (ETDEWEB)

O' Neil, E. [AMEC Earth and Environmental Ltd., Sydney, NS (Canada)

2007-04-01

Located in Nova Scotia, the MacDonald Dam was commissioned in 1928. The dam consists of a 122 metre-long, 16 metre-high concrete structure comprised of an intake structure, stoplog openings, and a 34 metre-long free-overflow spillway. A 488 metre-long power canal was added as an upgrade in the 1950s. This paper provided details of the roller-compact concrete (RCC) used in the dam's recent rehabilitation following a dam failure analysis in 2003 by Nova Scotia Power Inc. RCC was chosen to help keep the dam's construction project on schedule. The layout and cross-section of the spillway was selected with consideration given to the RCC placing operation. A lift thickness of 0.20 m was selected. A formed ogee crest consisting of conventional reinforced concrete was constructed on top of the RCC. The downstream steps of the spillway were also covered with cast-in-place concrete. A low level sluice was designed to resist the weight of the wet RCC. The design compressive strength of the RCC was 20 MPa. The forms used to support the cast-in-place facing concrete on the upstream face of the dam were constructed full height and were braced back to the downstream face of the existing concrete structure prior to the start of RCC placement. Formwork inserts were placed in the facing concrete as construction progressed. Crack inducers were pre-placed on the forms. Aggregates from a local source were transported to a pug mill as the RCC construction progressed. The RCC was spread into 0.20 m lifts using a small bull-dozer, and the facing concrete was vibrated into the lift below. RCC lifts were compacted using a 9 tonne vibratory drum roller. The RCC placing operation was completed over a period of 10 days. Following the completion of the RCC portion of the dam, the remainder of the cast-in-place concrete was completed. It was concluded that the RCC provided a durable, low-maintenance structure that was completed at a lower price and in a shorter time-frame than

Dam break flood wave under different reservoir's capacities and ...

Indian Academy of Sciences (India)

Farhad Hooshyaripor

2017-07-14

Jul 14, 2017 ... Dam failure has been the subject of many hydraulic engineering studies due to its ... the role of the side slopes on dam break flood wave, such that lower side slope ... improve the inputs and advance our knowledge about the.

Heavy metal contamination of water and fish in peri-urban dams ...

African Journals Online (AJOL)

Heavy metals were measured in water, sediment and fish in dams located downstream of effluent discharge zones in Bulawayo and were compared to those in a pristine upstream dam. Water conductivity indicated pollution of downstream dams. Levels of lead (0.13 – 0.28 ppm) and cadmium (0.02 – 0.06 ppm) in water from ...

A microwave inverse Cerenkov Accelerator (MICA)

International Nuclear Information System (INIS)

Hirshfield, Jay L.

1999-01-01

The objective of this Phase II SBIR research program was to complete the final design originated during Phase I for a prototype Microwave Inverse Cerenkov Accelerator (MICA), to fabricate the-prototype MICA, and to test its performance as an electron accelerator. This report contains details of the design, predictions of accelerator performance, results of cold tests on the MICA structure, and details of the installation of MICA on the Yale Beam Physics Laboratory 6-MeV beamline. Discussion of future work is also included

Estimated strength of shear keys in concrete dams

Energy Technology Data Exchange (ETDEWEB)

Curtis, D.D. [Hatch Energy, Niagara Falls, ON (Canada); Lum, K.K.Y. [BC Hydro, Burnaby, BC (Canada)

2008-07-01

BC Hydro requested that Hatch Energy review the seismic stability of Ruskin Dam which was constructed in 1930 at Hayward Lake in British Columbia. The concrete gravity dam is founded nearly entirely on rock in a narrow valley. The vertical joints between blocks are keyed and grouted. The strength of the shear keys was assessed when a non-linear finite element model found that significant forces were being transferred laterally to the abutments during an earthquake. The lateral transfer of loads to the abutment relies on the strength of the shear keys. The dynamic finite element analysis was used to determine the stability of the dam. A review of the shear strength measurements reported in literature showed that the measurements compared well to those obtained by BC Hydro from cores taken from Ruskin Dam. The cohesive strength obtained using the Griffith failure criteria was also in good agreement with both sets of measurements. A simple ultimate shear strength equation was developed using the Mohr-Coulomb failure criteria to determine combined cohesive and frictional strength of shear keys. Safety factors of 2.0 for static loads and 1.5 for seismic loads were proposed to reduce the ultimate strength to allowable values. It was concluded that given the relatively high shear strength established for the shear keys, the abutment rock or dam/abutment contact will control the amount of load which can arch to the abutments. 8 refs., 4 tabs., 5 figs.

Wynoochee Dam Foundation Report

Science.gov (United States)

1988-01-01

schists and in propylitized andesite volcanic rocks. Tests on chlorite-bearing graywackes (Lumni Island and Robe Quarry, Seattle District) and... propylitized chlorite-bearing andesites (Blue River and Lookout Point Dams, Portland District) have shown these rocks to be durable materials with only minor