WorldWideScience

Sample records for caissons

  1. Impedance of flexible suction caissons

    DEFF Research Database (Denmark)

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

    2007-01-01

    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......-dependent coefficients corresponding to different degrees of freedom. The dynamic stiffness coefficients for the skirted foundation are evaluated using a three-dimensional coupled boundary element/finite element model. Comparisons with known analytical and numerical solutions indicate that the static and dynamic...

  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...... 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....

  3. WAVE INTERACTION WITH PERFORATED CAISSON BREAKWATERS

    Institute of Scientific and Technical Information of China (English)

    Chen Xue-feng

    2003-01-01

    The reflection coefficient of perforated caissons and the total horizontal forces acting on them were experimentally and numerically analyzed and discussed when wave propagates normally. To consider the viscosity effect of fluid and nonlinear action of waves on structures, the VOF (Volume Of Fluid) method combined with the k-ε turbulence model was used to simulate the interaction between waves and structures. Governing equations were solved with the finite difference method. Through 2D experimental study in the wave flume, the empirical relationship between the reflection coefficient of perforated caissons and the main affecting factors were obtained from the experimental data using the least square method. Also the correlation between the ratio of the total horizontal force acting on perforated caisson and the force acting on solid caisson and the main affecting factors were regressed from the experimental data.

  4. 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

  5. Dynamic Behaviour of Suction Caissons

    DEFF Research Database (Denmark)

    Liingaard, Morten

    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...... 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...... that the concept is useful for use in applications where the performance of the wind turbine are to be analysed. Experimental modal analyses have been carried out with the intention of estimating the natural frequencies of an existing Vestas 3.0 MW offshore wind turbine. The experimental modal analysis of the wind...

  6. Suction caissons subjected to monotonic combined loading

    DEFF Research Database (Denmark)

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

    2016-01-01

    Suction caissons are being increasingly used as offshore foundation solutions in shallow and intermediate water depths. The convenient installation method through the application of suction has rendered this type of foundation as an attractive alternative to the more traditional monopile foundation...... models of the caisson-soil are developed in order to derive the failure envelopes considering both sand and clay profiles. The numerical modelling is being validated by the failure mechanisms reported in the literature for skirted foundations. The sensitivity of the load response curves on the selection...

  7. 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...... weight and same geometries are tested under regular and irregular waves. It is found that, under breaking conditions, the expected inaccuracy of the prediction of the force, inherent on the variability of the breaking process, induce unacceptable errors in the prediction of the sliding. This observation...

  8. Dynamic stiffness of horizontally vibrating suction caissons

    DEFF Research Database (Denmark)

    Latini, Chiara; Zania, Varvara; Cisternino, Michele

    2016-01-01

    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...

  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. Failure Loci of Suction Caisson Foundations Under Combined Loading Conditions

    Institute of Scientific and Technical Information of China (English)

    WANG Dong; JIN Xia

    2008-01-01

    Suction caissons are widely used to support offshore fixed platforms in coastal areas. The loadings transferred to suction caissons include the eccentric lateral force induced by waves and self weight of the platform structure. However, under this kind of combined loading conditions, the failure mechanism of caissons with shallow embedment depths is quite different from conventional deep foundations or onshore shallow footings. The behaviour of caissons subjected to combined loadings may be described with the "failure locus" in force resultant spaces. Here the failure loci of smooth caissons are studied by use of finite element approach, with the embedment ratio of caissons varying in the range of 0.25~1.0 and eccentricity ratio of horizontal loadings in 0~10. The platform settlement and tilt limits are involved into determination of failure loci, thus the platforms can avoid significant displacements for the combined loadings located inside the failure locus. Three families of loading paths are used to map out the locus. It is found that the shape of failure loci depends on 3 non-dimensional parameters, and the failure locus of a given caisson changes gradually from the elliptical curve to hooked curve with increasing shear strength of soil. The lateral capacity of short caissons may be enhanced by vertical forces, compared with the maximum lateral capacity of long caissons occurring at the vertical force being zero. The critical embedment ratios partitioning elliptical and hooked loci are proposed.

  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 caisson...

  13. Numerical Method for Wave Forces Acting on Partially Perforated Caisson

    Institute of Scientific and Technical Information of China (English)

    姜峰; 唐晓成; 金钊; 张莉; 陈洪洲

    2015-01-01

    The perforated caisson is widely applied to practical engineering because of its great advantages in effectively wave energy consumption and cost reduction. The attentions of many scientists were paid to the fluid–structure interaction between wave and perforated caisson studies, but until now, most concerns have been put on theoretical analysis and experimental model set up. In this paper, interaction between the wave and the partial perforated caisson in a 2D numerical wave flume is investigated by means of the renewed SPH algorithm, and the mathematical equations are in the form of SPH numerical approximation based on Navier–Stokes equations. The validity of the SPH mathematical method is examined and the simulated results are compared with the results of theoretical models, meanwhile the complex hydrodynamic characteristics when the water particles flow in or out of a wave absorbing chamber are analyzed and the wave pressure distribution of the perforated caisson is also addressed here. The relationship between the ratio of total horizontal force acting on caisson under regular waves and its influence factors is examined. The data show that the numerical calculation of the ratio of total horizontal force meets the empirical regression equation very well. The simulations of SPH about the wave nonlinearity and breaking are briefly depicted in the paper, suggesting that the advantages and great potentiality of the SPH method is significant compared with traditional methods.

  14. Vibration mechanism research of large-scale and deep-water caisson

    Institute of Scientific and Technical Information of China (English)

    Yin Haihua; Han Jingjing

    2011-01-01

    According to the construction method of Taizhou Bridge, numerical simulation is conducted to analyze the vibration of caisson under wind and water flows to determine the main factors of the caisson vibration. Meanwhile, the localization system of caissons and anchors of Taizhou Bridge is modeled in order to summarize the vibration mechanism of caissons under deep-water and jet-flow condition, and further pertinent vibration-control measures are proposed. The obtained results are well verified in engineering practice, and consequently the safety risk of positioning the caisson is reduced.

  15. Numerical Simulation of Wave Interaction with Perforated Caisson Breakwaters

    Institute of Scientific and Technical Information of China (English)

    陈雪峰; 李玉成; 王永学; 董国海; 白雪

    2003-01-01

    The volume of fluid (VOF) method is presented to determine the reflection coefficient of and the total horizontal wave force on perforated caisson breakwaters. The present numerical model is compared with a linear analytic solution obtained by Sahoo et al. (2000). Also this model is verified with the authors′ laboratory data. It is found that the numerical model is in good agreement with the regression equations obtained from the experimental data. The present numerical method is further discussed to relate porosity, the relative wave absorbing chamber depth, the reflection coefficient of perforated caissons and the total horizontal force on them.

  16. Apparatus for ground water chemistry investigations in field caissons

    Energy Technology Data Exchange (ETDEWEB)

    Cokal, E.J.; Stallings, E.; Walker, R.; Nyhan, J.W.; Polzer, W.L.; Essington, E.H.

    1985-01-01

    Los Alamos is currently in its second season of ground water chemistry and hydrology experimentation in a field facility that incorporates clusters of six, 3-meter-diameter by 6-meter-deep, soil-filled caissons and required ancillaries. Initial experience gained during the 1983 field season indicated the need for further development of the technology of this type of experimentation supporting hydrologic waste management research. Uniform field application of water/matrix solutions to the caisson, matrix and tracer solution blending/storage, and devices for ground water sampling are discussed.

  17. Apparatus for ground water chemistry investigations in field caissons

    International Nuclear Information System (INIS)

    Los Alamos is currently in its second season of ground water chemistry and hydrology experimentation in a field facility that incorporates clusters of six, 3-meter-diameter by 6-meter-deep, soil-filled caissons and required ancillaries. Initial experience gained during the 1983 field season indicated the need for further development of the technology of this type of experimentation supporting hydrologic waste management research. Uniform field application of water/matrix solutions to the caisson, matrix and tracer solution blending/storage, and devices for ground water sampling are discussed

  18. Thickness measurement of A-1 reactor caisson tube walls

    International Nuclear Information System (INIS)

    The equipment is described of measuring the thickness of caisson pipes built in the Bohunice A-1 reactor. The pulse-type ultrasonic thickness gauge is based on the reflection method using the double probe. The measurement accuracy is 0.1 mm. (J.B.)

  19. Electrokinetic Treatment for Model Caissons with Increasing Dimensions

    Directory of Open Access Journals (Sweden)

    Eltayeb Mohamedelhassan

    2012-01-01

    Full Text Available Electrokinetic treatment has been known in geotechnical engineering for over six decades, yet, the technique is rarely used. This stems from the absence of design guidelines and specifications for electrokinetic treatment systems. An important issue that need to be investigated and understood in order to devise guidelines from experimental results is the effect of the foundation element size on the outcome of the treatment. Also important is determining the optimum distance between the electrodes and estimating the energy consumption prior to treatment. This experimental study is a preliminary step in understanding some of the issues critical for the guidelines and specifications. Four model caissons with surface areas between 16000 and 128000 mm2 were embedded in soft clayey soil under water and treated for 168 hr with a dc voltage of 6 V. From the results, a distance between the anode (model caisson and the cathode equal 0.25 times the outside diameter of the model caisson was identified as optimum. Relationships between the surface area and axial capacity of the model caisson and the surface area and energy consumption were presented. The equations can be used to preliminary estimate the load capacity and the energy consumption for full-scale applications.

  20. Wave Impacts on Caisson Breakwaters Situated in Multidirectionally Breaking Seas

    DEFF Research Database (Denmark)

    Grønbech, J.; Burcharth, Hans F.; Frigaard, Peter;

    1999-01-01

    Attention has been addressed to the effects of wave obliquity and multidirectionality on the wave loads on vertical caisson breakwaters situated in non breaking seas. Within the joint European (MAST-LIP-TAW) research project, a 3D model investigation was carried out at Delft Hydraulics to assess...

  1. Wave Impacts on Caisson Breakwaters Situated in Multidirectionally Breaking Seas

    DEFF Research Database (Denmark)

    Grønbech, J.; Burcharth, Hans F.; Frigaard, Peter;

    1998-01-01

    Attention has been addressed to the effects of wave obliquity and multidirectionality on the wave loads on vertical caisson breakwaters situated in non breaking seas. Within the joint European (MAST-LIP-TAW) research project, a 3D model investigation was carried out at Delft Hydraulics to assess...

  2. 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.

  3. Technical research on control of caisson construction for the middle tower foundation of Taizhou Bridge

    Institute of Scientific and Technical Information of China (English)

    Liu Jianbo; Yang Yanhua; Zhang Yongtao; Du Song

    2011-01-01

    The real-time informational monitoring system is adopted in the construction of middle tower foundation of Taizhou Bridge for the first time. The geometric state of the caisson, the stress of upstream and downstream anchorage cables, underwater topography, the drag forces of the caisson cutting edge and frictional resistances of the sidewall and etc. are monitored in real time. According to the synthesized data analysis and decision-making system, the spatial states of the caisson are adjusted in time to locate and embed the deep water caisson precisely. The offset error of the caisson is less than 30 cm and the vertical error is 1/363 at the final stage. The control technology for construction of large caisson under deep water is concluded and would be helpful for the construction of bridge foundation in the future.

  4. Vibrating-Rocking Motion of Caisson Breakwater Under Breaking Wave Impact

    Institute of Scientific and Technical Information of China (English)

    王元战; 郑斌

    2001-01-01

    The possible motions of a caisson breakwater under dynamic load excitation include vibrating, vibrating-sliding andvibrating-rocking motions. The models of vibrating motion and vibrating-sliding motion have been proposed in an earlypaper. In this paper, a model of vibrating-rocking motion of caisson breakwaters under breaking wave impact is presented, which can be used to simulate the histories of vibrating-rocking motion of caisson breakwaters. The effect of rocking motion on the displacement, rotation, sliding force and overturning moment of breakwaters is investigated. In casethe overturning moment exceeds the stability moment ofa caisson, the caisson may only rock. The caisson overturns only in case the rocking angle exceeds the critical angle. It is shown that the sliding force and overturning moment of break-waters can be reduced effectively due to the rocking motion. It is proposed that some rocking motion should be allowedin breakwater design.

  5. VIBRATING-UPLIFT ROCKING MOTION OF CAISSON BREAKWATERS UNDER VARIOUS BREAKING WAVE IMPACT FORCES

    Institute of Scientific and Technical Information of China (English)

    WANG Yuan-zhan; ZHOU Zhi-rong; YANG Hai-dong

    2005-01-01

    Overturning is one of principal failure types of caisson breakwaters and is an essential content of stability examination in caisson breakwater design. The mass-springdashpot model of caisson-foundation system is used to simulate the vibrating-uplift rocking motion of caisson under various types of breaking wave impact forces, i.e., single peak impact force, double peak impact force, and shock-damping oscillation impact force. The effects of various breaking wave types and the uplift rocking motion on dynamic response behaviors of caisson breakwaters are investigated. It is shown that the dynamic responses of a caisson are significantly different under different types of breaking wave impact forces even when the amplitudes of impact forces are equal. Though the rotation of a caisson is larger due to the uplift rocking motion, the displacement, the sliding force and the overturning moment of the caisson are significantly reduced. It provides the theoretical base for the design idea that the uplift rocking motion of caisson is allowed in design.

  6. Vibrating-Sliding Motion of Caisson Breakwaters Under Various Breaking Wave Impact Forces

    Institute of Scientific and Technical Information of China (English)

    王元战; 于红霞

    2003-01-01

    Sliding is one of the principal failure types of caisson breakwaters and is an essential content of stability examination in caisson breakwater design. Herein, the mass-spring-dashpot model of caisson-base system is used to simulate the vibrating-sliding motion of the caisson under various types of breaking wave impact forces, i.e., single peak impact force, double peak impact force, and shock-damping oscillation impact force. The effects of various breaking wave impacts and the sliding motion on the dynamic response behaviors of caisson breakwaters are investigated and the calculation of relevant system parameters is discussed. It is shown that the dynamic responses of the caisson are significantly different under different types of breaking wave impact forces even when the amplitudes of impact forces are equal. The amplitude of dynamic response of the caisson is lower under single peak impact excitation than that under double peak impact or shock-damping oscillation impact excitation. Though the displacement of the caisson is large due to sliding, the rotation, the sliding force and the overturning moment of the caisson are significantly reduced.

  7. Reliability Index of Caisson Breakwaters for Load Variables Correlated

    Institute of Scientific and Technical Information of China (English)

    郄禄文; 李炎保

    2004-01-01

    In order to suit the condition that the wave uplift is correlated with the horizontal wave load acting on a vertical breakwater, a generally used method for determining the reliability index β of the breakwater, i.e. the Hasofer-Lind method, is extended in a generalized stochastic space for correlative variables. The computational results for a caisson breakwater indicate that the value of β for the case of correlated variables is obviously smaller than that for the case of independent variables.

  8. Three-dimensional numerical simulation of wave interaction with perforated quasi-ellipse caisson

    Directory of Open Access Journals (Sweden)

    Yong-xue WANG

    2011-03-01

    Full Text Available The finite difference method and the VOF method have been used to develop a three dimensional numerical model to study wave interaction with a perforated caisson. And the partial cell method is also adopted to this type of problems for the first time. The validity of the present model, with and without the presence of structures, is examined by comparing the model results with experimental data. Then, the numerical model is used to investigate the effects of various wave and structure parameters on the wave forces and the wave runup of the perforated quasi-ellipse caisson. Compared with the solid quasi-ellipse caisson, the wave force of the perforated quasi-ellipse caisson is significantly reduced with the increasing of porosity on the perforated quasi-ellipse caisson. Furthermore, the perforated quasi-ellipse caisson can reduce the wave runup compared with the solid quasi-ellipse caisson. This reduction tends to increase as the porosity of the perforated quasi-ellipse caisson and relative wave height increase.

  9. 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...

  10. REFLECTION OF OBLIQUE INCIDENT WAVES BY PERFORATED CAISSONS WITH TRAVERSE WALL

    Institute of Scientific and Technical Information of China (English)

    LI Yu-cheng; LIU Hong-jie; DONG Guo-hai

    2005-01-01

    The interaction of oblique incident waves with infinite number of perforated caissons is investigated. The fluid domain is divided into infinite sub-domains by the caissons, and eigen-function expansion is applied to expand velocity potentials in each domain. A phase relation is introduced for wave oscillation in each caisson, and the structure geometry is considered in constructing the models of reflection waves. The reflected waves with the present analysis include all of the waves traveling in different directions when incident wave period is short. Numerical examinations show that velocities at the inner and outer sides of the front walls of caissons are close to each other, and reflection coefficients satisfy the energy conservation relation very well when porous effect parameter is infinite. Numerical results show that the reflection coefficients of oblique incident waves are smaller for shorter caissons at low frequency, and decrease with the increase of wave incident angle.

  11. Modelling of Performance of Caisson Type Breakwaters under Extreme Waves

    Science.gov (United States)

    Güney Doǧan, Gözde; Özyurt Tarakcıoǧlu, Gülizar; Baykal, Cüneyt

    2016-04-01

    Many coastal structures are designed without considering loads of tsunami-like waves or long waves although they are constructed in areas prone to encounter these waves. Performance of caisson type breakwaters under extreme swells is tested in Middle East Technical University (METU) Coastal and Ocean Engineering Laboratory. This paper presents the comparison of pressure measurements taken along the surface of caisson type breakwaters and obtained from numerical modelling of them using IH2VOF as well as damage behavior of the breakwater under the same extreme swells tested in a wave flume at METU. Experiments are conducted in the 1.5 m wide wave flume, which is divided into two parallel sections (0.74 m wide each). A piston type of wave maker is used to generate the long wave conditions located at one end of the wave basin. Water depth is determined as 0.4m and kept constant during the experiments. A caisson type breakwater is constructed to one side of the divided flume. The model scale, based on the Froude similitude law, is chosen as 1:50. 7 different wave conditions are applied in the tests as the wave period ranging from 14.6 s to 34.7 s, wave heights from 3.5 m to 7.5 m and steepness from 0.002 to 0.015 in prototype scale. The design wave parameters for the breakwater were 5m wave height and 9.5s wave period in prototype. To determine the damage of the breakwater which were designed according to this wave but tested under swell waves, video and photo analysis as well as breakwater profile measurements before and after each test are performed. Further investigations are carried out about the acting wave forces on the concrete blocks of the caisson structures via pressure measurements on the surfaces of these structures where the structures are fixed to the channel bottom minimizing. Finally, these pressure measurements will be compared with the results obtained from the numerical study using IH2VOF which is one of the RANS models that can be applied to simulate

  12. Numerical Simulations for Nonlinear Waves Interaction with Multiple Perforated Quasi-Ellipse Caissons

    Directory of Open Access Journals (Sweden)

    Xiaozhong Ren

    2015-01-01

    Full Text Available A three-dimensional numerical flume is developed to study cnoidal wave interaction with multiple arranged perforated quasi-ellipse caissons. The continuity equation and the Navier-Stokes equations are used as the governing equation, and the VOF method is adopted to capture the free surface elevation. The equations are discretized on staggered cells and then solved using a finite difference method. The generation and propagation of cnoidal waves in the numerical flume are tested first. And the ability of the present model to simulate interactions between waves and structures is verified by known experimental results. Then cnoidal waves with varying incident wave height and period are generated and interact with multiple quasi-ellipse caissons with and without perforation. It is found that the perforation plays an effective role in reducing wave runup/rundown and wave forces on the caissons. The wave forces on caissons reduce with the decreasing incident wave period. The influence of the transverse distance of multiple caissons on wave forces is also investigated. A closer transverse distance between caissons can produce larger wave forces. But when relative adjacent distance L/D (L is the transverse distance and D is the width of the quasi-ellipse caisson is larger than 3, the effect of adjacent distance is limited.

  13. 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)

  14. Analysis Model of Dynamic Response on the Circular Caisson Breakwater Under Random Wave

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The random wave load is applied to dynamic response analysis of circular caisson breakwater. The motion process of circular caisson breakwater is classified as rotation motion mode and rotation-and-sliding motion mode. The dynamic model system composed of damper-antislider to control the lateral sliding is introduced, and corresponding dynamic equations of two motion modes are established. The formulas to calculate added mass and new conversion relation of the unit rotational stiffness coefficient are put forward according to the characteristic of the circular caisson breakwater. An engineering case is calculated by a program compiled in Fortran language using proposed dynamic model and method. The validity of the model is calibrated.

  15. Numerical analysis on bearing capacity of middle pylon caisson foundation of Taizhou Bridge

    Institute of Scientific and Technical Information of China (English)

    Wang Jun; Shao Guojian; Hu Feng; Gu Lijun

    2012-01-01

    Because of the computation difficulty of the beating capacity of large underwater caisson foundation on thick overburden layer ground, the geotechnieal software FLAC3D was utilized in the 3D numerical analysis on the bearing capacity of middle pylon foundation. From the computational results, it is concluded that the caisson foundation has a good bearing capacity on thick overburden layer ground and the beating capacity can be improved assuming that the soil near the area of basal comer is reinforced.

  16. Response of Skirted Suction Caissons to Monotonic Lateral Loading in Saturated Medium Sand

    Institute of Scientific and Technical Information of China (English)

    李大勇; 张雨坤; 冯凌云; 郭彦雪

    2014-01-01

    Monotonic-lateral-load-model-tests-were-carried-out-on-steel-skirted-suction-caissons-embedded-in-the-saturated-medium-sand-to-study-the-bearing-capacity.-A-three-dimensional-continuum-finite-element-model-was-developed-with-Z-SOIL-software.-The-numerical-model-was-calibrated-against-experimental-results.-Soil-deformation-and-earth-pressures-on-skirted-caissons-were-investigated-by-using-the-finite-element-model-to-extend-the-model-tests.-It-shows-that-the“skirted”structure-can-significantly-increase-the-lateral-capacity-and-limit-the-deflection,-especially-suitable-for-offshore-wind-turbines,-compared-with-regular-suction-caissons-without-the“skirted”at-the-same-load-level.-In-addition,-appropriate-determination-of-rotation-centers-plays-a-crucial-role-in-calculating-the-lateral-capacity-by-using-the-analytical-method.-It-was-also-found-that-the-rotation-center-is-related-to-dimensions-of-skirted-suction-caissons-and-loading-process,-i.e.-the-rotation-center-moves-upwards-with-the-increase-of-the“skirted”width-and-length;moreover,-the-rotation-center-moves-downwards-with-the-increase-of-loading-and-keeps-constant-when-all-the-sand-along-the-caisson’s-wall-yields.-It-is-so-complex-that-we-cannot-simply-determine-its-position-like-the-regular-suction-caisson-commonly-with-a-specified-position-to-the-length-ratio-of-the-caisson.

  17. Finite Element Analysis of Laterally Loaded Suction Caisson in Anisotropic Clay

    Institute of Scientific and Technical Information of China (English)

    WANG Dong; JIN Xia

    2006-01-01

    Naturally deposited clay is usually characterized by strength anisotropy; however, the effect of anisotropy on the capacity of a suction caisson was seldom investigated. The conventional Hill yield surface includes undrained strengths in triaxial shear, simple shear and pressuremeter shear simultaneously but it can not specify differences in respect to the mode of loading for a given shearing mode. A new technique of updating strength is integrated into incremental finite element (FE) calculation to consider the mode of loading, which is applied to the study of variation of capacity with the aspect ratio of suction caissons in anisotropic clay. Compared with the upper bound limit analysis, FE simulation is capable of offering the lateral capacity of short caissons. In the normal range of anisotropic strength properties, the Mises yield surface with simple shear strength predicts the horizontal capacity of which the error is less than 10% for rough caissons and 15% for smooth caissons. It is also found that the friction of caisson affects the capacity significantly.

  18. A Probabilistic Method for Motion Analysis of Caisson Breakwaters

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    It is assumed that, during the design period, the waves acting on breakwaters are divided into three types: standing wave, broken wave and breaking wave,and the wave heights fit the Rayleigh distribution while the water depths, wave periods and duration of breaking wave impact force fit normal distribution. Based on the random samples of water depths, wave heights, wave periods and duration of breaking wave impact force, the types of waves acting on breakwaters are distinguished and the time-history model of the wave force is determined. The motions of caisson breakwaters under the wave force are simulated by a dynamic numerical model and the statistic characteristics of the dynamic responses are analyzed with the Monte Carlo method. A probabilistic procedure to analyze the motion of the breakwater is developed therein. The procedure is illustrated by an example.

  19. Dynamic Stability Analysis of Caisson Breakwater in Lifetime Considering the Annual Frequency of Severe Storm

    Institute of Scientific and Technical Information of China (English)

    王禹迟; 王元战; 洪宁宁

    2015-01-01

    In the dynamic stability analysis of a caisson breakwater, most of current studies pay attention to the motion characteristics of caisson breakwaters under a single periodical breaking wave excitation. And in the lifetime stability analysis of caisson breakwater, it is assumed that the caisson breakwater suffers storm wave excitation once annually in the design lifetime. However, the number of annual severe storm occurrence is a random variable. In this paper, a series of random waves are generated by the Wen Sheng-chang wave spectrum, and the histories of successive and long-term random wave forces are built up by using the improved Goda wave force model. It is assumed that the number of annual severe storm occurrence is in the Poisson distribution over the 50-year design lifetime, and the history of random wave excitation is generated for each storm by the wave spectrum. The response histories of the caisson breakwater to the random waves over 50-year design lifetime are calculated and taken as a set of samples. On the basis of the Monte Carlo simulation technique, a large number of samples can be obtained, and the probability assessment of the safety of the breakwater during the complete design lifetime is obtained by statistical analysis of a large number of samples. Finally, the procedure of probability assessment of the breakwater safety is illustrated by an example.

  20. Dynamic model of vibrating-sliding-uplift rocking coupled motion and dynamic design method of caisson breakwaters

    Institute of Scientific and Technical Information of China (English)

    WANG; Yuanzhan; HUA; Leina; DONG; Shaowei

    2004-01-01

    Vibrating, sliding and uplift rocking are three elementary motion types of caisson breakwaters. The dynamic model and the numerical simulation method of vibrating-sliding-uplift rocking coupled motion of caisson breakwaters are developed. The histories of displacement, rotation, sliding force and overturning moment of a caisson breakwater under the excitation of breaking wave impact are calculated for the motion models of vibrating, vibrating-sliding, vibrating-uplift rocking and vibrating-sliding-uplift rocking. The effects of various motion models on the stability of caisson breakwaters are investigated. The feasibility of the dynamic design idea that the sliding motion and the uplift rocking motion of caisson breakwaters are allowed under the excitation of breaking wave impact is discussed.

  1. 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

    Using large suction caissons for offshore wind turbines is an upcoming cost-effective technology also referred to as bucket foundations. During operation, the monopod bucket foundation is loaded by a large overturning moment from the wind turbine and the wave loads. However, during installation...... 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...... are introduced, based on the buckling mode shapes from a linear eigenvalue buckling analysis. Different imperfect geometries are introduced to reveal how sensitive the buckling load is to these imperfections. Including the first 21 mode shapes as imperfect geometries will reduce the buckling pressure compared...

  2. 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

    During wave slamming, caisson movement may occur as a combination of sliding along the caisson–foundation interface and local failure in the foundation and seabed. The paper presents a comparison between different techniques applied to the analysis of this movement. Thus, a finite-difference anal......During wave slamming, caisson movement may occur as a combination of sliding along the caisson–foundation interface and local failure in the foundation and seabed. The paper presents a comparison between different techniques applied to the analysis of this movement. Thus, a finite...

  3. Experimental study of reflection coefficient and wave forces acting on perforated caisson

    Institute of Scientific and Technical Information of China (English)

    陈雪峰; 李玉成; 孙大鹏; 陈仁友

    2002-01-01

    -- The reflection coefficient and the total horizontal forces of regular waves acting on the perforated caisson are experimentally investigated. The empirical relationship between reflection coefficient and the ratio of the total horizontal forces acting on the perforated caisson to those on solid vertical walls with the relative chamber width, relative water depth and porosity of perforated wall, etc. are given. Moreover, the results of the ratio of the total horizontal forces are also compared with formulas given by Chinese Harbour Design Criteria and Takahashi, which may be useful for the practical engineering application.

  4. Numerical Simulation of Nonlinear Wave Force on a Quasi-ellipse Caisson

    Institute of Scientific and Technical Information of China (English)

    Yongxue Wang; Xiaozhong Ren; Guoyu Wang

    2011-01-01

    A three dimensional numerical model of nonlinear wave action on a quasi-ellipse caisson in a time domain was developed in this paper.Navier-Stokes equations were solved by the finite difference method,and the volume of fluid (VOF) method was employed to trace the free surface.The partial cell method was used to deal with the irregular boundary typical of this type of problem during first-time wave interaction with the structure,and a satisfactory result was obtained.The numerical model was verified and used to investigate the effects of the relative wave height H/d,relative caisson width kD,and relative length-width ratio B/D on the wave forces of the quasi-ellipse caisson.It was shown that the relative wave height H/d has a significant effect on the wave forces of the caisson.Compared with the non-dimensional inline wave force,the relative length-width ratio B/D was shown to have significant influence on the non-dimensional transverse wave force.

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

    DEFF Research Database (Denmark)

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

    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...

  6. 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 ...

  7. 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,

  8. 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...

  9. 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

    induced loading and overtopping on caisson breakwaters situated in breaking seas. Regarding the wave forces only minor differences between breaking and non breaking waves in deep water were observed, and it was found that the prediction formula of Goda also seems to apply well for multidirectionally...... breaking waves at deep water. The study on wave overtopping showed that the 3D wave overtopping formula suggested by Franco et al., 1995b, predicts the wave overtopping reasonable well for both non breaking and breaking waves at deep water.......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...

  10. Risk Analysis of Breakwater Caisson Under Wave Attack Using Load Surface Approximation

    Institute of Scientific and Technical Information of China (English)

    Dong Hyawn KIM

    2014-01-01

    A new load surface based approach to the reliability analysis of caisson-type breakwater is proposed. Uncertainties of the horizontal and vertical wave loads acting on breakwater are considered by using the so-called load surfaces, which can be estimated as functions of wave height, water level, and so on. Then, the first-order reliability method (FORM) can be applied to determine the probability of failure under the wave action. In this way, the reliability analysis of breakwaters with uncertainties both in wave height and in water level is possible. Moreover, the uncertainty in wave breaking can be taken into account by considering a random variable for wave height ratio which relates the significant wave height to the maximum wave height. The proposed approach is applied numerically to the reliability analysis of caisson breakwater under wave attack that may undergo partial or full wave breaking.

  11. Seismic response of bridge pier on rigid caisson foundation in soil stratum

    Institute of Scientific and Technical Information of China (English)

    C. Tsigginos; N. Gerolymos; D. Assimaki; G. Gazetas

    2008-01-01

    An analytical method to study the seismic response of a bridge pier supported on a rigid caisson foundation embedded in a deep soil stratum underlain by a homogeneous half space is developed. The method reproduces the kinematic and inertial responses, using translational and rotational distributed Winkler springs and dashpots to simulate the soil-caisson interaction. Closed-form solutions are given in the frequency domain for vertical harmonic S-wave excitation. Comparison with results from finite element (FE) analysis and other available solutions demonstrates the reliability of the model. Results from parametric studies are given for the kinematic and inertial responses. The modification of the fundamental period and damping ratio of the bridge due to soil-structure interaction is graphically illustrated.

  12. Prediction Method of Seismic Residual Deformation of Caisson Quay Wall in Liquefied Foundation

    Institute of Scientific and Technical Information of China (English)

    WANG Li-yan; LIU Han-long; JIANG Peng-ming; CHEN Xiang-xiang

    2011-01-01

    The multi-spring shear mechanism plastic model in this paper is defined in strain space to simulate pore pressure generation and development in sands under cyclic loading and undrained conditions,and the rotation of principal stresses can also be simulated by the model with cyclic behavior of anisotropic consolidated sands.Seismic residual deformations of typical caisson quay walls under different engineering situations are analyzed in detail by the plastic model,and then an index of liquefaction extent is applied to describe the regularity of seismic residual deformation of caisson quay wall top under different engineering situations.Some correlated prediction formulas are derived from the results of regression analysis between seismic residual deformation of quay wall top and extent of liquefaction in the relative safety backfill sand site.Finally,the rationality and the reliability of the prediction methods are validated by test results of a 120 g-centrifuge shaking table,and the comparisons show that some reliable seismic residual deformation of caisson quay can be predicted by appropriate prediction formulas and appropriate index of liquefaction extent.

  13. A Study of the system control model of caisson dewatering of the north anchorage of Taizhou Bridge

    Institute of Scientific and Technical Information of China (English)

    Zhao Yanrong; Zhou Zhifang; Ruan Jing

    2011-01-01

    A caisson foundation is applied to the north anchorage of Taizhou Yangtze River Highway Bridge of which the initial caisson sinking requires dewatering. Since the caisson foundation is quite close to nearby buildings, a system control model is established with source (sink) distribution and intensity being the object function, minimum requirements of settlement and deformation of surroundings caused by dewatering and dynamic water levels during different working procedures being constraints, and the design parameter of pumping wells being the variable, so as to lower the jeopardizing of surrounding buildings, which provides a new method for active control over settlement during dewatering. Such a method of dewatering based on system control model should be of significance for similar projects involving dewatering.

  14. Characteristics of Wave Reflection for Vertical and Slit Caissons with Porous Structures

    Directory of Open Access Journals (Sweden)

    Tae-Hwa Jung

    2012-01-01

    Full Text Available Offshore structures are occasionally located at a relatively deep water region, the outside of breakwater. In this case, these structures may be damaged by the supposition of incident and reflected waves from a vertical breakwater. To prevent the damage, the reflected waves are controlled by installing porous structures at the face of the vertical breakwater. In this study, numerical experiments are carried out to identify the characteristics of wave reflection from the porous structures installing in front of a vertical or slit caisson.

  15. Large-scale vertical shaft excavation using super-open caisson system. Construction of Tamasato vertical shaft (Ishioka vertical shaft No.5); Jidoka open caisson koho ni yoru daikibo tatekui no kussaku. Tamasato tateko (Ishioka dai5 tateko) shinsetsu koji

    Energy Technology Data Exchange (ETDEWEB)

    Tanimura, D. [Ministry of Construction, Tokyo (Japan); Ueda, J.; Tani, Y. [Konoike Construction Co. Ltd., Osaka (Japan)

    1998-07-25

    The above-named work is part of the Ministry of Construction`s water conveyance system construction work for Lake Kasumigaura. The super-open caisson system (SOCS) is a method developed from the conventional open caisson method by enlarging the construction area, improving construction accuracy, enhancing rationalization, etc. This report discusses the first application of the new system. SOCS comprises an automatic excavation/soil-lifting system, consisting of a back-hoe type automatic submarine excavator and an automatic soil-lifter of the bridge crane type, and an automatic settlement management system that automatically controls a press-in jack on the real-time basis in compliance with information from various sensors installed on the driven body of the press-in type open caisson. In view of the results of the execution of this construction work using the new SOCS system, it is acknowledged that the automatic excavation/soil-lifting system is accurate enough to manage caisson settlement and that its handling of hard sandy soil is so efficient as to satisfy the designed performance specifications. 15 figs., 3 tabs.

  16. Barodontalgias, dental and orofacial barotraumas: a survey in Swiss divers and caisson workers.

    Science.gov (United States)

    Zanotta, Cristina; Dagassan-Berndt, Dorothea; Nussberger, Peter; Waltimo, Tuomas; Filippi, Andreas

    2014-01-01

    Changing ambient pressure can lead to medical conditions in body cavities filled with air. Intraoral pain elicited by changes in pressure is referred to as barodontalgia. Dental barotraumas are defined as pressure-induced damages of teeth and restorations. The pathophysiologic background so far is not completely clear. The present study deals with dental and orofacial symptoms which can occur as a result of pressure variations. With the aid of cantonal administrations, diving associations, and tunnel construction firms, 520 pressure-exposed individuals (499 scuba/ professional divers, 21 caisson workers operating at excess pressure) were questioned regarding dental problems. A personal interview was conducted with affected individuals. Problems in the dental area were experienced by 15% of all respondents. Toothaches were suffered by 10.2% of the participants. Tooth injuries occurred in 6.3% of all interviewees (26 fractured amalgam restorations, 4 crown fractures, 3 losses of tooth fragments). A proportion of 11.3% among the respondents complained about temporomandibular joint problems or mucosal irritations (for example aphthae) related to the mouthpieces. Barotraumas outside the dental area were incurred by 31.9% of the divers. Of these, 69.9% concerned the ears and 65.6% occurred during the descent. Based on the results obtained from the survey and taking into account the current literature, recommendations for the prevention of barotraumas in divers and caisson workers were prepared. Diagnostic exclusion of dental pathologies and avoidance of retentive reconstruction materials are important factors for the prevention of barodontalgias and dental barotraumas.

  17. 77 FR 74193 - Request for Information on Edel-Kindwall Caisson Tables for Preventing Decompression Illness in...

    Science.gov (United States)

    2012-12-13

    ... HUMAN SERVICES Centers for Disease Control and Prevention (CDC) Request for Information on Edel-Kindwall Caisson Tables for Preventing Decompression Illness in Construction Workers AGENCY: National Institute for Occupational Safety and Health (NIOSH) of the Centers for Disease Control and Prevention (CDC), Department...

  18. 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

    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...... 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...

  19. Experimental and Theoretical Investigation of Wave Forces on A Partially-Perforated Caisson Breakwater with A Rock-Filled Core

    Institute of Scientific and Technical Information of China (English)

    LIU Yong; LI Yu-cheng; TENG Bin; JIANG Jun-jie

    2006-01-01

    The total horizontal and vertical forces acting on a partially-perforated caisson breakwater and their phase difference are investigated in this study. The perforated breakwater sits on the rubble filled foundation, and has a rock-filled core. An analytical solution is developed based on the eigenfunction expansion and matching method to solve the wave field around the breakwater. The finite element method is used for simulating the wave-induced flow in the rubble-filled foundation. Experiments are also conducted to study the wave forces on the perforated caissons. Numerical predictions of the present model are compared with experimental results. The phase differences between the total horizontal and vertical forces are particularly analyzed by means of experimental and numerical results. The major factors that affect the wave forces are examined.

  20. Consolidation and dynamics of 3D unsaturated porous seabed under rigid caisson breakwater loaded by hydrostatic pressure and wave

    Institute of Scientific and Technical Information of China (English)

    YE JianHong; JENG DongSheng; CHAN A H C

    2012-01-01

    In this study,based on the dynamic Biot's theory "u-p" approximation,a 3D finite element method (FEM) numerical soil model is developed,in which the Generalized Newmark-β method is adopted to determine the time integration.The developed 3D FEM soil model is a part of the coupled model PORO-WSSI 3D for 3D wave-seabed-marine structures interaction problem,and is validated by the analytical solution proposed by Wang (2000) for a laterally infinite seabed loaded by a uniform force.By adopting the developed 3D soil model,the consolidation of seabed under a caisson breakwater and hydrostatic pressure is investigated.The numerical results show that the caisson breakwater built on seabed has very significant effect on the stresses/displacements fields in the seabed foundation after the transient deformation and primary consolidation are completed.The parametric study indicates that the Young's modulus E of seabed is the most important parameter to affect the settlement of breakwater,and the displacement fields in seabed foundation.Taking the consolidation status as the initial condition,the interaction between ocean wave,caisson breakwater and seabed foundation is briefly investigated.The 3D ocean wave is determined by solving the Navier-Stokes equations with finite volume method (FVM).The numerical results indicate that there is intensive interaction between ocean wave,caisson breakwater and seabed foundation; and the breakwater indeed can effectively block the wave energy propagating to the coastline.

  1. Numerical analyses of caisson breakwaters on soft foundations under wave cyclic loading

    Science.gov (United States)

    Wang, Yuan-zhan; Yan, Zhen; Wang, Yu-chi

    2016-03-01

    A caisson breakwater is built on soft foundations after replacing the upper soft layer with sand. This paper presents a dynamic finite element method to investigate the strength degradation and associated pore pressure development of the intercalated soft layer under wave cyclic loading. By combining the undrained shear strength with the empirical formula of overconsolidation clay produced by unloading and the development model of pore pressure, the dynamic degradation law that describes the undrained shear strength as a function of cycle number and stress level is derived. Based on the proposed dynamic degradation law and M-C yield criterion, a dynamic finite element method is numerically implemented to predict changes in undrained shear strength of the intercalated soft layer by using the general-purpose FEM software ABAQUS, and the accuracy of the method is verified. The effects of cycle number and amplitude of the wave force on the degradation of the undrained shear strength of the intercalated soft layer and the associated excess pore pressure response are investigated by analyzing an overall distribution and three typical sections underneath the breakwater. By comparing the undrained shear strength distributions obtained by the static method and the quasi-static method with the undrained shear strength distributions obtained by the dynamic finite element method in the three typical sections, the superiority of the dynamic finite element method in predicting changes in undrained shear strength is demonstrated.

  2. Numerical Analyses of Caisson Breakwaters on Soft Foundations Under Wave Cyclic Loading

    Institute of Scientific and Technical Information of China (English)

    王元战; 焉振; 王禹迟

    2016-01-01

    A caisson breakwater is built on soft foundations after replacing the upper soft layer with sand. This paper presents a dynamic finite element method to investigate the strength degradation and associated pore pressure development of the intercalated soft layer under wave cyclic loading. By combining the undrained shear strength with the empirical formula of overconsolidation clay produced by unloading and the development model of pore pressure, the dynamic degradation law that describes the undrained shear strength as a function of cycle number and stress level is derived. Based on the proposed dynamic degradation law and M-C yield criterion, a dynamic finite element method is numerically implemented to predict changes in undrained shear strength of the intercalated soft layer by using the general-purpose FEM software ABAQUS, and the accuracy of the method is verified. The effects of cycle number and amplitude of the wave force on the degradation of the undrained shear strength of the intercalated soft layer and the associated excess pore pressure response are investigated by analyzing an overall distribution and three typical sections underneath the breakwater. By comparing the undrained shear strength distributions obtained by the static method and the quasi-static method with the undrained shear strength distributions obtained by the dynamic finite element method in the three typical sections, the superiority of the dynamic finite element method in predicting changes in undrained shear strength is demonstrated.

  3. Feature articles, thermal power and atomic power. Evaluation technique of antiseismic stability of caisson foundation bulkhead. Karyoku, genshiryoku. Keson shiki gogan no taishin anteisei hyoka gijutsu ni tsuite

    Energy Technology Data Exchange (ETDEWEB)

    Shimada, M.; Fujitani, M. (Tokyo Electric Power Co., Inc. (Japan))

    1994-05-31

    One of the site construction for nuclear power plant is an offshore artificial island system. In this case, the breakwater bulkhead constructed around the island plays an important role in keeping the safety of the whole site. Accordingly the establishment of evaluation technique of antiseismic stability is also important. This study reproduced the seismic behavior of the breakwater bulkhead by means of model vibration experiment. Various factors affecting the sliding of caisson were considered by taking into account the conventional design method and concept. The experimental results were numerically simulated. For analytically obtaining the settlement of the backward ground due to the sliding of caisson, the applicability of (1) elasto-plastic finite element method using the joint element, and (2) individual element method was investigated. Each of them proved to be effective for quantitatively evaluating the deformation behavior of caisson foundation bulkhead in case of earthquake. 5 refs., 19 figs., 5 tabs.

  4. Analysis of Construction and Effect ofthe Test Section of Cylindrical Open Caisson%沉井(圆筒)试验段的施工与效果分析

    Institute of Scientific and Technical Information of China (English)

    任绍东

    2000-01-01

    Based on the construction of test section of open caisson for Zhujiang dike protection, it mainly introduces the construction method and construction effect of small-scale open caisson at specific river section of urban district.%以广州珠江堤防工程沉井试验段的施工情况为主,着重介绍在市区特定的河段,采用小规模沉井方案的施工方法及施工效果。

  5. Reflection of regular and irregular waves from a partially perforated caisson breakwater with a rock-filled core

    Institute of Scientific and Technical Information of China (English)

    LIU Yong; LI Yucheng; TENG Bin; MA Baolian

    2007-01-01

    The reflection of regular and irregular waves from a partially perforated caisson breakwater with a rock-filled core is examined. The present mathematical model is developed by means of the matched eigenfunction method. Numerical results of the present model are compared with the experimental data of different researchers. Numerical examples are given to examine the effect of rock fill on the reflection coefficient. The differences between regular and irregular waves are also investigated by means of theoretical and experimental results. It is found that the minimum reflection coefficient of irregular waves is larger than that of corresponding regular waves, but the contrary is the case for the maximum reflection coefficient.

  6. On-site tests to estimate aquifer permeability of drainage area of south caisson anchorage construction of Taizhou Bridge

    Institute of Scientific and Technical Information of China (English)

    Feng Zhaoxiang; Zhao Yanrong

    2011-01-01

    During the construction of the south caisson anchorage of Taizhou Bridge, the drainage area is located in the lower reaches of the Yangtze River and the permeability of stratums there is considerable. In order to maintain progress and guarantee safety during the sinking of the caisson, water should be drained in the initial period. Subsequently, detailed information about the aquifer permeability is required to make sure that the drainage will proceed successfully,which consequently necessitates the on-site estimation of the aquifer permeability in the drainage area. Therefore, the traditional pumping test and slug test are implemented respectively on site. The comparison of computational results of these two tests indicates that they are consistent overall. Notwithstanding, as slug test can be conducted with portable facilities in a short time and the manipulation is easy and few people need to be involved, the advantages of slug test is conspicuous compared with the traditional pumping test. It could be speculated that slug test will gain a prevalent application in the measurement of aquifer permeability in the future.

  7. 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...... multidirectional waves, causing mainly spilling and occasionally plunging breakers, in the CRF-LSF (Wallingford, UK) wave basin. Seven adjacent modules were instrumented with synchronized force transducers. Pulsating and breaking loads were distinguished on the basis of the frequency content and the spatial...... correlation of the force per unit length was fitted to a single or a double bell shaped distribution. The experimental autocorrelation function for pulsating loads agrees with theoretical solutions; for breaking waves it has a Taylor microscale which is approximately 7% of wavelength, only slightly dependent...

  8. 武汉鹦鹉洲长江大桥北锚碇新型沉井基础设计%Design of New Type Caisson Foundation for North Anchorage of Yingwuzhou Changjiang River Bridge in Wuhan

    Institute of Scientific and Technical Information of China (English)

    李明华; 杨灿文

    2011-01-01

    The main bridge of Yingwuzhou Changjiang River Bridge in Wuhan is a three-tower and four-span suspension bridge. After comparison of different design proposals, it was determined that a new type caisson structure of circular cross section and with multiple round wells would be used for the north anchorage foundation of the bridge. In the big size well in the center of the caisson, the crisscross diaphragm was set and along the periphery within the caisson, a number of small size wells were uniformly set. The caisson is 43 m high and has totally 8 lifts, of which the first lift is a steel shell concrete caisson and the rest parts of the caisson from the second to the eighth lifts are all of reinforced concrete caissons. In the construction of the caisson, the caisson was sunk down by no dewatering and the air curtain was provided in the caisson wall to reduce sinking difficulty and construction risk. The software FLAC3D was used to conduct numerical simulation and analysis of the construction process of the sinking and to evaluate the construction safety, the environmental effect caused by the construction and the deformation of the foundation to be applied with load after the bridge was put into operation. The results of the a-nalysis show that in the process of sinking the caisson in lifts, the caisson structure and ground deformation can meet the relevant requirements in the codes and the adverse influence of the construction on the ambient buildings and the river dyke can be effectively avoided.%武汉鹦鹉洲长江大桥主桥为三塔四跨悬索桥.该桥北锚碇基础经多方案比选采用多圆孔环形截面新型沉井结构.沉井中间大圆孔内设置十字形隔墙,圆环内沿圆周均布有小直径井孔.沉井总高43 m,共分8节,第1节为钢壳混凝土沉井,第2~8节均为钢筋混凝土沉井.北锚碇施工中采用不排水下沉、井壁增加空气幕等措施减小施工难度及风险.采用软件FLAC3D对沉井施工过程进

  9. 沉箱加桩复合基础地震响应离心试验%Centrifuge tests for seismic response of caisson-pile composite foundation

    Institute of Scientific and Technical Information of China (English)

    钟锐; 黄茂松

    2014-01-01

    针对沉箱加桩复合基础地震响应问题开展动力离心试验研究。采用砂质粉土作为地基土,上部结构简化为质点和柱体,基础类型包括单桩、沉箱、沉箱加桩复合基础,利用层状剪切模型箱消除边界反射,以上海人工中波为输入波,在50 g离心加速度场下进行水平地震试验。根据基础形式的不同进行3组试验,试验结果表明:对于刚度较小的土,地震波向上传播过程中具有加速度衰减的特征;沉箱底部加桩对于降低基础和结构地震响应有积极的效果,有利于增强其抗震能力;地表、基础、结构的地震响应频率特性各不相同,这取决于其各自不同的自振特性;土与基础、基础与结构之间均会发生地震相互作用,但只有与相互作用对象自振频率均较接近的地震频域分量才能引起明显的相互作用。%Dynamic centrifuge tests are carried out to study seismic response of caisson-pile composite foundation. With Shanghai sandy silt chosen as test soil, laminar shearing box used to eliminate reflection at the boundary, and Shanghai artificial middle wave is taken as the input motion, three tests with different foundation types are conducted under the centrifuge acceleration of 50g. Single pile, caisson and caisson-pile composite foundation are the foundation types for those three tests, and all the superstructures in these tests are simplified as mass points and connecting columns. Test results indicate that, for soil with low stiffness acceleration decays in the process of earthquake wave propagating upwards;adding piles under the caisson could decrease the earthquake responses of both the foundation and structure, so the reinforcement of the system in resisting earthquakes is expected;frequency characteristics of the responses at soil surface, foundation and structure are all different from each other depending on their own natural vibration characteristics

  10. Design and Construction of Open Caisson Enclosure Structure in Deep Soft Soil Condition%深厚软土地基沉井围护结构设计与施工

    Institute of Scientific and Technical Information of China (English)

    肖策

    2012-01-01

    The sewage pumping station in Road A of Hengqin New City, Zhuhai is situated in deep soft soil area. Because of poor load capacity of the earth and insufficient side friction along the sidewall of open caisson wells, it is difficult to adopt the normal construction methods of big excavation, underground diaphragm and up-down construction. During open caisson construction, the soft soil earth was reinforced by lime dry jet mixing piles and high pressure jet grouting piles to improve its load capacity. The open caisson construction was completed within the scheduled construction time with. The construction method also insures the engineering quality and safety.%珠海横琴新区A号路污水泵站坐落在在深厚淤泥质地区,由于地基承载力和井壁侧摩阻力不足,常规大开挖施工、地下连续墙施工和逆作法施工非常困难.采用石灰粉喷桩和高压旋喷桩加固软土地基,提高地基承载力后进行沉井施工,工程质量和安全得到有力保证,顺利按工期要求完成沉井施工作业.

  11. Scheme of Pressure Boost and Floating Aid for Steel Open Caisson of Main Ship Channel Bridge of Hutong Changjiang River Bridge%沪通长江大桥主航道桥钢沉井增压助浮方案

    Institute of Scientific and Technical Information of China (English)

    余允锋; 邱琼海; 王立忠

    2015-01-01

    The main ship channel bridge of the Hutong Changjiang River Bridge is a double-py-lon continuous steel truss girder cable-stayed bridge with span arrangement (140+462+1 092+462+140) m .T he foundations for the main piers of the bridge are all the open caissons ,of w hich the plan dimensions of the caisson top of the main pier No .29 are 86 .9 m × 58 .7 m and in the plan of the caisson ,24 well holes are arranged .The total height of the caisson of the pier is 115 m and the lower part of the caisson is the steel caisson that is 56 m in height .In the state of free floating , the draught of the steel caisson is 12 .5 m ,the caisson can not be floated out of the shipyard be-cause of the deep draught and has the risk of grounding in the floating .To reduce the draught of the caisson and to keep the pressure in the air cabins of the caisson stable ,the scheme of pressure boost and floating aid for the caisson was proposed ,that was ,12 well holes in the caisson were symmetrically closed to make the well holes the sealed cabins .Meanwhile ,the active pressure boost system was arranged and the air was injected into the cabins from the tops of the closing cov-er plates of the well holes .The pressure boost system was composed of the air compressor ,main air pipes ,branch air pipes ,extension air pipes ,air pressure meters ,check valves ,stop valves and liquid level sensors .By the measures of injecting the air for pressure boost and releasing the air for pressure reduction ,the air pressure in each cabin was controlled .With the scheme of the pressure boost and floating aid ,the steel open caisson of the pier was finally floated out from the shipyard to the pier site only in 3 h and the effect of the scheme implementation was sound .%沪通长江大桥主航道桥为(140+462+1 092+462+140 ) m双塔连续钢桁梁斜拉桥 ,该桥主墩均采用沉井基础 ,其中 ,29号主墩沉井顶平面尺寸为86 .9 m × 58 .7 m ,平面布置24个井孔 ,高115m,下部钢沉井高56

  12. 砂土中吸力式沉箱基础的最大承载力计算方法%Calculation method for maximum bearing capacity of suction caisson foundation in sand

    Institute of Scientific and Technical Information of China (English)

    黎冰; 高玉峰; 沙成明; 童小东

    2012-01-01

    To accurately determine the maximum pull-out loading capacity of suction caisson foundation in sand, the limit equilibrium method is applied. Based on the mechanical characteristics of suction caisson foundation with horizontal translation, a method for three-dimensional limit equilibrium analysis of maximum pull-out loading capacity of suction caisson foundation in sand is proposed. In the proposed method, the development process of earth pressure and shear resistance with displacement, and the characteristics of different earth pressure and side shear resistance over the caisson cross-section are considered. The earth pressure acting on the caisson is assumed to obey the Winkler model and is not in excess of the limiting earth pressure. The shear resistance between caisson and soil is assumed to be linearly proportional to the relative displacement between them before reaching its ultimate value. Fifteen model tests of suction caisson foundation under horizontal loading in sand are conducted to investigate its pull-out behaviors, and the load-displacement curves are obtained. The calculation results by the proposed method agree well with the experimental results, indicating that the proposed method is accurate and effective. Key w%为了准确确定砂土中吸力式沉箱基础的最大承载力,应用极限平衡法对其进行分析.基于吸力式沉箱基础平动时的受力特点,充分考虑土压力和摩擦力的发挥过程以及沉箱横截面上各点土压力大小的不同,提出了一种计算砂土中吸力式沉箱基础最大承载力的三维极限平衡方法.方法中假定沉箱侧壁土压力满足Winkler模型,但其值不超过水平极限土压力值;假定沉箱侧壁与地基土之间的摩擦力在达到最大值之前与两者之间的相对位移成线性正比关系.开展了15组水平荷载作用下吸力式沉箱基础的模型试验,得到了吸力式沉箱基础的荷载-位移曲线.利用所提方法得到的计

  13. The Finite Element Calculation of Circular Caisson Structure with a Partition%带隔墙的圆沉箱结构有限元计算浅析

    Institute of Scientific and Technical Information of China (English)

    王家鑫

    2013-01-01

      本文应用 Robot Millennium 有限元软件对带隔墙的圆沉箱结构建立空间模型,分别采用两种不同的建模形式进行内力计算,并对计算结果进行了分析。分析结构表明,在不考虑底板与地基土之间相互作用的情况下,选用半整体建模方式,其计算结果较为安全可靠。%This paper using finite element software Robot Mi-l ennium establishes the space model of circular caisson struct-ure with a partition, by using two different modeling forms to calculate the internal force, and analyzes the calculation results. Analysis of the structure shows that, without considering the interaction between the bot om plate and foundation soil con-ditions, using semi integrated modeling method, the calculate-ion result is more safe and reliable.

  14. Behaviour of a pre-stressed concrete pressure-vessel subjected to a high temperature gradient; Comportement d'un caisson en beton precontraint soumis a un gradient de temperature eleve

    Energy Technology Data Exchange (ETDEWEB)

    Dubois, F. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires; Bonvalet, Ch.; Dawance, G.; Marechal, J.C. [Centre Experimental de Recherches et d' Etudes du Batiment et des Travaux Publics (CEBTP), 76 - Harfleur (France)

    1965-07-01

    results obtained make it possible both to draw up a programme for future tests and to propose a calculation model for pre-stressed concrete pressure-vessels. (authors) [French] Apres avoir rappele les problemes poses par les caissons pour les reacteurs atomiques (formes des caissons, pressions, ouvertures, fondations, etc.), on expose l'interet presente par les caissons en beton precontraint, par rapport aux caissons en acier. Toutefois, l'utilisation des caissons en beton precontraint souleve de nombreuses difficultes liees aux proprietes des betons. Ainsi, faute de connaissances approfondies du materiau, il est necessaire de placer une peau d'etancheite en acier contre le beton, d'avoir un isolant thermique ou un circuit de refroidissement pour limiter les deformations et les contraintes, etc. Par suite, l'etude du comportement du beton precontraint et du caisson soumis a un gradient eleve de temperature peut apporter des informations utiles. Une maquette au l/10eme d'un caisson cylindrique en beton precontraint sans fond ni ouverture laterale, a ete realisee. Avant de decrire les essais effectues, quelques considerations theoriques sont developpees concernant les conditions de similitude 'modele reduit - ouvrage reel' et le calcul des sollicitations thermiques et mecaniques. La maquette de caisson en beton precontraint etait chauffee interieurement par un element de pyrotenax et refroidie exterieurement par un violent courant d'air. Le beton etait precontraint par des cables horizontaux et verticaux a 80 kg/cm{sup 2}; le gradient thermique atteignait 160 deg. C, Les deformations globales et locales, la variation de la teneur en eau, le module d'elasticite, la tension et le fluage des cables, la profondeur des fissures ont ete mesures au cours des differents essais. Les deformations globales observees sont compatibles avec les theories des deformations thermiques et le fluage des cables a atteint 20 a 30 pour cent

  15. 超大型沉井首次接高受力及变形规律初探%Research on stress and settlement of super-large open caisson during first lifts

    Institute of Scientific and Technical Information of China (English)

    朱建民; 龚维明; 穆保岗; 米长江

    2012-01-01

    During the construction of south anchorage open caisson of Ma'anshan Yangtze-River Bridge, the settlement of the open caisson, the earth pressure under the cross wall, the stress of the bottom steel plate of cross wall were monitored. It is found that the super-large open caisson has the characteristics of both strip footing and block foundation. As large settlement is acceptable for the first lifts, the open caisson settlement control method is more suitable than the soil bearing capacity control method. The earth pressure under the common cross wall is smaller than the division cross wall; and the ultimate bearing capacity of soil under the common cross wall is also smaller. When the limit equilibrium state for soil under the common cross wall is reached, the load added during the following lifts is taken by the division cross wall (or the side wall). The stress in the bottom steel plate of cross wall is determined mainly by the concrete pouring of the very first lift, and it is less affected by other following lifts. The stress of the bottom steel plate of cross wall is smaller at the inner part, and bigger at the outer part. The tensile stress near the open caisson side wall can be reduced remarkably by sound compaction of soil backfilled outside.%依托马鞍山长江大桥南锚碇沉井的首次接高,对其竖向沉降、隔墙墙底土压力和隔墙底板受力情况进行了监测.结果表明,超大型沉井兼有条形基础的特点和整体工作性能,能够承受较大的竖向变形,与单纯考虑地基承载力相比,更适合于按变形控制接高.沉井接高时普通隔墙下的土压力小于分区隔墙,并且普通隔墙下部土体会先达极限承载力,后续接高产生的荷载转而由分区隔墙(或井壁)来承担.沉井首节混凝土浇筑就已决定了隔墙底板的应力大小和分布情况,后续接高不会再引起大的改变;隔墙底板中间部分受力较小,外围拉应力较大,通过井壁外土体的密实

  16. 沉井预封底水力冲洗下沉工艺在砂质地层中的应用%Application of bottom sealing of caisson hydraulic flushing sinking process in sandy stratum

    Institute of Scientific and Technical Information of China (English)

    安治国

    2013-01-01

    The main geology around Shanghai branch gas pipeline (area of Jiangsu,Zhejiang,Shanghai) of the east segment of the Second West-to-East Gas Pipeline Project,is sandy soil,with high moisture content of soil and underground water level.In order to solve the problems like water and sand gushing,long bottom sealing cycle and so on,in light of the current construction way of pipe-jacking tunnels and caisson at Yongli River,prefabed bottom sealing is adopted.Combined with engineering cases,the paper presents the control points such as geological prospecting,process design,equipment selection,deviation-rectifying of sink,risk prediction,preventive measures and so on.The successful application of bottom sealing of caisson hydraulic flushing sinking process shortens the construction period about 39 %,saves about 37.28 % of construction costs,reduces the disturbance to the formation outside the caisson,ensures the safety of structures around the environment,lowers the difficulty in coordinating public relations.%西气东输二线东段上海支干线途经区域(苏浙沪地区)地质主要为砂质地层,土壤含水率及地下水位较高,为解决顶管隧道沉井涌水涌砂、封底周期长等难题,针对永利河顶管隧道沉井施工现状,采用沉井预封底水力冲洗下沉工艺进行施工.结合工程实例,阐述了地质勘查、工艺制定、设备选择、沉井纠偏、风险预测及防范措施等控制要点.沉井预封底水力冲洗下沉工艺在该工程中的成功应用,有效缩短施工周期约39%,降低施工成本约37.28%,减少了对井外地层的扰动,保证了周围建(构)筑物的安全,降低了公共关系协调难度.

  17. 锚碇沉箱基础与升浆基床摩擦性能研究%Research on friction property between anchorage caisson foundation and grouting bed

    Institute of Scientific and Technical Information of China (English)

    耿铁锁; 陈亮; 张哲

    2015-01-01

    According to the first domestic offshore suspension bridge using caisson foundation,the friction property between prepacked aggregate riprap grouting bed and concrete under water,the friction coefficients between gravel bed and concrete structure are mainly studied.Firstly,the friction coefficients between gravel bed and concrete structure are obtained by laboratory and field experiments,and then,the friction property between prepacked aggregate riprap grouting bed and concrete structure under water is acquired by the numerical analysis method.The experimental results show that the friction coefficients between the common gravel bed and the concrete caisson are in the range of 0.5-0.6,which meets the corresponding code,and the friction coefficient between the prepacked aggregate riprap grouting bed and the concrete caisson is within 0.7-0.8,or even 0.9 considering the film cohesive force of concrete.%针对国内首个采用沉箱基础的海上悬索桥,主要对水下预填骨料抛石升浆基床与混凝土之间的摩擦性能,以及碎石基床与混凝土结构的摩擦因数展开研究.首先通过室内和现场实验得到碎石基床与混凝土结构的摩擦因数,在此基础上采用数值分析方法得到水下预填骨料抛石升浆基床与混凝土结构之间的摩擦性能.结果表明,普通碎石基床与混凝土沉箱之间的摩擦因数在设计规范规定的0.5~0.6内,而预填骨料抛石升浆基床与混凝土沉箱之间的摩擦因数为0.7~0.8,如考虑混凝土之间的黏结力膜作用,摩擦因数可达0.9.

  18. 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...

  19. Dynamic stiffness of suction caissons

    DEFF Research Database (Denmark)

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

    -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...

  20. SIMPLIFIED ANALYTICAL METHOD FOR SEISMIC RESPONSE OF COMPOSITE CAISSON-PILES FOUNDATIONS%沉箱加桩复合基础地震响应简化分析方法

    Institute of Scientific and Technical Information of China (English)

    钟锐; 黄茂松

    2013-01-01

      采用动力 Winkler 地基模型,推导解析方法对沉箱加桩复合基础的地震响应。首先,考虑复合基础与土的相互作用以及沉箱部分和群桩部分的连接,分析复合基础在简谐S波作用下的运动响应;然后,对基础和上部结构系统建立“基础–柱–质点”简化模型,并应用Fourier变换实现地震响应的频域求解;第三,应用DRM两阶段时程有限元方法对采用沉箱加桩复合基础的土–基础–结构系统地震响应进行计算,与本文简化方法对比,验证本文方法的正确性。最后,通过算例研究加桩对增强基础和结构抗震能力的效果,并得出加桩抗震的主要机制在于消除了沉箱基础的类共振现象。%Seismic response of a new type of foundation,the composite caisson-piles foundation,is studied through a simplified analytical method. The focus is the contribution of the piles beneath the caisson in increasing the earthquake resistance of the foundation-superstructure system. Firstly,considering the interaction between the soil and foundation with dynamic Winkler model,the equation of kinematic response of the composite foundation under S-wave is derived. Secondly,a simplified model for the seismic response of the foundation-column-lumped mass system in frequency domain is built;and with Fourier transformation this method is applied to transient seismic problems. Thirdly,with an example of soil-foundation-superstructure seismic behavior,this proposed method is validated by comparison against 3D dynamic FEM modeling,in which domain reduction method(DRM) is utilized. Lastly,the significance and mechanism of adding piles in improving the earthquake resistance of the foundation and superstructure are analyzed through examples in different soil conditions. Discovery in this study is that adding piles under the caisson is an efficient way to increase the seismic resistant capability of the soil

  1. 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.

  2. Effect of Short-Crestedness on Wave Loads on Caisson

    DEFF Research Database (Denmark)

    Frigaard, Peter; Helm-Petersen, J.; Christensen, M.;

    1995-01-01

    This repor concerns experiments carried out as a combined LIP-MAST-TAW PROJECT DURING May to July, 1994, in the Vinje-Basin at Delft Hydraulics......This repor concerns experiments carried out as a combined LIP-MAST-TAW PROJECT DURING May to July, 1994, in the Vinje-Basin at Delft Hydraulics...

  3. Decompression syndrome (Caisson disease in an Indian diver

    Directory of Open Access Journals (Sweden)

    Phatak Uday

    2010-01-01

    Full Text Available Acute decompression syndrome (Caisson′s disease is an acute neurological emergency in divers. It is caused due to release of nitrogen gas bubbles that impinge the blood vessels of the spinal cord and brain and result in severe neurodeficit. There are very few case reports in Indian literature. There are multiple factors in the pathogenesis of Acute decompression syndrome (Caisson′s disease such as health problems in divers (respiratory problems or congenital heart diseases like atrial septal defect, patent ductus arteriosus etc, speed of ascent from the depth and habits like smoking that render divers susceptible for such neurological emergency. Usually, immediate diagnosis of such a condition with MRI is not possible in hospitals in the Coastal border. Even though, MRI is performed, it has very low specificity and sensitivity. Facilities like hyperbaric oxygen treatment are virtually non-existent in these hospitals. Therefore, proper education of the divers and appropriate preventive measures in professional or recreational divers is recommended.

  4. 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...

  5. 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...

  6. 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...

  7. Characteristics of Wave Reflection for Vertical and Slit Caissons with Porous Structures

    OpenAIRE

    Tae-Hwa Jung; Sung-Jae Lee; Yong-Sik Cho

    2012-01-01

    Offshore structures are occasionally located at a relatively deep water region, the outside of breakwater. In this case, these structures may be damaged by the supposition of incident and reflected waves from a vertical breakwater. To prevent the damage, the reflected waves are controlled by installing porous structures at the face of the vertical breakwater. In this study, numerical experiments are carried out to identify the characteristics of wave reflection from the porous structures inst...

  8. Three-Dimensional Model Test Study of Modified 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. The report describe the model testing of the proposed modifications to the existing...

  9. 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...

  10. Comparison of Rectangular Caissons and Cylindrical Caissons Used in the Bulkhead Wharf%岸壁式码头中采用方形、圆形沉箱的比较

    Institute of Scientific and Technical Information of China (English)

    刘盛武; 丁志军

    2001-01-01

    通过对秦皇岛港丁西码头和己西码头分别采用方沉箱和圆沉箱结构建造码头岸壁的比较,说明采用圆沉箱建造码头岸壁,从设计、施工以及经济性均有很多优点,可以在重力式码头中推广应用.

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

    International Nuclear Information System (INIS)

    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

  12. Anti-corrosion Design for Gravity Caisson Structures%重力式沉箱结构防腐设计的分析

    Institute of Scientific and Technical Information of China (English)

    董华钢

    2007-01-01

    介绍重力式沉箱结构防腐设计的思路,并结合施工具体情况提出采用低强度高性能混凝土并结合透水模板及海工防腐涂料的防腐措施,在经济、合理的前提下提高重力式码头结构耐久性.

  13. 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.

  14. Small Concrete Caisson Applied to Underwater Pipeline Construction%小型混凝土沉箱在水下管道施工中的应用

    Institute of Scientific and Technical Information of China (English)

    李伟民

    2012-01-01

    以上海外高桥油脂加工区泵房取水口管道工程为例,介绍了施工中遇到的降水和选择何种方案的难题。由此,通过各方分析和论证,采用了小型预制钢筋混凝土沉箱整体沉放的方法,顺利地解决了难题。经施工应用表明,该方法质量可靠、施工简便、造价低、工期短,取得了较好的效益。

  15. Floating stability calculation of floating-caisson of tidal power plants%潮汐电站厂房浮运结构的浮运稳定计算

    Institute of Scientific and Technical Information of China (English)

    范波芹; 索丽生

    2000-01-01

    基于神经网络技术建立了浮运结构的重心知识库和稳性参数知识库,用于计算潮汐电站厂房浮运结构在浮运和沉放过程中的稳定性.该知识库克服了公式计算的局限性,无需预知模型的形式,建模简单,易于程序化.计算实例表明,该知识库可以有效地预报浮运结构稳定性能.

  16. Feature articles, thermal power and atomic power. Study on antiseismic property of breakwater bulkhead (model experiment of caisson dike and its numerical simulator). Karyoku, genshiryoku. Bohagogan no teishinsei ni kansuru kenkyu (keson tei no mokei jikken to sono suchi simulation)

    Energy Technology Data Exchange (ETDEWEB)

    Tochigi, H. (Central Research Inst. of Electric Power Industry, Tokyo (Japan))

    1994-05-31

    Recently the social demand is increasing for utilizing the offshore marine space for building an artificial island for air port or power plant. The improvement in reliability of safety of breakwater bulkhead is thus required. In order to rationalize and sensitize the evaluation method of antiseismic stability, the investigation in which the seismic behaviors such as sliding and settling are taken into consideration is required in addition to the conventional investigation based on the seismic intensity method. In this case, if the breakwater bulkhead constructed as the outer shell of the island can keep the stability of the reclaimed ground against the waves even after being deformed to some extent by sliding and settling, the stability of the backward facilities can be kept. In this study, a large scale experiment was conducted for understanding the seismic behavior of the breakwater bulkhead. A numerical simulation was also made for performing various dynamic test on the strength, deformation characteristic, and settlement property of the large size aggregate and for investigating the evaluation of seismic behavior. 7 refs., 16 figs., 1 tab.

  17. 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.......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....

  18. 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...

  19. 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...

  20. 38 CFR Appendix B to Part 4 - Numerical Index of Disabilities

    Science.gov (United States)

    2010-07-01

    ..., subacute, or chronic. 5001 Bones and Joints, tuberculosis. 5002 Arthritis, rheumatoid (atrophic). 5003... Arthritis, other types (specify). 5010 Arthritis, due to trauma. 5011 Bones, caisson disease. 5012 Bones..., bronchial. 6603 Emphysema, pulmonary. 6604 Chronic obstructive pulmonary disease. Lungs and...

  1. 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.

  2. Reliability Evaluation of Monolithic Vertical Wall Breakwaters Considering Impulsive Wave Breaking Forces and Failure Modes of the Foundation

    DEFF Research Database (Denmark)

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

    1994-01-01

    Impulsive wave breaking forces on a vertical caisson breakwater has been included by Takahashi et al, (1994) in Goda's wave pressure formula (Goda et al. 1972 and Goda 1974). Based on these formulae a deterministic design method following the Japanese recommendations has been used for the design...... of a caisson structure. A reliability evaluation of the same structure is then performed using a level II FORM analysis. In this only the failure modes sliding and overturning are taken into account. The various modes of the foundation slip failures are presented. The method of probabilistic foundation...

  3. 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 B...

  4. Wave Motion Compensation Scheme and Its Model Tests for the Salvage of An Ancient Sunken Boat

    Institute of Scientific and Technical Information of China (English)

    YE Jia-wei; CHEN Yuan-ming; WANG Dong-jiao; LIU Yue-qin; SONG Xin; HUANG Yuan-tian

    2006-01-01

    The application of the vertical hoisting jack and wave motion compensation techniques to the salvage of an ancient sunken boat is introduced. The boat is wooden, loaded with cultural relics. It has been immersed at the bottom of the South China Sea for more than 800 years. In order to protect the structure of the boat and the cultural relics inside to the largest extent, an open caisson is used to hold the sunken boat and the silts around before they are raised from the seabed all together as a whole. In the paper, first, the seakeeping model test of the system of the salvage barge and the open caisson is done to determine some important wave response parameters. And then a further experimental study of the application of the vertical hoisting jack and wave motion compensation scheme to the salvage of the sunken boat is carried out. In the model tests, the techniques of the integrative mechanic-electronic-hydraulic control, wave motion forecast and wave motion compensation are used to minimize the heave motion of the open caisson. The results of the model tests show that the heave motion of the open caisson can be reduced effectively by the use of the present method.

  5. On Optimum Safety Levels of Breakwaters

    DEFF Research Database (Denmark)

    Burcharth, Hans F.; Sørensen, John Dalsgaard

    2006-01-01

    The paper presents results from numerical simulations performed with the objective of identifying optimum design safety levels of conventional rubble mound and caisson breakwaters, corresponding to the lowest costs over the service life of the structures. The work is related to the PIANC Working...

  6. 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...

  7. 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...... capable of simulating dynamic frequency dependent behaviour of the structure-foundation system....

  8. 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...

  9. 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....

  10. 38 CFR 4.71a - Schedule of ratings-musculoskeletal system.

    Science.gov (United States)

    2010-07-01

    ..., substantiated by X-ray findings: Rate as arthritis, degenerative. 5011Bones, caisson disease of: Rate as... Spine Rating General Rating Formula for Diseases and Injuries of the Spine (For diagnostic codes 5235 to... in the area of the spine affected by residuals of injury or disease Unfavorable ankylosis of...

  11. 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...

  12. Displacement of Monolithic Rubble-Mound Breakwater Crown-Walls

    DEFF Research Database (Denmark)

    Nørgaard, Jørgen Harck; Andersen, Lars Vabbersgaard; Andersen, Thomas Lykke;

    2012-01-01

    studies on caisson breakwaters, but correction terms are suggested in the present paper to obtain almost equal measured and estimated displacements. This is of great practical importance since many existing rubble-mound crown-walls are subjected to increasing wave loads due to rising sea water level from...

  13. 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...

  14. Taizhou Yangtze River Bridge——The first kilometer level three-pylon two-span suspension bridge in the world

    Institute of Scientific and Technical Information of China (English)

    Zhong Jianchi

    2011-01-01

    Taizhou Bridge, located at the middle of Jiangsu Province, connecting Taizhou City and Zhenjiang City, started in Dec. 2007. The bridge is the first kilometer level three-pylon suspension bridge in the world, and it adopts longitudinal herringbone shape steel middle pylon for the first time in the world. The foundation of the middle tower is the deepest underwater caisson in soil on earth. A great many of technical innovations such as the design techniques of three-pylon suspension bridge,precisely locating and bottom-sealing techniques of the large scale caisson foundation,manufacturing, combination techniques of steel and concrete in the middle tower, welding of extra thick steel plate,manufacture and control techniques of abnormal sections of the middle tower and so on were introduced.

  15. 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;

    2016-01-01

    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 appli...... and FE analyses, new expressions for depth factor of shallow foundations have 15 been validated for embedment ratios (aspect ratios) up to unity, calibrating the fitting parameters 16 by employing data from a range of soil profiles....... application of vertical load. It was found that the drained capacity of suction caissons is 12 dependent on embedment ratio. On the other hand, predictions from conventional semi-empirical 13 depth factors were found to somewhat underestimate when applied to rough foundations. On the 14 basis of the tests...

  16. Prototype bucket foundation for wind turbines - natural frequency estimation

    Energy Technology Data Exchange (ETDEWEB)

    Ibsen, Lars Bo; Liingaard, M.

    2006-12-15

    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 and a real-time data-acquisition system. The report concerns the in service performance of the wind turbine, with focus on estimation of the natural frequencies of the structure/foundation. The natural frequencies are initially estimated by means of experimental Output-only Modal analysis. The experimental estimates are then compared with numerical simulations of the suction caisson foundation and the wind turbine. The numerical model consists of a finite element section for the wind turbine tower and nacelle. The soil-structure interaction of the soil-foundation section is modelled by lumped-parameter models capable of simulating dynamic frequency dependent behaviour of the structure-foundation system. (au)

  17. 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.

  18. Structural Optimization of an Offshore Wind Turbines Transition Pieces for Bucket Foundations

    OpenAIRE

    Nezhentseva, Anastasia; Andersen, Lars Vabbersgaard; Ibsen, Lars Bo; Sørensen, Eigil V.

    2011-01-01

    Traditionally, offshore constructions are made of steel. The focus of this paper is optimization of a transition piece (TP) connecting the offshore wind turbine column with a suction bucket foundation. Suction caissons, typically used for shallow water depths, have been proved to be adequate in residual soil conditions for depths up to approximately 40 m. The existing design practice is limited to the use of steel-flange-reinforced shear panels. Desirable outcome is proposal of an alternative...

  19. 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 hi...... Kvitsøy near Stavanger, Norway. The research study is intended to be of direct use to engineers analyzing design and stability of the pilot plant....

  20. 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.

  1. 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

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

    International Nuclear Information System (INIS)

    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

  3. [Medical aspects of the environmental sanitation of workplaces in compressed air work in Japan].

    Science.gov (United States)

    Mano, Y; Shibayama, M

    1987-01-01

    Actual follow-up investigations were made for a period of 5 yr and 10 months since February 1980 on 55 places of caisson and shield work. The maximum bottom pressure in caisson work was 3.6 kg/cm2 (4.6 ATA) and that of shield work was 1.6 kg/cm2. The number of exposures of workers was 23,737 in caisson work and 75,244 in shield work. The items of geomedical measurements were temperature (degrees C), humidity, dust, illumination, noise, oxygen, carbonic acid gas and others. In compressed air work, it is most important to prevent decompression sickness (bends) from the view of occupational health. The incidence of bends has decreased in recent years because of strict control by regulations. Environmental hygiene, however, has seldom been discussed in this field and little geomedical control has been made on compressed air work. In view of this situation, we have, therefore, studied, observed, and measured the hygienic factors of this work during the past five years. This investigation is without doubt the first of its kind in Japan and the areas covered most of the regions where compressed air works have been made in the past. From these results, it can be concluded as follows: The working temperature was controlled, but humidity was too high (nearly 90%). Illumination was insufficient. Dust was a problem, but high humidity played an important role in decreasing the volume. The environment was noisy. It is therefore natural that environmental studies should be continued and hygienic consideration be further emphasized in compressed air work. PMID:3613254

  4. 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

  5. Structure Design of the Deep & Shallow Basin Water-stop Bund and Water-stop System%深浅坞挡水构筑物及止水系统设计

    Institute of Scientific and Technical Information of China (English)

    温秀媛; 谷文强

    2014-01-01

    Mainly introduces the structure design of the deep&shallow basin water-stop bund and water-stop system for Hongkong-Zhuhai-Macau Bridge temporary casting yard for tunnel elements in Guishan. The water-stop bound is mainly composed of Anti-seepage processed undisturbed rock and caisson gravity dam. The key design of water-stop system includes the Anti-seepage treatment between caisson gravity dam and rock foundation,the joint between caisson gravity dam and undisturbed rock,and the treatment to undisturbed rocks. The mainly anti-seepage treatment is grouting combination with embedded Z9-30 rubber water-stop and casting plan concrete,etc.%主要介绍港珠澳大桥沉管预制厂深浅坞挡水构筑物及其止水系统设计。挡水构筑物主要由防渗处理过的原状岩石山体和重力式沉箱拦水坝结构组成。止水系统设计的重点包含重力式沉箱拦水坝和岩石坝基之间的防渗,拦水坝结构与原状岩石山体连接处的防渗以及原状岩石山体的防渗处理。主要采用注浆防渗的处理方法,结合预埋Z9-30橡胶止水带以及现浇素混凝土等进行防渗设计。

  6. Port Adriano, 2D-Model tests

    DEFF Research Database (Denmark)

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

    and the crown have been recorded. The maximum of horizontal wave force and the related tilting moment together with the pressure distribution are documented for waves in the range of design conditions. The parameters and results in the report are given in full-scale values, if nothing else is stated....... 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. 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.)

  8. 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;

    2016-01-01

    application of vertical load. It was found that the drained capacity of suction caissons is 12 dependent on embedment ratio. On the other hand, predictions from conventional semi-empirical 13 depth factors were found to somewhat underestimate when applied to rough foundations. On the 14 basis of the tests...... and FE analyses, new expressions for depth factor of shallow foundations have 15 been validated for embedment ratios (aspect ratios) up to unity, calibrating the fitting parameters 16 by employing data from a range of soil profiles....

  9. 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.

  10. 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.......1). Subsequently, the assembly of the dynamic stiffness matrix for the foundation is considered (section 1.2), and the solution for obtaining the steady state response, when using lumped-parameter models is given(section 1.2)....

  11. Report on the cooperating researches utilizing fusion engineering facilities completed in the fiscal year 2008 (Joint research)

    International Nuclear Information System (INIS)

    The Division of Fusion Energy Technology of the Fusion Research and Development Directorate is carrying out cooperating researches with universities, research institutes and industries using five fusion engineering facilities; Caisson Assembly for Tritium Safety Study (CATS), Fusion Neutronics Source (FNS), JAEA Electron Beam Irradiation System (JEBIS), RF Test Stand (RFTS). In the fiscal year 2007 (from April 1, 2008 to March 31, 2009), 19 activities were carried out as the cooperating researches. This report reviews the results of 8 activities which were completed in the fiscal year 2008. (author)

  12. 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.

  13. Time Domain Simulation of Shallow Footings Dynamics on Dense Silica Sand

    DEFF Research Database (Denmark)

    Barari, Amin; Ibsen, Lars Bo

    2016-01-01

    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...

  14. Stability of the Guiding Dike in Yangtze Estuary Under the Wave Load

    Institute of Scientific and Technical Information of China (English)

    YAN Shu-wang; LIU Run; FAN Qi-jin; XIE Shi-leng

    2005-01-01

    During the construction of the guiding dike in the Yangtze Estuary, some of the caisson structures sank into the soil for 1~5 m or slid about 20 m away from the original place when a strong storm attacked this area. Dynamic triaxial tests were carried out to simulate the behavior of foundation soils under wave loading. The test results show that the excessive settlement and lateral movement of the caissons are due to the weakening of the soft clay strength during the strong storm. The test results also show that the ability of the soft clay to resist the wave force will be greatly increased when the soft soil samples are suitably improved. Based on the test results, an improvement method combining vertical drains with surcharge loading was proposed to strengthen the foundation soil. On the improved soil foundation, the dike has been reconstructed and undergone several strong storms without any damage. A finite element approach has been developed for analyzing the settlement and stability of the dike under the action of strong storm.

  15. 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.

  16. 泰州大桥中塔沉井基础承载力模型试验研究%Physics model experimental research on the bearing capability of the middle tower caission foundation of Taizhou Bridge

    Institute of Scientific and Technical Information of China (English)

    阮静; 胡丰

    2012-01-01

    泰州大桥中塔位于江中心,基础覆盖层高达200m.通过多方面比选,基础采用58 m×44 m四角倒圆的矩形沉井,高76 m.为确保泰州大桥中塔沉井基础的安全和稳定,开展了1∶100的模型试验,获取了泰州大桥沉井极限承载力以及沉井埋深、土体含水量、侧壁摩阻力对极限承载力的影响.%The foundation of the middle pylon of Taizhou Bridge is located above the overlying deposit with the height of 200 m in the water. The round rectangular caisson foundation with the plane dimension of 58 m × 44 m and the height of 76 m is employed. To verify the safety and stability of the middle pylon of Taizhou Bridge, a physics model with the scale of 1: 100 to the real structure is built up. The ultimate bearing capacity of the caisson foundation and the influence of sinking depth, soil moisture content, and the side wall friction on the bearing capacity are obtained.

  17. Leaching of solutes from ion-exchange resins buried in Bandelier Tuff

    Energy Technology Data Exchange (ETDEWEB)

    Essington, E.H.; Fuentes, H.R.; Polzer, W.L.; Lopez, E.A.; Stallings, E.A.

    1986-10-01

    Prediction of solute transport at shallow land burial facilities requires a knowledge of the rates of release of solutes (source term) from the buried wastes and of those processes affecting transport through the surrounding media. The leaching (removal) of lithium, strontium, and cesium from a resin/tuff mixture (Bandelier Tuff) was conducted under unsaturated steady and unsteady (drainage) flow conditions in both laboratory columns and large-scale field caissons to approximate the conditions of buried contaminated-waste resins. Lithium was leached most rapidly and strontium least rapidly. Stopping the flow for a period of 40 to 60 days to create drainage (unsteady flow) conditions had very little effect on the concentrations of solutes leached from the resin/tuff layer. Leaching of these solutes in laboratory columns simulated the large-scale (caisson) leaching very well. Thus, laboratory studies may be reasonable predictors of leaching under certain large-scale field conditions. Also, leaching appears to be a kinetics-controlled process that, for the experimental conditions of this study, may be represented by simple first-order kinetics. Further work should concentrate on understanding the effect of environmental factors such as solute mixtures, concentrations, and temperature, as well as those mechanisms that control leaching of solutes. Also, the evaluation and development of alternative mathematical models for describing the source term are needed.

  18. Design of north bulkhead of Hitachi-Naka thermal power station and characteristics of the coastal hydraulics; Hitachinaka karyoku hatsudensho kitagogan no sekkei to kaigan suirijo no tokusei

    Energy Technology Data Exchange (ETDEWEB)

    Fukazawa, A.; Sato, Y.; Fujita, Y. [Electric Power Development Co. Ltd., Tokyo (Japan)

    1995-01-05

    For the bulkhead construction of Hitachi-Naka No. 4 Quay where the Hitachi-Naka Thermal Power Station is to be built, Electric Power Development Co., Ltd. is constructing the north bulkhead. The north bulkhead is constructed perpendicularly to the coast line. Since the wave affects the structures as an alongshore wave, the flow condition surrounding the levee body, stability of root protection blocks, and wave pressure affecting caissons are considered to be different from the common case in which the incident wave comes from the front of levee body. This paper describes the design of north bulkhead, in which these phenomena are taken into account. The north bulkhead has been designed as a breakwater combining the rubble-mound inclined breakwater and the caisson type composite breakwater. For the design of north bulkhead, weight of the root protection block was decided considering influence of the slanting wave incidence. Furthermore, results of investigation on the flow condition surrounding the breakwater are described. Are illustrated the periodic change of incident wave, the frequency spectrum and directional spectrum of incident wave, the water level variation surrounding breakwater, wave height distribution surrounding breakwater, and the flow velocity distribution surrounding breakwater. 8 refs., 20 figs., 4 tabs.

  19. Comparison of seismic capacity/demand ratios of two kinds of foundation schemes of Taizhou Bridge

    Institute of Scientific and Technical Information of China (English)

    Zhao Yi; Peng Tianbo; Han Lei

    2012-01-01

    Pile group foundation and caisson foundation are two common foundation schemes of long-span bridges, and the seismic performances of the two kinds of foundations are different. Taking Taizhou Bridge as an example, which is the first kilometer level three-pylon two-span suspension bridge in the world, two foundation schemes are designed for the middle pylon, and two whole bridge models with two different foundation schemes of the middle pylon are established respectively in this paper. The effects of foundation-soil interaction are simulated by equivalent linear soil springs whose stiffnesses are calculated according to m method. Seismic capacity/demand ratios of the two models are calculated. The following conclusions can be drawn: the weak positions of the two schemes are not the same; if caisson foundation is adopted for the middle pylon, the weak position is the bearing capacity of the middle pylon foundation, while if pile group foundation is adopted for the middle pylon, the weak position is the bearing capacity of the side pylon foundation.

  20. Basic safety principles of KLT-40C reactor plants

    International Nuclear Information System (INIS)

    The KLT-40 NSSS has been developed for a floating power block of a nuclear heat and power station on the basis of ice-breaker-type NSSS (Nuclear Steam Supply System) with application of shipbuilding technologies. Basic reactor plant components are pressurised water reactor, once-through coil-type steam generator, primary coolant pump, emergency protection rod drive mechanisms of compensate group-electromechanical type. Basic RP components are incorporated in a compact steam generating block which is arranged within metal-water shielding tank's caissons. Domestic regulatory documents on safety were used for the NSSS design. IAEA recommendations were also taken into account. Implementation of basic safety principles adopted presently for nuclear power allowed application of the KLT-40C plant for a floating power unit of a nuclear co-generation station. (author)

  1. 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....

  2. 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...

  3. Drained Response of Bucket Foundations under Cyclic Lateral Load

    DEFF Research Database (Denmark)

    Foglia, Aligi; Ibsen, Lars Bo

    2013-01-01

    Introduction The monopod bucket foundation is an innovative support structure for offshore wind turbines. It consists of a shallow embedded foundation which penetrates the seabed by means of a suction created within the caisson. The behaviour of bucket foundations against long-term lateral cyclic...... loading is by far unexplored, and yet, this is the most common loading condition in offshore environment. Approach In this paper the behaviour of bucket foundations with different geometries, under lateral cyclic loading, is explored by means of a small-scale physical model. The scale of the model is 1...... the experimental results. The aim of the study is to explore how the parameters of the analytical model change as a function of the skirt length. Conclusion This will elucidate important information on the response of shallow embedded foundations under cyclic loading and, besides, enable a comparison with other...

  4. Structural Optimization of an Offshore Wind Turbines Transition Pieces for Bucket Foundations

    DEFF Research Database (Denmark)

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

    Traditionally, offshore constructions are made of steel. The focus of this paper is optimization of a transition piece (TP) connecting the offshore wind turbine column with a suction bucket foundation. Suction caissons, typically used for shallow water depths, have been proved to be adequate...... in residual soil conditions for depths up to approximately 40 m. The existing design practice is limited to the use of steel-flange-reinforced shear panels. Desirable outcome is proposal of an alternative material which does not require extensive welding work. Compact reinforced composite (CRC) is suggested...... as an alternative to steel. CRC has an excellent durability and higher compressive strength compared to traditional concrete. This material has also an increased ductility owing to integration of large contents of short, strong and stiff steel fibres. At present, application of high-tension concrete is limited...

  5. 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....

  6. 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.

  7. Fast track developments, Gulf of Mexico -- options and organization

    International Nuclear Information System (INIS)

    The pressure continues to compress the 'idea to barrel' time period -- to get oil and gas from a discovery into the pipeline as quickly, cheaply and safely as possible. This paper discusses the range of development options presently available in the Gulf of Mexico (GoM) to meet these goals, and a project organizational structure that allows for maximum implementation efficiency. The structural options range from a standard 4-pile to a single, freestanding caisson, and the spectrum of 'minimum structures' in between. Developments in water depths of 100 feet and 200 feet are addressed, as are each system's associated costs, relative risks and startup times. Project organization is also addressed in terms of an effective in-house and out-of-house project organizational structure, the necessary attributes of the key members of this organization, and the most effective types of contracting

  8. 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.

  9. Investigations on the porous media equations and resistance coefficients for coastal structures

    DEFF Research Database (Denmark)

    Jensen, Bjarne; Jacobsen, Niels Gjøl; Christensen, Erik Damgaard

    2014-01-01

    previously found in the literature. Constant values for the resistance coefficients for a broad range of flow conditions were recommended based on the new calibrations. The model was validated for the main physical processes that occur in wave–structure interaction in coastal structures including three...... some shortcomings which were identified. The applied type of porosity models relies on empirical resistance coefficients which often need to be measured or calibrated. Only few examples of calibration for numerical models which are present in the literature often applied the same experimental results......-dimensional wave–structure interaction, run-up, run-down and pressure damping, regular and irregular wave conditions and evaluation of overtopping. Simple two and three dimensional uniform caisson structures and breakwater layouts were investigated. The model was implemented in the open source CFD library Open...

  10. Feasibility studies for the treatment and reuse of contaminated marine sediments.

    Science.gov (United States)

    Bonomoa, L; Careghini, A; Dastoli, S; De Propris, L; Ferrari, G; Gabellini, M; Saponaro, S

    2009-07-01

    This paper presents preliminary results of laboratory tests aimed at evaluating the easibility of the remediation of marine sediments, which are polluted by mercury and petroleum hydrocarbons, dredged at the bay of Augusta (SR, Italy). The treatment is composed of two sequential steps: in the first, a cement-based granular material is produced (based on a high performance concrete approach); then, the volatile and the semi-volatile compounds in the granular material are removed by a thermal desorption step. Treated materials could be reused or put into caissons, according to their mechanical properties and environmental compatibility. The experiments were focused on evaluating the effect of the process parameter values on: (i) the evolution of cement hydration reactions, (ii) thermal desorption removal efficiencies, (iii) leaching behaviour of the treated material. PMID:19705665

  11. The force of oblique incident wave on the breakwater with a partially perforated wall

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Wave forces induced by the interaction between the oblique incident wave and the breakwater with a partially perforated front wall is investigated. The fluid domain is divided into two sub-domains and the eigen-function expansion method is applied to expanding velocity potentials in each domain. In the eigen-expansion of the velocity potential, evanescent waves are included. Numerical results of the present model are compared with other theories and a good agreement can be found between them. Experimental data have been compared with the present theoretical results. The effect of the traverse wall on wave forces has been discussed in detail. On the basis of the linear wave theory, it is shown that in the range of engineering practice, the incident angle of wave has small influence on wave forces on the unit length of perforated caisson.

  12. Development of technology for the design of shallow land burial facilities at arid sites

    Science.gov (United States)

    Nyhan, J. W.; Abeele, W. V.; Drennon, B. J.; Herrera, W. J.; Lopez, E. A.; Langhorst, G. J.; Stallings, E. A.; Walker, R. D.; Martinez, J. L.

    The Los Alamos field research program involving technology development for arid shallow land burial (SLB) sites is described. Field data are presented for an integrated field experiment, which was designed to test individual SLB component experiments related to erosion control, biobarriers, and subsurface capillary and migration barriers. Field tests of biointrusion barriers at waste disposal sites and in experimental plots are reported. The results of a joint DOE/NRC experiment to evaluate leaching and transport of sorbing (Cs, Sr, Li) and nonsorbing (I, Br) solutes in sandy silt backfill are presented for steady-state and unsteady-state flow conditions. A capillary barrier experiment performed in a large caisson (3-m diameter, 6.1 m deep) is described and a year's worth of field data is presented.

  13. Development of technology for the design of shallow land burial facilities at arid sites

    Energy Technology Data Exchange (ETDEWEB)

    Nyhan, J.W.; Abeele, W.V.; Drennon, B.J.; Herrera, W.J.; Lopez, E.A.; Langhorst, G.J.; Stallings, E.A.; Walker, R.D.; Martinez, J.L.

    1985-01-01

    The Los Alamos field research program involving technology development for arid shallow land burial (SLB) sites is described. Field data are presented for an integrated field experiment, which was designed to test individual SLB component experiments related to erosion control, biobarriers, and subsurface capillary and migration barriers. Field tests of biointrusion barriers at waste disposal sites and in experimental plots are reported. The results of a joint DOE/NRC experiment to evaluate leaching and transport of sorbing (Cs, Sr, Li) and nonsorbing (I, Br) solutes in sandy silt backfill are presented for steady-state and unsteady-state flow conditions. A capillary barrier experiment performed in a large caisson (3-m diameter, 6.1 m deep) is described and a year's worth of field data is presented.

  14. 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.

  15. Working mechanism and numerical simulation of assembly coastal building techniques

    Institute of Scientific and Technical Information of China (English)

    陈育民; 刘汉龙; 陈泽

    2008-01-01

    A new coastal technique, named as assembly coastal building, was introduced. The main concept of the technique was the assembling components which could be combined and locked together to form a large caisson. The assembly coastal building technique was used in a sea access road in Zhuanghai 4X1 well, Dagang Oilfield. The design plans and in-situ tests in the sea access road project were introduced in detail. According to the Zhuanghai project, the numerical simulation method of assembly coastal building technique was proposed. 2D numerical simulations were performed in FLAC to analyze the displacement and stability of the technique in the construction process and post-construction period. The settlement calculated is close to the in-situ results, which proves that the proposed numerical method is reasonable. Results show that the assembly coastal building technique has large safety factor under the gravity loading and wave loadings.

  16. On the instability of offshore foundations: theory and mechanism

    Science.gov (United States)

    Gao, FuPing; Li, JinHui; Qi, WenGang; Hu, Cun

    2015-12-01

    As the offshore engineering moving from shallow to deep waters, the foundation types for fixed and floating platforms have been gradually evolving to minimize engineering costs and structural risks in the harsh offshore environments. Particular focus of this paper is on the foundation instability and its failure mechanisms as well as the relevant theory advances for the prevailing foundation types in both shallow and deep water depths. Piles, spudcans, gravity bases, suction caissons, and plate anchors are detailed in this paper. The failure phenomena and mechanisms for each type of foundations are identified and summarized, respectively. The theoretical approaches along with sophisticated empirical solutions for the bearing capacity problems are then presented. The major challenges are from flow-structure-soil coupling processes, rigorous constitutive modeling of cyclic behaviors of marine sediments, and the spatial variability of soil properties for large-spreading structures. Further researches are suggested to reveal the instability mechanisms for underpinning the evolution of offshore foundations.

  17. Horizontal Coherence of Wave Forces on Vertical Wall Breakwaters

    DEFF Research Database (Denmark)

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

    2001-01-01

    Spatial coherence of wave impact pressures at a vertical breakwater in multidirectional seas is studied as part of an EU project under the LSF‐TMR programme. The lay out and programme of tests are shortly described. A method for the identification of breaking waves is presented. The percentage...... 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....

  18. Field lysimeter facility for evaluating the performance of commercial solidified low-level waste

    International Nuclear Information System (INIS)

    Analyzing the potential migration of radionuclides from sites containing solid low-level wastes requires knowledge of contaminant concentrations in the soil solution surrounding the waste. This soil solution concentration is generally referred to as the source term and is determined by such factors as the concentration of radionuclides in the solid waste, the rate of leachate formation, the concentration of dissolved species in the leachate, any solubility reactions occurring when the leachate contacts the soil, and the rate of water flow in the soil surrounding the waste. A field lysimeter facility established at the Hanford site is being used to determine typical source terms in arid climates for commercial low-level wastes solidifed with cement, Dow polymer (vinyl ester-styrene), and bitumen. The field lysimeter facility consists of 10, 3-m-deep by 1.8-m-dia closed-bottom lysimeters situated around a 4-m-deep by 4-m-dia central instrument caisson. Commercial cement and Dow polymer waste samples were removed from 210-L drums and placed in 8 of the lysimeters. Two bitumen samples are planned to be emplaced in the facility's remaining 2 lysimeters during 1984. The central caisson provides access to the instrumentation in the individual lysimeters and allows selective sampling of the soil and waste. Suction candles (ceramic cups) placed around the waste forms will be used to periodically collect soil-water samples for chemical analysis. Meteorological data, soil moisture content, and soil temperature are automatically monitored at the facility. Characterization of the soils and waste forms have been partially completed. These data consist of moisture release characteristics, particle-size distribution, and distributions and concentrations of radionuclides in the waste forms. 11 references, 12 figures, 5 tables

  19. Design of bridges against large tectonic deformation

    Institute of Scientific and Technical Information of China (English)

    I.Anastasopoulost; G.Gazetas; V.Drosos; T.Georgarakos; R.Kourkoulis

    2008-01-01

    The engineering community has devoted much effort to understanding the response of soil-structure systems to seismic ground motions,but little attention to the effects of an outcropping fault offset.The 1999 earthquakes of Turkey and Taiwan,offering a variety of case histories of structural damage due to faulting,have (re)fueled the interest on the subject.This paper presents a methodology for design of bridges against tectonic deformation.The problem is decoupled in two analysis steps:the first (at the local level) deals with the response of a single pier and its foundation to fault rupture propagating through the soil,and the superstructure is modeled in a simplified manner;and the second (at the global level)investigates detailed models of the superstructure subjected to the support (differential) displacements of Step 1.A parametric study investigates typical models of viaduct and overpass bridges,founded on piles or caissons.Fixed-head piled foundations are shown to be rather vulnerable to faulting-induced deformation.End-bearing piles in particular are unable to survive bedrock offsets exceeding 10 cm.Floating piles perform better,and if combined with hinged pile-to-cap connections,they could survive much larger offsets.Soil resilience is beneficial in reducing pile distress.Caisson foundations are almost invariably successful.Statically-indeterminate superstructures are quite vulnerable,while statically-determinate are insensitive (allowing differential displacements and rotations without suffering any distress).For large-span cantilever construction bridges,where a statically determinate system is hardly an option,inserting resilient seismic isolation bearings is advantageous as long as ample seating can prevent the deck from falling off the supports.An actual application of the developed method is presented for a major bridge,demonstrating the feasibility of design against tectonic deformation.

  20. Managing Spent Nuclear Fuel at the Idaho National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Thomas Hill; Denzel L. Fillmore

    2005-10-01

    The Idaho National Laboratory (INL) has a large inventory of diverse types of spent nuclear fuel (SNF). This legacy derives from the history of the INL as the National Reactor Testing Station, and from its mission to recover HEU from SNF and to test and examine SNF after irradiation. The INL also has a large diversity of SNF storage facilities, some 50 years old. SNF at INL has many forms—from intact assemblies down to metallurgical mounts, and some fuel has been wet stored for over 40 years. SNF is stored bare or in metal cans under water, or dry in vaults, caissons or casks. Inspection shows varying corrosion and degradation of the SNF and its storage cans. SNF has been stored in 10 different facilities: 5 pools, one cask storage pad, one vault, two generations of caisson facilities, and one modular Independent Spent Fuel Storage Installation (ISFSI). The pools range in age from 40 years old to the most modern in the US Department of Energy (DOE) complex. The near-term objective is to move SNF from older pools to interim dry storage, allowing shutdown and decommissioning of the older facilities. This move involves drying methods that are dependent on fuel type. The long-term objective is to have INL SNF in safe dry storage and ready to be shipped to the National Repository. The unique features of the INL SNF requires special treatments and packaging to meet the proposed repository acceptance criteria and SNF will be repackaged in standardized canisters for shipment and disposal in the National Repository. Disposal will use the standardized canisters that can be co-disposed with High Level Waste glass logs to limit the total fissile material in a repository waste package. The DOE standardized canister also simplifies the repository handling of the multitude of DOE SNF sizes and shapes.

  1. 离心模型试验中深水防波堤上波浪循环荷载的模拟研究%CENTRIFUGE MODELING STUDY OF CYCLIC WAVE LOAD ON BREAKWATER IN DEEP WATER

    Institute of Scientific and Technical Information of China (English)

    蒋敏敏; 蔡正银; 徐光明; 王志选; 肖昭然

    2013-01-01

    suction caisson breakwater centrifuge model test. Test results show that the device can apply wave load accurately and steadily,and can adjust load amplitude randomly. Cyclic displacement characteristics of suction caisson breakwater under wave load are as follows:accumulated value and amplitude of dynamic tilt angle both increase;horizontal displacement amplitude increases notably;while accumulated value of vertical displacement increases significantly. Suction caisson breakwater has oscillation-rock coupled motion mode.

  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. A study on the flow characteristics of a direct drive turbine for energy conversion generation by experiment and CFD

    Science.gov (United States)

    Cho, Y. J.; Zullah, M. A.; Faizal, M.; Choi, Y. D.; Lee, Y. H.

    2012-11-01

    A variety of technologies has been proposed to capture the energy from waves. Some of the more promising designs are undergoing demonstration testing at commercial scales. Due to the complexity of most offshore wave energy devices and their motion response in different sea states, physical tank tests are common practice for WEC design. Full scale tests are also necessary, but are expensive and only considered once the design has been optimized. Computational Fluid Dynamics (CFD) is now recognized as an important complement to traditional physical testing techniques in offshore engineering. Once properly calibrated and validated to the problem, CFD offers a high density of test data and results in a reasonable timescale to assist with design changes and improvements to the device. The purpose of this study is to investigate the performance of a newly developed direct drive hydro turbine (DDT), which will be built in a caisson for extraction of wave energy. Experiments and CFD analysis are conducted to clarify the turbine performance and internal flow characteristics. The results show that commercial CFD code can be applied successfully to the simulation of the wave motion in the water tank. The performance of the turbine for wave energy converter is studied continuously for a ongoing project.

  4. Expeditious remediation of a leaking underground tank

    International Nuclear Information System (INIS)

    An inactive leaking diesel fuel tank, at a TV transmitter site in Memphis, Tennessee, was removed just prior to transfer of ownership. The removal of contaminated soil resulted in an excavated to a depth of about 5.5 m (18 ft) by a contractor from Memphis. This excavation partially undermined the building, and furthermore exposed two friction pilings which supported the transmitter building. Rogers and Associates Engineering (RAE) accepted project management. The excavation was backfilled with gravel to stabilize the site and prevent damage to the foundation of the building. Site characterization, including bore holes and groundwater monitoring wells indicated that essentially all of the remaining contamination was in the area immediately beneath where the tank had been located. Final mitigation was performed using a 1.5-m (5-ft) diameter caisson auger to excavate the material to a depth of 11 m beneath the surface. A steel casing was driven behind the auger to the full depth to provide site stability and prevent caving. Simultaneous drilling and driving the casing resulted in essentially no mixing of material and removal of the contaminated soil, without impact on the building. Sampling from the excavation and additional groundwater monitoring verified full remediation had been accomplished. The monitoring wells were plugged according to Tennessee requirements and the area of the excavation was capped. This phase of the site characterization and remediation were completed within about one month and the State verified the closure

  5. Construction and start-up testing experience of Kashiwazakikariwa Nuclear Power Station Unit No.1

    International Nuclear Information System (INIS)

    In order to overcome the new location condition in Japan Sea coast, new techniques were developed and adopted to ensure the safety in construction and to shorten the construction period as far as possible. The commercial operation was started on September 18, 1985. This plant is a BWR plant of 1100 MWe output. The results of the improvement and standardization of BWRs and the measures for reliability improvement and radiation dose reduction were fully adopted in this plant. The site of the power station and the layout of the main facilities are explained. As the features of the location condition, the severe weather condition in winter such as snow, wind and lightning and high waves in the sea were considered. The rockbed for installing the foundation of the reactor building was deep, and the aseismatic design condition was made stricter, accordingly, the quantity of materials increased. A tent dome was developed to cover above the reactor containment vessel being assembled, a lightning forecast system was installed, and synchro-lift method was adopted for caisson breakwaters. The countermeasures to the deep rockbed and the measures to shorten the construction period were taken. The results of the trial operation are reported. (Kako, I.)

  6. Status of outdoor radioactive contamination at the Hanford Site

    Energy Technology Data Exchange (ETDEWEB)

    McKinney, S.M.; Markes, B.M.

    1994-12-01

    This document summarizes the status of outdoor radioactive contamination near Hanford Site facilities and disposal sites. It defines the nature and areal extend of the radioactively contaminated areas and describes the historical, ongoing, and planned radiological monitoring and control activities. Radioactive waste has been disposed of to the soil column since shortly after the reactors and production facilities began operating. Radioactive liquid wastes were placed directly into the ground via liquid discharges to cribs, ponds, ditches, and reverse wells. Solid wastes were placed in trenches, burial vaults, and caissons. Although the Hanford Site covers 1,450 km{sup 2}, the radioactively contaminated area is only about 36 km{sup 2} or 2.5% of the original site. Over time, contamination has migrated from some of the waste management sites through various vectors (e.g., burrowing animals, deep-rooted vegetation, erosion, containment system failure) or has been deposited to the surface soil via spills and unplanned releases (e.g., line leaks/breaks, tank leaks, and stack discharges) and created areas of outdoor radioactivity both on and below the surface. Currently 26 km{sup 2} are posted as surface contamination and 10 km{sup 2} are posted as underground contamination.

  7. 向海洋工程要经济效益

    Institute of Scientific and Technical Information of China (English)

    陈浩波; 赵彤

    2000-01-01

    Up to now, Dalian New Shipyard has completed more than 25 offshore projects for new constructions, repairing and convertion of jack-ups, semi-submersible low hulls, living quarters, drilling caisson and FPSO etc. both from the domestic and world market. By taking advantage of its dry dock in 355m(L)×80m(W)×12.7m(D)equipped with a 900t gantry crane and other advanced equipment available, Dalian New Shipyard becomes very competitive and competent for all typed offshore projects in the world market. Besides, Xingang Shipyard,Beihai Shipyard and Shanhaiguan Shipyard in north China are also active in offshore projects for the construction and repairing of accommodation, self-walking drilling platform, man-made island for shallow water oil field, jack-ups as well as the VLCC tanker convertion. All these projects have helped the shipyards to upgrade their technical levels for further offshore projects and establish good records to participate in bidding competition in offshore market.

  8. Design of an intermediate-scale experiment to validate unsaturated- zone transport models

    International Nuclear Information System (INIS)

    An intermediate-scale experiment is being carried out to evaluate instrumentation and models that might be used for transport-model validation for the Yucca Mountain Site Characterization Project. The experimental test bed is a 6-m high x 3-m diameter caisson filled with quartz sand with a sorbing layer at an intermediate depth. The experiment involves the detection and prediction of the migration of fluid and tracers through an unsaturated porous medium. Pre-test design requires estimation of physical properties of the porous medium such as the relative permeability, saturation/pressure relations, porosity, and saturated hydraulic conductivity as well as geochemical properties such as surface complexation constants and empircial Kd'S. The pre-test characterization data will be used as input to several computer codes to predict the fluid flow and tracer migration. These include a coupled chemical-reaction/transport model, a stochastic model, and a deterministic model using retardation factors. The calculations will be completed prior to elution of the tracers, providing a basis for validation by comparing the predictions to observed moisture and tracer behavior

  9. Floating type ocean wave power station equipped with hydroelectric unit

    Science.gov (United States)

    Okamoto, Shun; Kanemoto, Toshiaki; Umekage, Toshihiko

    2013-10-01

    The authors have invented the unique ocean wave power station, which is composed of the floating type platform with a pair of the floats lining up at the interval of one wave pitch and the counter-rotating type wave power unit, its runners are submerged in the seawater at the middle position of the platform. Such profiles make the flow velocity at the runner is twice faster than that of the traditional fixed/caisson type OWC, on the ideal flow conditions. Besides, the runners counter-rotate the inner and the outer armatures of the peculiar generator, respectively, and the relative rotational speed is also twice faster than the speed of the single runner/armature. Such characteristics make the runner diameter large, namely the output higher, as requested, because the torque of the power unit never act on the floating type platform. At the preliminary reseach, this paper verifies to get the power using a Wells type single runner installed in the model station. The runner takes the output which is affected by the oscillating amplitude of the platform, the rotational speed and the inertia force of the runner, etc.

  10. 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».

  11. Project B-589, 300 Area transuranic waste interim storage project engineering study

    International Nuclear Information System (INIS)

    The purpose of the study was to look at various alternatives of taking newly generated, remote-handled transuranic waste (caisson waste) in the 300 Area, performing necessary transloading operations and preparing the waste for storage. The prepared waste would then be retrieved when the Waste Isolation Pilot Plant becomes operational and transshipped to the repository in New Mexico with a minimum of inspection and packaging. The scope of this study consisted of evaluating options for the transloading of the TRU wastes for shipment to a 200 Area storage site. Preconceptual design information furnished as part of the engineering study is listed below: produce a design for a clean, sealed waste canister; hot cell loadout system for the waste; in-cell loading or handling equipment; determine transshipment cask options; determine assay system requirements (optional); design or specify transport equipment required; provide a SARP cost estimate; determine operator training requirements; determine waste compaction equipment needs if desirable; develop a cost estimate and approximate schedule for a workable system option; and update the results presented in WHC Document TC-2025

  12. Design and construction of steel plate pile cofferdam used in bearing platform with embedded rock%嵌岩承台钢板桩围堰的设计与施工

    Institute of Scientific and Technical Information of China (English)

    张芳

    2012-01-01

    In light of geological condition of especially big bridge on Jin-Chi railway,the paper analyzes and compares three kinds of water resisting schemes including vertical shaft,caisson,and steel plate pile cofferdam,determines to apply steel plate pile cofferdam,specifically introduces calculation methods of corresponding design,and describes construction technology.In the end,it summarizes the features and matters needing attention in the construction of steel plate pile cofferdam,with a view to guide similar engineering in future.%针对锦赤铁路洗矿厂特大桥地质条件,对比分析了竖井、沉井、钢板桩围堰三种阻水方案,确定采用钢板桩围堰方案,详细介绍了相关设计计算方法,并对施工工艺作了具体阐述,并总结了钢板桩围堰的特点及施工注意事项,以指导今后同类工程。

  13. Study on Information Management for the Conservation of Traditional Chinese Architectural Heritage - 3d Modelling and Metadata Representation

    Science.gov (United States)

    Yen, Y. N.; Weng, K. H.; Huang, H. Y.

    2013-07-01

    After over 30 years of practise and development, Taiwan's architectural conservation field is moving rapidly into digitalization and its applications. Compared to modern buildings, traditional Chinese architecture has considerably more complex elements and forms. To document and digitize these unique heritages in their conservation lifecycle is a new and important issue. This article takes the caisson ceiling of the Taipei Confucius Temple, octagonal with 333 elements in 8 types, as a case study for digitization practise. The application of metadata representation and 3D modelling are the two key issues to discuss. Both Revit and SketchUp were appliedin this research to compare its effectiveness to metadata representation. Due to limitation of the Revit database, the final 3D models wasbuilt with SketchUp. The research found that, firstly, cultural heritage databasesmustconvey that while many elements are similar in appearance, they are unique in value; although 3D simulations help the general understanding of architectural heritage, software such as Revit and SketchUp, at this stage, could onlybe used tomodel basic visual representations, and is ineffective indocumenting additional critical data ofindividually unique elements. Secondly, when establishing conservation lifecycle information for application in management systems, a full and detailed presentation of the metadata must also be implemented; the existing applications of BIM in managing conservation lifecycles are still insufficient. Results of the research recommends SketchUp as a tool for present modelling needs, and BIM for sharing data between users, but the implementation of metadata representation is of the utmost importance.

  14. Characterization of crushed tuff for the evaluation of the fate of tracers in transport studies in the unsaturated zone

    International Nuclear Information System (INIS)

    Results of field-scale (caisson) transport studies under unsaturated moisture and steady and nonsteady flow conditions indicate variability and a lack of conservation of mass in solute transport. The tuff materials used in that study were analyzed for the presence of tracers and of freshly precipitated material to help explain the variability and lack of conservation of mass. Selected tuff samples were characterized by neutron activation analysis for tracer identification, by x-ray diffraction for mineral identification, by petrographic analysis for identification of freshly precipitated material, and by x-ray fluorescence analysis for identification of major and trace elements. The results of these analyses indicate no obvious presence of freshly precipitated material that would retard tracer movement. The presence of the nonsorbing tracers (bromide and iodide) suggest the retention of these tracers in immobile water. The presence of the nonsorbing tracers (bromide and iodide) suggest the retention of these tracers in immobile water. The presence of sorbing and nonsorbing tracers on the tuff at some locations (even cesium at the 415-cm depth) and not at others suggests variability in transport. 15 refs., 14 figs., 9 tabs

  15. 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.

  16. 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...

  17. Decommissioning plan and current status of JRR-2

    International Nuclear Information System (INIS)

    Japan Research Reactor No.2 (JRR-2), heavy water moderated and cooled tank type research reactor with maximum thermal power of 10 MW, was used over 36 years, and was permanently shut down in December, 1996. Afterward, dismantling report was submitted to the STA, and dismantling was begun in 1997. Decommissioning of JRR-2 is planned in 11 years, and the program are divided into 4 phases. Phase l had already been ended, phase 2 is being executed at present. Reactor body will be removed in phase 4 by one piece removal or caisson techniques. On reactor building, it is planned to use effectively as a hot experimental facilities after decommissioning ends. For ensuring safety under decommissioning, detailed examination on work method, exposure and radioactive waste quantities is executed on each dismantling in advance. On exposure of worker in phase 1, it was achieved to control lower than the estimate. How to treat tritium contamination also becomes an important problem to achieve ensuring safety. On heavy water, transportation to foreign country is planned in phase 2. On primary cooling system and reactor building concrete, various investigation and examination is being advanced aiming at phase 3 and 4. (author)

  18. Design and construction of the south bulkhead of Hitachinaka Thermal Power Plant; Hitachinaka Karyoku Hatsudensho minami gogan no sekkei to seko

    Energy Technology Data Exchange (ETDEWEB)

    Kuwabara, S.; Takahashi, Y.; Noguchi, K. [Tokyo Electric Power Co., Inc. (Japan)

    1996-11-05

    Hitachinaka Thermal Power Plant is a coal fired thermal power plant that Tokyo Electric Power Co. and Electric Power Development Corp. have planned to install a machine of an output of 1,000MW each respectively, totalling an output of 2,000MW jointly in the north wharf of Hitachinaka harbor now planned by Ibaraki Prefecture. It is anticipated to be the main power source for the prefecture in the early 21st century. In addition, in the above north wharf area, there are public facilities to be constructed by Ministry of Transport and Ibaraki Prefecture. The construction of the bulkhead of this north wharf has been designed and executed by the above 4 bodies in taking the respective shares and completed in 3 years. In this report, the outline of cost reduction concerning the design and construction of the south bulkhead (total length: 250m) including the intake of the plant is introduced from among the bulkhead construction works which Tokyo Electric Power Co. has taken its share and executed. The structure of the bulkhead is a caisson type composite embankment. At the time of designing it, the east breakwater, the bulkhead and the public quay were already partially built, hence taking into consideration their shielding effects as well as relaxation of the construction conditions, its rational cross section has been determined and also ingenuity has been taxed on its actual construction work. 4 refs., 15 figs., 2 tabs.

  19. 重力式码头抛石基床掏空的诊断、处理和预警

    Institute of Scientific and Technical Information of China (English)

    万涛; 邵成

    2015-01-01

    Based on the actual example in the project, we discuss the diagnosis methods and reinforcement measures when rubble bed of gravity is damaged by water flow from tugboat's starting.The position and extent of damage of rubble bed can be diag-nosed through diving inspection and underwater topograghic survey and analysis the socuring trend of the wharf foundation.Combined with the engineering characteristics,wo putforward the scheme of building underwater unscattered concrete to fill cavity of caisson toe and integral pouring underwater concrete in the range of 3M.%结合工程实际,论述了重力式码头抛石基床在现阶段大马力拖轮螺旋桨高速水流作用下破损掏空后的检测方法和加固治理方法。通过水下潜水检查能得到基础破损空洞的部位和大小,并通过测量水底标高分析码头前沿基础存在的冲刷趋势,结合工程特点,提出浇筑水下不离析混凝土填充沉箱前趾下空洞,前沿3m范围内整体浇筑水下混凝土的加固方案。

  20. Radionuclide release from low-level waste in field lysimeters

    International Nuclear Information System (INIS)

    A field program has been in operation for 8 years at the Savannah River Plant (SRP) to determine the leaching/migration behavior of low-level radioactive waste using lysimeters. The lysimeters are soil-filled caissons containing well characterized wastes, with each lysimeter serving as a model of a shallow land burial trench. Sampling and analysis of percolate water and vegetation from the lysimeters provide a determination of the release rates of the radionuclides from the waste/soil system. Vegetative uptake appears to be a major pathway for migration. Fractional release rates from the waste/soil system are less than 0.01% per year. Waste-to-soil leach rates up to 10% per year have been determined by coring several of the lysimeters. The leaching of solidified wasteforms under unsaturated field conditions has agreed well with static, immersion leaching of the same type waste in the laboratory. However, releases from the waste/soil system in the lysimeter may be greater than predicted based on leaching alone, due to complexation of the radionuclides by other components leached from the wastes to form mobile, anionic species

  1. Circulatory bubble dynamics: from physical to biological aspects.

    Science.gov (United States)

    Papadopoulou, Virginie; Tang, Meng-Xing; Balestra, Costantino; Eckersley, Robert J; Karapantsios, Thodoris D

    2014-04-01

    Bubbles can form in the body during or after decompression from pressure exposures such as those undergone by scuba divers, astronauts, caisson and tunnel workers. Bubble growth and detachment physics then becomes significant in predicting and controlling the probability of these bubbles causing mechanical problems by blocking vessels, displacing tissues, or inducing an inflammatory cascade if they persist for too long in the body before being dissolved. By contrast to decompression induced bubbles whose site of initial formation and exact composition are debated, there are other instances of bubbles in the bloodstream which are well-defined. Gas emboli unwillingly introduced during surgical procedures and ultrasound microbubbles injected for use as contrast or drug delivery agents are therefore also discussed. After presenting the different ways that bubbles can end up in the human bloodstream, the general mathematical formalism related to the physics of bubble growth and detachment from decompression is reviewed. Bubble behavior in the bloodstream is then discussed, including bubble dissolution in blood, bubble rheology and biological interactions for the different cases of bubble and blood composition considered.

  2. MANAGING SPENT NUCLEAR FUEL WASTES AT THE IDAHO NATIONAL LABORATORY

    Energy Technology Data Exchange (ETDEWEB)

    Hill, Thomas J

    2005-09-01

    The Idaho National Engineering Laboratory (INL) has a large inventory of diverse types of spent nuclear fuel (SNF). This legacy is in part due to the history of the INL as the National Reactor Testing Station, in part to its mission to recover highly enriched uranium from SNF and in part to it’s mission to test and examine SNF after irradiation. The INL also has a large diversity of SNF storage facility, some dating back 50 years in the site history. The success of the INL SNF program is measured by its ability to: 1) achieve safe existing storage, 2) continue to receive SNF from other locations, both foreign and domestic, 3) repackage SNF from wet storage to interim dry storage, and 4) prepare the SNF for dispositioning in a federal repository. Because of the diversity in the SNF and the facilities at the INL, the INL is addressing almost very condition that may exist in the SNF world. Many of solutions developed by the INL are applicable to other SNF storage sites as they develop their management strategy. The SNF being managed by the INL are in a variety of conditions, from intact assemblies to individual rods or plates to powders, rubble, and metallurgical mounts. Some of the fuel has been in wet storage for over forty years. The fuel is stored bare, or in metal cans and either wet under water or dry in vaults, caissons or casks. Inspections have shown varying degrees of corrosion and degradation of the fuel and the storage cans. Some of the fuel has been recanned under water, and the conditions of the fuel inside the second or third can are unknown. The fuel has been stored in one of 10 different facilities: five wet pools and one casks storage pad, one vault, two generations of caisson facilities, and one modular Independent Spent Fuel Storage Installation (ISFSI). The wet pools range from forty years old to the most modern pool in the US Department of Energy (DOE) complex. The near-term objective is moving the fuel in the older wet storage facilities to

  3. Large-scale offshore wind energy. Cost analysis and integration in the Dutch electricity market

    International Nuclear Information System (INIS)

    The results of analysis of the construction and integration costs of large-scale offshore wind energy (OWE) farms in 2010 are presented. The integration of these farms (1 and 5 GW) in the Dutch electricity distribution system have been regarded against the background of a liberalised electricity market. A first step is taken for the determination of costs involved in solving integration problems. Three different types of foundations are examined: the mono-pile, the jacket and a new type of foundation: the concrete caisson pile: all single-turbine-single-support structures. For real offshore applications (>10 km offshore, at sea-depths >20 m), the concrete caisson pile is regarded as the most suitable. The price/power ratios of wind turbines are analysed. It is assumed that in 2010 turbines in the power range of 3-5 MW are available. The main calculations have been conducted for a 3 MW turbine. The main choice in electrical infrastructure is for AC or DC. Calculations show that at distances of 30 km offshore and more, the use of HVDC will result in higher initial costs but lower operating costs. The share of operating and maintenance (O ampersand M) costs in the kWh cost price is approximately 3.3%. To be able to compare the two farms, a base case is derived with a construction time of 10 years for both. The energy yield is calculated for a wind regime offshore of 9.0 m/s annual mean wind speed. Per 3 MW turbine this results in an annual energy production of approximately 12 GWh. The total farm efficiency amounts to 82%, resulting in a total farm capacity factor of 38%. With a required internal rate of return of 15%, the kWh cost price amounts to 0.24 DFl and 0.21 DFl for the 1 GW and 5 GW farms respectively in the base case. The required internal rate of return has a large effect on the kWh cost price, followed by costs of subsystems. O ampersand M costs have little effect on the cost price. Parameter studies show that a small cost reduction of 5% is possible when

  4. MANAGING SPENT NUCLEAR FUEL WASTES AT THE IDAHO NATIONAL LABORATORY

    International Nuclear Information System (INIS)

    The Idaho National Engineering Laboratory (INL) has a large inventory of diverse types of spent nuclear fuel (SNF). This legacy is in part due to the history of the INL as the National Reactor Testing Station, in part to its mission to recover highly enriched uranium from SNF and in part to it's mission to test and examine SNF after irradiation. The INL also has a large diversity of SNF storage facility, some dating back 50 years in the site history. The success of the INL SNF program is measured by its ability to: (1) achieve safe existing storage, (2) continue to receive SNF from other locations, both foreign and domestic, (3) repackage SNF from wet storage to interim dry storage, and (4) prepare the SNF for dispositioning in a federal repository. Because of the diversity in the SNF and the facilities at the INL, the INL is addressing almost very condition that may exist in the SNF world. Many of solutions developed by the INL are applicable to other SNF storage sites as they develop their management strategy. The SNF being managed by the INL are in a variety of conditions, from intact assemblies to individual rods or plates to powders, rubble, and metallurgical mounts. Some of the fuel has been in wet storage for over forty years. The fuel is stored bare, or in metal cans and either wet under water or dry in vaults, caissons or casks. Inspections have shown varying degrees of corrosion and degradation of the fuel and the storage cans. Some of the fuel has been recanned under water, and the conditions of the fuel inside the second or third can are unknown. The fuel has been stored in one of 10 different facilities: five wet pools and one casks storage pad, one vault, two generations of caisson facilities, and one modular Independent Spent Fuel Storage Installation (ISFSI). The wet pools range from forty years old to the most modern pool in the US Department of Energy (DOE) complex. The near-term objective is moving the fuel in the older wet storage facilities to

  5. Design for Huaxi Bridge in Highway around Guiyang City%贵阳环城高速公路花溪大桥设计

    Institute of Scientific and Technical Information of China (English)

    金令

    2012-01-01

    Huaxi Bridge is a super large bridge across above Huaxi reservoir in the south line of Guiyang City Highway. The main bridge, which is a 192 m half-through concrete-filled steel tube arch bridge with 29.3 m in full width ( bi-direction four lanes plus sidewalks) and 100 km/h design speed, is the key bridge and controlling project of the whole line. The author illustrates the general design situation of the bridge, including bridge-type selection, design parameters, structure details and construction methods. According to the situations at the bridge site, Huaxi Bridge is the first bridge using the technologies such as triangular space truss arch, cutting caisson foundation, self-compacting concrete-filled steel tube in Guizhou region, which can give some references for the same type of bridge constructions in mountainous karst area.%花溪大桥为贵阳环城高速公路南环线跨越花溪水库的一座特大型桥梁,主桥为192 m的中承式钢管混凝土拱桥,大桥全宽29.3 m(双向四车道+人行道),设计速度100 km/h,是全线重点桥梁和控制性工程.介绍该桥的总体设计情况,包括桥式选择、设计参数、构造细节、施工方法.根据桥址处的条件大桥在贵州地区首次采用了三角形空间桁架拱、挖井基础、自密实钢管混凝土等技术,对多山岩溶地区同类型桥梁建设具有参考意义.

  6. 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.

  7. Nuclear reactor (1960); Reacteurs nucleaires (1960)

    Energy Technology Data Exchange (ETDEWEB)

    Maillard, M.L. [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires; Leo, M.B. [Electricite de France (EDF), 75 - Paris (France)

    1960-07-01

    The first French plutonium-making reactors G1, G2 and G3 built at Marcoule research center are linked to a power plant. The G1 electrical output does not offset the energy needed for operating this reactor. On the contrary, reactors G2 and G3 will each generate a net power of 25 to 30 MW, which will go into the EDF grid. This power is relatively small, but the information obtained from operation is great and will be helpful for starting up the power reactor EDF1, EDF2 and EDF3. The paper describes how, previous to any starting-up operation, the tests performed, especially those concerned with the power plant and the pressure vessel, have helped to bring the commissioning date closer. (author) [French] Les premiers reacteurs industriels plutonigenes francais G1 - G2 - G3 du Centre de Marcoule comportent une installation de recuperation d'energie. La production d'electricite de G1 ne compense pas l'energie depensee par ailleurs pour le fonctionnement de l'ensemble, par contre, G2 et G3 doivent fournir chacun une puissance de 25 a 30 MW au reseau national d'Electricite de France. Cette puissance est modeste, mais l'experience acquise grace a ces reacteurs est tres grande et c'est grace a elle qu'il nous sera possible de mettre en exploitation les reacteurs energetiques EDF1 - EDF2 - EDF3. Le memoire decrit comment, avant tout demarrage du reacteur, les essais effectues, en particulier ceux concernant l'installation de recuperation d'energie et le caisson, ont permis d'abreger la phase de montee en puissance. (auteur)

  8. Puente de hormigón pretensado sobre el rio Ulúa, Honduras

    Directory of Open Access Journals (Sweden)

    Editorial, Equipo

    1967-07-01

    Full Text Available In the course of an international competition, the Compagnie Française d'Entreprises has submitted two designs, and the one adopted is a cantilever box section type bridge, prestressed transversally and longitudinally and built by successive overhangs. The present article describes in considerable detail the above road bridge, of three spans, the two end ones being 60 m long, and the centre one is 120 m long. The two middle piles rest on caissons. The overhanging sections of the main span are each 42 m long, and the middle part of the span, which is simply supported on overhanging sections, is 36 m long. The bridge is now open to traffic and is a great aid to the communications network of Honduras.En concurso internacional, la Compagnie Française d'Entreprises presentó dos soluciones, adoptándose la de un puente, tipo cantilever, de sección en cajón, pretensado transversal y longitudinalmente y construido en voladizo. La obra que en este trabajo se describe con bastante detalle es un puente para carretera, de tres tramos, dos laterales de 60 m de luz y uno central de 120 m. Las dos pilas centrales se apoyan sobre cajones. Los brazos en voladizo tienen 42 m de longitud y la pieza central de cierre, simplemente apoyada sobre las extremidades de los citados brazos, una longitud de 36 metros. El puente se halla actualmente en servicio y constituye una gran mejora en la red vial hondureña.

  9. Landfill stabilization focus area: Technology summary

    International Nuclear Information System (INIS)

    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

  10. 地下水水位变动对建筑物影响的实例分析%The Example Analysis of the Impact of Groundwater TableChanges on Building

    Institute of Scientific and Technical Information of China (English)

    祁星星

    2015-01-01

    受自然降水、人工使用等因素的影响,地下水水位十分不稳定,在水浮力和土体有效自重压力作用下,地基土整体收缩膨胀,会对上部建筑物的使用产生不利的影响.本文结合工程案例,模拟沉井降水进行现场抽水试验,对地下水水位变动、周围建筑物主体结构和楼地面的损伤观察记录,分析验证地下水水位的变动对建筑物产生的影响,以供从业者参考.%Groundwater table is very unstable,due to the influence of factors such as natural rainfall, artificial factors and so on. Under the influence of water buoyancy and soil mass, the shrinkage and expansion of the foundation soil will have a negative effect on the usage of the superstructure.Combined with the engineering case, the pumping test was conducted by simulating open caisson precipitation.Based on the test,thechanges of the groundwater table,the damage of the main building structure and the ground floor were recorded, the influence of the change of groundwater table to the building was analyzed and verified, to provide reference for practitioners.

  11. Solute transport benchmark studies for TRACR3D code verification

    International Nuclear Information System (INIS)

    A three-dimensional code called TRACR3D, which is applicable to solute transport in both unsaturated and saturated media, is being used to model hypothetical transport of radioactive and nonradioactive constituents from calcined high-level radioactive waste (HLW) at the Idaho Chemical Processing Plant (ICPP). The modeling studies are part of a documentation process which will be required for evaluation of onsite disposal in a near-surface facility as a possible alternative strategy for the long-term management of ICPP HLW. This report discusses the results of a benchmark study for code verification. The problems modeled were: (1) A one-dimensional problem involving the transport of the pertechnetate ion (TcO4-) through a 5-cm diameter by 30-cm-long soil column at ICPP. (2) A one-dimensional problem involving the transport of the iodide ion (I-) through a large caisson (3-m diameter by 6-m depth) at LANL. (3) A three-dimensional problem involving the transport of radioactive ruthenium (Ru-106) from a single-shell tank leak into the vadose zone at the Hanford site. For the three benchmark studies performed, it was concluded that the predicted results from TRACR3D were in agreement with documented and reported solute transport problems, that the input data files were properly configured, and that the code correctly performed the mathematical operations specified in the numerical models. These results will provide a greater degree of confidence in results obtained for planned modeling studies at ICPP. 6 refs., 8 figs., 2 tabs

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

    International Nuclear Information System (INIS)

    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

  13. 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.

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

    International Nuclear Information System (INIS)

    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

  15. Process of constructing a lightweight x-ray flight mirror assembly

    Science.gov (United States)

    McClelland, Ryan S.; Biskach, Michael P.; Chan, Kai-Wing; Espina, Rebecca A.; Hohl, Bruce R.; Saha, Timo T.; Zhang, William W.

    2014-07-01

    Lightweight and high resolution optics are needed for future space-based x-ray telescopes to achieve advances in highenergy astrophysics. NASA's Next Generation X-ray Optics (NGXO) project has made significant progress towards building such optics, both in terms of maturing the technology for spaceflight readiness and improving the angular resolution. Technology Development Modules (TDMs) holding three pairs of mirrors have been regularly and repeatedly integrated and tested both for optical performance and mechanical strength. X-ray test results have been improved over the past year from 10.3 arc-seconds Half Power Diameter (HPD) to 8.3 arc-seconds HPD. A vibration test has been completed to NASA standard verification levels showing the optics can survive launch and pointing towards improvements in strengthening the modules through redundant bonds. A Finite Element Analysis (FEA) study was completed which shows the mirror distortion caused by bonding is insensitive to the number of bonds. Next generation TDMs, which will demonstrate a lightweight structure and mount additional pairs of mirrors, have been designed and fabricated. The light weight of the module structure is achieved through the use of E-60 Beryllium Oxide metal matrix composite material. As the angular resolution of the development modules has improved, gravity distortion during horizontal x-ray testing has become a limiting factor. To address this issue, a facility capable of testing in the vertical orientation has been designed and planned. Test boring at the construction site suggest standard caisson construction methods can be utilized to install a subterranean vertical vacuum pipe. This facility will also allow for the testing of kinematically mounted mirror segments, which greatly reduces the effect of bonding displacements. A development platform demonstrating the feasibility of kinematically mounting mirror segments has been designed, fabricated, and successfully tested.

  16. 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.

  17. Optimisation de la commande d'un séchoir solaire à bois

    Science.gov (United States)

    Coulibaly, B.; Fournier, M.; Amouroux, M.

    1992-04-01

    A solar dryer has been built at Kourou (French Guyana) in 1986. A mathematical model has been validated by experimental results. A wood drying process implies that internal dryer conditions respect wood drying table. The classic behaviour has followed until now a “bang bang” control. This law is consistent with the wood quality but may be more efficient. The introduction in the model of new command laws more sophisticated for air flow regulation and better adapted to solar fluctuations allow to reduce the drying time, improving performance with respect for the product quality. Un séchoir solaire à bois a été réalisé à Kourou (Guyane) en 1986. Il a été modélisé puis a été validé en comparant les résultats théoriques et expérimentaux. Une opération de séchage de bois implique que l'atmosphère interne du caisson de dessication respecte les conditions de la table de séchage de l'essence de bois en question. La conduite classique de cette opération a suivi juqu'à présent une loi de commande “tout ou rien” qui respectait la qualité du bois mais n'optimisait pas le rendement thermique. L'introduction dans le modèle de lois de commande -d'une part plus sophistiquées pour réguler les débits d'air, dans les capteurs solaires et dans le circuit de renouvellement, - d'autre part mieux adaptées aux caractéristiques fluctuantes de la source d'énergie solaire, permet de réduire les durées de séchage des charges de bois à sécher en améliorant les rendements thermiques et en respectant la qualité du bois.

  18. 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

  19. Deployment of a Long-Term Broadband Seafloor Observatory in Monterey Bay

    Science.gov (United States)

    McGill, P.; Neuhauser, D.; Stakes, D.; Romanowicz, B.; Ramirez, T.; Uhrhammer, R.

    2002-12-01

    MOBB (Monterey bay Ocean floor Broad Band project) is a collaborative project between the Monterey Bay Aquarium Research Institute (MBARI) and the Berkeley Seismological Laboratory (BSL). Its goal is to install and operate a permanent seafloor broadband seismic station as a first step towards extending the on-shore broadband seismic network in northern California to the seaside of the North-America/Pacific plate boundary, providing better azimuthal coverage for regional earthquake and structure studies. The successful MOBB deployment took place 40km off shore at a water depth of 1000m during three dives on April 9-11, 2002. The seismometer was buried in a 60-cm deep caisson, which was later back filled with glass beads to stabilize the instrument. New tools, including a high-pressure water-jet excavator, were developed for the ROV Ventana to accomplish these tasks. The ocean-bottom MOBB station currently comprises a three-component seismometer package, a current-meter, and a recording and battery package. Data recovery dives, during which the recording and battery package will be exchanged, are planned every three months for the next three years. A differential pressure gauge (DPG) (Cox et al., 1984) will be deployed as part of the recording package during the next data recovery dive in September 2002. The station is currently recording data autonomously. Eventually, it will be linked to the planned (and recently funded) MARS (Monterey Accelerated Research System; rl {http://www.mbari.org/mars/}) cable and provide real-time, continuous seismic data to be merged with the rest of the northern California real-time seismic system. The data are archived at the NCEDC for on-line availability, as part of the Berkeley Digital Seismic Network (BDSN). This project follows the 1997 MOISE experiment, in which a three-component broadband system was deployed for a period of three months, 40km off shore in Monterey Bay. MOISE was a cooperative program sponsored by MBARI, UC

  20. Adaptaciones metodológicas en la aplicación del análisis estratigráfico constructivo: el Santuario de San Juan de la Penyagolosa (Castellón y la iglesia de San Juan de los Reyes en Granada

    Directory of Open Access Journals (Sweden)

    Mileto, Camilla

    2003-12-01

    Full Text Available This text presents two cases of the application of stratigraphic wall study in which two specific adaptations, stemming from the original case of the building analysed, were developed. In the first case, the study of the Santuario de San Juan de la Peñagolosa, the notable size of the shrine meant that data collection and management were highly complex. For this reason, a methodology was tested whereby information was hierarchized, allowing it to be managed faster and more efficiently. In the second case, the study of the church of San Juan de los Reyes, a complementary study was carried out in addition to the stratigraphic wall study. The same construction technique used in the building (wall stonework with brick buttresses and limestone boulder caissons brought about the possibility of carrying out a study of the distribution of the weep holes.En este texto se presentan dos casos de aplicación del estudio estratigráfico constructivo en los cuales se desarrollaron dos adaptaciones específicas ocasionadas por el caso concreto del edificio analizado. En el primer caso, el estudio del Santuario de San Juan de la Peñagolosa, la notable dimensión del conjunto conllevaba una complejidad de recogida y gestión de la información. Por esta razón, se ensayó una metodología de jerarquización de la información que permitiera una gestión de la misma más rápida y eficaz. En el segundo caso, el estudio de la iglesia de San Juan de los Reyes, además del estudio estratigráfico se realizó un estudio complementario. La misma técnica utilizada en el edificio (fábricas de machones de ladrillo y cajones de cantos rodados y cal sugirió la posibilidad de realizar el estudio del ritmo de la distribución de los mechinales.

  1. Progress on the NEPTUNE Canada Seismograph Network

    Science.gov (United States)

    Rogers, G. C.; Meldrum, R. D.; Heesemann, M.; Mulder, T. L.; Brillon, C. D.; Cassidy, J. F.

    2012-12-01

    NEPTUNE Canada is the world's first deep-sea regional multi-disciplinary scientific cabled ocean observatory. In the fall of 2007 an 800 kilometer ring of powered fiber optic cable was laid on the seafloor over the northern part of the Juan de Fuca plate and connected to a shore facility near Port Alberni on Vancouver Island. In September 2009, three broadband OBS packages were deployed in the form of a large triangle with apexes at mid plate near ODP 1027 (water depth of 2654m) and two sites on the continental slope, near ODP 889 (1256m) and Barkley Canyon (396m). The broadband systems comprise a broadband seismometer and strong motion accelerometer in a spherical titanium case surficially buried in a caisson backfilled with glass beads. Noise levels observed are as expected with the spectra being similar to, or quieter than, coastal seismograph stations in approximately the 10 to 20 second period range. The OBS's have higher noise levels at longer periods where ocean swells and the resultant infragravity waves dominate the noise spectra, and in the 1-10 Hz bandwidth typically used for locating local earthquakes. The shallowest site at Barkley Canyon has the highest noise levels. A small array, about 6 km in maximum dimension, is under construction on the Endeavour segment of the Juan de Fuca Ridge to record earthquake activity in the vicinity of the many NEPTUNE Canada multi-disciplinary ridge experiments. Two short period instruments were installed there in 2010. A broadband instrument and two additional short period instruments are planned to complete the initial ridge array. Even though the NEPTUNE Canada seismograph network is not yet complete, measured by the use of its data, it is a success already. The data are routinely used along with data from land seismographs of the Canadian National Seismograph Network for locating earthquakes in the region. However, the smallest seismic arrivals picked on the land stations cannot be routinely picked on the OBS

  2. 陕西湿陷性黄土区域风机基础设计研究%Study on Design of WTG Foundation in Collapsible Loess Region in Shaanxi Province

    Institute of Scientific and Technical Information of China (English)

    张立英; 李梦; 刘嫔

    2014-01-01

    Design of WTG foundation of the wind farm construction in collapsible loess region in Shaanxi Province is the key and difficult factor.In combination with practice of the wind farm construction in Dingbian and Jingbian countries, the foundation treatment method applicable to the WTG foundation is provided.Meanwhile, determination method of the negative friction-resistance length is proposed for the first time based on the WTG foundation importance, possibility of the foundation possibly soaked and the vertical soaking tests.Fur-thermore, the caisson pile with its end enlargement is raised according to the characteristics of the foundation parameters in northern Shaanxi Province.The bearing capacity of the pile end is fully utilized to reduce the pile length.Accordingly, the WTG foundation is op-timized in term of its volume and quantity.Those applications provide the design of WTG foundation of the wind farm construction in col-lapsible loess region in Shaanxi Province with reference.%在陕西湿陷性黄土区域进行风电建设,风机基础设计是风电场设计的重点和难点。本文结合在定边、靖边多风电场的建设经验,提出了风机基础适用的地基处理方法;根据风机基础的重要性、地基受水浸湿可能性的大小,通过多工程的竖向浸水试验首次提出负摩阻长度的确定方法;根据陕北地基参数特点,提出采用扩底灌注桩,充分利用桩端承载力的方法,显著减小桩长,优化风机基础工程量。为陕西湿陷性黄土区域风机基础设计提供参考。

  3. 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

  4. A Long-Term Seismic Array on the Endeavour Segment of the Juan de Fuca Ridge

    Science.gov (United States)

    McGill, P. R.; Wilcock, W. S.; Stakes, D. S.; Barclay, A. H.; Ramirez, T. M.; Toomey, D. R.

    2003-12-01

    The Keck Foundation with additional support from the Monterey Bay Aquarium Research Institute and the University of Washington has funded a five-year, five-million dollar program for archetypic experiments on the northern Juan de Fuca Plate. The goal of this program is to constrain the linkages between deformation (earthquakes), fluid flow and chemistry, and microbial response across the northern Juan de Fuca Plate in the northeastern Pacific Ocean. A key component of these studies is an array of ocean-bottom seismometers to record the temporal and spatial distribution of seismic activity in the region. The current network, deployed in August of 2003, is comprised of eight autonomous instruments: one broadband seismometer and seven short-period seismometers. The instruments are distributed within and around the axial valley at the center of the Endeavour segment and spaced about 4 km apart, composing an array about 7 km wide and 9 km long. The short-period instruments, sensitive over a frequency range of 1 to 32 Hz, utilize an MBARI/GEOSense BH1 three-axis corehole geophone connected to an MBARI/GEOSense LP1 data logger. For five of these instruments the corehole sensor is inserted into a 7 cm diameter hole drilled into the basaltic basement rock, thus providing excellent coupling. For the other two instruments where suitable drilling sites were not available, the sensors are inserted into 55 kg concrete blocks placed on the sediment. The broadband instrument is a Guralp CMG-1T three-axis seismometer, sensitive over a frequency range of 2.8 mHz (360 sec) to 50 Hz. The sensor is completely buried in sediment inside a 60 cm deep by 60 cm diameter caisson, thus reducing the effects of water currents on the recorded data. A 20 m cable connects the sensor to an LP1 data logger and a 30 kW-hr battery sitting on the sediment. A complete data set will be recovered from the array when the instruments are revisited during the summer of 2004. However, data from two events, an

  5. 海洋油气开发用水下紧凑型多相分离技术%Underwater Compact Multiphase Separation Technology for Offshore Petroleum Development

    Institute of Scientific and Technical Information of China (English)

    李锐锋; 陈家庆; 姬宜朋; 李汉勇; 王春升

    2012-01-01

    The seafloor multistage separation technology is the key to the subsea oil and gas processing technology in offshore pe-troleum development as well as an important part of underwater production system. Distinguished international petroleum companies have attached great importance to the underwater compact multistage separation technology in recent years, developing some new underwater compact multistage separation technologies and equipments. The paper introduces the structure and operating principle of seabed vertical caisson separator, vertical vessel separator, horizontal single coil pipe separator and vertical multi-pipe separator. The history of devel-opment and the corresponding progress of engineering cases are also introduced. Part of the paper tocuses on the technological scheme for gas-liquid separation of produced fluid of oil well, which breaks the traditional thinking pattern in umltiphase separator design and provides the referenee for domestic researchers in independent development of the compact muhiphase separation technology.%海底多相分离技术是海洋油气开发中海底处理技术的核心,也是水下生产系统的重要组成部分。世界知名石油公司近年来非常重视水下紧凑型多相分离技术,研制开发了多种新型水下紧凑型多相分离技术和设备。介绍了海底立式沉箱类分离器、立式容器类分离器、卧式单根盘管式分离器、立式多管分离器等的结构和工作原理,并介绍了研发历程和相应的工程案例进展。部分侧重于进行油井产出液气一液分离用的技术方案打破了多相分离器设计的传统思维模式,为国内相关人员自主研发紧凑型多相分离技术提供了参考指导。

  6. Diseño y construcción de las bóvedas por cruceros en España durante el siglo XVI

    Directory of Open Access Journals (Sweden)

    Palacios, J. C.

    2013-10-01

    Full Text Available The aim of this text is to present the historical guidelines, design and construction of the grid crossing vaults built in Spain during the 16th century to show how the Gothic tradition of building ribbed vaults could be adapted to classical aesthetic principles. In the Andalusia of the 16th century, both a Renaissance classical architecture and another extraordinarily evolved Gothic one reached, at the same time, their full development, taking place between them interesting knowledge, stylistic and technical transfers. In this respect, the grid crossing vaults are a remarkable example of the formal autonomy of Gothic ribs which, without losing their medieval construction principles, are capable of adapting themselves to Renaissance models. We will see how in the grid crossing vaults, the Gothic crossings adapted themselves to the shape of a classical grid structure, drawing on the surface of the vault a design of caissons according to the stricter Roman Canon.El objetivo de este texto es dar a conocer las pautas históricas, de diseño y construcción de las bóvedas por cruceros erigidas en España durante el siglo XVI, como muestra de cómo la tradición gótica de construir bóvedas con nervaduras pudo adaptarse a los principios estéticos clásicos. En la Andalucía del siglo XVI, una arquitectura clásica renacentista y otra gótica extraordinariamente evolucionada alcanzaron, al mismo tiempo, su pleno desarrollo; entre ambas se produjeron interesantes transferencias de conocimiento, estilísticas y técnicas. En este sentido, las bóvedas por cruceros constituyen un notable ejemplo de autonomía formal de la nervadura gótica que, sin perder sus principios constructivos medievales, es capaz de adaptarse a modelos renacentistas. Veremos como en las bóvedas por cruceros, las crucerías góticas se adaptan a la forma de una trama reticular clásica, dibujando sobre la superficie de la bóveda un diseño de casetones conforme al canon

  7. Investigation and discussion of marine structures integrated with ocean energy devices%海工构筑物海洋能集成利用技术探讨

    Institute of Scientific and Technical Information of China (English)

    王树杰; 王举田; 刘锦昆; 袁鹏; 刘臻; 徐志刚; 季文峰

    2015-01-01

    将海工构筑物作为海洋能获能装置的安装载体可大幅降低海洋能发电的成本,同时,海工构筑物等海上设施客观上存在利用海洋能实现能量供应的需求,因此海洋能发电装置与海工构筑物相互结合具有良好的综合效益,将是未来海洋能利用的一个发展方向。针对波浪能和潮流能两种海洋能发电方式,分别对柔性叶片潮流能水轮机与进海路集成利用技术;垂直轴和水平轴潮流能水轮机以及振荡浮子式波能装置与导管架石油平台集成利用技术;OWC波能装置与沉箱防波堤集成利用技术进行了探讨,并提出海工构筑物海洋能集成利用技术中需要解决的几点问题。%Ocean energy devices installed on marine structures can greatly reduce the cost of ocean energy power generation. On the other hand, marine structures such as offshore installations need to gain power generated by ocean energy nearby. Therefore, marine structures equipped with ocean energy devices have comprehensive benefits, which will be developed in the future. According to the classification of ocean energy power generation utilizing wave and tidal current, some types of integrated utilization are investigated and discussed, such as flexible tidal current turbines integrated with perforated sea roads, vertical and horizontal tidal current turbines integrated with jacket platforms, oscillating buoys integrated with jacket platforms and OWC wave energy devices integrated with caisson breakwaters. At the same time, some questions and suggestions are put forward in order to make the utilization mature.

  8. 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

  9. 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

  10. 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

  11. 大连星海湾跨海大桥主桥总体设计%Overall Design of Main Bridge of Xinghai Bay Sea-Crossing Bridge in Dalian

    Institute of Scientific and Technical Information of China (English)

    檀永刚; 陈亮; 张哲

    2015-01-01

    大连星海湾跨海大桥主桥为(180+460+180) m双层地锚式悬索桥,主梁为钢桁架结构形式,采用整体节点构造,上、下2层桥面板均采用正交异性钢桥面板,桥面上铺装5.5 cm厚双层环氧沥青。锚碇采用空腹三角形框架混凝土重力式锚碇,设置在水深20~30 m的海床上,锚碇基础采用整体大沉箱,单个沉箱重达26000 t ,在船坞内预制完成后用拖轮拖运到桥位处安装在碎石基床上,碎石基床采用升浆技术进行加固。桥塔采用钢筋混凝土框架结构,设上、下2道横梁。主缆由钢丝强度等级为1770 M Pa的平行钢丝索股组成,并用长达16 m的刚性拉杆锚固在锚碇上,同时采用除湿系统结合传统防腐涂装体系的结构进行防腐,以提高缆索系统的耐久性。%T he main bridge of Xinghai Bay Bridge in Dalian is a double‐deck earth‐anchored sus‐pension bridge with span arrangement of (180+ 460+ 180) m .The stiffening girder adopts the type of steel truss girder structure with integrated nodes .The upper and lower bridge decks are fitted with orthotropic steel plate deck paved with 5 .5 cm thick double‐layer epoxy asphalt .The anchorages are the concrete gravity anchor blocks with open‐web triangular framework ,sitting on the seabed that is 20~30 m under the sea ,the foundations of w hich adopt the large integrated cais‐sons ,each weighing up to 26 000 t .The caissons were prefabricated in the ship yard ,and then towed to the bridge site by the tug boats ,and sunk to the crushed stone seabed that are strength‐ened by prepackaged aggregate concrete technology .Bridge towers are the reinforced concrete frame structures ,equipped with an upper and a lower cross beams .The main cables are made up of prefabricated parallel wire strands ,each with a strength of 1 770 MPa ,anchored to the anchor blocks using the 16 m long rigid anchoring roads .T he main cables are corrosion

  12. Scheme Comparison and Selection for Anchor Foundation of Maputo Bridge in Mozambique%莫桑比克马普托大桥锚碇基础方案比选

    Institute of Scientific and Technical Information of China (English)

    周健; 邹恩杰; 李元博; 孟令亮

    2014-01-01

    莫桑比克马普托(M aputo )大桥主桥为单跨680 m悬索桥,为确定马普托大桥锚碇基础方案,依据大桥桥位处的地质和水文情况,以及重力式锚碇的结构受力特点,针对锚碇基础基底持力层选择、施工工艺的适用性、技术可行性、经济性、合理性,分别对沉井基础和地下连续墙基础进行研究。研究结果表明:采用地下连续墙基础,施工期间可以避免由于地质情况变化带来的风险,如翻砂、突涌等;可以严格控制锚碇基础施工过程中对周围土体造成的沉降,最大限度地减少对周围铁路正常运营的影响。在确定地下连续墙基础形式后,针对施工过程中的突涌问题,对深地下连续墙和浅地下连续墙+灌浆帷幕+深井抽排水降低水头方案进行研究。研究结果表明:采用深地下连续墙基础,投入设备相对单一,施工工艺、工序简单,施工工效相对较高,施工工期较短,工期可控,应为马普托大桥合理的锚碇基础方案。%The main bridge of Maputo Bridge in Mozambique is a suspension bridge with a sin‐gle span of 680 m .In order to make a rational anchor foundation scheme ,the types of caisson foundation and underground diaphragm wall were studied in accordance with the geological and hydrological condition at the bridge site and the load bearing characteristics of gravity anchor .I‐tems such as the selection of the base bearing stratum for the anchor foundation ,feasibility of the construction techniques and the applicability ,economic performance and rationality of the tech‐niques were also taken into account in the study .The results of the study indicate that the adapta‐tion of the underground diaphragm wall foundation is able to avoid the risks induced by variation of geological condition ,such as quicksand and heavy‐piping ,and is possible to strictly control the surrounding soil settlement during the

  13. 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

  14. On the spatial variability of the hyporheic zone: in-situ investigation of porosity and grain size using diving bells and 3D photogrammetry

    Science.gov (United States)

    Frings, R. M.; Vollmer, S.

    2012-04-01

    In order to improve the ecological status of rivers, lakes and other water bodies, recent legislation, such as the European Water Framework Directive, requires for each water body an assessment of its suitability as habitat for organisms. Such an assessment, though, is not easy. This is especially true for the lowest part of the water body: the substrate or hyporheic zone. Even if it is known which kind of hyporheic zone is preferred by an organism, it remains difficult to determine where it can be found, because it is often impossible to observe the hyporheic zone from the banks or shores. It has become common to classify an entire water body as suitable or unsuitable as habitat, using only limited field observations of the hyporheic zone. This is a doubtful practice, which disregards the huge spatial variability of this zone. The objective of this study was to quantify the spatial variability in hyporheic-zone characteristics in the river Rhine. We focused on two basic characteristics: grain size and porosity, the latter being a primary control on the transport of nutrients, heat, oxygen and organic matter. A diving bell (caisson) was used to obtain access to the river bed, which enabled undisturbed sampling of the hyporheic zone. Between 1968 and 2009 6436 sediment samples were taken and sieved to determine their grain size distribution. Furthermore, in 2009 and 2011 about 100 porosity measurements were carried out, using a novel technique based on a combination of field measurements using three-dimensional photogrammetry and laboratory measurements using the water displacement method. The measurements revealed a strong cross-sectional variability in porosity and grain size. Each river cross-section contains spots with high porosity (order 0.40) and spots with low porosity (order 0.10). The large cross-sectional variability made it impossible to recognize systematic streamwise porosity trends from the data. Therefore we investigated if porosity was correlated to

  15. Pegase: safety studies - experimental study of burn-out risks in transient operation; Pegase: etude de surete - etude experimentale des risques de burn out en regime transitoire

    Energy Technology Data Exchange (ETDEWEB)

    Vernier, P. [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

    1968-07-01

    An experiment out-of-pile experimental set up is proposed simulating the breakage of a pipe supplying the core of the reactor Pegase. The two fast phenomena, depressurization of the vessel and flow reversal, are reproduced. The aluminium heating channel has the same shape as that of the reactor channel but has twice the heat capacity. The starting conditions are V= 4.50 and 6 m/sec., T{sub E} = 50 and 60 degrees C and P{sub E} = 4 bars. The results show that the critical flux PHI{sub C} varies with the flow-rate from 45 to 60 W/cm{sup 2} in the case where there is no power reduction. For fluxes of 90 W/cm{sup 2} the results lead to the conclusion that the hot channel attains a state of burn-out after 0.1 sec. and that its temperature reaches 500 C in 0.8 sec. The hydrodynamic conditions in the channels after the accident involve periodic expulsion (0.2 to 0.5 sec.), characteristic of boiling at low pressure. A study of the steady state flow redistribution through a by-pass has given flux redistribution PHI{sub R} of 190 W/cm{sup 2} for a flow rate of 4.5 m/sec. at 50 and of 175 W/cm{sup 2} at 60 C. These values increase which has to be made between the critical flux PHI{sub C} during the periodic expulsion conditions and the flux redistribution PHI{sub R} during the steady state, has been shown. (author) [French] On propose un schema experimental hors pile d'une rupture du tuyau alimentant le coeur du reacteur PEGASE. On reproduit les phenomenes rapides de depressurisation du caisson et d'inversion du debit dans le coeur. Le canal chauffant en aluminium a la meme geometrie que le canal du reacteur, mais une capacite calorifique double. Les conditions initiales sont V= 4.5 et 6 m/s, T{sub E} = 50 et 60 C et P{sub E} = 4 bars. Les resultats montrent que le flux critique PHI{sub C} evolue avec la vitesse de 45 a 60 60 W/cm{sup 2} dans le cas ou il n'y a pas reduction de puissance. Pour des flux de 90 W/cm{sup 2} l'interpretation des resultats

  16. 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)

  17. The use and evolution of the CEA research reactors; Utilisation et evolution des reacteurs de recherche du C.E.A

    Energy Technology Data Exchange (ETDEWEB)

    Rossillon, F.; Chauvez, C. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1964-07-01

    combustibles refractaires et de graphites speciaux, et l'etude du comportement des liquides organiques sous radiations. Les installations de MELUSINE sont actuellement en cours de modernisation. La Pile SILOE, egalement du type piscine, est en fonctionnement a 15 MW depuis la fin de l'annee 1963. Les performances realisees constituent un progres considerable dans le domaine des piles piscines, les flux obtenus etant d'un ordre de grandeur qui exigeait jusqu'a present l'adoption d'une structure 'a caisson' dont on connait les nombreux inconvenients pour la realisation des experiences. La pile SILOE sera surtout utilisee pour l'etude des materiaux de structure, du graphite, des combustibles refractaires, et pour la physique du solide. La Pile PEGASE, en service au Centre de Cadarache depuis 1963, est destinee uniquement au test, en vraie grandeur, des elements combustibles des filieres EDF et EL4. Le programme actuel pour les 8 boucles de la Pile concerne les elements des Piles EDF 2, EDF 3 et EL 4. De nouvelles boucles sont en cours d'etude pour les elements combustibles des piles EDF 4 et EDF 5. L'orientation des programmes du CEA a mis en evidence d'importants besoins d'irradiations en neutrons rapides. La Pile OSIRIS, actuellement en cours de realisation, permettra de completer les moyens du CEA dans ce domaine, tout en venant compenser, pour le Centre de Saclay, l'arret prochain de EL 2. OSIRIS est une pile a eau legere, mais dont la structure assez particuliere permettra un fonctionnement a 50 MW sans les inconvenients habituels lies a l'existence d'un caisson lourd et etanche. Cette pile, dont la mise en service est prevue pour 1966, sera surtout utilisee pour l'etude des materiaux de structure, du graphite et des combustibles refractaires; elle permettra egalement d'accroitre la production des radioisotopes a haute activite specifique, et de developper les techniques d

  18. Method for analyzing cyclic bearing capacity of suction anchor with taut mooring system using cyclic strengths%利用循环强度分析张紧式吸力锚循环承载力的方法

    Institute of Scientific and Technical Information of China (English)

    王建华; 李书兆; 周杨锐; 刘晶磊

    2012-01-01

    A limiting equilibrium method for calculating cyclic bearing capacities of suction anchors in soft clays using undrained cyclic shear strength of soft clays was developed based on the failure mode of suction anchors with inclined loads at the optimal loading point. Effects of average shear stresses due to average mooring loads on cyclic shear strengths of soft clays and cyclic bearing capacities of suction anchors were considered for the method. In order to verify its feasibility, a large number of model tests of suction anchors with combined average and cyclic mooring loads were conducted associated with different test parameters. The displacement criterion to failure at the loading point associated with the vertical pullout failure mode was determined based on test results. Cyclic bearing capacities of model tests with different parameters were determined based on the criterion. Cyclic bearing capacities associated with different model tests were further calculated by limiting equilibrium analyses using the relationship determined by undrained cyclic triaxial tests between normalized cyclic strengths and normalized average stresses and measuring shear strengths of model test strata. Comparison between calculating and testing results show that calculating results larger than testing results for the vertical pullout failure mode of suction anchors with taut mooring system. The average difference between them is 1.9%. Most of differences are not more than 10%. Therefore, it is appropriate that the calculating result is decreased 10% if the cyclic bearing capacity associated with the vertical pullout failure mode is calculated using the method for suction caissons with taut mooring system in soft clays.%按照在最佳系泊点受倾斜荷载作用的张紧式吸力锚的破坏机制,建议了利用软土不排水循环剪切强度计算软土中吸力锚循环承载力的极限平衡分析方法.该方法考虑了平均系泊荷载在土中引起的平均剪应力

  19. 骨梗死的诊断与手术治疗%Diagnosis and operative treatment of bone infarction

    Institute of Scientific and Technical Information of China (English)

    张耀; 赵德伟; 王卫明; 刘宇鹏; 于晓兵

    2014-01-01

    Objective To investigate the diagnosis and operative treatment results of long bone infarction and the understanding of this disease.Methods From September 2009 to August 2012, 15 patients underwent operative treatment for the long bone infarction. There were 9 males and 6 females, whose average age was 46 years old ( range: 23-58 years ). The lesions were located in the proximal humerus (n=1 ), the proximal femur (n=2 ), the distal femur (n=7 ), the proximal tibia (n=4 ) and the distal femur together with the proximal tibia (n=1 ). Bilateral bone infarction was noticed in the distal femur (n=4 ) and in the proximal tibia (n=2 ). The etiology of bone infarction was idiopathic or unknown in 5 cases, which was caused by corticosteroids in 3 cases, a traumatic event in 3 cases, alcohol abuse in 2 cases and caisson disease in 2 cases. The deifnite diagnosis was determined before the operation through the clinical and imaging examinations and aspiration biopsy or pathological examination. The surgical fenestration of bone segments was performed locally. The lesions and sclerotic region were completely resected, and the blocked medullary cavity was broken through. The defects were packed fully with autogenous bone and allogeneic bone grafts. The locking titanium plate was then ifxed crossing the lesion area in order to increase the mechanical strength of the bone. All the patients underwent the clinical and radiographic examinations at every 4 weeks postoperatively, and they were reviewed since full weight bearing on the affected limbs at 2 to 3 months intervals thereafter. The changes of symptoms and the recurrence of bone infarction were observed, and the union of the planted bone was checked based on the X-ray in the follow-up.Results All the patients were followed up for an average period of 23 months ( range: 14-37 months ). The postoperative pain and uncomfortable symptoms were alleviated in 14 patients, whose limb functions were also restored. Mild pain would

  20. Deep soil moisture dynamic of typical irrigation farmland in piedmont of Taihang mountain%太行山前平原典型灌溉农田深层土壤水分动态

    Institute of Scientific and Technical Information of China (English)

    景冰丹; 靳根会; 闵雷雷; 沈彦俊

    2015-01-01

    continuous monitoring on the soil water content and soil matrix potential for three years (October 1, 2011 to September 30, 2014). A neutron tube with a depth of 1540 cm was installed to measure the soil water content. Seventeen tensiometers (Institute of Geographic Sciences and Natural Resources Research, CAS) were installed for the measurement of soil water matric potential with a maximum depth of 800 cm based on an open caisson (with inner diameter of 1.5 m and depth of 9 m) whose inner sidewall was brick lined. Based on the measured data, combined with the meteorological data of the study area, the soil water dynamics and movement was investigated. The results were as follows: 1) At the layer of 0-800 cm, the soil water content varied from0.03 to 0.47 cm3/cm3 and the soil water matrix potential was between -628.21 and 0 cm; Moreover, the distribution of soil water in the vertical profile was affected by the soil texture; 2) At the layer of 0-200 cm, the soil water content varied from 0.14 to 0.47 cm3/cm3and the soil water matrix potential ranged from -628.21 to 0 cm; Soil water potential gradient changed significantly in this soil layer; Under the influence of infiltration and evaporation, the soil water could move upward or downward in this layer; 3) Below the root zone (200-800 cm), the soil water content varied from 0.03 to 0.41 cm3/cm3and the soil water matrix potential ranged from -311.79 to 0 cm, which implied that the soil water content approximately ranged from saturated situation to the field capacity and the velocity of the wetting front could be up to as high as 0.13 m/day below the root zone;The value of soil water potential gradient was positive (positive potential gradient value means the downward direction of soil water movement in this study), thus soil water moved downward below the root zone; 4)The soil water matric potential changed from -311.79 cm to 0 cm and water potential gradient varied from 0.1 to 5.61 cm/cm at the layer of 200-600 cm; In the