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Sample records for caissons

  1. Dynamic stiffness of suction caissons

    DEFF Research Database (Denmark)

    Ibsen, Lars Bo; Liingaard, Morten; Andersen, Lars

    The purpose of this report is to evaluate the dynamic soil-structure interaction of suction caissons for offshore wind turbines. The investigation is limited to a determination of the vertical dynamic stiffness of suction caissons. The soil surrounding the foundation is homogenous with linear...... viscoelastic properties. The dynamic stiffness of the suction caisson is expressed by dimensionless frequency-dependent dynamic stiffness coefficients corresponding to the vertical degree of freedom. The dynamic stiffness coefficients for the foundations are evaluated by means of a dynamic three...

  2. Dynamic stiffness of suction caissons

    DEFF Research Database (Denmark)

    Ibsen, Lars Bo; Liingaard, Morten; Andersen, Lars

    This report concerns the dynamic soil-structure interaction of steel suction caissons applied as foundations for offshore wind turbines. An emphasis is put on torsional vibrations and coupled sliding/rocking motion, and the influence of the foundation geometry and the properties of the surrounding...... soil is examined. The soil is simplified as a homogenous linear viscoelastic material and the dynamic stiffness of the suction caisson is expressed in terms of dimensionless frequency-dependent coefficients corresponding to the different degrees of freedom. The dynamic stiffness coefficients...... for the skirted foundation are evaluated by means of a three-dimensional coupled boundary element/finite element model. Comparisons with known analytical and numerical solutions indicate that the static and dynamic behaviour of the foundation are predicted accurately with the applied model. The analysis has been...

  3. Impedance of flexible suction caissons

    DEFF Research Database (Denmark)

    Liingaard, Morten; Andersen, Lars; Ibsen, Lars Bo

    2007-01-01

    The dynamic response of offshore wind turbines is affected by the properties of the foundation and the subsoil. The aim of this paper is to evaluate the dynamic soil-structure interaction of suction caissons for offshore wind turbines. The investigations include evaluation of the vertical...... and coupled sliding-rocking vibrations, influence of the foundation geometry and examination on the properties of the surrounding soil. The soil is simplified as a homogenous linear viscoelastic material and the dynamic stiffness of the suction caisson is expressed in terms of dimensionless frequency...... behaviours of the foundation are predicted accurately using the applied model. The analysis has been carried out for different combinations of the skirt length, Poisson's ratio of the subsoil and the ratio of the soil stiffness to the skirt stiffness....

  4. Experimental Investigation on Caisson Breakwater Sliding

    DEFF Research Database (Denmark)

    Ruol, Piero; Martin, Paolo; Andersen, Thomas Lykke

    2014-01-01

    This note presents wave flume experiments, carried out at Aalborg University, measuring the horizontal sliding distance of a vertical breakwater in 1:40 scale. Horizontal and uplift wave induced pressures were accurately measured simultaneously with the caisson movements. Caissons of different we...

  5. Suction caissons subjected to monotonic combined loading

    DEFF Research Database (Denmark)

    Penzes, P.; Jensen, M.R.; Zania, Varvara

    2016-01-01

    for offshore wind turbines. The combined loading imposed typically to a suction caisson has led to the estimation of their bearing capacity by means of 3D failure envelopes. This study aims to analyse the behaviour of suction caissons for offshore wind turbines subjected to combined loading. Finite element...

  6. Dynamic lateral response of suction caissons

    DEFF Research Database (Denmark)

    Latini, Chiara; Zania, Varvara

    2017-01-01

    Deeper water installations of offshore wind turbines may be supported by jacket structures. This study investigates the dynamic response of suction caissons for jackets by analysing 3D finite element models in the frequency domain. The numerical modelling was firstly validated by analytical...... solutions for pile foundations. Groups of crucial dimensionless parameters related to the soil profile and the foundation geometry are identified and their effects on the response of suction caissons are studied. Static stiffness coefficients are presented in a form of mathematical formulas obtained...... by fitting the numerical results, pertaining foundations with different slenderness ratios and embedded in different soil profiles. Sensitivity of the dynamic impedances of suction caissons on the skirt length was showed in this study. Moreover, the results for the suction caissons indicated that the overall...

  7. Dynamic behaviour of suction caissons

    Energy Technology Data Exchange (ETDEWEB)

    Liingaard, M.

    2006-12-15

    Offshore wind energy is a promising source of energy in the near future, and is rapidly becoming competitive with other power generating technologies. The continuous improvement in wind turbine technology means that the wind turbines have increased tremendously in both size and performance during the last 25 years. In order to reduce the costs, the overall weight of the wind turbine components is minimized, which means that the wind turbine structures become more flexible and thus more sensitive to dynamic excitation. Since the first resonance frequency of the modern offshore wind turbines is close to the excitation frequencies of the rotor system, it is of outmost importance to be able to evaluate the resonance frequencies of the wind turbine structure accurately as the wind turbines increase in size. In order to achieve reliable responses of the wind turbine structure during working loads it is necessary to account for the possibilities of dynamic effects of the soil-structure interaction. The aim of this thesis is to evaluate the dynamic soil-structure interaction of foundations for offshore wind turbines, with the intention that the dynamic properties of the foundation can be properly included in a composite structure-foundation system. The work has been focused on one particular foundation type; the suction caisson. The frequency dependent stiffness (impedance) of the suction caisson has been investigated by means of a three-dimensional coupled Boundary Element/Finite Element model, where the soil is simplified as a homogenous linear viscoelastic material. The dynamic stiffness of the suction caisson is expressed in terms of dimensionless frequencydependent coefficients corresponding to the different degrees of freedom. Comparisons with known analytical and numerical solutions indicate that the static and dynamic behaviour of the foundation are predicted accurately with the applied model. The analysis has been carried out for different combinations of the

  8. Structural damage monitoring of harbor caissons with interlocking condition

    Energy Technology Data Exchange (ETDEWEB)

    Huynh, Thanh Canh; Lee, So Young; Nauyen, Khac Duy; Kim, Jeong Tae [Pukyong National Univ., Busan (Korea, Republic of)

    2012-12-15

    The objective of this study is to monitor the health status of harbor caissons which have potential foundation damage. To obtain the objective, the following approaches are performed. Firstly, a structural damage monitoring(SDM) method is designed for interlocked multiple caisson structures. The SDM method utilizes the change in modal strain energy to monitor the foundation damage in a target caisson unit. Secondly, a finite element model of a caisson system which consists of three caisson units is established to verify the feasibility of the proposed method. In the finite element simulation, the caisson units are constrained each other by shear key connections. The health status of the caisson system against various levels of foundation damage is monitored by measuring relative modal displacements between the adjacent caissons.

  9. D Digital Simulation of Minnan Temple Architecture CAISSON'S Craft Techniques

    Science.gov (United States)

    Lin, Y. C.; Wu, T. C.; Hsu, M. F.

    2013-07-01

    Caisson is one of the important representations of the Minnan (southern Fujian) temple architecture craft techniques and decorative aesthetics. The special component design and group building method present the architectural thinking and personal characteristics of great carpenters of Minnan temple architecture. In late Qing Dynasty, the appearance and style of caissons of famous temples in Taiwan apparently presented the building techniques of the great carpenters. However, as the years went by, the caisson design and craft techniques were not fully inherited, which has been a great loss of cultural assets. Accordingly, with the caisson of Fulong temple, a work by the well-known great carpenter in Tainan as an example, this study obtained the thinking principles of the original design and the design method at initial period of construction through interview records and the step of redrawing the "Tng-Ko" (traditional design, stakeout and construction tool). We obtained the 3D point cloud model of the caisson of Fulong temple using 3D laser scanning technology, and established the 3D digital model of each component of the caisson. Based on the caisson component procedure obtained from interview records, this study conducted the digital simulation of the caisson component to completely recode and present the caisson design, construction and completion procedure. This model of preserving the craft techniques for Minnan temple caisson by using digital technology makes specific contribution to the heritage of the craft techniques while providing an important reference for the digital preservation of human cultural assets.

  10. Dynamic stiffness of horizontally vibrating suction caissons

    DEFF Research Database (Denmark)

    Latini, Chiara; Zania, Varvara; Cisternino, Michele

    2016-01-01

    The promising potential for offshore wind market is on developing wind farms in deeper waters with bigger turbines. In deeper waters the design foundation configuration may consist of jacket structures supported by floating piles or by suction caissons. Taking the soil-structure interaction effects...... of this type of foundation using the finite element method (FEM) to account for the interaction with the soil. 3D numerical models for both the soil and the suction caisson are formulated in a frequency domain. The response of the soil surrounding the foundation is considered linear viscoelastic...... with hysteretic type damping. In addition, non-reflective boundaries are included in the model. Two different soil profiles are presented, one when the rigid bedrock is set close to the seabed and the other one when it is far away. The dynamic impedances at the top of the foundation are determined and compared...

  11. Dynamic stiffness of suction caissons - vertical vibrations

    Energy Technology Data Exchange (ETDEWEB)

    Ibsen, Lars Bo; Liingaard, M.; Andersen, Lars

    2006-12-15

    The dynamic response of offshore wind turbines are affected by the properties of the foundation and the subsoil. The purpose of this report is to evaluate the dynamic soil-structure interaction of suction caissons for offshore wind turbines. The investigation is limited to a determination of the vertical dynamic stiffness of suction caissons. The soil surrounding the foundation is homogenous with linear viscoelastic properties. The dynamic stiffness of the suction caisson is expressed by dimensionless frequency-dependent dynamic stiffness coefficients corresponding to the vertical degree of freedom. The dynamic stiffness coefficients for the foundations are evaluated by means of a dynamic three-dimensional coupled Boundary Element/Finite Element model. Comparisons are made with known analytical and numerical solutions in order to evaluate the static and dynamic behaviour of the Boundary Element/Finite Element model. The vertical frequency dependent stiffness has been determined for different combinations of the skirt length, Poisson's ratio and the ratio between soil stiffness and skirt stiffness. Finally the dynamic behaviour at high frequencies is investigated. (au)

  12. Design of Vertical Wall Caisson Breakwaters using Partial Safety Factors

    DEFF Research Database (Denmark)

    Burcharth, H. F.; Sørensen, John Dalsgaard

    1999-01-01

    The paper presents a new system for implementation of target reliability in caisson breakwater designs by means of partial safety factors. The development of the system is explained, and tables of partial safety factors are presented for important overall stability failure modes related to caisso...

  13. Computer tomography in Caisson's disease

    Energy Technology Data Exchange (ETDEWEB)

    Horvath, F.; Csobaly, S.

    1981-07-01

    Computer tomography was performed on 20 patients with the early stages of Caisson osteoarthropathy, as well as in other patients with chronic bone infarcts. From their results the authors have formed the opinion that CT is valuable, not only in the diagnosis of early cases, but that it can provide significant information concerning the osteopathy and bone infarcts.

  14. 3D DIGITAL SIMULATION OF MINNAN TEMPLE ARCHITECTURE CAISSON'S CRAFT TECHNIQUES

    Directory of Open Access Journals (Sweden)

    Y. C. Lin

    2013-07-01

    Full Text Available Caisson is one of the important representations of the Minnan (southern Fujian temple architecture craft techniques and decorative aesthetics. The special component design and group building method present the architectural thinking and personal characteristics of great carpenters of Minnan temple architecture. In late Qing Dynasty, the appearance and style of caissons of famous temples in Taiwan apparently presented the building techniques of the great carpenters. However, as the years went by, the caisson design and craft techniques were not fully inherited, which has been a great loss of cultural assets. Accordingly, with the caisson of Fulong temple, a work by the well-known great carpenter in Tainan as an example, this study obtained the thinking principles of the original design and the design method at initial period of construction through interview records and the step of redrawing the "Tng-Ko" (traditional design, stakeout and construction tool. We obtained the 3D point cloud model of the caisson of Fulong temple using 3D laser scanning technology, and established the 3D digital model of each component of the caisson. Based on the caisson component procedure obtained from interview records, this study conducted the digital simulation of the caisson component to completely recode and present the caisson design, construction and completion procedure. This model of preserving the craft techniques for Minnan temple caisson by using digital technology makes specific contribution to the heritage of the craft techniques while providing an important reference for the digital preservation of human cultural assets.

  15. Numerical Buckling Analysis of Large Suction Caissons for Wind Turbines on Deep Water

    DEFF Research Database (Denmark)

    Madsen, Søren; Andersen, Lars Vabbersgaard; Ibsen, Lars Bo

    2013-01-01

    the suction caisson is loaded by external pressure (internal suction) due to evacuation of water inside the bucket and vertical forces due to gravity. The risk of structural buckling during installation of large-diameter suction caissons is addressed using numerical methods. Initial imperfect geometries...

  16. 3-D Effects Force Reduction of Short-Crested Non-Breaking Waves on Caissons

    DEFF Research Database (Denmark)

    Burcharth, H. F.; Liu, Z.

    1998-01-01

    The effect of wave short-crestedness on the horizontal wave force on a caisson is twofold. The one is the force reduction due to the reduction of point pressure on the caisson, named point-pressure reduction. The other is the force reduction due to the fact that the peak pressures do not occur si...

  17. Dynamic stiffness of suction caissons - torsion, sliding and rocking

    Energy Technology Data Exchange (ETDEWEB)

    Ibsen, Lars Bo; Liingaard, M.; Andersen, Lars

    2006-12-15

    This report concerns the dynamic soil-structure interaction of steel suction caissons applied as foundations for offshore wind turbines. An emphasis is put on torsional vibrations and coupled sliding/rocking motion, and the influence of the foundation geometry and the properties of the surrounding soil is examined. The soil is simplified as a homogenous linear viscoelastic material and the dynamic stiffness of the suction caisson is expressed in terms of dimensionless frequency-dependent coefficients corresponding to the different degrees of freedom. The dynamic stiffness coefficients for the skirted foundation are evaluated by means of a three-dimensional coupled boundary element/finite element model. Comparisons with known analytical and numerical solutions indicate that the static and dynamic behaviour of the foundation are predicted accurately with the applied model. The analysis has been carried out for different combinations of the skirt length and the Poisson's ratio of the subsoil. Finally, the high-frequency impedance has been determined for future use in lumped-parameter models of wind turbine foundations in aero-elastic codes. (au)

  18. Experimental investigation on the relationship between sluice caisson shape of tidal power plant and the water discharge capability

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Dal Soo; Oh, Sang-Ho; Yi, Jin-Hak; Park, Woo-Sun [Coastal Engineering and Ocean Energy Research Department, Korea Ocean Research and Development Institute, Ansan 426-744 (Korea); Cho, Hyu-Sang; Kim, Duk-Gu; Ahn, Suk-Jin [Technology Research and Development Institute, Hyein E and C Co. Ltd., Seoul 157-861 (Korea); Eom, Hyun-Min [Global Environment System Research Laboratory, National Institute of Meteorological Research/KMA, Seoul 156-720 (Korea)

    2010-10-15

    The change of water discharge capability of the sluice caisson of tidal power plant according to the change of geometrical shape of the sluice caisson was investigated by performing laboratory experiments. The major design parameters that constitute general shape of the sluice caisson were deduced and a total of 32 different shapes of sluice caisson models were subjected to the hydraulic experiments. For every sluice caisson model, the water discharge capability was estimated with five different flow rates and three different water level conditions. The experiments were carried out in an open channel flume with a great care to measure flow rate and water level accurately, which are key physical quantities in estimating the water discharge capability of the sluice caisson models. By analyzing the experimental results, influence of the respective design parameters on the performance of the sluice caisson was examined and the general guidelines to enhance the water discharge capability were suggested. The discharge coefficient of the best sluice caisson model ranged from 2.3 to 3.1 depending on the experimental conditions, which is far higher than the values that were adopted in the past feasibility studies in Korea. (author)

  19. Analyses of Stability of Caisson Breakwaters on Rubble Foundation Exposed to Impulsive Loads

    DEFF Research Database (Denmark)

    Burcharth, Hans F.; Andersen, Lars; Andersen, Thomas Lykke

    2009-01-01

    The paper deals with the analysis of the overall stability of caisson breakwaters exposed to impulsive wave loadings, in particular regarding sliding failure and failure in the subsoil. A comparison is made between prediction of sliding distances by a simple onedimensional (1-D) dynamic analysis ...

  20. Long term effects of cyclic loading on suction caisson foundations in sand

    NARCIS (Netherlands)

    Lupea, C.; Thijssen, R.; Van Tol, A.F.

    2014-01-01

    Offshore wind turbine projects have been characterised by an increase in costs, sizes and distances from shore, EWEA 2012 This created a need of investigating the adequacy of alternative and more fìnancially attractive foundation types such as suction caissons. Within a multi-footing configuration,

  1. Three-Dimensional Model Test Study of Modified Caisson Breakwater at Port of Castellon, Spain

    DEFF Research Database (Denmark)

    Nørgaard, Jørgen Harck; Andersen, Thomas Lykke

    caisson breakwater at Port of Castellon, Spain, tested earlier (Nørgaard & Lykke Andersen, 2013). Associate Prof. Thomas Lykke Andersen and M.Sc. Jørgen Quvang Harck Nørgaard were in charge of the model tests. Engineer assistant Niels Drustrup assisted in the laboratory with the construction...

  2. Theoretical Investigation of Peak-Delay Force Reduction for Caissons Exposed to Non-breaking Short-Crested Waves

    DEFF Research Database (Denmark)

    Burcharth, H. F.; Liu, Z.

    In nature coastal structures are exposed to oblique short-crested waves. The effect of wave incident angle on total wave force on a long caisson are twofold. The one is the force reduction due to the reduction of instantaneous point pressure on the caisson, named point-pressure force reduction....... The other is the force reduction due to the fact that the peak pressures do not occur simultaneously along the caisson, named peak-delay force reduction. These two reduction effects can also be expected with short-crested waves, as the short-crestedness of waves means the spreading of wave energy over...... on the peak-delay force reduction of caissons exposed to non-breaking short-crested waves. Battjes (1982) has investigated theoretically the peak-delay force reduction of shortcrested waves with only one frequency component. Such a force reduction factor cannot be applied because in nature waves are composed...

  3. Present knowledge about Laboratory Testing of Axial Loading on Suction Caissons

    DEFF Research Database (Denmark)

    Manzotti, E.; Vaitkunaite, Evelina; Ibsen, Lars Bo

    Offshore wind turbines are increasing in both efficiency and size. More economical foundations for such light structures are under investigation, and suction caisson was shown to be particularly suitable for this purpose. In multi-pod foundation configuration, the overturning moment given by loads...... on the structure is resisted by push-pull loads on the vertical axis of each suction caisson. Relevant works where this situation is examined by means of laboratory testing are summarized in this article, then different conclusions are followed by discussion and comparison. In the initial theoretical section......, an overview of phenomena related with the case of study is presented. Drained and undrained condition, liquefaction and suction are examined from the theoretical point of view for mechanisms related to the case of study....

  4. Alternative Shape of Suction Caisson to Reduce Risk of Buckling under high Pressure

    DEFF Research Database (Denmark)

    Madsen, Søren; Andersen, Lars Vabbersgaard; Ibsen, Lars Bo

    2013-01-01

    Using large suction caissons for offshore wind turbines is an upcoming technology also referred to as bucket foundations. During operation the bucket foundation is loaded by a large overturning moment from the wind turbine and the wave loads. However, during installation the bucket is loaded...... by uniform external pressure and vertical forces. The bucket foundation does not require heavy installation equipment, but since it is constructed as a thin steel shell structure, instability, in the form of buckling, becomes a crucial issue during installation. Typically, the bucket foundation is a large...... cylindrical monopod foundation made of steel. In this paper, an alternative design/shape of the suction caisson, having a smaller risk of buckling under high pressure is presented. The risk of structural buckling is addressed using numerical methods to determine the buckling pressures of the re-designed...

  5. Wave Loading and Overtopping on Caisson Breakwaters in Multidirectional Breaking Seas

    DEFF Research Database (Denmark)

    Grønbech, J.; Hald, Tue; Frigaard, Peter

    1997-01-01

    The present paper concerns the results and findings of a physical study on wave impacts on vertical caisson breakwaters situated in irregular, multidirectional breaking seas. The study has taken place as a part of the framework programme "Dynamics of Structures" financially supported by the Danish...... Technical Research Council, during the period of January 97 to July 97. The tests were carried out in 3D wave basin at the Hydraulics and Coastal Engineering Laboratory, Aalborg University....

  6. Effect of Short-Crestedness and Obliquity on Non-Breaking and Breaking Wave Forces Applied to Vertical Caisson Breakwaters

    DEFF Research Database (Denmark)

    Martinelli, Luca; Lamberti, Alberto; Frigaard, Peter

    2007-01-01

    This paper addresses wave forces applied to vertical caisson breakwaters. Design diagrams are proposed to evaluate the reduction of the breaker wave force with increasing horizontal length of the units. A model in 1:100 scale of a typical Italian vertical breakwater was tested under multidirectio......This paper addresses wave forces applied to vertical caisson breakwaters. Design diagrams are proposed to evaluate the reduction of the breaker wave force with increasing horizontal length of the units. A model in 1:100 scale of a typical Italian vertical breakwater was tested under...

  7. Hydraulic Response of Caisson Breakwaters in Multidirectional Breaking and Non-Breaking Waves

    DEFF Research Database (Denmark)

    Grønbech, J.; Kofoed, Jens Peter; Hald, Tue

    1998-01-01

    The present paper concerns the results and findings of a physical study on wave impacts on vertical caisson breakwaters situated in irregular, multidirectional breaking seas. The study has taken place as part of the framework programme "Dynamic of Structures" financially supported by the Danish...... Technical Research Council, during the period of January '97 to December '97. The tests were carried out in the 3D wave basin at the Hydraulics and Coastal Engineering Laboratory, Aalborg University. The objective of the study was to asses the effects of wave obliquity and multidirectionality on the wave...

  8. Desing and construction of caissons for wave activated power generation at Haramachi thermal power plant; Haramachi karyoku hatsudensho haryoku hatsuden`yo keson no sekkei to seko

    Energy Technology Data Exchange (ETDEWEB)

    Endo, M.; Saski, A.; Otaka, M. [Tohoku Electric Power Co. Ltd., Sendai (Japan)

    1995-11-05

    At the Haramachi thermal power plant, demonstration tests are planned for the water valve intensive wave activated power generation system which utilizes a part of the caisson composite breakwater of the south breakwater. Power is generated by combining a 130KW rated output power generating system to the caisson for wave activated generation, and power is sent to a 6KV power system to collect and analyze the basic data in actual sea area, verify the efficiency of each member, verify the rectification effect of water valves, and verify power generation and as system interconnection characteristics. A report is made on the establishment of the basic form of the wave force caisson, design method, result of hydraulic model test, fabricating method, and the processes. The fabrication of the wave force caisson started in 1994, and completed with the fabrication made on land and on sea. The construction joint of two wave force caissons on the sea has been completed and cured on a temporary placing mound, and compaction of the wave force caisson foundation mound is now underway. The installation is scheduled to start in November, 1995, and the verification test is expected to be made from 1996. 4 refs., 18 figs., 4 tabs.

  9. Special Foundation by means of reinforced-concrete caisson in Valencia Port; Cimentaciones especiales de los cajones del Muello Este. Puerto de Valencia

    Energy Technology Data Exchange (ETDEWEB)

    Gama Costa, P. M.

    2010-07-01

    This paper describes the process to construct a foundation by means of reinforced-concrete caisson on breakwaters. the project required to develop minimal dredging solutions as well as to improve the foundation areas of the what caissons. The improvement technique applied to the foundation area was based on gravel columns, since this solution was the most suitable for areas with high fine fraction contents, as it was the case. Gravel columns were executed following a bottom-feed method, and two different techniques: gravel tank top-feeding and gravel pumping. (Author)

  10. Chapter 4: Pulsating Wave Loads Section 4.3: 3D Effects Force Reduction of Short-Crested Non-Breaking Waves on Caissons

    DEFF Research Database (Denmark)

    Burcharth, Hans F.; Liu, Zhou

    1999-01-01

    simultaneously along the caisson, named peak-delay reduction. Model test results indicate that the point-pressure reduction can be predicted by the Goda formula. Based on linear wave theory, Battjes (1982) presented a formula for the peak-delay force reduction of short-crested waves with only one frequency...... ion of peakdelay force reduction factor for oblique long-crested and short-crested non-breaking waves are derived analytically. Theoretical formula for the maximum non-dimensional horizontally turning moment around the center of the caisson by oblique regular waves is also presented. Finally the paper...... gives a summary of the model test results on the force reduction of non-breaking and breaking short-crested waves....

  11. H-M bearing capacity of a modified suction caisson determined by using load-/displacement-controlled methods

    Science.gov (United States)

    Zhang, Yu-kun; Gao, Yu-feng; Li, Da-yong; Mahfouz, Ali H.

    2016-12-01

    This paper presents a series of monotonically combined lateral loading tests to investigate the bearing capacity of the MSCs (modified suction caissons) in the saturated marine fine sand. The lateral loads were applied under load- and displacement-controlled methods at the loading eccentricity ratios of 1.5, 2.0 and 2.5. Results show that, in the displacement-controlled test, the deflection-softening behavior of load-deflection curves for MSCs was observed, and the softening degree of the load-deflection response increased with the increasing external skirt length or the decreasing loading eccentricity. It was also found that the rotation center of the MSC at failure determined by the load-controlled method is slightly lower than that by the displacement-controlled method. The calculated MSC capacity based on the rotation center position in serviceability limit state is relatively conservative, compared with the calculated capacity based on the rotation center position in the ultimate limit state. In the limit state, the passive earth pressures opposite the loading direction under load- and displacement-controlled methods decrease by 46% and 74% corresponding to peak values, respectively; however, the passive earth pressures in the loading direction at failure only decrease by approximately 3% and 7%, compared with their peak values.

  12. 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

    Energy Technology Data Exchange (ETDEWEB)

    Tochigi, Hitoshi; Kanatani, Mamoru; Kawai, Tadashi [Central Research Inst. of Electric Power Industry, Abiko, Chiba (Japan). Abiko Research Lab

    1999-02-01

    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)

  13. Dynamic Behaviour of Suction Caissons

    DEFF Research Database (Denmark)

    Liingaard, Morten

    the last 25 years. In order to reduce the costs, the overall weight of the wind turbine components is minimized, which means that the wind turbine structures become more flexible and thus more sensitive to dynamic excitation. Since the first resonance frequency of the modern offshore wind turbines is close...... to account for the possibilities of dynamic effects of the soil-structure interaction. The aim of this thesis is to evaluate the dynamic soil-structure interaction of foundations for offshore wind turbines, with the intention that the dynamic properties of the foundation can be properly included...... to the excitation frequencies of the rotor system, it is of outmost importance to be able to evaluate the resonance frequencies of the wind turbine structure accurately as the wind turbines increase in size. In order to achieve reliable responses of the wind turbine structure during working loads it is necessary...

  14. Foundation Design of Caisson Breakwaters

    DEFF Research Database (Denmark)

    Groot, M.B. De; Andersen, K.H.; Burcharth, H. F.

    1996-01-01

    This document has been prepared as a part of the dissemination of results of the MCS-Project (Contract No. MAS2-CT92-0047) which was led by the University of Hannover (Coordinator: H. Oumeraci) within the 2nd Research Programme of the European Union (EU) on Marine and Science Technology. The supp...

  15. Monitoring the performance of an alternative cover using caisson lysimeters

    Energy Technology Data Exchange (ETDEWEB)

    Waugh, W.J.; Smith, G.M.; Mushovic, P.S.

    2004-02-29

    The U.S. Department of Energy (DOE) office in Grand Junction, Colorado, and the U.S. Environmental Protection Agency (EPA), Region 8, collaborated on a series of field lysimeter studies to design and monitor the performance of an alternative cover for a uranium mill tailings disposal cell at the Monticello, Utah, Superfund Site. Because groundwater recharge is naturally limited at Monticello in areas with thick loess soils, DOE and EPA chose to design a cover for Monticello using local soils and a native plant community to mimic this natural soilwater balance. Two large drainage lysimeters fabricated of corrugated steel culvert lined with high-density polyethylene were installed to evaluate the hydrological and ecological performance of an alternative cover design constructed in 2000 on the disposal cell. Unlike conventional, lowpermeability designs, this cover relies on (1) the water storage capacity of a 163-cm soil “sponge” layer overlying a sand-and-gravel capillary barrier to retain precipitation while plants are dormant and (2) native vegetation to remove precipitation during the growing season. The sponge layer consists of a clay loam subsoil compacted to 1.65 g/cm2 in one lysimeter and a loam topsoil compacted to 1.45 g/cm2 in the other lysimeter, representing the range of as-built conditions constructed in the nearby disposal cell cover. About 0.1 mm of drainage occurred in both lysimeters during an average precipitation year and before they were planted, an amount well below the EPA target of <3.0 mm/yr. However, the cover with less compacted loam topsoil sponge had a 40% greater water storage capacity than the cover with overly compacted clay loam subsoil sponge. The difference is attributable in part to higher green leaf area and water extraction by plants in the loam topsoil. The lesson learned is that seemingly subtle differences in soil types, sources, and compaction can result in salient differences in performance. Diverse, seeded communities of predominantly native perennial species were established on both lysimeters during an extended 3-yr drought, highlighting the importance of a sound understanding of the local ecology and of implementing the science and methods of disturbed-land revegetation.

  16. Two-Dimensional Model Test Study of the New Caisson Breakwater at Playa Blanca, Lanzarote

    DEFF Research Database (Denmark)

    Andersen, Thomas Lykke; Garborg, Karsten; Stagsted, Esben Rubech

    This report present the results of 2-D physical model tests (length scale 1:42.5) carried out in a wave flume at Department of Civil Engineering, Aalborg University (AAU) on behalf of SENER Ingenera y Sistemas S.A. Associate Prof. Thomas Lykke Andersen was in charge of the model tests, assisted b...

  17. Laboratory Setup for Vertically Loaded Suction Caisson Foundation in Sand and Validation of Responses

    DEFF Research Database (Denmark)

    Manzotti, E.; Vaitkunaite, Evelina; Ibsen, Lars Bo

    devices usually installed in farms, therefore many inexpensive foundations are needed. Suction Bucket foundations are a suitable option for this purpose, but for large scale utilization more research is required, especially for in-service performance. Size of offshore wind turbine has been increasing...... during the last years and, following this trend, design choice will turn into foundation composed of three or four suction bucket foundations, called respectively tripod and tetrapod. Overturning moment in tripod and tetrapod is carried by vertical loading; therefore vertical pull-out capacity is tested...

  18. Large Scale Experiments on the Interaction of a Caisson Breakwater with Breaking Waves

    DEFF Research Database (Denmark)

    Stagonas, Dimitris; Marzeddu, Andrea; Buccino, Mariano

    2014-01-01

    measurements were complimented with high speed and high definition video records. ln addition, a pressure mapping system employing tactile pressure sensors was deployed in cornbination with force panels, both positioned at still water level. Although at a very early stage, data analysis yields promising...

  19. Caisson Movement Caused by Wave Slamming—a Comparison of ABAQUS and FLAC Analyses

    DEFF Research Database (Denmark)

    Andersen, Lars; Burcharth, Hans F.; Andersen, Thomas Lykke

    2010-01-01

    -difference analysis has been performed by means of the commercial code FLAC. Similarly, ABAQUS has been employed for finiteelement analyses based on linear as well as quadratic spatial interpolations, assuming fully drained conditions and utilizing an elastic–plastic model for the rubble foundation and the seabed...

  20. Three-Dimensional Model Test Study on the Existing Caisson Breakwater at Port of Castellon, Spain

    DEFF Research Database (Denmark)

    Nørgaard, Jørgen Harck; Andersen, Thomas Lykke

    This report present the results of 3-D physical model tests (length scale 1:60) carried out in a wave basin at Department of Civil Engineering, Aalborg University (AAU) on behalf of the client; BP OIL ESPAÑA. Associate Prof. Thomas Lykke Andersen and M.Sc. Jørgen Quvang Harck Nørgaard were in cha...

  1. 77 FR 74193 - Request for Information on Edel-Kindwall Caisson Tables for Preventing Decompression Illness in...

    Science.gov (United States)

    2012-12-13

    ... submitting comments can be found at: http://www.regulations.gov . NIOSH includes all comments received... be formatted as Microsoft Word. Please make reference to CDC 2012-0012 and docket number NIOSH-254... projects. Compressed air is used to prevent seepage of water or to stabilize unstable soil conditions...

  2. Characterization of materials for a reactive transport model validation experiment: Interim report on the caisson experiment. Yucca Mountain Site Characterization Project

    Energy Technology Data Exchange (ETDEWEB)

    Siegel, M.D.; Cheng, W.C. [Sandia National Labs., Albuquerque, NM (United States); Ward, D.B.; Bryan, C.R. [Univ. of New Mexico, Albuquerque, NM (United States). Dept. of Earth and Planetary Sciences

    1995-08-01

    Models used in performance assessment and site characterization activities related to nuclear waste disposal rely on simplified representations of solute/rock interactions, hydrologic flow field and the material properties of the rock layers surrounding the repository. A crucial element in the design of these models is the validity of these simplifying assumptions. An intermediate-scale experiment is being carried out at the Experimental Engineered Test Facility at Los Alamos Laboratory by the Los Alamos and Sandia National Laboratories to develop a strategy to validate key geochemical and hydrological assumptions in performance assessment models used by the Yucca Mountain Site Characterization Project.

  3. 76 FR 13453 - Marine Mammals; Incidental Take During Specified Activities

    Science.gov (United States)

    2011-03-11

    ... islands, ice islands, bottom-founded structures [steel drilling caisson (SDC)], ice pads and ice roads... floating drill units; helicopter support; and drill ships such as the Steel Drilling Caisson (SDC), CANMAR...

  4. 76 FR 47009 - Marine Mammals; Incidental Take During Specified Activities

    Science.gov (United States)

    2011-08-03

    ..., bottom-founded structures [steel drilling caisson (SDC)], ice pads and ice roads; oil spill prevention... support; and drill ships such as the Steel Drilling Caisson (SDC), CANMAR Explorer III, and the Kulluk...

  5. Insight into the lateral response of offshore shallow foundations

    DEFF Research Database (Denmark)

    Barari, Amin; Ibsen, Lars Bo

    2017-01-01

    Highlights •Suction caissons are often subjected to cyclic lateral loads caused by the action of wind or waves. •Excessive lateral deformations may be induced during a caisson’s service life. •Results of performance measure parameters for caissons harmonically oscillating on homogeneous soil are ...

  6. The Importance of Pressure Sampling Frequency in Models for Determination of Critical Wave Loadingson Monolithic Structures

    DEFF Research Database (Denmark)

    Burcharth, Hans F.; Andersen, Thomas Lykke; Meinert, Palle

    2008-01-01

    This paper discusses the influence of wave load sampling frequency on calculated sliding distance in an overall stability analysis of a monolithic caisson. It is demonstrated by a specific example of caisson design that for this kind of analyses the sampling frequency in a small scale model could...... be as low as 100 Hz in model scale. However, for design of structure elements like the wave wall on the top of a caisson the wave load sampling frequency must be much higher, in the order of 1000 Hz in the model. Elastic-plastic deformations of foundation and structure were not included in the analysis....

  7. On the Evaluation of Failure Probability on Monolithic Vertical Wall Breakwaters

    DEFF Research Database (Denmark)

    Burcharth, H. F.; Sørensen, Jørgen S.; Christiani, E.

    1994-01-01

    The paper presents a level II, FORM-evaluation of the reliability against sliding of a caisson breakwater. Further, a reliability-based optimal design procedure for breakwaters exposed to multifailure mode is discussed....

  8. The Importance of Pressure Sampling Frequency in Models for Determination of Critical Wave Loadings on Monolithic Structures

    DEFF Research Database (Denmark)

    Burcharth, Hans F.; Andersen, Thomas Lykke; Meinert, Palle

    2008-01-01

    Wave induced pressures on model scale monolithic structures like caissons and concrete superstructures on rubble mound breakwaters show very peaky variations, even in cases without impacts from slamming waves....

  9. Validity of Simplified Analysis of Stability of Caison Breakwaters on Rubble Foundation Exposed to Impulsive Loads

    DEFF Research Database (Denmark)

    Andersen, Lars; Burcharth, Hans F.; Andersen, Thomas Lykke

    Excessive sliding and foundation failures are common failure modes for caisson breakwaters on rubble foundations. An accurate evaluation of these failure modes demands a dynamic analysis in the time domain, and due to the complexity of the material response, numerical solution methods must...... be applied. The waveload time series as well as elastic-plastic modelling of the seabed soil, the rubble foundation and the caisson are needed as input for such an exercise....

  10. SNF shipping cask shielding analysis

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, J.O.; Pace, J.V. III

    1996-01-01

    The Waste Management and Remedial Action Division has planned a modification sequence for storage facility 7827 in the Solid Waste Storage Area (SWSA). The modification cycle is: (1) modify an empty caisson, (2) transfer the spent nuclear fuel (SNF) of an occupied caisson to a hot cell in building 3525 for inspection and possible repackaging, and (3) return the package to the modified caisson in the SWSA. Although the SNF to be moved is in the solid form, it has different levels of activity. Thus, the following 5 shipping casks will be available for the task: the Loop Transport Carrier, the In- Pile Loop LITR HB-2 Carrier, the 6.5-inch HRLEL Carrier, the HFIR Hot Scrap Carrier, and the 10-inch ORR Experiment Removal Shield Cask. This report describes the shielding tasks for the 5 casks: determination of shielding characteristics, any streaming avenues, estimation of thermal limits, and shielding calculational uncertainty for use in the transportation plan.

  11. Application of lumped-parameter models

    DEFF Research Database (Denmark)

    Ibsen, Lars Bo; Liingaard, Morten

    This technical report concerns the lumped-parameter models for a suction caisson with a ratio between skirt length and foundation diameter equal to 1/2, embedded into an viscoelastic soil. The models are presented for three different values of the shear modulus of the subsoil (section 1.1). Subse......This technical report concerns the lumped-parameter models for a suction caisson with a ratio between skirt length and foundation diameter equal to 1/2, embedded into an viscoelastic soil. The models are presented for three different values of the shear modulus of the subsoil (section 1...

  12. Damage Accumulation in Vertical Breakwaters due to Combined Impact Loading and Pulsating Wave Loads

    DEFF Research Database (Denmark)

    Sørensen, John Dalsgaard; Nielsen, Søren R. K.

    1999-01-01

    Vertical wall breakwaters used to protect for example an harbour from large waves usually consist of large concrete caissons placed on the seabed. The wave loads can be divided in two types, pulsating and impact loads. For some types of breakwaters especially the impact wave loads can be very large...

  13. Wave Pressures on Seawave Slot-Cone Generator

    DEFF Research Database (Denmark)

    Vicinanza, Diego; Kofoed, Jens Peter; Frigaard, Peter

    2006-01-01

    This paper presents results on loading action on an innovative caisson breakwater for electricity production. The work reported here contributes to the European Union Sixth Framework programme priority 6.1 (Sustainable Energy System), contract 019831, titled "Full- scale demonstration of robust a...

  14. Prototype bucket foundation for wind turbines

    DEFF Research Database (Denmark)

    Ibsen, Lars Bo; Liingaard, Morten

    The first full scale prototype bucket foundation for wind turbines has been installed in October 2002 at Aalborg University offshore test facility in Frederikshavn, Denmark. The suction caisson and the wind turbine have been equipped with an online monitoring system, consisting of 15 accelerometers...

  15. On the Choice of Structure and Layout of Rubble Mound Breakwater Heads

    DEFF Research Database (Denmark)

    Maciñeira, Enrique; Burcharth, Hans F.

    2006-01-01

     The paper discusses the various functional, environmental and structural conditions to consider related to the choice of breakwater head type. Results from hydraulic model tests of rubble mound and caisson head solutions for the new deep water port at Punto Langosteira, La Coruña, Spain, are pre...

  16. 46 CFR 2.10-25 - Definitions.

    Science.gov (United States)

    2010-10-01

    ... offshore drilling unit with a ship shape displacement hull intended for operation in the floating condition... capable of engaging in drilling operations for the exploration or exploitation of subsea resources that is... columns or caissons, that is intended for drilling operations in the floating condition. Small passenger...

  17. Experimental Study of Wave Field Around the Outer Part of a Rubble Mound Roundhead Solution for the new Port of La Coruña at Punto Langosteira

    DEFF Research Database (Denmark)

    Burcharth, Hans F.; Pedersen, Thomas Schmidt

    The wave agitation in the port and at the entrance to the port depends on the length of the outer part of the breakwater (west of the spur breakwater) and on the type of structure, e.g. caissons or rubble mound. In the present study is investigated the wave field around a rubble mound head armoured...

  18. On Optimum Safety Levels of Breakwaters

    DEFF Research Database (Denmark)

    Burcharth, Hans F.; Sørensen, John Dalsgaard

    2006-01-01

    Group 47 on "Selection of type of breakwater structures". The paper summaries results given in Burcharth and Sorensen (2005) related to outer rubble mound breakwaters but focus on optimum safety levels for outer caisson breakwaters on low and high rubble foundations placed on sea beds strong enough...

  19. Buckling Analysis of Bucket Foundations for Wind Turbines in Deep Water

    DEFF Research Database (Denmark)

    Madsen, Søren; Andersen, Lars; Ibsen, Lars Bo

    2011-01-01

    Using large suction caissons for offshore wind turbines is an upcoming technology also referred to as bucket foundations. The bucket foundation does not require heavy installation equipment, but since it is constructed as a thin steel shell structure, instability, in form of buckling, becomes...

  20. SWEEP Project RAT

    DEFF Research Database (Denmark)

    Ibsen, Lars Bo; Madsen, Søren; Petersen, L. B.

    This report presents the results from the design analyses made for the clustered suction caisson used as foundation for a Riser Access Tower (RAT). The RAT is intended built next to the K15-FA-1 Platform in the Dutch Sector of the North Sea....

  1. SWEEP Project RAT

    DEFF Research Database (Denmark)

    Ibsen, Lars Bo; Madsen, Søren; Roesen, Hanne Ravn

    In this report the design basis for the geotechnical design of the suction caisson at the K15-FA-1 location is described. The derived design soil parameters are based on the site specific CPTs conducted autumn 2010 by Wintershall Nederlands B.V. (Wintershall Netherlands B.V. and Noordhoek Survey ...

  2. Importance d'annexes latérales artificielles pour le recrutement en juvéniles de poissons dans un fleuve aménagé, le Bas-Rhône

    Directory of Open Access Journals (Sweden)

    NICOLAS Y.

    1995-04-01

    Full Text Available Au siècle dernier, des digues submersibles, délimitant des «caissons», ont été érigées dans le chenal principal du Bas-Rhône. En comparant le peuplement en juvéniles de poissons du chenal, de 10 caissons et de 2 bras morts, nous avons mis en évidence une nette distinction faunistique de ces milieux, les caissons étant qualitativement et quantitativement les plus riches. II apparaît que la richesse en juvéniles de ces biotopes dépend de la diversité d'habitats et du taux de submersion par le fleuve. Les abondances des 7 espèces principales sont influencées par au moins une des 10 variables décrivant les milieux. Les caissons jouent donc un rôle essentiel comme sites de nursery, à la place de l'ancienne plaine alluviale, et contribuent au maintien de la biodiversité piscicole de ce secteur.

  3. Generating electricity at a breakwater in a moderate wave climate

    NARCIS (Netherlands)

    Schoolderman, J.; Reedijk, B.; Vrijling, J.K.; Molenaar, W.F.; Ten Oever, E.; Zijlema, M.

    2011-01-01

    A new concept for wave energy conversion is examined as a proof of concept for generating electricity in a moderate wave climate while being integrated in a caisson breakwater. Physical model testing is performed to analyse the preliminary efficiency of the device and to identify areas of

  4. Notes on the Operations of 21 Army Group. 6 June 1944 - 5 May 1945

    Science.gov (United States)

    1945-09-01

    contained D. coosidcn~a:P1e n’JDbcr of concreto Cl~rple.cenents, due;-outs etc. All were ’,·?ired and coverc:c1 by extcnsi ve tuneficlds. Coc,st...floating piers and pierheads were of concreto and steel, some 50,000 tons of steel being usod in their construction. Concrete caissons, each some

  5. Embedment Effects on the Vertical Bearing Capacity of Offshore Bucket Foundations on Cohesionless Soil

    DEFF Research Database (Denmark)

    Barari, Amin; Ibsen, Lars Bo; Ghalesari, Abbasali Taghavi

    2017-01-01

    This paper presents the results from a series of physical modeling and three-dimensional finite 9 element (FE) analyses, which examined the uniaxial vertical capacity of suction caissons for 10 offshore wind turbines. The experiments were carried out in quartz sand and involved monotonic 11...

  6. Port Adriano, 2D-Model tests

    DEFF Research Database (Denmark)

    Burcharth, Hans F.; Meinert, Palle; Andersen, Thomas Lykke

    the crown wall have been measured. The model has been subjected to irregular waves corresponding to typical conditions offshore from the intended prototype location. Characteristic situations have been video recorded. The stability of the toe has been investigated. The wave-generated forces on the caisson...

  7. Soil treatment by vibroflottation – Application to protection structures of DjenDjen port, Jijel, Algeria

    Directory of Open Access Journals (Sweden)

    KHELALFA HOUSSAM

    2016-12-01

    Full Text Available Soil treatment by vibroflotation is a recent technique for improving soil with poor geo-mechanical properties. In addition, this treatment minimizes the risk of liquefaction and the instability of the caisson. This work allows us to establish a two-dimensional numerical simulation of a real vibroflotation test, based on our model and our hypothesis of modeling this mechanism in finite elements. On the other hand, the work consists in making a two-dimensional numerical study of the stability of the caisson carried out on the treated soil, in order to verify its influence on the stability of the structure. The calculation results will be compared with in-situ measurements to validate the numerical model.

  8. [Working ability between air and trimix breathing gas under 8 ATA air condition].

    Science.gov (United States)

    Shibayama, M; Kosugi, S; Mohri, M; Yamamura, I; Oda, S; Kimura, A; Takeuchi, J; Mano, Y

    1990-04-01

    Pneumatic caisson work in Japan has come into operation since 1924. Afterward, this technique of compressed air work has been widely utilized in the construction of foundation basements, shafts of the bottom tunnel shields for subway and so forth. While using this technique of compressed air work means that workers have to be exposed to hyperbaric environment, this technique has risks of not only decompression sickness (DCS) but also toxicity of poisonous gas and/or oxygen deficiency. However, this technique is independent of city construction work and the operation of compressed air work higher than 5ATA (4.0 kg/cm2G) is actually been planning recently. Accordingly unmanned caisson work is considered as a better technique for such higher pressurized work, even though workers must enter into hyperbaric working fields for maintenance or repair of unmanned operated machinery and materials. This research is to establish the safe work under hyperbaric air environment at 8ATA.

  9. Horizontal Coherence of Wave Forces on Vertical Wall Breakwaters

    DEFF Research Database (Denmark)

    Archetti, R.; Frigaard, Peter; Lamberti, A.

    2001-01-01

    of breaking waves for increasing wave height are estimated and compared with existing empirical formulae. The horizontal dimension of the breaker is investigated using two different methodologies: the first analyses the decreasing of the highest 1/250 force with increasing horizontal dimension of the caisson......, with special attention to the effects of wave spreading, and the second analyses the spatial correlation of impulsive force per unit length along the breakwater....

  10. Madison Milton Design Build Bridge Construction

    OpenAIRE

    Johnson, Murray

    2013-01-01

    The design build team will provide an overview of the Madison Milton Ohio River Bridge Project construction. There will be a brief discussion of the design-build process. Specific discussions of the retrofits to the existing caissons and piers that allowed for the existing substructure to be reused as well as discussions of the truss design, erection, span lifts, and sliding will be provided.

  11. AGARD Highlights 90/2. Part 2

    Science.gov (United States)

    1990-09-01

    l’appareil s’dcrasa dans les Andes, sans crashed in the Andes, and Saint-Exupdry oublier Saint-Exup~ry pilote et porte. the pilot and poet. Les bases...passagers au crash ), d’un caisson benches (for testing passenger seats in d’incendie demi-grandeur, de "canons the event of a crash ), a half-scale...3 3 A 34 0 ....................................................... 3 7 SA.T.R. ATR42

  12. Wave Loading and Overtopping on Vertical Wall Breakwaters in Multidirectional Breaking Seas

    DEFF Research Database (Denmark)

    Kofoed, Jens Peter; Grønbech, J.; Hald, Tue

    1998-01-01

    The present paper concerns the results and findings of a physical study on wave impacts on vertical caisson breakwaters situated in irregular, multidirectional breaking seas. The study has taken place as part of the framework programme "Dynamics of Structures" financially supported by the Danish...... Technical Research Council, during the period of January 97 to December 97. The test were carried out in the 3D wave basin at the Hydraulics and Coastal Engineering Laboratory, Aalborg University....

  13. Construction safety in DOE. Part 2, Students guide

    Energy Technology Data Exchange (ETDEWEB)

    Handwerk, E.C.

    1993-08-01

    This report is the second part of a compilation of safety standards for construction activities on DOE facilities. This report covers the following areas: floor and wall openings; cranes, derricks, hoists, elevators, and conveyors; motor vehicles, mechanized equipment, and marine operations; excavations; concrete and masonry construction; steel erection; underground construction, caisson, cofferdams, and compressed air; demolition; blasting and the use of explosives; power transmission and distribution; rollover protective structures, overhead protection; and ladders.

  14. Condition Assessment Survey (CAS) Program. Deficiency standards and inspections methods manual: Volume 1, 0.01 Foundations and footings

    Energy Technology Data Exchange (ETDEWEB)

    1993-05-01

    General information is presented for asset determinant factor/CAS repair codes/CAS cost factors; guide sheet tool & material listing; testing methods; inspection frequency; standard system design life tables; system work breakdown structure; and general system/material data. Deficiency standards and inspection methods are given for footings - spread/strip/grade beams; foundation walls; foundation dampproofing/waterproofing; excavation/backfill/ and piles & caissons.

  15. Study on the Performance of the “Pendulor” Wave Energy Converter in an Array Configuration

    Directory of Open Access Journals (Sweden)

    Sudath Prasanna Gunawardane

    2016-04-01

    Full Text Available For over three decades the “Pendulor” wave energy device has had a significant influence in this field, triggering several research endeavours. It includes a top-hinged flap propelled by the standing waves produced in a caisson with a back wall on the leeward side. However, one of the main disadvantages which impedes its progress is the enormous expense involved in the construction of the custom made typical caisson structure, about a little more than one-quarter of the wave length. In this study, the influence of such design parameters on the performance of the device is investigated, via numerical modelling for a device arranged in an array configuration, for irregular waves. The potential wave theory is applied to derive the frequency-dependent hydrodynamic parameters by making a distinction in the fluid domain into a separate sea side and lee side. The Cummins equation was utilised for the development of the time domain equation of motion while the transfer function estimation methods were used to solve the convolution integrals. Finally, the device was tested numerically for irregular wave conditions for a 50 kW class unit. It was observed that in irregular wave operating conditions, the caisson chamber length could be reduced by 40% of the value estimated for the regular waves. Besides, the device demonstrated around 80% capture efficiency for irregular waves thus allowing provision for avoiding the employment of any active control.

  16. Characterization of 618-11 solid waste burial ground, disposed waste, and description of the waste generating facilities

    Energy Technology Data Exchange (ETDEWEB)

    Hladek, K.L.

    1997-10-07

    The 618-11 (Wye or 318-11) burial ground received transuranic (TRTJ) and mixed fission solid waste from March 9, 1962, through October 2, 1962. It was then closed for 11 months so additional burial facilities could be added. The burial ground was reopened on September 16, 1963, and continued operating until it was closed permanently on December 31, 1967. The burial ground received wastes from all of the 300 Area radioactive material handling facilities. The purpose of this document is to characterize the 618-11 solid waste burial ground by describing the site, burial practices, the disposed wastes, and the waste generating facilities. This document provides information showing that kilogram quantities of plutonium were disposed to the drum storage units and caissons, making them transuranic (TRU). Also, kilogram quantities of plutonium and other TRU wastes were disposed to the three trenches, which were previously thought to contain non-TRU wastes. The site burial facilities (trenches, caissons, and drum storage units) should be classified as TRU and the site plutonium inventory maintained at five kilograms. Other fissile wastes were also disposed to the site. Additionally, thousands of curies of mixed fission products were also disposed to the trenches, caissons, and drum storage units. Most of the fission products have decayed over several half-lives, and are at more tolerable levels. Of greater concern, because of their release potential, are TRU radionuclides, Pu-238, Pu-240, and Np-237. TRU radionuclides also included slightly enriched 0.95 and 1.25% U-231 from N-Reactor fuel, which add to the fissile content. The 618-11 burial ground is located approximately 100 meters due west of Washington Nuclear Plant No. 2. The burial ground consists of three trenches, approximately 900 feet long, 25 feet deep, and 50 feet wide, running east-west. The trenches constitute 75% of the site area. There are 50 drum storage units (five 55-gallon steel drums welded together

  17. Cells for the examination of irradiated plutonium fuel elements - two years operation - may 1961/may 1963 (1963); Cellules pour examen d'elements combustibles au plutonium irradies - deux ans d'exploitation - mai 1961/mai 1963 (1963)

    Energy Technology Data Exchange (ETDEWEB)

    Valentin, A. [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

    1963-07-01

    Within the framework of the 'Rapsodie' fast reactor program, prototype plutonium fuel elements are irradiated and then examined in an {alpha} {beta} {gamma} laboratory at Saclay. This laboratory consists of five in line cells and a lead enclosure microscope. Each cell contains an {alpha} sealed removable box 4 ft 3 in. high, 4 ft 11 in. wide and 5 ft 1 in. deep, fitted with one or two magnetic transmission indirect manipulators. The boxes are contained in an {beta} {gamma} shielded enclosure whose front face is constructed of cast iron panels 21-2/3 in. thick. Nitrogen circulating in a closed loop forms the atmosphere of the boxes. This laboratory is essentially intended for metallurgical research. The functions of the various cells are as follows: transferring and packing, cutting, density measurement and cathodic etching, storage and metallography. Work on radioactive materials began in April 1961. Operational incidents have always been of a material nature only. (author) [French] Dans le cadre du projet de reacteur rapide Rapsodie, des elements combustibles prototypes au plutonium sont, apres irradiation, examines a Saclay dans un laboratoire {alpha} {beta} {gamma}. Celui-ci comprend cinq cellules en ligne et une enceinte en plomb contenant un microscope telecommande. Chaque cellule est constituee d'un caisson etanche (1, 3 m x 1, 5 m x 1, 56m) equipee d'un ou deux manipulateurs indirects a transmissions magnetiques. Les caissons sont places, dans une enceinte {beta} {gamma} dont la face avant est formee de blocs en fonte ayant 55 cm d'epaisseur. L'atmosphere des caissons est de l'azote, circulant en circuit ferme. Ce laboratoire est destine essentiellement a des recherches metallurgiques. Les fonctions des differentes cellules sont: conditionnement et transferts, tronconnage, mesure de densite et polissage ionique, stockage, metallographie. Le travail sur materiaux radioactifs a commence en avril 1961. Les incidents d

  18. Reliability Analysis of Geotechnical Failure Modes for Vertical Wall Breakwaters

    DEFF Research Database (Denmark)

    Sørensen, John Dalsgaard; Burcharth, H. F.

    2000-01-01

    Vertical wall breakwaters are usually designed as concrete caissons placed on the top of a rubble mound foundation or a rubble bedding layer. The purpose of the breakwater is usually to protect the area behind the breakwater from being flooded by large waves. The area protected can for example...... be a harbour of small or large importance, an important industrial area or a heavily populated coast line. This implies that vertical wall breakwaters are used under quite different conditions and therefore the consequences of a complete or partial failure also are very different. This implies...

  19. Validity of simplified Analysis of Stability of Caison Breakwaters on Rubble Foundation Exposed to Impulsive Loads

    DEFF Research Database (Denmark)

    Andersen, Lars; Burcharth, Hans F.; Andersen, Thomas Lykke

    2011-01-01

    Wave slamming on vertical breakwaters cause a sudden, impulsive load that may cause a caisson to slide on its foundation. Alternatively, geotechnical failure may occur in the subsoil. This paper investigates whether simple analytical solutions, accounting only for the sliding along the caisson–foundation...... interface, can be utilized to properly determine the deformations of the breakwater. Comparisons are made with results obtained by numerical models that include the material response of the soil. Firstly, a computational model is suggested that assumes a fully drained behavior of the subsoil. Secondly...

  20. A case of aseptic vertebral necrosis in the context of metastatic lumbar disease

    Energy Technology Data Exchange (ETDEWEB)

    Panow, C. [Radiologie Florissant, Geneva (Switzerland); Valavanis, A. [Institut fuer Neuroradiologie, Universitaetsspital Zuerich (Switzerland)

    2002-03-01

    Aseptic bone necrosis has many well recognized etiologies: caisson disease, corticosteroids, alcohol, Gaucher's disease and sickle cell anemia being a few of a long list. Little attention has been paid to metastatic disease as a possible cause and we were unable to find reference in the literature to this association. We present imaging features of metastatic Ewing's sarcoma involving the vertebral spine, which, in certain aspects, mimics other well-known entities of this region, such as Kuemmell's and Scheuermann's diseases. (orig.)

  1. A rational methodology for the study of foundations for marine structures; Una metdologia racional para el estudio de cimentaciones de estructuras marinas

    Energy Technology Data Exchange (ETDEWEB)

    Mira Mc Willams, P.; Fernandez-Merodo, J. A.; Pastor Perez, M.; Monte Saez, J. L.; Martinez Santamaria, J. M.; Cuellar Mirasol, V.; Martin Baanante, M. E.; Rodriguez Sanchez-Arevalo, I; Lopez Maldonando, J. D.; Tomas Sampedro, A.

    2011-07-01

    A methodology for the study of marine foundations is presented. The response in displacements, stresses and pore water pressures in obtained from a finite element coupled formulation. Loads due to wave action of the foundation are obtained from a volume of fluid type fluid-structure interaction numerical model. Additionally, the methodology includes a Generalized Plasticity based constitutive model for granular materials capable of representing liquefaction fenomena of sands subjected to cyclic loading, such as those frequently appearing in the problems studied. Calibration of this model requires a series of laboratory tests detailed herein. This methodology is applied to the study of the response of a caisson breakwater foundation. (Author) 10 refs.

  2. CISM course on mechanical behaviour of soils under environmentally induced cyclic loads

    CERN Document Server

    Wood, David; Mechanical Behaviour of Soils Under Environmentally Induced Cyclic Loads

    2012-01-01

    The book gives a comprehensive description of the mechanical response of soils (granular and cohesive materials) under cyclic loading. It provides the geotechnical engineer with the theoretical and analytical tools necessary for the evaluation of settlements developng with time under cyclic, einvironmentally idncued loads (such as wave motion, wind actions, water table level variation) and their consequences for the serviceability and durability of structures such as the shallow or deep foundations used in offshore engineering, caisson beakwaters, ballast and airport pavements and also to interpret monitoring data, obtained from both natural and artificial slopes and earth embankments, for the purposes of risk assessment and mitigation.

  3. A Macro-Element Approach for Non-linear Response of Offshore Skirted Footings

    DEFF Research Database (Denmark)

    Barari, Amin; Ibsen, Lars Bo

    2017-01-01

    In recent times, shallow foundations have become more diverse, and now include concrete or steel bucket foundations used as anchors for floating platforms or as foundation for offshore wind turbines. They are always subjected to significant cyclic lateral loads due to wind and wave action. A work......-hardening plasticity model for the moment and horizontal force resultants associated with the displacements of the offshore suction caissons is herein developed. In addition, in order to better understand the performance of offshore bucket foundations under cyclic lateral loads series of cyclic lateral load tests were...

  4. Vertical Dynamic Stiffness of Offshore Foundations

    DEFF Research Database (Denmark)

    Latini, Chiara; Cisternino, Michele; Zania, Varvara

    2016-01-01

    Nowadays, pile and suction caisson foundations are widely used to support offshore structures which are subjected to vertical dynamic loads. The dynamic soil-structure interaction of floating foundations (foundations embedded in a soil layer whose height is greater than the foundation length......) is investigated by numerical analyses of representative finite element models. The 3D numerical model is compared and validated with existing analytical solutions. A parametric study is carried out analyzing the effect of the slenderness ratio Hp/d and the height and the stiffness of the soil layer on the dynamic...

  5. Spatial Distribution of Wave Pressures on Seawave Slot-Cone Generator

    DEFF Research Database (Denmark)

    Vicinanza, Diego; Margheritini, Lucia; Frigaard, Peter

    2009-01-01

    This paper presents results on loading acting on an innovative caisson breakwater for electricity production. The work reported here is part of the European Union Sixth Framework programme priority 6.1 (Sustainable Energy System), contract 019831, titled "Full-scale demonstration of robust and high......-efficiency wave energy converter" (WAVESSG). Information on wave loadings acting on Wave Energy Convert (WEC) Seawave Slot-Cone Generator (SSG) exposed to extreme wave conditions are reported. The SSG concept is based on the principle of overtopping and storing the wave energy in several reservoirs placed one...

  6. Investigation of seepage around the bucket skirt during installation in sand

    DEFF Research Database (Denmark)

    Koteras, Aleksandra Katarzyna; Ibsen, Lars Bo

    pressure that will create piping channels at exit, which is near to seabed and to the caisson wall, along bucket wall and at the tip. That is how the limits for suction installation can be assumed. Finally, the critical suction is used for predicting the reduction of penetration resistance and the method...... describing this approach is presented in the report with its assumptions. The method is called AAU CPT-based method and it is a great step in the development of practical design tool for bucket foundation installation process....

  7. River Rance Tidal Power Plant nears 20 years in operation: conservative approach in structural and component testing pays off

    Energy Technology Data Exchange (ETDEWEB)

    Booda, L.L.

    1985-09-01

    The author presents a brief history of the power plant, on which work began in 1961; the last unit, the 24th, went into service in December 1967. Thoroughness marked the engineering of the plant; for example, research was conducted on the ideal concrete mix to withstand the loads and to last for a long time in the marine environment. The most challenging engineering problem was how to construct the cofferdams for working in the dry, the principal problem being that of setting the caissons during the wide range of tides. Total installed power is 240 MW, and net annual productivity of 544 million kWh.

  8. Ceodouro project : overall design of an OWC in the new OPorto break water

    Energy Technology Data Exchange (ETDEWEB)

    Martins, E.; Carrilho, L. [EDP, Lisboa (Portugal); Neumann, F. [Centro de Energia das Ondas, Lisboa (Portugal); Ramos, F. Silveira [Consulmar, Lisboa (Portugal); Justino, Paulo Alexandre [INETI/DER, Lisboa, (Portugal); Gato, L.M.C. [Dep. de Engenharia Mecanica, IST, Lisboa, (Portugal); Trigo, L. [Kymaner, S. Domingos de Rana, (Portugal)

    2005-07-01

    The purpose of this work is to present and describe the design approach of the integration of an OWC wave energy plant in a caisson breakwater to be built at the Portuguese northern coast as a promising solution towards sustainable port structures. The presentation of different case study results by Neumann and Sarmento (2000) suggested that such a combination turns out to be a realistic alternative to the traditional coastal protection schemes. The large Portuguese engineering consulting company Consulmar, being responsible for a number of coastal and maritime engineering projects, has accepted the challenge of leading a project for an OWC integration in a caisson breakwater head in Northern Portugal. After the concession of the breakwater construction in 2004, a Consortium has proceeded with preliminary works concerning the integration of an OWC into the breakwater. The Portuguese companies Labelec (EDP group), Kymaner (mechanical components), EFACEC (electrical components) and the Institutions IPTM (Port and Maritime Institute), LNEC (Hydraulic Laboratory), INETI (National Laboratory), IST (University) and the WEC (Wave Energy Centre) are further contributors in the planning phase. This paper presents an overall description of the project, its steps and present state of development.

  9. Planning and design of the Ikedako bride (temporary name); Ikedakokyo (kasho) no keikaku to sekkei

    Energy Technology Data Exchange (ETDEWEB)

    Mochizuki, H.; Iizuka, Y.; Yukawa, Y. [Japan Highway Public Corporation, Tokyo (Japan)

    1997-09-30

    This paper describes the planning and design of the Ikeda-Lake Bridge of the Tokushima Express Way. This bridge is a PC (prestressed concrete) five-span continuous balanced arch bridge with a length 705 m. This bridge transverses prefectural road, Ikeda Dam Lake of Yoshino River, park, JR line, national highway, and town road, and both ends of the bridge are tunnels, resulting in the complicated bridging condition. Various bridging methods were examined from the viewpoint of structural characteristics, workability, profitability, maintenance/management, and aspect. A bridge with PC stiffening girders was adopted. The maximum interval between supports is 200 m. This bridge has the largest scale as a concrete arch bridge in Japan. Basements of bridge piers were constructed by pneumatic caisson method and large-diameter deep basement method. Since basements were located in the dam lake and they were quickly constructed in a short period in a non-flood season, steel caissons were separately fabricated in the dock, towed and placed for excavation. For the construction of upper section, overhang method was adopted using movable working vehicle. For the construction of arch section, the arch was overhung simultaneously in the both sides by composing the truss using stiffened girders, arch ribs, vertical members, and temporary cable stayed members, which was the first in Japan. In 1997, basement construction was completed, and construction of bridge piers and a part of the construction of upper section have been started. 2 refs., 12 figs.

  10. Tritium release experiments with CATS and numerical simulation

    Energy Technology Data Exchange (ETDEWEB)

    Munakata, Kenzo, E-mail: kenzo@gipc.akita-u.ac.jp [Faculty of Engineering and Resource Sciences, Akita University, Tegata-gakuen-cho 1-1, Akita 010-8502 (Japan); Wajima, Takaaki; Hara, Keisuke; Wada, Kohei [Faculty of Engineering and Resource Sciences, Akita University, Tegata-gakuen-cho 1-1, Akita 010-8502 (Japan); Takeishi, Toshiharu; Shinozaki, Yohei; Mochizuki, Kazuhiro; Katekari, Kenichi [Interdisciplinary Graduate School of Engineering Science, Kyushu University, Hakozaki 6-10-1, Higashi-ku, Fukuoka 812-8581 (Japan); Kobayashi, Kazuhiro; Iwai, Yasunori; Hayashi, Takumi; Yamanishi, Toshihiko [Tritium Technology Group, Japan Atomic Energy Agency, Tokai, Ibaraki 319-1195 (Japan)

    2010-12-15

    In D-T fusion power plants, large amounts of tritium would be handled. Tritium is the radioisotope of protium, and is easily taken into the human body, and thus the behavior of tritium accidentally released in fusion power plants should be studied for the safety design and radioprotection of workers. Therefore, it is necessary to investigate the behavior of tritium released into large rooms with objectives, since complex flow fields should exist in such rooms and they could influence the ventilation of the air containing released tritium. Thus, tritium release experiments were conducted using Caisson Assembly for Tritium Safety Study (CATS) in TPL/JAEA. Some data were taken for tritium behavior in the ventilated area and response of tritium monitors. In the experiments, approximately 17 GBq of tritium was released into Caisson with the total volume of 12 m{sup 3}, and the room was ventilated at the rate of 12 m{sup 3}/h after release of tritium. It was found that placement of an objective in the vessel substantially affects decontamination efficiency. With regard to an experimental result, numerical calculation was performed and the experimental result and the result of numerical calculation were compared, which indicates that experimental results are qualitatively reproduced by numerical calculation. However, further R and D needs to be carried out for quantitative reproduction of the experimental results.

  11. Optimization of power take-off equipment for an oscillating water column wave energy plant

    Energy Technology Data Exchange (ETDEWEB)

    Gato, L.M.C.; Falcao, Antonio de F.O. [Dept. de Engenharia Mecanica do IST, Lisboa (Portugal); Paulo Alexandre Justino [INETI/DER, Lisboa (Portugal)

    2005-07-01

    The paper reports the optimization study of the electro-mechanical power take-off equipment for the OWC plant whose structure is a caisson forming the head of the new Douro breakwater. The stochastic approach is employed to model the wave-to-wire energy conversion. The optimization includes rotational speed (for each sea state), turbine geometry and size, and generator rated power. The procedure is implemented into a fully integrated computer code, that yields numerical results for the multi-variable optimization process and for the electrical power output (annual average and for different sea states) with modest computing time (much less than if a time-domain model were used instead). Although focused into a particular real case, the paper is intended to outline a design method that can be applied to a wider class of wave energy converters.

  12. Material Composition of Bucket Foundation Transition Piece for Offshore Wind Turbines

    DEFF Research Database (Denmark)

    Nezhentseva, Anastasia; Andersen, Lars; Ibsen, Lars Bo

    2010-01-01

    In Denmark, production of renewable energy is focused on offshore wind turbines, since they make little if any inconvenience for residents in inhabited areas. High requirements are placed on the installation of the foundations which can cost about 30% of the total cost of the wind turbine....... This paper deals with the transition piece for a relatively novel type of foundation, the so-called suction bucket (caisson), focusing on the design of a transition piece connecting the turbine column with a suction bucket used as a monopod foundation for an offshore wind turbine. Since the current design...... practice is limited to the use of steel-flange-reinforced shear panels for the transition piece—a production that requires extensive welding work—a desirable solution is to find a material that provides lower cost and easier manufacturing without compromising the strength and stiffness. The paper compares...

  13. Wave Forces on Transition Pieces for Bucket Foundations for Offshore Wind Turbines

    DEFF Research Database (Denmark)

    Nezhentseva, Anastasia; Andersen, Thomas Lykke; Andersen, Lars Vabbersgaard

    Since offshore wind turbines continually increase in size and move to deep water depths (>25 m), significant wave loading becomes a major concern for their design. A monopile foundation is one of the most commonly used types of the offshore wind turbine foundations today. This solution, however...... to a bucket foundation (suction caisson) located at 35 m water depth in the North Sea. Several models of the TPs (wedge-shaped steel flange-reinforced shear panels, conical and doubly curved with or without cutaways) are tested in a wave flume and compared with respect to wave loading. Due to a larger size...... of the suggested TPs compared to a typical slender monopole foundation, wave loads acting on these TPs are also expected to be considerably higher and much more difficult to predict. The results of the present investigation can be further applied for other wind turbine types....

  14. Hydraulic Characteristics of Seawave Slot-cone Generator Pilot Plant at Kvitsøy (Norway)

    DEFF Research Database (Denmark)

    Margheritini, Lucia; Vicinanza, Diego; Kofoed, Jens Peter

    2007-01-01

    This paper presents results on wave overtopping and loading on an innovative caisson breakwater for electricity production. The work reported here contributes to the European Union FP6 priority 6.1 (Sustainable Energy System). The design of the structure consists of three reservoirs one on the top...... of each other to optimize the storage of potential energy in the overtopping water. The wave loadings on the main structure can be estimated using experiences from breakwater design, but the differences between the structures is so large that more reliable knowledge is needed. Model tests were carried out...... in a second phase the model has been adapted and equipped with pumps to measure the overtopping flow rates in the single reservoirs. The results of the tests highlight differences between 2D and 3D conditions in terms of pressures and hydraulic efficiency....

  15. Evaluation of Elevated Tritium Levels in Groundwater Downgradient from the 618-11 Burial Ground Phase I Investigations

    Energy Technology Data Exchange (ETDEWEB)

    Dresel, P.E.; Smith, R.M.; Williams, B.A.; Thompson, C.J.; Evans, J.C.; Hulstrom, L.C.

    2000-05-01

    This report describes the results of the preliminary investigation of elevated tritium in groundwater discovered near the 618-11 burial ground, located in the eastern part of the Hanford Site. Tritium in one well downgradient of the burial ground was detected at levels up to 8,140,000 pCi/L. The 618-11 burial ground received a variety of radioactive waste from the 300 Area between 1962 and 1967. The burial ground covers 3.5 hectare (8.6 acre) and contains trenches, large diameter caissons, and vertical pipe storage units. The burial ground was stabilized with a native sediment covering. The Energy Northwest reactor complex was constructed immediately east of the burial ground.

  16. Fluctuations de l'arc et du jet de plasma liées au mouvement du pied d'arc dans des plasmatrons

    OpenAIRE

    Kaminska, A.; Dudeck, M.

    1995-01-01

    L'étude présentée porte sur le comportement dynamique de l'arc électrique dans un plasmatron et du jet de plasma dans un caisson à pression réduite. La variation de la fréquence caractéristique et les écarts de tension sont étudiés et discutés en fonction de la pression, du débit gazeux et du courant d'arc. Une corrélation entre les fluctuations de la tension d'arc et les fluctuations de la pression dynamique dans les jets de plasma d'argon et d'azote créés par arc électrique a été mise en év...

  17. Modeling study of solute transport in the unsaturated zone: Workshop proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Springer, E.P.; Fuentes, H.R. (eds.)

    1987-04-01

    Issues addressed were the adequacy of the data for the various models, effectiveness of the models to represent the data, particular information provided by the models, the role of caisson experiments in providing fundamental knowledge of porous-media water flow and solute transport, and the importance of geochemistry to the transport of nonconservative tracers. These proceedings include the presentations made by each of the modelers; the summary document written by the panel; and a transcript of the discussions, both the discussions that followed individual presentations and the general discussion held on the second day. This publication completes the series on the workshop. Volume I in the series (NUREG/CR-4615, Vol. I) contains background information and the data sets provided each modeler.

  18. Corrosion protection of Arctic offshore structures: Final report. [Effects of temperature and salinity on required cathodic protection current

    Energy Technology Data Exchange (ETDEWEB)

    Sackinger, W.M.; Rogers, J.C.; Feyk, C.; Theuveny, B.

    1985-10-01

    Results are presented for a research program on corrosion prevention for Arctic offshore structures which are in contact with sea ice for a significant portion of the year. The electrical method most adaptable for structure protection involves the injection of impressed current from several remote anodes buried just beneath the sea floor. The electrical resistivity of annual sea ice as a function of temperature and salinity is presented. Details of the interface layers formed between sea ice and steel in the presence of current injection are shown. A computer program was developed to enable the calculation of protective current density into the structure, in the presence of ice rubble and ridges around the structure. The program and the results of an example calculation are given for a caisson- retained island structure. 81 refs., 103 figs., 3 tabs.

  19. Korea tidal power and beyond

    Science.gov (United States)

    Song, W. O.; van Walsum, E.

    A study evaluating the tidal power potential on the west coast of Korea is presented. The tidal power plant concept applied to all sites features prefabricated caissons from which the powerhouse and the sluice sections of the plant are built up. In the screening process, all 13 potential sites were compared on the basis of a single basin and single effect schemes operated to produce the maximum amount of energy. The four sites identified as having potential for development (the inner Asan Bay, the outer Asan Bay, the Incheon Bay, and the Garorim Bay) are economically evaluated. It is noted that harbor development and land reclamation can proceed in conjunction with tidal power development.

  20. Numerical study of breakwater failure due to tsunami-like undular bore impacts: The case of the port of Soma.

    Science.gov (United States)

    Martin-Medina, Manuel; Morichon, Denis; Abadie, Stephane; Le Roy, Sylvestre; Lemoine, Anne

    2017-04-01

    The Tohoku tsunami, that impacted the Japanese coast in 2011, caused great damages on many offshore vertical breakwaters ranging from the erosion of the rubble mound to the partial displacement or total collapse of caissons. The breakwater failure mechanisms were function of the tsunami wave types that vary along the Japanese coast according to the bathymetry features. The Iwate coast, characterized by deep water depths and steep slopes, was mainly impacted by tsunami overflow leading in particular to the failure of the world's deepest breakwater of Kamaishi. In the shallow waters of the Sendai bay, observations showed that breakwaters protecting harbor entrances were impacted by short waves train resembling to undular bore. This work aims to investigate this latter type of tsunami wave impacts that are less reported in the literature. We chose to focus on the highly damaged offshore breakwater of Soma, located in the south part of the Sendai bay. The hydrodynamics conditions during the tsunami impact are investigated using the VARANS Thetis code (Desombre et al., 2012), which allows to simulate both the free surface flow and the flow inside the rubble mound simulated by a porous medium. The model is forced at the offshore boundaries by the Funwave Boussinesq code that describes the transformation of the tsunami waves from the source to the generation of undular bores in shallow waters. The study includes the computation of forces acting on the caissons. We discuss the relevance of describing the hydrodynamics at the short wave scale to assess breakwater stability in the course of tsunami-like undular bore impact. References Desombre, J., Morichon, D., & Mory, M. (2012). SIMULTANEOUS SURFACE AND SUBSURFACE AIR AND WATER FLOWS MODELLING IN THE SWASH ZONE. Coastal Engineering Proceedings, 1(33), 56.

  1. Fundaciones para turbinas eólicas costa afuera Foundations for offshore wind turbines

    Directory of Open Access Journals (Sweden)

    Felipe Alberto Villalobos Jara

    2009-01-01

    Full Text Available Este artículo describe el comienzo y la evolución de la hoy en día creciente mundialmente industria de la energía eólica costa afuera. Como un caso particular, se describe la actual política de energías renovables en el Reino Unido. Se explican las características de las cargas ambientales existentes costa afuera, tipos de suelos del fondo marino y las fundaciones que se utilizan comúnmente. El tipo de estructura y régimen de carga establecen nuevas condiciones desde el punto de vista de la Ingeniería Civil. Se presentan las cámaras a succión como una fundación alternativa para turbinas de viento costa afuera. Las cámaras a succión son actualmente una alternativa aceptada en vez de usar pilotes en aplicaciones para la industria del petróleo y el gas. Sin embargo, este no es el caso todavía en aplicaciones para aerogeneradores costa afuera.This paper describes the beginning and evolution of the now worldwide growing offshore wind energy industry. In particular, the current renewable energy policy in the UK is described. The characteristics of the environmental loads offshore, type of seabed soils and foundations commonly adopted are explained. The type of structure and loading regime establish new conditions from a Civil Engineering point of view. Suction caissons are introduced as an alternative foundation for offshore wind turbines. Suction caissons are currently an accepted alternative to pile foundations in applications for the oil and gas industry. However, this is not yet the case in applications for offshore wind turbines.

  2. El puente Bendorf sobre el Rin (Alemania

    Directory of Open Access Journals (Sweden)

    Hirschfeld, Kurt

    1966-03-01

    Full Text Available This recently completed bridge over the Rhine is 524 m long, and is a reinforced concrete structure, built by successive overhangs, without the aid of formwork or scaffolding. The centre span is 208 m in length, and the other six vary between 43 and 71 m. The deck consists of two independent parts, including a continuous box girder, with a hinge at the crown of the main span. It is stiffened with transversal diaphragms, spaced every 34 m. The piles rest on pneumatic caissons, which go down to 16 m below the river bed. The attachment between the piles and the caissons is rigid, at the central pile, and at the other piles it operates through a roller bearing. The central span was constructed without intermediate supports for the first 40 m, and beyond that stage, for greater safety, a provisional movable tower was built, as a temporary point of support for the free overhang. The various sections were concreted and post-tensioned with 32 mm bars, by the Dywidag procedure. Account was taken of the varying deformations that took place at each section, so as to add the necessary counter-deflection that finally enabled the two sides of the arch to meet at the crown at the calculated point.Este puente, recientemente construido, sobre el Rin, tiene una longitud total de 524 m, es de hormigón armado y se ha realizado por el procedimiento de voladizos sucesivos, sin entramado auxiliar ni cimbras. La luz del tramo central es de 208 m, y las de los otros seis oscilan entre 43 y 71 m. La estructura del tablero se compone de dos partes independientes, formadas por una viga tipo cajón, continua, con una articulación en la clave del tramo central y rigidizada con diafragmas transversales espaciados a 34 m. Las pilas centrales se apoyan sobre cajones neumáticos que descienden 16 m debajo del fondo del río. La unión entre estas pilas y la estructura cajón es rígida, y de tipo rodillo en las otras pilas. El tramo central se ha construido por voladizos

  3. Chemical Processing Department monthly report, April 1961

    Energy Technology Data Exchange (ETDEWEB)

    Reinker, P.H.

    1961-05-22

    Pu nitrate production was above revised forecast. 141 kCi Sr-90 was isolated in Purex and stored for decay; to date, 1190 kCi has been recovered from Purex wastes. Casks of Cs-137 and Sr-90 were turned over to AEC for ORNL. Production of UO{sub 3}, Pu metal buttons, and weapon component fabrication exceeded forecasts. Purex processing continued until April 14. The Purex neptunium campaign had low yield because of loss to waste system. The cartridge in the Purex co-decontamination column scrub section was replaced with a new design. After the Redox organic distillation pot was replaced, {gamma} activity in Redox recovered hexone increased 300 {times}; product quality returned to normal after the faulty steam traps were replaced. Fabricated parts underwent dimensional changes after machining and gaging; part dimensions have been altered to compensate. Design for the proposed caisson-lateral leak detection system was revised to contain 3 horizontal laterals beneath each tank and 7 vertical wells around each tank. A ratio exists between the Cs-137 in the coating waste solution and the total U in liquid and precipitate phases. (DLC)

  4. Castor and Pollux - shielded cells for studying fuel treatment processes; Castor et Pollux chaines blindees d'etudes de procedes de traitement de combustibles

    Energy Technology Data Exchange (ETDEWEB)

    Faudot, G.; Bathellier, A. [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

    1969-07-01

    CASTOR and POLLUX, two alpha, beta, gamma cells are described in the present paper. They are located in the CEN at Fontenay-aux-Roses (France). They are designed for improvement studies of the various aqueous separation processes used in irradiated fuels reprocessing plants. Located in the same air-tight steel encasement, they arc inter-connected by a pneumatic transfer. These two cells have a similar in-line conception and they include: a gamma shielding in lead of 10 cm of thickness; an inner air-tight box, made with stainless steel and plexiglas, is maintained in lowering in comparison to room pressure. Eleven Hobson model seven master-slave manipulators allow inner manipulations. Then the inner equipment is described briefly. (author) [French] Le present document decrit les cellules alpha, beta, gamma CASTOR et POLLUX edifiees au Centre d'Etudes Nucleaires de Fontenay-aux-Roses. Elles sont destinees aux etudes visant a l'amelioration des procedes de separation par voie aqueuse utilises dans les usines de retraitement des combustibles irradies. Ces deux chaines, implantees dans le meme caisson et reliees par convoyeur pneumatique, sont de conception identique et comprennent: une protection biologique constituee par 10 cm d'epaisseur de plomb; une enceinte interieure etanche alpha, en acier inoxidable et plexiglas, maintenue en depression. Des telemanipulateurs Hobson, modele 7, permettent les manipulations interieures. On decrit ensuite brievement les installations annexes. (auteur)

  5. Pull-Out Strength and Bond Behavior of Prestressing Strands in Prestressed Self-Consolidating Concrete

    Directory of Open Access Journals (Sweden)

    Wu-Jian Long

    2014-10-01

    Full Text Available With the extensive use of self-consolidating concrete (SCC worldwide, it is important to ensure that such concrete can secure uniform in-situ mechanical properties that are similar to those obtained with properly consolidated concrete of conventional fluidity. Ensuring proper stability of SCC is essential to enhance the uniformity of in-situ mechanical properties, including bond to embedded reinforcement, which is critical for structural engineers considering the specification of SCC for prestressed applications. In this investigation, Six wall elements measuring 1540 mm × 2150 mm × 200 mm were cast using five SCC mixtures and one reference high-performance concrete (HPC of normal consistency to evaluate the uniformity of bond strength between prestressing strands and concrete as well as the distribution of compressive strength obtained from cores along wall elements. The evaluated SCC mixtures used for casting wall elements were proportioned to achieve a slump flow consistency of 680 ± 15 mm and minimum caisson filling capacity of 80%, and visual stability index of 0.5 to 1. Given the spreads in viscosity and static stability of the SCC mixtures, the five wall elements exhibited different levels of homogeneity in in-situ compressive strength and pull-out bond strength. Test results also indicate that despite the high fluidity of SCC, stable concrete can lead to more homogenous in-situ properties than HPC of normal consistency subjected to mechanical vibration.

  6. Pull-Out Strength and Bond Behavior of Prestressing Strands in Prestressed Self-Consolidating Concrete.

    Science.gov (United States)

    Long, Wu-Jian; Khayat, Kamal Henri; Lemieux, Guillaume; Hwang, Soo-Duck; Xing, Feng

    2014-10-10

    With the extensive use of self-consolidating concrete (SCC) worldwide, it is important to ensure that such concrete can secure uniform in-situ mechanical properties that are similar to those obtained with properly consolidated concrete of conventional fluidity. Ensuring proper stability of SCC is essential to enhance the uniformity of in-situ mechanical properties, including bond to embedded reinforcement, which is critical for structural engineers considering the specification of SCC for prestressed applications. In this investigation, Six wall elements measuring 1540 mm × 2150 mm × 200 mm were cast using five SCC mixtures and one reference high-performance concrete (HPC) of normal consistency to evaluate the uniformity of bond strength between prestressing strands and concrete as well as the distribution of compressive strength obtained from cores along wall elements. The evaluated SCC mixtures used for casting wall elements were proportioned to achieve a slump flow consistency of 680 ± 15 mm and minimum caisson filling capacity of 80%, and visual stability index of 0.5 to 1. Given the spreads in viscosity and static stability of the SCC mixtures, the five wall elements exhibited different levels of homogeneity in in-situ compressive strength and pull-out bond strength. Test results also indicate that despite the high fluidity of SCC, stable concrete can lead to more homogenous in-situ properties than HPC of normal consistency subjected to mechanical vibration.

  7. Exercises in Heavy Lowering

    CERN Multimedia

    2006-01-01

    Driving up to Point 5, one can't help but notice the impressively enormous red structure climbing up and over Building 3585. This unusual bridge-like construction is CMS'new crane, otherwise known as 'the gantry'. CMS'impressive "gantry" was recently installed at Building 3585. The 'gantry'was constructed by VSL, a Swiss company that is used to building such uniquely designed cranes used for major construction jobs, including lifting the roofs of various stadiums and the huge Airbus A380 assembly hall in Toulouse or bridge foundation caissons. CMS's crane was custom-built to sustain up to 2000 tonnes of machinery and detectors and slowly lower them down into the experimental cavern. The feature of two towers, one on either side of the building, each 24 m high, is the reason behind the nickname of this amazing crane. Two large beams, 28 m long and 3.4 m high, run along the width of the roof and four openings, each 5 m long, in the ceiling will allow the cables to pass through into the gallery. Unlike typic...

  8. Autopista Bilbao-Behobia España

    Directory of Open Access Journals (Sweden)

    Editorial, Equipo

    1978-11-01

    Full Text Available The construction of the Oyarzun-Behovia stretch of the Bilbao-Behovia motorway has meant the completion of this important means of communication in the Basque Country. Earth moving work has been of the order of 25 million cubic meters. The project includes 7 overpasses, 16 underpasses and three bridges. The structures have been built using poststresser light-weight slabs, reinforced caissons and poststressed girders with «reinforced earth work» abutments.

    La construcción del tramo Oyarzun-Behobia ha permitido finalizar la Autopista Bilbao-Behobia, importante realización para las comunicaciones en el País Vasco. Se ha hecho movimiento de tierras, del orden de los 25 millones de metros cúbicos. La obra consta de: - 7 pasos superiores, - 16 pasos inferiores, y - 3 puentes. Las estructuras han sido realizadas con losas aligeradas postensadas, cajones armados y vigas postensadas con estribos de «tierra armada».

  9. Adaptations for marine habitat and the effect of Triassic and Jurassic predator pressure on development of decompression syndrome in ichthyosaurs.

    Science.gov (United States)

    Rothschild, B M; Xiaoting, Z; Martin, L D

    2012-06-01

    Decompression syndrome (caisson disease or the "the bends") resulting in avascular necrosis has been documented in mosasaurs, sauropterygians, ichthyosaurs, and turtles from the Middle Jurassic to Late Cretaceous, but it was unclear that this disease occurred as far back as the Triassic. We have examined a large Triassic sample of ichthyosaurs and compared it with an equally large post-Triassic sample. Avascular necrosis was observed in over 15% of Late Middle Jurassic to Cretaceous ichthyosaurs with the highest occurrence (18%) in the Early Cretaceous, but was rare or absent in geologically older specimens. Triassic reptiles that dive were either physiologically protected, or rapid changes of their position in the water column rare and insignificant enough to prevent being recorded in the skeleton. Emergency surfacing due to a threat from an underwater predator may be the most important cause of avascular necrosis for air-breathing divers, with relative frequency of such events documented in the skeleton. Diving in the Triassic appears to have been a "leisurely" behavior until the evolution of large predators in the Late Jurassic that forced sudden depth alterations contributed to a higher occurrence of bends.

  10. Doppler ultrasound surveillance in deep tunneling compressed-air work with Trimix breathing: bounce dive technique compared to saturation-excursion technique.

    Science.gov (United States)

    Vellinga, T P van Rees; Sterk, W; de Boer, A G E M; van der Beek, A J; Verhoeven, A C; van Dijk, F J H

    2008-01-01

    The Western Scheldt Tunneling Project in The Netherlands provided a unique opportunity to evaluate two deep-diving techniques with Doppler ultrasound surveillance. Divers used the bounce diving techniques for repair and maintenance of the TBM. The tunnel boring machine jammed at its deepest depth. As a result the work time was not sufficient. The saturation diving technique was developed and permitted longer work time at great depth. Thirty-one divers were involved in this project. Twenty-three divers were examined using Doppler ultrasound. Data analysis addressed 52 exposures to Trimix at 4.6-4.8 bar gauge using the bounce technique and 354 exposures to Trimix at 4.0-6.9 bar gauge on saturation excursions. No decompression incidents occurred with either technique during the described phase of the project. Doppler ultrasound revealed that the bubble loads assessed in both techniques were generally low. We find out, that despite longer working hours, shorter decompression times and larger physical workloads, the saturation-excursion technique was associated with significant lower bubble grades than in the bounce technique using Doppler Ultrasound. We conclude that the saturation-excursion technique with Trimix is a good option for deep and long exposures in caisson work. The Doppler technique proved valuable, and it should be incorporated in future compressed-air work.

  11. Damaged quay restoring construction by using a traveling type overhanging rack. Harbor stage piling construction method; Sokoshiki haridashi kadai ni yoru hisai ganpeki fukkyu koji. Harbor stage piling koho

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, S.; Hashimoto, Y.; Doi, S. [Kajima Corp., Tokyo (Japan)

    1997-06-25

    A harbor stage piling construction method was adopted and executed for a construction to restore caisson-type quay damaged by the Great Hygoken-Nanbu Earthquake. The conventional construction method which uses marine working vessels in constructions to restore existing quays have problems in safety and reliability due to effects of waves and currents, or in workability affected by traffics of other vessels. Therefore, the present construction method which allows working from an existing quay was adopted and executed, because it makes the construction works possible under the same conditions as working on the ground. With this method, a traveling type overhanging rack partly overhung onto the sea side travels on rails to perform positioning, steel pipe bottoms are settled onto the sea bottom by using a lifting equipment placed on the sea side tip, and the rack is fixed. Excavation work is carried out by an excavating machine mounted on the sea side overhanging section. Even though the construction was carried out with the adjacent berths being used for frequent arrivals and departures of freighters, placement of 318 pile-type steel sheet piles with a diameter of 120 cm and a length of 31.5 m was completed within the scheduled construction period. 14 figs., 1 tab.

  12. Environmental life cycle assessment of permeable reactive barriers: effects of construction methods, reactive materials and groundwater constituents.

    Science.gov (United States)

    Mak, Mark S H; Lo, Irene M C

    2011-12-01

    The effects of the construction methods, materials of reactive media and groundwater constituents on the environmental impacts of a permeable reactive barrier (PRB) were evaluated using life cycle assessment (LCA). The PRB is assumed to be installed at a simulated site contaminated by either Cr(VI) alone or Cr(VI) and As(V). Results show that the trench-based construction method can reduce the environmental impacts of the remediation remarkably compared to the caisson-based method due to less construction material consumption by the funnel. Compared to using the zerovalent iron (Fe(0)) and quartz sand mixture, the use of the Fe(0) and iron oxide-coated sand (IOCS) mixture can reduce the environmental impacts. In the presence of natural organic matter (NOM) in groundwater, the environmental impacts generated by the reactive media were significantly increased because of the higher usage of Fe(0). The environmental impacts are lower by using the Fe(0) and IOCS mixture in the groundwater with NOM, compared with using the Fe(0) and quartz sand mixture. Since IOCS can enhance the removal efficiency of Cr(VI) and As(V), the usage of the Fe(0) can be reduced, which in turn reduces the impacts induced by the reactive media.

  13. Health and efficiency in trimix versus air breathing in compressed air workers.

    Science.gov (United States)

    Van Rees Vellinga, T P; Verhoeven, A C; Van Dijk, F J H; Sterk, W

    2006-01-01

    The Western Scheldt Tunneling Project in the Netherlands provided a unique opportunity to evaluate the effects of trimix usage on the health of compressed air workers and the efficiency of the project. Data analysis addressed 318 exposures to compressed air at 3.9-4.4 bar gauge and 52 exposures to trimix (25% oxygen, 25% helium, and 50% nitrogen) at 4.6-4.8 bar gauge. Results revealed three incidents of decompression sickness all of which involved the use of compressed air. During exposure to compressed air, the effects of nitrogen narcosis were manifested in operational errors and increased fatigue among the workers. When using trimix, less effort was required for breathing, and mandatory decompression times for stays of a specific duration and maximum depth were considerably shorter. We conclude that it might be rational--for both medical and operational reasons--to use breathing gases with lower nitrogen fractions (e.g., trimix) for deep-caisson work at pressures exceeding 3 bar gauge, although definitive studies are needed.

  14. Experimental analysis of 7.62 mm hydrodynamic ram in containers

    Science.gov (United States)

    Deletombe, E.; Fabis, J.; Dupas, J.; Mortier, J. M.

    2013-02-01

    The design of fuel tanks with a reduced vulnerability with respect to hydrodynamic ram pressure (HRAM) effects is of an increasing need in the Civil (e.g. the Concorde accident), and Defence (military aircraft, unmanned vehicle systems) aircraft industries. The presented work concerns experimental research which aims at observing two hydraulic ram events - both induced by a 7.62 mm bullet shot in very different containers - throughout their various steps until the final collapse of the generated cavity, in order to study the nature of HRAM, the influence of the containers geometry, and to measure original dynamic data for numerical modelling developments and validation. For that purpose, test configurations and experimental results are described, documented and discussed. They concern two types of firing tests that were performed at ONERA using the NATO 7.62 mm projectile, respectively in the frame of ONERA (pool) and EUCLID (caisson) funded research projects. The authors concentrate on two topics: on the one hand, digital image analysis to measure the cavity geometry during its growth and collapse phases and, on the other hand, pressure measurements that catch the transient shock wave. The originality of the work consists in the fact that - compared with other published works - the phenomenon is studied up to tens of milliseconds in a very large pool for theoretical analysis of the bullet/liquid interactions only, and in a realistic fuel tank specimen to consider influence of boundary conditions onto the cavity characteristics (geometry, dynamics).

  15. Results of the reactant sand-fracking pilot test and implications for the in situ remediation of chlorinated VOCs and metals in deep and fractured bedrock aquifers.

    Science.gov (United States)

    Marcus, D L; Bonds, C

    1999-08-12

    Permeable reactive barriers (PRBs), such as the Waterloo Funnel and Gate System, first implemented at Canadian Forces Borden facility in 1992, are a passive remediation technology capable of controlling the migration of, and treating contaminated groundwater in situ. Most of the PRBs installed to date have been shallow installations created by backfilling sheet-pile shored excavations with iron filing reactive media. More recently continuous trenchers [R. Puls, Installation of permeable reactive barriers using continuous trenching equipment, Proceedings of the RTDF Permeable Barriers Work Group, Virginia Beach, VA, September 1997] and Caissons [J. Vogan, Caisson installation of a pilot scale, permeable reactive barrier in situ treatment zone at the Sommersworth Landfill, NH, Presented to the RTDF Permeable Barriers Work Group, Alexandria, VA, April 1996], and vertical fracturing emplacements [G. Hocking, Vertical hydraulic fracture emplacement of permeable reactive barriers, Progress Report delivered to the Permeable Reactive Barriers Workgroup of the Remedial Technology Development Forum, Beaverton, OR, April 1998] have been used to create reactive barriers in soil. None of the prior methods are capable of adequately addressing groundwater contamination in deep and fractured bedrock aquifers. The purpose of the RSF pilot study was to install reactive media into an impacted bedrock aquifer, and to evaluate the effectiveness of in situ treatment of chlorinated volatile organic compounds (CVOCs) and metals in that type of aquifer. Three discrete fractures were identified and treated and were subjected to testing before and after treatment. Between 300 and 1700 lb. of 1 mm diameter reactive proppants were injected into each zone to facilitate treatment. Monitoring data obtained from adjacent observation wells verified that fracking fluids reached at least 42 ft from the treatment well following hydrofracturing. The concentrations of many of the CVOCs decreased up to

  16. Accurate measurements of vadose zone fluxes using automated equilibrium tension plate lysimeters: A synopsis of results from the Spydia research facility, New Zealand.

    Science.gov (United States)

    Wöhling, Thomas; Barkle, Greg; Stenger, Roland; Moorhead, Brian; Wall, Aaron; Clague, Juliet

    2014-05-01

    Automated equilibrium tension plate lysimeters (AETLs) are arguably the most accurate method to measure unsaturated water and contaminant fluxes below the root zone at the scale of up to 1 m². The AETL technique utilizes a porous sintered stainless-steel plate to provide a comparatively large sampling area with a continuously controlled vacuum that is in "equilibrium" with the surrounding vadose zone matric pressure to ensure measured fluxes represent those under undisturbed conditions. This novel lysimeter technique was used at an intensive research site for investigations of contaminant pathways from the land surface to the groundwater on a sheep and beef farm under pastoral land use in the Tutaeuaua subcatchment, New Zealand. The Spydia research facility was constructed in 2005 and was fully operational between 2006 and 2011. Extending from a central access caisson, 15 separately controlled AETLs with 0.2 m² surface area were installed at five depths between 0.4 m and 5.1 m into the undisturbed volcanic vadose zone materials. The unique setup of the facility ensured minimum interference of the experimental equipment and external factors with the measurements. Over the period of more than five years, a comprehensive data set was collected at each of the 15 AETL locations which comprises of time series of soil water flux, pressure head, volumetric water contents, and soil temperature. The soil water was regularly analysed for EC, pH, dissolved carbon, various nitrogen compounds (including nitrate, ammonia, and organic N), phosphorus, bromide, chloride, sulphate, silica, and a range of other major ions, as well as for various metals. Climate data was measured directly at the site (rainfall) and a climate station at 500m distance. The shallow groundwater was sampled at three different depths directly from the Spydia caisson and at various observation wells surrounding the facility. Two tracer experiments were conducted at the site in 2009 and 2010. In the 2009

  17. Field lysimeter studies for performance evaluation of grouted Hanford defense wastes

    Energy Technology Data Exchange (ETDEWEB)

    Last, G.V.; Serne, R.J.; LeGore, V.L.

    1995-02-01

    The Grout Waste Test Facility (GWTF) consisted of four large field lysimeters designed to test the leaching and migration rates of grout-solidified low-level radioactive wastes generated by Hanford Site operations. Each lysimeter was an 8-m-deep by 2-media closed-bottom caisson that was placed in the ground such that the uppermost rim remained just above grade. Two of these lysimeters were used; the other two remained empty. The two lysimeters that were used (A-1 and B-1) were backfilled with a two-layer soil profile representative of the proposed grout disposal site. The proposed grout disposal site (termed the Grout Treatment Facility Landfill) is located immediately east of the Hanford Site`s 200 East Area. This soil profile consisted of a coarse sand into which the grout waste forms were placed and covered by 4 m of a very fine sand. The A-1 lysimeter was backfilled in March 1985, with a grout-solidified phosphate/sulfate liquid waste from N Reactor decontamination and ion exchange resin regeneration. The B-1 lysimeter was backfilled in September 1985 and received a grout-solidified simulated cladding removal waste representative of waste generated from fuel reprocessing operations at the head end of the Plutonium Uranium Extraction (PUREX) plant. Routine monitoring and leachate collection activities were conducted for over three years, terminating in January 1989. Drainage was collected sporadically between January 1989 and December 1992. Decontamination and decommissioning of these lysimeters during the summer of 1994, confirmed the presence of a 15 to 20-cm-long hairline crack in one of the bottom plate welds. This report discusses the design and construction of the GWTF, presents the routine data collected from this facility through January 1989 and subsequent data collected sporadically between 1989 and 1993, and provides a brief discussion concerning preliminary interpretation of the results.

  18. Wave Reflection and Loss Characteristics of an Emerged Quarter Circle Breakwater with Varying Seaside Perforations

    Science.gov (United States)

    Binumol, S.; Rao, Subba; Hegde, Arkal Vittal

    2017-09-01

    Breakwaters are one of the most important harbour structures constructed to withstand and dissipate the dynamic energy due to the action of the waves. Due to fast growing need of the universe and advances in technology different types of breakwaters are being developed. Quarter circle breakwater is a new type of breakwater emerged from semi circular breakwater and the first model was developed in Peoples Republic of China (2006). Quarter circle breakwater with perforations posses merits of caisson as well as perforated breakwaters such as low weight, requires less materials, suited for poor soil conditions, easily transported, handled and placed at the site, aesthetically pleasing, cost effective, eco-friendly and stable. Therefore it is necessary to carry out detailed studies on hydrodynamic characteristics to investigate the suitability and applicability of various types of quarter circle breakwaters. The present study investigates the wave reflection and loss characteristics of an emerged seaside perforated quarter circle breakwater of radius 55 cm and with varying ratios of spacing to diameter of perforations, for different water depths and wave conditions. The tests were conducted in the two-dimensional monochromatic wave flume available in Marine Structures laboratory of Department of Applied Mechanics and Hydraulics of National Institute of Technology, Surathkal, Karnataka, India. The results were plotted as non-dimensional graphs and it was observed that the reflection coefficient increases with increase in wave steepness for all values of ratio of height of breakwater structure to water depth. For a constant water depth, wave reflection increases with increase in ratio of spacing to diameter of perforations. It was also found that the loss coefficient decreases with increase in wave steepness for all values of ratio of height of breakwater structure to water depth, and ratio of spacing to diameter of perforations.

  19. DESIGN, PERFORMANCE, AND SUSTAINABILITY OF ENGINEERED COVERS FOR URANIUM MILL TAILINGS

    Energy Technology Data Exchange (ETDEWEB)

    Waugh, W. Jody

    2004-04-21

    Final remedies at most uranium mill tailings sites include engineered covers designed to contain metals and radionuclides in the subsurface for hundreds of years. Early cover designs rely on compacted soil layers to limit water infiltration and release of radon, but some of these covers inadvertently created habitats for deep-rooted plants. Root intrusion and soil development increased the saturated hydraulic conductivity several orders of magnitude above design targets. These covers may require high levels of maintenance to sustain long-term performance. Relatively low precipitation, high potential evapotranspiration, and thick unsaturated soils favor long-term hydrologic isolation of buried waste at arid and semiarid sites. Later covers were designed to mimic this natural soil-water balance with the goal of sustaining performance with little or no maintenance. For example, the cover for the Monticello, Utah, Superfund site relies on a thick soil-sponge layer overlying a sand-and-gravel capillary barrier to store precipitation while plants are dormant and on native vegetation to dry the soil sponge during the growing season. Measurements of both off-site caisson lysimeters and a large 3-ha lysimeter built into the final cover show that drainage has been well below a U.S. Environmental Protection Agency target of less than 3.0 mm/yr. Our stewardship strategy combines monitoring precursors to failure, probabilistic riskbased modeling, and characterization of natural analogs to project performance of covers for a range of possible future environmental scenarios. Natural analogs are needed to understand how ecological processes will influence cover performance, processes that cannot be predicted with short-term monitoring and existing numerical models.

  20. Batch and column studies of adsorption of Li, Ni and Br by a reference sand for contaminant transport experiments

    Energy Technology Data Exchange (ETDEWEB)

    Seigel, M.D. [Sandia National Labs., Albuquerque, NM (United States); Ward, D.B.; Bryan, C.R. [Univ. of New Mexico, Albuquerque, NM (United States)] [and others

    1995-09-01

    A processed quartz sand (Wedron 510), mined from the St. Peter sandstone, has been characterized by a variety of chemical and physical methods for use as a reference porous media in transport model validation experiments. Wedron 510 sand was used in an intermediate-scale experiment involving migration of Ni, Li and Br through a 6-m high x 3-m diameter caisson. Ni and Li adsorption/desorption, and Li/Ni site-competition experiments yielded information on the importance of the trace mineral phases to adsorption of Li and Ni by the sand. The presence of an iron hydroxide coating similar to goethite on the sand grains is suggested by visual observation and leaching experiments. Kaolinite was identified by SEM and XRD as a significant trace mineral phase in the sand and occurs as small particles coating the sand grains. Quartz, the predominant constituent of the sand by weight, does not appear to contribute significantly to the adsorption properties of the sand. Qualitatively, the adsorption properties of the sand can be adequately modeled as a two-mineral system (goethite and kaolinite). The studies described in this report should provide a basis for understanding transport of Ni, Li and Br through porous media similar to the reference sand. Techniques were developed for obtaining parameter values for surface complexation and kinetic adsorption models for the sand and its mineral components. These constants can be used directly in coupled hydrogeochemical transport codes. The techniques should be useful for characterization of other natural materials and elements in high-level nuclear waste in support of coupled hydrogeochemical transport calculations for Yucca Mountain.

  1. FINITE ELEMENT ANALYSIS OF CENTRELESS-LUNETTE TURNING OF HEAVY SHAFT

    Directory of Open Access Journals (Sweden)

    Yu. V. Vasilevich

    2017-01-01

    Full Text Available Dynamics of huge renovated lathe is simulated. Turning scheme concerns to heavy rotor shaft finishing. Lofty parts and milling head may create dynamic problems. Static, modal and harmonic frequency response function simulations were provided. Bearing system consists of bed, support, tool, lunettes, tailstock. Headstock didn’t take part in shaft holding. Static and dynamic rigidities founded 3–4 times less for support than for shaft. Tool rigidity lessens from 186.5 to 11.9 N/µm for speeding from slow to near resonance turning. Twelve lathe eigenmodes were evaluated. Two eigenmodes are most dangerous. It is “shaft swinging on lunettes” (M1, 26.7 Hz and “support pecking” (M3, 54.4 Hz. Bed has excessive flexibility due to through holes and lack of inner ribbing. Polymer concrete filling is moderately effective. Changing two-lunette (2L scheme to three-lunette (3L increases rigidity of shaft at 2.09 times at statics but gives limited action in dynamics. Resonant peaks on frequency response function are lowered only at 1.32 times for M1, M3. Effect of dynamic damping is revealed under condition of proximity middle lunette to lofty support. Support serves as tuned mass damper. Measures of machine tool reinforcement are simulated. Shaft swinging according to M1 may hardly be blocked by passive means. It would be better to bypass it. “Support pecking” resonance (M3 succumbs to only full set of measures. Small effect of partial reinforcement is predicted. Three frequency intervals are recommended for turn-milling at huge lathe: pre-resonant (<20 Hz, inter-resonant (35–45 Hz and post-resonant (>65 Hz. The last one is more suited. Next design step is to create triangle inner ribbing system or caissons inside of bed.

  2. Centro administrativo y de investigación de una compañía de seguros Viena – Austria

    Directory of Open Access Journals (Sweden)

    Hlaweniczka, Kurt

    1978-09-01

    Full Text Available This building is shaped in the form of a cross, with ten towers, six of which are 70 m high and the other four 45 m high. The most outstanding feature is their slender Steel, water-filled columns supporting the floor construction. The columns, in their turn rest on cross beams placed on box trusses (caisson connecting the towers. The towers were built using sliding forms, while the box trusses were built using scaffold forms. Infra-red rays were used in different construction stages to achieve the fast curing of the concrete. The building contains, among other areas, an electronic data processing facility, a teaching hall, mess hall, lounge, etc.

    Este edificio tiene forma de una cruz, con diez torres, cuatro de ellas con una altura de 70 m y las otras seis con una altura de 45 m. Su rasgo más característico son unas columnas delgadas de acero llenas de agua, sobre las que se apoyan los forjados de las plantas. Estas columnas, a su vez, se apoyan sobre vigas transversales colocadas sobre las vigas-cajón que unen las torres. Las torres fueron realizadas mediante encofrados deslizantes, mientras las vigas-cajón lo fueron con cimbras. En diversas fases de la construcción se utilizaron rayos ¡infrarrojos para conseguir un endurecimiento rápido del hormigón. El edificio consta de una instalación de elaboración electrónica de datos, una sala de enseñanza, comedor, sala de estar, etc.

  3. Applications of the observational method in deep foundations

    Directory of Open Access Journals (Sweden)

    Fathi M. Abdrabbo

    2012-12-01

    Full Text Available The observational method was introduced into geotechnical engineering to improve both theories and construction techniques. This method was developed to avoid highly conservative assumptions about soil properties in geotechnical design when faced with unavoidable uncertainties of natural ground conditions. The assumptions involved in soil mechanics theories usually differ to a certain extent from reality. These assumptions can be improved by employing an observational database. Thus, theories of geotechnical engineering can be developed by observations during the construction stage. Moreover, precise management of construction work by close observations is essential to avoid risk and to alter the design if needed to match the real conditions. This paper sheds some light on the importance of the observational concept in deep foundations through three case studies. The first one demonstrates the effect of working hypotheses on design outputs of an open caisson of 22 m internal diameter. The other two case studies present the difference between theory and reality during construction stage of auger cast-in-place piles (ACIP in difficult subsoil conditions. Importance of merging the documented theories with the available observations is discussed. The study shows that working hypotheses and engineering models affect the cost and the time required for construction of deep foundations. Field observations are essential during installation of ACIP at a site. Some precautions should be considered when drilling ACIP through sandstone of inclined top surface. These precautions are mainly dependent upon field observations during construction. ACIP can be used effectively in soil formations that have galleries and caves using a cement–bentonite mixture to fill the holes of the unsuccessful piles. Finally, the paper shares a series of practical guidelines with engineering community all over the world that may assist in design and construction of deep

  4. Landfill stabilization focus area: Technology summary

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-06-01

    Landfills within the DOE Complex as of 1990 are estimated to contain 3 million cubic meters of buried waste. The DOE facilities where the waste is predominantly located are at Hanford, the Savannah River Site (SRS), the Idaho National Engineering Laboratory (INEL), the Los Alamos National Laboratory (LANL), the Oak Ridge Reservation (ORR), the Nevada Test Site (NTS), and the Rocky Flats Plant (RFP). Landfills include buried waste, whether on pads or in trenches, sumps, ponds, pits, cribs, heaps and piles, auger holes, caissons, and sanitary landfills. Approximately half of all DOE buried waste was disposed of before 1970. Disposal regulations at that time permitted the commingling of various types of waste (i.e., transuranic, low-level radioactive, hazardous). As a result, much of the buried waste throughout the DOE Complex is presently believed to be contaminated with both hazardous and radioactive materials. DOE buried waste typically includes transuranic-contaminated radioactive waste (TRU), low-level radioactive waste (LLW), hazardous waste per 40 CFR 26 1, greater-than-class-C waste per CFR 61 55 (GTCC), mixed TRU waste, and mixed LLW. The mission of the Landfill Stabilization Focus Area is to develop, demonstrate, and deliver safer,more cost-effective and efficient technologies which satisfy DOE site needs for the remediation and management of landfills. The LSFA is structured into five technology areas to meet the landfill remediation and management needs across the DOE complex. These technology areas are: assessment, retrieval, treatment, containment, and stabilization. Technical tasks in each of these areas are reviewed.

  5. TECHNOLOGY FOR INSTALLATION OF REINFORCED CONCRETE FLOOR SLABS LIGHTENED BY CORE DRIVERS WITH PRELIMINARY REINFORCEMENT STRESS

    Directory of Open Access Journals (Sweden)

    S. N. Leonovich

    2015-01-01

    Full Text Available The paper presents technology for installation of floor slabs lightened by plastic core drivers which are preliminary stressed under construction conditions.  Efficiency of such constructive solution is justified by the action of preliminary concrete compression in the tensile zone while reducing structure dead weight due to void arrangement.  The paper provides classification of systems for preliminary stress and contains recommendations on selection of the system depending on peculiariar features of the designed construction.  Main products and materials required for execution of works , requirements to stressed wire rope reinforcement, its main characteristics have been considered in the paper.Principal diagram of the lightened preliminary stressed slab stipulates arrangement of so called  dummy caisson. Strands of reinforcement ropes are located within the framework of bars passing over supporting structures (over vertical bearing structures of  the framework and voids are formed in the cells between bars by laying hollow plastic items joined together by a cage. The paper presents technological sequence of operations required for arrangement of the lightened preliminary stressed slab, schemes for equipment arrangement and characteristics of the applied devices and units (pushing device for reinforcement ropes, hydraulic jack with delivery hydraulic pump, mixing station, injection pump and others.  Recommendations have been given for execution of works in cold weather. The paper considers problems pertaining to control quality of the materials and items which are supplied to a construction site and directly execution of works on preliminary stress of a cellular slab.The executed analysis of technology permits to conclude that it is characterized by high level of applicability for import substitution. It is necessary to consider the possibility to apply the technology at objects of various application while comparing it with other

  6. Geotechnical conditions and ice loading for an offshore drilling platform in the Canadian Beaufort Sea

    Energy Technology Data Exchange (ETDEWEB)

    Martens, S.; Eshraghian, A.; Rogers, B. [Klohn Crippen Berger Ltd., Calgary, AB (Canada)

    2009-07-01

    This paper addressed the geotechnical aspects of the deployment of the steel drilling caisson (SDC) at the Paktoa site in the Canadian Beaufort Sea. The SDC is a bottom founded mobile offshore drilling platform that can operate in 8 to 25 m of water in an Arctic environment. It is mated to a submersible barge in order to resist large ice forces on the structure at sites with relatively weak soils, without the need for site preparation. To date, the SDC has been deployed at 8 sites in the Canadian and Alaskan Beaufort Sea. This paper focused on the Paktoa location, where the SDC was deployed 50 km offshore in a water depth of 14 m during the winter of 2005-2006. Geotechnical investigations were conducted from the landfast ice prior to deployment and from the SDC deck. This paper described the soil properties and design loading; design stability; and deformation analysis. The environmental loads considered for the SDC design included ice push, waves and earthquakes. The ice loading was the dominant loading case. The instrumentation installed in the seabed included 2 push-in piezometers and an inclinometer. An ice loading event in February 2006 resulted in considerable displacements in the in-place inclinometer string below the SDC. Several analysis methods were used to estimate the magnitude of the ice load during this event in order to better understand the magnitude of ice loading for future Arctic deployments of gravity based drilling platforms. It was concluded that further deployments should have a minimum of 2 and preferably 4 in-place inclinometer strings to measure real-time deformation of the seabed to enable measurement of rotation of the structure that may occur due to asymmetrical ice loading. 10 refs., 2 tabs., 15 figs.

  7. Puente sobre el río Jarama, España

    Directory of Open Access Journals (Sweden)

    Rodríguez-Borlado, Ramiro

    1965-12-01

    Full Text Available As the previous bridge connecting Barajas with Paracuellos, on the 5th km of the road joining these villages, had been destroyed, a new one has been built. It is made of steel, has five spans, with a total length of 178.85 ms, has a 7 m wide pavement, and two 1.10 m wide sidewalks. The main feature of this bridge is a continuous girder, running over the three central spans, one 36.9 m long, and the other two 24.2 m each. This girder has a continuous web, of double T section. It has two halves, 6.2 ms apart, suitably linked together. The depth varies, and increases slightly over the central supports. The central piles rest on new foundations, consisting of caissons. The rest of the old foundations have been preserved. At the central pile the attachment is fixed, and on the two adjacent piles roller bearings have been fitted. At the end supports the deck structure rests on neoprene plates, 12 mm thick. To ensure the stability of the deck slab, a number of adequately spaced dilation joints have been provided.Por haber sido socavado y destruido el puente primitivo, situado en el punto kilométrico 4,800, y con objeto de restablecer el tráfico en la carretera de Barajas a Paracuellos, se ha construido uno nuevo, de estructura metálica, de cinco tramos, con una longitud total de 178,85 m, calzada de 7 m y dos andenes de 1,10 m de anchura cada uno. La parte principal de esta obra consiste en una viga continua que salva los tres tramos centrales, uno de 36,90 m de luz y los dos adyacentes a él de 24,20 m. Esta viga está constituida por dos de alma llena, de sección en forma de doble T, espaciadas a 6,20 m y convenientemente arriostradas entre ellas. Su canto es variable, aumentando linealmente en las proximidades de los dos apoyos centrales, hasta estos mismos. Las pilas de los tres tramos centrales se apoyan sobre nuevos cimientos, realizados con cajones, conservando los demás cimientos existentes. El apoyo sobre la pila central es fijo, y de

  8. Puentes Santa María y Pantano, en la Autopista del Sol (Italia

    Directory of Open Access Journals (Sweden)

    Frizzi, Dorian

    1966-03-01

    Full Text Available Of all the constructional features along the 750 km of the Milan-Napoles motor road, only the two above mentioned bridges will be described. Both have have a large radius curvature in the horizontal plane, two independent pavements, and in both cases the deck is supported by a palisade of cylindrical columns, some of them very tall and of considerable diameter. The main spans are 40 m long, and the piles can reach a height of up to 40 m above their base. The foundations of these have necessitated the adoption of pneumatic caissons. The longest beams of the Santa Maria bridge are prestressed, concreted in the workshop and placed with the aid of auxiliary girders and travelling cranes, which lift them to their final emplacement. At the Fosso Pantano viaduct the girders were concreted at one end of the deck, and were then transported to their final position with the help of a provisional tubular framework. The beams rest either on led or neoprene plates, in order to provide suitable flexible joints.Entre todas las obras de fábrica, construidas a lo largo de los 750 km de esta autopista Milán-Nápoles, se describen aquí sólo los dos puentes enunciados. Ambos tienen su eje en curva circular de gran radio, dos calzadas independientes y soportes formando palizadas de montantes de fuste cilíndrico, algunas de gran diámetro y altura. Los tramos de mayor importancia son de 40 m de luz, y sus soportes ganan la mayor cota a unos 40 m de la base. Para los cimientos de estos últimos ha sido necesario el empleo de cajones neumáticos. Las vigas de mayor longitud en el puente de Santa María son de hormigón pretensado, hormigonadas en taller y lanzadas con vigas auxiliares, provistas de un puente-grúa para llevarlas a su posición definitiva. En el viaducto de Fosso Pantano, las vigas se hormigonaron en una extremidad del tablero y se riparon después hasta llevarlas a su posición definitiva, para lo cual se preparó previamente un entramado tubular

  9. Joint pain and Doppler-detectable bubbles in altitude (Hypobaric) decompression

    Science.gov (United States)

    Powell, Michael R.

    1993-01-01

    The observation that altitude decompression sickness (DCS) is associated with pain in the lower extremities is not new, although it is not a consistent finding. DCS in divers is generally in the upper body, an effect often attributed to non-loading of the body while immersed. In caisson workers, DCS is reported more in the lower extremities. Surprisingly, many researchers do not mention the location of DCS joint pain, apparently considering it to be random. This is not the case for the tissue ratios encountered in studying decompression associated with simulated EVA. In NASA/JSC tests, altitude DCS generally presented first in either the ankle, knee, or hip (83 percent = 73/88). There was a definite statistical relation between the maximum Spencer precordial Doppler Grade and the incidence of DCS in the extremity, although this is not meant to imply a casual relation between circulating gas bubbles and joint pain. The risk of DCS with Grade 4 was considerably higher than that of Grades 0 to 3. The DCS risk was independent of the 'tissue ratio.' There was a predominance of lower extremity DCS even when exercise was performed with the upper body. The reason for these locations we hypothesize to be attributed to the formation of tissue gas micronuclei from kinetic and tensile forces (stress-assisted nucleation) and are the result of the individuals ambulating in a 1g environment. Additionally, since these showers of Doppler bubbles can persist for hours, it is difficult to imagine that they are emanating solely from tendons and ligaments, the supposed site of joint pain. This follows from Henry's law linking the volume of joint tissue (the solvent) and the solubility coefficient of inert gas; there is volumetrically insufficient connective tissue to produce the prolonged release of gas bubbles. If gas bubbles are spawned and released from connective tissue, their volume is increased by those from muscle tissue. Therefore, the nexus between Doppler-detectable gas

  10. Varios puentes de Berlín

    Directory of Open Access Journals (Sweden)

    Heusel, Hanns

    1963-03-01

    Full Text Available The last war destroyed a large number of civil works, among which were the Berlin bridges. As the number of these was considerable, it was decided to improve on the original designs and methods of construction, taking advantage of new materials and prestressing techniques. Of the 84 reconstructed bridges, 24 of them have been made in prestressed concrete. This emphasizes what considerable importance was attached to this constructional method at a time when this technology had not yet reached its present day mature development. The rebuilt bridges have spans varying between 25 and 100 ms. Their foundations differ considerably in each particular case. Some consist of pile structures, others are of sheet piling, and others again are caissons. At present the most important prestressed bridge in Berlin is the Disching bridge, which runs over the Havel, and carries the road to Spandau. Its single span is 94 ms long, and the ratio of rise to span is 1/63.1.La última guerra mundial destruyó una serie de obras públicas, entre las cuales se hallaban muchos puentes de Berlín. Como el número de puentes destruidos es considerable, se pensó en mejorar las obras originales y los métodos de construcción, para lo cual se contaban con nuevos materiales y la técnica del pretensado, actualmente en estado de madurez. De las 84 obras que se han reconstruido, 24 son de hormigón pretensado. Esto pone de relieve la importancia que se le dio a este sistema en aquellos momentos en que la técnica de este tipo de construcciones no había alcanzado todavía el actual desarrollo. Los puentes reconstruidos tienen luces que varían de 25 a 100 metros. Los cimientos de estas obras son muy distintos y variados: unos están formados por tablestacas, otros se apoyan sobre pilotes y, finalmente, otros, constituidos por cajones. El puente pretensado más importante actualmente en Berlín es el de Disching, que salva el río Havel y cuyo objeto es el de dar paso a la

  11. Study of an experimental methodology for thermal properties diagnostic of building envelop

    Science.gov (United States)

    Yang, Yingying; Sempy, Alain; Vogt Wu, Tingting; Sommier, Alain; Dumoulin, Jean; Batsale, Jean Christophe

    2017-04-01

    The building envelope plays a critical role in determining levels of comfort and building efficiency. Its real thermal properties characterization is of major interest to be able to diagnose energy efficiency performance of buildings (new construction and retrofitted existing old building). Research and development on a possible methodology for energy diagnostic of the building envelop is a hot topic and necessary trend. Many kinds of sensors and instruments are used for the studies. The application of infrared (IR) thermography in non-destructive evaluation has been widely employed for qualitative evaluations for building diagnostics; meanwhile, the IR thermography technology also has a large potentiality for the evaluation of the thermal characteristics of the building envelope. Some promising recent research studies have been carried out with such contactless measurement technique. Nevertheless, research efforts are still required for in situ measurements under natural environmental conditions. In order to develop new solutions for non-intrusive evaluation of local thermal performance, enabling quantitative assessment of thermal properties of buildings and materials, experiments were carried out on a multi-layer pratical scale wall fixed on a caisson placed in a climatic chamber. Six halogen lamps (1.5 kW for each lamp) placed in front of objective wall were used to emulate sunny conditions. The radiative heat flux emitted was monitored and modulated with time according to typical weather data set encountered in France. Both steady state and transient regime heat transfer were studied during these experiments. Contact sensors (thermocouples, heat flux meters, Peltier sensors) and non-contact sensors (thermal IR camera, pyranometer) were used to measure the temperatures and heat flux density evolution. It has to be noticed that the Peltier sensors have been tuned and used with a specific processing to set them compliant for heat flux density measurements. The

  12. Nuevo puente de La Barca sobre el río Ter

    Directory of Open Access Journals (Sweden)

    Rodríguez-Borlado, Ramiro

    1967-12-01

    Full Text Available The new La Barca bridge, over the river Ter, is on the northern approach to Gerona, and carries the CN II road from Madrid to France, passing through Barcelona. It substitutes another bridge of the same name, which was inadequate for the heavy increase in traffic, during recent years. The bridge is 128 m long, consisting of two lateral spans, each 37 m long, and a central span of 54 m. The superstructure consists of ten hollow metal girders, of variable depth, arranged as three-part cantilevered structures. The lateral sections are cantilevered towards the centre, and the middle part of the span rests on their extremities. The girders support a reinforced concrete slab of 16 cm thickness and 14 m width: 8 m for the roadway, and 3 m for each of the sidewalks. The structure rests on two piles and two abutments of reinforced concrete, based on caisson foundations, except for one of the abutments, which is a reinforced concrete block. The project is completed by the approach roads and stonemasonry.El nuevo puente de La Barca, sobre el río Ter, está situado en el acceso norte a Gerona de la C. N. II de Madrid a Francia por Barcelona. Sustituye a otro del mismo nombre que resultaba insuficiente para la elevada intensidad de tráfico de esta vía. La luz del puente es de 128 m, dividida en dos tramos laterales, de 37 m de luz, y un tramo central, de 54 m. La superestructura está constituida por cinco vigas metálicas, huecas, de canto variable, dispuestas como vigas cantilever de tres elementos. Los elementos laterales se prolongan hacia el centro en voladizo, apoyándose sobre ellos el elemento central. Las vigas soportan una losa de hormigón armado de 16 cm de espesor, y 14 m de anchura: 8 m para la calzada y 3 m para cada uno de los andenes laterales. El conjunto se apoya sobre dos pilas y dos estribos, de hormigón armado, cimentados sobre cajones indios, excepto uno de los estribos, que está cimentado sobre macizo de hormigón armado

  13. Le sanctuaire gallo-romain de Drevant (Cher : état des connaissances et nouvelle approche archéologique des façades sud et est The Gallo-Roman sanctuary of Drevant (Cher: state of knowledges and new archeological approch of south and east faces

    Directory of Open Access Journals (Sweden)

    Frédéric Méténier

    2012-01-01

    Full Text Available Les fouilles archéologiques préventives menées en 2007 et 2008 sur le sanctuaire gallo-romain de Drevant (Cher sont intervenues dans le cadre d’un projet de restauration et de mise en valeur des maçonneries antiques commandé par la Conservation Régionale des Monuments Historiques de la Direction Régionale des Affaires Culturelles du Centre. Elles ont été prescrites et contrôlées par le service régional de l’Archéologie du Centre. L’occupation du site débute au cours du second âge du Fer mais les premières installations pérennes sont réalisées à la période augustéenne avec la création d’un péribole simple à la construction soignée. Cette construction est rapidement agrémentée d’un second mur en retrait de la façade orientale engendrant la création d’une galerie couverte (porticus. Au centre de la façade est, un pavillon d’accès dont on conserve le perron monumental est également réalisé. La seconde moitié du premier siècle de notre ère voit la création d’un nouvel accès monumental au sud-ouest. L’ensemble est vraisemblablement détruit par un incendie dans le dernier quart du premier siècle.Un nouveau programme architectural plus homogène voit le jour à la transition entre le ier et le iie s., avec la mise en œuvre d’un second péribole à l’intérieur de l’enceinte originelle dans le but de créer des galeries de circulations périphériques (quadriportique autour du temenos. Ces espaces, galeries et aire sacrée, sont remblayés afin de mettre en place de nouveaux sols de béton, tuileaux et calcaire. Les deux accès monumentaux sont arasés, l’angle sud-ouest est refermé alors qu’un nouveau seuil monumental est créé en façade est. Aux angles nord-est et sud-est, des pavillons installés sur des caissons-contreforts ceignent la façade orientale. Enfin, au Bas-Empire, la façade occidentale est rythmée par trois exèdres à chevet plat dont deux à abside interne. La

  14. Industrializing Offshore Wind Power with Serial Assembly and Lower-cost Deployment - Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Kempton, Willett [Univ. of Delaware, Newark, DE (United States)

    2017-12-11

    A team of engineers and contractors has developed a method to move offshore wind installation toward lower cost, faster deployment, and lower environmental impact. A combination of methods, some incremental and some breaks from past practice, interact to yield multiple improvements. Three designs were evaluated based on detailed engineering: 1) a 5 MW turbine on a jacket with pin piles (base case), 2) a 10 MW turbine on a conventional jacket with pin piles, assembled at sea, and 3) a 10 MW turbine on tripod jacket with suction buckets (caissons) and with complete turbine assembly on-shore. The larger turbine, assembly ashore, and the use of suction buckets together substantially reduce capital cost of offshore wind projects. Notable capital cost reductions are: changing from 5 MW to 10 MW turbine, a 31% capital cost reduction, and assembly on land then single-piece install at sea an additional 9% capital cost reduction. An estimated Design 4) estimates further cost reduction when equipment and processes of Design 3) are optimized, rather than adapted to existing equipment and process. Cost of energy for each of the four Designs are also calculated, yielding approximately the same percentage reductions. The methods of Design 3) analyzed here include accepted structures such as suction buckets used in new ways, innovations conceived but previously without engineering and economic validation, combined with new methods not previously proposed. Analysis of Designs 2) and 3) are based on extensive engineering calculations and detailed cost estimates. All design methods can be done with existing equipment, including lift equipment, ports and ships (except that design 4 assumes a more optimized ship). The design team consists of experienced offshore structure designers, heavy lift engineers, wind turbine designers, vessel operators, and marine construction contractors. Comparing the methods based on criteria of cost and deployment speed, the study selected the third design

  15. Life cycle assessment of offshore and onshore sited wind farms

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2004-10-15

    environmental impacts. The foundations of the offshore wind farms make up a considerable factor to the total environmental impacts, as steel is a large constituent part of the foundations, some of which is abandoned at the seabed after dismantling of the farm. Therefore, the foundation of the offshore wind farms is selected as a focus area in connection with possibilities of product optimisation. Other types of foundations are assessed, and it is found that all the assessed foundation types give the same environmental impact, even though one of the types (caisson) will be completely removed from the seabed whereas in the case of other types (mono pile and tripod) everything more than 1 metre below the seabed is abandoned. Even though the operation does not contribute considerably to the environmental impacts, the environmental differences in using helicopter contra boat at maintenance of the offshore turbines have been examined. The differences are significant, as servicing by boat is insignificantly small. But irrespective of the way of transport the servicing will not contribute largely to the total impact from the entire farm in the total lifetime. (BA)

  16. Dique seco de carena. Génova

    Directory of Open Access Journals (Sweden)

    Gai, Luigi

    1965-02-01

    Full Text Available After elaborate planning, the building, towing and sinking of the ship repairing dry dock at Genoa has now been completed. The dock is 260x52x21.5 m in size. Its structure is cellular and it is made of reinforced and prestressed concrete. A special feature of this dock is that it rests on a flexible bed of sand, dredged from the sea bed. To prepare this, the following operations were carried out: mud was first dredged away, the stony outcrops were levelled off, the spaces in between the rocks were filled with concrete, then the layer of sand was placed, and finally a surface of larger aggregate was prepared on top. The method of attaching the dock to the sea bed to ensure its stability is also noteworthy. After much thought, it was decided that once the dock was sunk at its final emplacement, if its cellular compartments were filled with sand ballast, its own weight would ensure its permanent stability in the face of rough seas. The maneuvers for floating the dock, and sinking it, were also complex, since it was essential to take carefully into account the state of the weather. Any storm might have severely damaged the dock's cellular structure. The prefabrication of the caissons, the jointing of them into a large structure, the construction of enclosing walls, the provision of galleries, companionways, and housing facilities inside the dock, and the towing, sinking and ballasting of this large and heavy structure, constitute a series of building and navigational operations of great complexity, which have tested the ability of the firm Fincosit, who specialise in hydraulic projects.Después de profundos estudios se ha terminado recientemente la construcción, remolque y hundimiento del dique seco de carena del puerto de Génova, cuyas dimensiones son: 260x52x21,5 metros. Es de estructura celular, y de hormigón armado y pretensado. La particularidad de la obra estriba en el apoyo de la plataforma sobre un lecho flexible de arena dragada del mar

  17. Engineering for Operation of a Future Belgian Deep Geological Repository for ILW and HLW - 12379

    Energy Technology Data Exchange (ETDEWEB)

    Haverkamp, B.; Biurrun, E.; Nieder-Westermann, G.H. [DBE TECHNOLOGY GmbH, Peine (Germany); Van Humbeeck, H. [ONDRAF/NIRAS, Brussels (Belgium); Van Cotthem, Alain [Tractebel Engineering SA, Brussels (Belgium)

    2012-07-01

    In Belgium, an advanced conceptual design is being elaborated for deep geologic disposal of high level waste (HLW) and for low and intermediate level waste (LILW) not amenable for surface disposal. The concept is based on a shielded steel and concrete container for disposal of HLW, i.e., the Super-container. LILW will be disposed of in separately designed concrete caissons. The reference host rock is the Boom Clay, a poorly indurated clay formation in northeastern Belgium. Investigations into the potential host rock are conducted at the HADES underground research laboratory in Mol, Belgium. In 2009 the Belgian Agency for Management of Radioactive Waste and Enriched Fissile Materials (ONDRAF/NIRAS) initiated a four year research project aimed at confirming the fundamental feasibility of building and operating a repository. The goal of the program is to demonstrate at a detailed conceptual level that the proposed geologic disposal system can be safely constructed, operated, and progressively closed. Part of the broader research efforts being conducted includes evaluations optimization of the waste transportation shaft, subsurface transportation system, ventilation system, and evaluation of backfilling and sealing concepts for the repository design. The potential for implementation of a waste retrieval strategy encompassing the first 100 years after emplacement is also considered. In the framework of a four year research program aimed at confirming the fundamental feasibility of building and operating a repository in poorly indurated clay design studies have been underway to optimize the waste transportation shaft, subsurface transportation system, and ventilation system. Additionally backfilling and sealing concepts proposed for the potential repository have been reviewed in conjunction with impacts related to the potential future inclusion of a retrievability requirement in governing regulations. The main engineering challenges in the Belgian repository concept are