WorldWideScience

Sample records for caissons

  1. 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.

  2. 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

  3. 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...... and University of Essen. The foundation aspects of caisson breakwaters are described. Special attention is paid to the dynamic response of the foundation to wave impacts, generation of pore pressures in the subsoil, degradation by repetitive loading and the interaction between all these aspects....... Several design levels are distinguished, varying from feasibility studies to research. The feasibility and preliminary design levels are discussed extensively, including a description of the most relevant models and illustrations with the help of example structures. The document may serve as a tool for...

  4. Experimental Investigation on Caisson Breakwater Sliding

    DEFF Research Database (Denmark)

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

    2014-01-01

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

  5. Dynamic stiffness of horizontally vibrating suction caissons

    DEFF Research Database (Denmark)

    Latini, Chiara; Zania, Varvara; Cisternino, Michele

    2016-01-01

    The promising potential for offshore wind market is on developing wind farms in deeper waters with bigger turbines. In deeper waters the design foundation configuration may consist of jacket structures supported by floating piles or by suction caissons. Taking the soil-structure interaction effec...

  6. 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.

  7. 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)

  8. 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.

  9. Numerical method for wave forces acting on partially perforated caisson

    Science.gov (United States)

    Jiang, Feng; Tang, Xiao-cheng; Jin, Zhao; Zhang, Li; Chen, Hong-zhou

    2015-04-01

    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.

  10. 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.

  11. 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.

  12. 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

  13. 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...

  14. 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...

  15. 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.)

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 77 FR 74193 - Request for Information on Edel-Kindwall Caisson Tables for Preventing Decompression Illness in...

    Science.gov (United States)

    2012-12-13

    ... Caisson Tables for Preventing Decompression Illness in Construction Workers AGENCY: National Institute for...) invites comments and information on decompression tables used for protecting tunneling (caisson) workers from developing decompression illnesses. Public Comment Period: Comments must be received by March...

  3. 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.

  4. 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.

  5. 3-D Effects Force Reduction of Short-Crested Non-Breaking Waves on Caissons

    DEFF Research Database (Denmark)

    Burcharth, H. F.; Liu, Z.

    1998-01-01

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

  6. 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

  7. 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.

  8. 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)

  9. 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...

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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...

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

    DEFF Research Database (Denmark)

    Nørgaard, Jørgen Harck; Andersen, Thomas Lykke

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

  17. 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,

  18. 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 ...

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

    DEFF Research Database (Denmark)

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

    Using large suction caissons for offshore wind turbines is an upcoming technology also referred to as bucket foundations. During operation the bucket foundation is loaded by a large overturning moment from the wind turbine and the wave loads. However, during installation the bucket is loaded by u...

  20. 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 a...... 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...

  1. 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.

  2. 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.

  3. 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

    waves, which resulted in impulsive conditions at the face of the caisson. Amongst our objectives was to look at the mechanisms occurring when a wave breaks at the structure and to investigate the validity of tactile pressure sensors. As such, for all experiments, pressure, force and surface elevation......Tests looking at the interaction of a caisson breakwater with steep, breaking waves are outlined here. 4 different wave generation methodologies were employed allowing for experiments with regular, irregular, focused and tailored made waves. The emphasis, however, is given in tests with focused...... 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...

  4. [Great depth pneumatic caisson and its load work involved with the efficiency of respiratory protection].

    Science.gov (United States)

    Shibayama, M; Oda, S; Takeuchi, J; Ikeda, Y; Yamamura, I; Mano, Y

    1989-07-01

    Pneumatic caisson work in Japan has been in operation since 1924. Afterward, this technique of compressed air work has been utilized in the constructions like as foundation works, the basements, and shafts of the bottom tunnel or shields for subway and so forth. While, it means for people to be exposed to hyperbaric environment that they use compressed air work, this technique has risks to be suffered from not only decompression sickness (DCS) but toxicity of poisonous gas or oxygen deficiency. However, this technique is necessary for urban civil engineering and recent compressed air works over than 1.0 kg/cm2 has been increased in 1.5 times more than in 1970's and the higher compressed air work more than 4.0 kg/cm2 will be actually planned in near future. So unmanned caisson work is considered as a better technique for such high pressure work, even though people must enter into hyperbaric working fields for maintenance or repair of unmanned operated machinery and materials. This research is to establish the safety work under hyperbaric environment within 7 kg/cm2. It is necessary for us to establish the system not only to keep safety but to maintain working efficiency. According to obtain the purpose, the effect of respiratory protection has been investigated and work load under hyperbaric caisson work has also been studied. PMID:2803373

  5. 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.

  6. 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 si...

  7. 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.

  8. 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.

  9. 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. PMID:24853026

  10. Finite element simulation of moisture movement and solute transport in a large caisson

    International Nuclear Information System (INIS)

    The results of the solute transport experiments performed on compacted, crushed Bandelier Tuff in caisson B of the experimental cluster described by DePoorter (1981) are simulated. Both one- and three-dimensional simulations of solute transport have been performed using two selected finite element codes. Results of bromide and iodide tracer experiments conducted during near-steady flow conditions have been analyzed for pulse additions made on December 6, 1984, and followed over a period of up to 60 days. In addition, a pulse addition of nonconservative strontium tracer on September 28, 1984, during questionably steady flow conditions has been analyzed over a period of 240 days. One-dimensional finite element flow and transport simulations were carried out assuming the porous medium to be homogeneous and the injection source uniformly distributed. To evaluate effects of the nonuniform source distribution and also to investigate effects of inhomogeneous porous medium properties, three dimensional finite element analyses of transport were carried out. Implications of the three-dimensional effects for the design and analysis of future tracer studies are discussed

  11. 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.

  12. 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。

  13. Transformation of the fourth power block of the Chernobyl atomic power station into a ecologically safe system by a dock-caisson technological complex

    International Nuclear Information System (INIS)

    The designers of the technical solution do not doubt that it is possible to transform the fourth power block of the Chernobyl APS into an ecologically safe system by help of Dock-Caisson technological complex. Application of the Dock-Caisson allows to make the operations of phases 1 and 2 of the Shelter installation transformation at the same time, i.e. to make the installation stabilization and preparation to radioactive wastes extraction simultaneously. By completion of first two phases the conditions are created for instant beginning of phase 3, i.e. disassembling of the content of the crashed power block

  14. 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.

  15. 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

  16. 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

  17. 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

  18. 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.

  19. 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

  20. 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

  1. Dynamic Behaviour of Suction Caissons

    DEFF Research Database (Denmark)

    Liingaard, Morten

    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...... 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, soil stiffness and the Poisson's ratio of the subsoil. Subsequently, the high-frequency impedance has......-parameter model approximations of the impedance have shown 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...

  2. 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

  3. General design and main problems of a gas-heavy-water power reactor contained in a pressure vessel; Conception generale et principaux problemes d'un reacteur de puissance eau lourde-gaz contenu dans un caisson resistant

    Energy Technology Data Exchange (ETDEWEB)

    Roche, R.; Gaudez, J.C. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1964-07-01

    In the framework of research carried out on a CO{sub 2}-cooled power reactor moderated by heavy water, the so-called 'pressure vessel' solution involves the total integration of the core, of the primary circuit (exchanges and blowers) and of the fuel handling machine inside a single, strong, sealed vessel made of pre-stressed concrete. A vertical design has been chosen: the handling 'attic' is placed above the core, the exchanges being underneath. This solution makes it possible to standardize the type of reactor which is moderated by heavy-water or graphite and cooled by a downward stream of carbon dioxide gas; it has certain advantages and disadvantages with respect to the pressure tube solution and these are considered in detail in this report. Extrapolation presents in particular.problems due specifically to the heavy water (for example its cooling,its purification, the balancing of the pressures of the heavy water and of the gas, the assembling of the internal structures, the height of the attic, etc. (authors) [French] Dans le cadre des etudes d'un reacteur de puissance modere a l'eau lourde et refroidi-au gaz carbonique, la solution dite 'en caisson' consiste en une integration totale du coeur, du circuit primaire (echangeurs et soufflantes) et du dispositif de manutention du combustible a l'interieur d'un meme caisson etanche et resistant en beton precontraint. La disposition envisagee est verticale; le grenier de manutention est dispose au-dessus du coeur, les echangeurs en dessous. Cette solution, qui permet d'uniformiser les types de reacteurs moderes a l'eau lourde ou au graphite et refroidis par une circulation descendante de gaz carbonique presente, par rapport a la solution a tube de force, des avantages et des inconvenients qui sont analyses dans cette etude. L'extrapolation pose, en particulier, des problemes specifiques a l'eau lourde (tels que son refroidissement, son epuration

  4. 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...

  5. 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.

  6. 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...

  7. 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 by...

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

    DEFF Research Database (Denmark)

    Nørgaard, Jørgen Harck; Andersen, Thomas Lykke

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

  9. 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...... depth of vertical stress, depending if the case of application is installation or pull-out....

  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

    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.

  12. 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

  13. 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.

  14. 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.

  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. 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...

  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....

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

    DEFF Research Database (Denmark)

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

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

  19. 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.

  20. SNF shipping cask shielding analysis

    International Nuclear Information System (INIS)

    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

  1. Results of experimental study on detritiation of atmosphere in large space

    International Nuclear Information System (INIS)

    In order to obtain data on tritium removal from the atmosphere of a room, which is needed for designing a reliable effective atmosphere detritiation system in a fusion reactor and for detailed analysis on its safety, intentional tritium release experiments have been carried out in a controlled space called Caisson under various atmosphere conditions at the Tritium Process Laboratory (TPL) in Japan Atomic Energy Research Institute (JAERI). In case there is no tritiated water vapor in the released tritium gas, tritium was ideally removed by constant ventilation in spite of atmospheric conditions and residence time. On the other hand, when tritiated water vapor existed in the released tritium, residual contamination on the wall of the Caisson was detected and it was found that it depended on the initial humidity in the Caisson. This tritium removal behavior was successfully analyzed by considering the adsorption and desorption reaction rates of tritiated water on the wall by the constant ventilation

  2. 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–fo......, a fully coupled dynamic pore-water-flow model is introduced. The computational examples clearly demonstrate that the deformations of the soil as well as the pore pressures must be accounted for in order to get a reliable prediction of caisson deformations during wave impact....

  3. 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...

  4. 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

    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...

  5. Wave Pressures on Seawave Slot-Cone Generator

    DEFF Research Database (Denmark)

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

    2006-01-01

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

  6. 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.

  7. 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...

  8. 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...

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

    DEFF Research Database (Denmark)

    Sørensen, John Dalsgaard; Burcharth, H. F.

    2000-01-01

    Vertical wall breakwaters are usually designed as concrete caissons placed on the top of a rubble mound foundation or a rubble bedding layer. The purpose of the breakwater is usually to protect the area behind the breakwater from being flooded by large waves. The area protected can for example be...

  10. 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....

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

    DEFF Research Database (Denmark)

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

    1999-01-01

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

  12. Development and Testing of Techniques for In-Ground Stabilization, Size Reduction and Safe Removal of Radioactive Wastes Stored in Large Containments in Burial Grounds - 13591

    International Nuclear Information System (INIS)

    Radioactive waste materials, including Transuranic (TRU) wastes from laboratories have been stored below ground in large containments at a number of sites in the US DOE Complex, and at nuclear sites in Europe. These containments are generally referred to as caissons or shafts. The containments are in a range of sizes and depths below grade. The caissons at the DOE's Hanford site are cylindrical, of the order of 2,500 mm in diameter, 3,050 mm in height and are buried about 6,000 mm below grade. One type of caisson is made out of corrugated pipe, whereas others are made of concrete with standard re-bar. However, the larger shafts in the UK are of the order of 4,600 mm in diameter, 53,500 mm deep, and 12,000 below grade. This paper describes the R and D work and testing activities performed to date to evaluate the concept of in-ground size reduction and stabilization of the contents of large containments similar to those at Hanford. In practice, the height of the Test Facility provided for a test cell that was approximately 22' deep. That prevented a 'full scale mockup' test in the sense that the Hanford Caisson configuration would be an identical replication. Therefore, the project was conducted in two phases. The first phase tested a simulated Caisson with surrogate contents, and part of a Chute section, and the second phase tested a full chute section. These tests were performed at VJ Technologies Test Facility located in East Haven, CT, as part of the Proof of Design Concept program for studying the feasibility of an in-situ grout/grind/mix/stabilize technology for the remediation of four caissons at the 618-11 Burial Ground at US Department of Energy Hanford Site. The test site was constructed such that multiple testing areas were provided for the evaluation of various tools, equipment and procedures under conditions that simulated the Hanford site, with representative soils and layout dimensions. (authors)

  13. Preliminary characterization of materials for a reactive transport model validation experiment

    International Nuclear Information System (INIS)

    The geochemical properties of a porous sand and several tracers (Ni, Br, and Li) have been characterized for use in a caisson experiment designed to validate sorption models used in models of inactive transport. The surfaces of the sand grains have been examined by a combination of techniques including potentiometric titration, acid leaching, optical microscopy, and scanning electron microscopy with energy-dispersive spectroscopy. The surface studies indicate the presence of small amounts of carbonate, kaolinite and iron-oxyhydroxides. Adsorption of nickel, lithium and bromide by the sand was measured using batch techniques. Bromide was not sorbed by the sand. A linear (Kd) or an isotherm sorption model may adequately describe transport of Li; however, a model describing the changes of pH and the concentrations of other solution species as a function of time and position within the caisson and the concomitant effects on Ni sorption may be required for accurate predictions of nickel transport

  14. Cleanup Verification Package for the 600-259 Waste Site

    Energy Technology Data Exchange (ETDEWEB)

    J. M. Capron

    2006-02-09

    This cleanup verification package documents completion of remedial action for the 600-259 waste site. The site was the former site of the Special Waste Form Lysimeter, consisting of commercial reactor isotope waste forms in contact with soils within engineered caissons, and was used by Pacific Northwest National Laboratory to collect data regarding leaching behavior for target analytes. A Grout Waste Test Facility also operated at the site, designed to test leaching rates of grout-solidified low-level radioactive waste.

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

    DEFF Research Database (Denmark)

    Vicinanza, Diego; Margheritini, Lucia; Frigaard, Peter

    This paper presents results on loading acting on an innovative caisson breakwater for electricity production. The work reported here is part of the European Union Sixth Framework programme priority 6.1 (Sustainable Energy System), contract 019831, titled "Full-scale demonstration of robust and high...... Kvitsøy near Stavanger, Norway. The research study is intended to be of direct use to engineers analyzing design and stability of the pilot plant....

  16. 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.

  17. 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.

  18. Cooling water intake and discharge facilities for Ikata Nuclear Power Station

    International Nuclear Information System (INIS)

    Igata Nuclear Power Station is located at the root of Sadamisaki peninsula in the western part of Ehime Prefecture, Japan, and faces the Iyonada sea area in Seto Inland Sea. The most part of the shoreline forms the cliffs, and the bottom of the sea is rather steep, reaching 60 m depth at 300 m offshore. Considering warm water discharge measures in addition to the natural conditions of tide and current, temperature of sea water, water quality and wave data, it was decided that the deep layer intake system using bottom laid intake pipes and the submerged discharge system with caisson penetrable dike would be adopted for cooling water. The latter was first employed in Japan, and the submerged discharge system with caisson penetrable dike had been developed. The intake was designed to take sea water of about 38 m3 per sec for each condenser unit at the depth of approximately 17 m with 4.8 m diameter and 116 m length pipes and its calculation details and construction are described. The discharge system was designed to provide a horseshoe-shaped discharge pond with inner diameter of approximately 50 m, surrounded by 17 concrete caissons, and to spout warm water discharge from eight openings of 1.58 m diameter, at the location of approximately 300 m eastward of the intake. Its hydraulic studies and model experiments and its construction are reported. (Wakatsuki, Y.)

  19. Study on seismic stability of seawall in man-made island. Pt. 2. Experimental study of seismic performance of seawall using a centrifuge

    International Nuclear Information System (INIS)

    In the development of the man-made island siting technology of nuclear power plants, one of the most important factors to be verified in design is the seismic performance of the seawalls bounding the island. The overall stability of the seawalls, expected residual deformations of the caisson and of the armored embankment are important factors that must be evaluated. For this purpose, a detailed experimental study examining the performance of a seawall with an armored embankment has been conducted using centrifuge testing method. The effects of existence of an armored embankment, substratum density, substratum thickness, and the extent of ground improvement beneath the structure on the residual deformations of the seawall were closely examined. From the experiment results, it is indicated that displacements of a seawall placed on a thin and dense seabed are small and that the density of the seabed directly beneath the crushed stone mound on which the caisson is placed mainly influences the caisson movements. Moreover it is indicated that the residual displacements of the prototype expected from the results of these tests were small enough to preserve the functions of the seawall in protecting an island against ocean waves overtopping. (author)

  20. 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

  1. 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

  2. [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

  3. 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。

  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. 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.

  6. Report on the cooperating researches utilizing fusion engineering facilities completed in the fiscal year 2007 (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), MeV Test Facility (MTF), JAEA Electron Beam Irradiation System (JEBIS), RF Test Stand (RFTS). In the fiscal year 2007 (from April 1, 2007 to March 31, 2008), 24 activities were carried out as the cooperating researches. This report reviews the results of 8 activities which were completed in the fiscal year 2007. (author)

  7. 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)

  8. Analysis of ettringite attack to stabilized railway bases and embankments

    OpenAIRE

    Ramon Tarragona, Anna; Alonso Pérez de Agreda, Eduardo

    2013-01-01

    Two cases of massive sulphate attack to cement treated embankments and track bases in a high speed railway line are described. In the first case, two large access embankments to a railway viaduct were treated with jet–grouting columns. In the second case a compacted cement treated soil was placed over a rigid concrete caisson. The treated layer, 1.5 m thick, expanded at a continuous rate of 0.9-1.3 mm/month. In the two cases the soil was excavated from nearby cuts in gypsiferous Tertiary (...

  9. Computing the effects of a contained sodium sheet fire: The 'FEUNA' code

    International Nuclear Information System (INIS)

    FEUNA is a computer code developed to calculate the thermodynamic effects of a sodium fire in a ventilated or unventilated containment volume. Developed jointly by the CEA/DSN and Novatome, the FEUNA code involves two oxide formation reactions, aerosol generation and deposits, heat transfer by convection, conduction and radiation, gas inflow and outflow through the ventilation system and the relief valves. The code was validated by comparing calculated values with the results of an actual sodium fire in a 400m3 caisson. (author)

  10. 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.)

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. Evaluation of the performance of solidified commercial low-level wastes in an arid climate

    International Nuclear Information System (INIS)

    Shallow land burial is being used as a disposal method for commercial low-level waste at waste disposal sites in arid (Hanford site near Richland, Washington) and humid (Barnwell, South Carolina) climatic regions. A field lysimeter facility has been established at the Hanford site in which to conduct waste-form leaching tests. The primary objective of this research is to determine typical source terms generated by commercial solidified low-level wastes. The field lysimeter facility consists of ten 3-m-deep by 1.8-m-diameter, closed-bottom lysimeters around a central instrument caisson, 4 m in diameter. Commercial cement and vinyl ester-styrene waste samples were removed from 210-L drums and placed in the 1.8-m-diameter lysimeters. Two bitumen samples are planned to be emplaced in the facility in 1984. The central caisson provides access to the instrumentation in the individual lysimeters and allows selective sampling of the soil and waste forms. Suction candles (ceramic cups) placed around the waste will be used to periodically collect soil water samples for chemical analysis. Meteorological data, 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, concentrations and distributions of radionuclides in the waste forms, concentrations of radionuclides in the waste streams, and concentrations of hydrophilic organic species in one of the waste steams. 8 references, 3 figures, 5 tables

  16. The tidal influence on oil and gas emissions from an abandoned oil well: Nearshore Summerland, California

    International Nuclear Information System (INIS)

    Oil and gas emissions were quantified for natural and human sources in nearshore waters off Summerland, California through deployment of custom designed collection tents. Seepage was measured at a repeatedly abandoned well, on the seabed from a caisson located along the historical location of the Treadwell Wharf, where the world's first off-shore oil wells were drilled at the end of the 19th century. Seepage rates at the capped T-10 Well, located in ∼5 m water, showed high correlation to tides. Site emissions were 2.4 and 38.7 L day-1 oil and gas, respectively. Emissions were measured from two areas of seepage at the T-10 Well Site. Oil and gas ratios were inversely correlated between the two seepage areas, demonstrating connectivity. Data were interpreted in terms of an electronic circuit model of seepage with respect to the time lag between local low tide and peak oil emissions

  17. 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

    /pulsating loadings while 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.......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...... carried out to measure wave loadings and overtopping rates using realistic random 2D and 3D wave conditions; the model scale used was 1:60 of the SSG pilot at the selected location in the island of Kvitsoy, Norway. Pressure transducers were placed in order to achieve information on impact...

  18. 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.

  19. 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......, becomes not very cost-effective in deep water depths. Therefore, it is essential to find some alternative economically efficient solutions. This paper presents an experimental study of wave loading on several shapes of transition pieces (TPs) used to transfer the loads from a 5 MW offshore wind turbine 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...

  20. 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.

  1. Outline of construction planning on No. 2 Reactor of the Shika Nuclear Power Plant

    International Nuclear Information System (INIS)

    The Hokuriku Electric Co., Ltd. carries out the expansion of the Shika Nuclear Power Plant No.2 (ABWR) to start its in March 2006. It is situated in north neighboring side of No. 1 reactor under operation at present, and its main buildings are planned to position a reactor building at mountain side and a turbine building at sea side as well as those in the No. 1 reactor. And, cooling water for steam condenser was taken in from an intake opening built at north side of the lifting space situated at the front of the power plant, and discharged into seawater from a flashing opening positioned about 600 m offing. Here were described on outline of main civil engineering such as base excavation engineering, concrete caisson production, oceanic establishment engineering, and facility for steam condenser, and characteristics of the engineering. (G.K.)

  2. 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

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

    International Nuclear Information System (INIS)

    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

  4. 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

  5. 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.

  6. Studies and research concerning BNFP: spent fuel dry storage studies at the Barnwell Nuclear Fuel Plant

    International Nuclear Information System (INIS)

    Conceptual designs are presented utilizing the Barnwell Nuclear Fuel Plant for the dry interim storage of spent light water reactor fuel. Studies were conducted to determine feasible approaches to storing spent fuel by methods other than wet pool storage. Fuel that has had an opportunity to cool for several years, or more, after discharge from a reactor is especially adaptable to dry storage since its thermal load is greatly reduced compared to the thermal load immediately following discharge. A thermal analysis was performed to help in determining the feasibility of various spent fuel dry storage concepts. Methods to reject the heat from dry storage are briefly discussed, which include both active and passive cooling systems. The storage modes reviewed include above and below ground caisson-type storage facilities and numerous variations of vault, or hot cell-type, storage facilities

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

    International Nuclear Information System (INIS)

    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

  8. 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.

  9. 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)

  10. 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

  11. Offshore atomic power plants

    International Nuclear Information System (INIS)

    Various merits of offshore atomic power plants are illustrated, and their systems are assessed. The planning of the offshore atomic power plants in USA is reviewed, and the construction costs of the offshore plant in Japan were estimated. Air pollution problem may be solved by the offshore atomic power plants remarkably. Deep water at low temperature may be advantageously used as cooling water for condensers. Marine resources may be bred by building artificial habitats and by providing spring-up equipments. In the case of floating plants, the plant design can be standardized so that the construction costs may be reduced. The offshore plants can be classified into three systems, namely artificial island system, floating system and sea bottom-based system. The island system may be realized with the present level of civil engineering, but requires the development of technology for the resistance of base against earthquake and its calculation means. The floating system may be constructed with conventional power plant engineering and shipbuilding engineering, but the aseismatic stability of breakwater may be a problem to be solved. Deep water floating system and deep water submerging system are conceivable, but its realization may be difficult. The sea bottom-based system with large caissons can be realized by the present civil engineering, but the construction of the caissons, stability against earthquake and resistance to waves may be problems to be solved. The technical prediction and assessment of new plant sites for nuclear power plants have been reported by Science and Technology Agency in 1974. The construction costs of an offshore plant has been estimated by the Ministry of International Trade and Industry to be yen71,026/kW as of 1985. (Iwakiri, K.)

  12. 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.

  13. 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.

  14. Subsurface Planar Vitrification Treatment of Problematic TRU Wastes: Status of a Technology Demonstration Program

    International Nuclear Information System (INIS)

    This paper provides a status of the In Situ Transuranic Waste Delineation and Removal Project in which the GeoMeltR Subsurface Planar VitrificationTM (SPVTM) process is being evaluated for the in situ treatment of burial sites containing remote handled mixed transuranic (TRU) waste. The GeoMeltR SPVTM process was invented and patented by Geosafe Corporation. AMEC holds the exclusive worldwide license to use this technology. The current project is part of a three-phase demonstration program to evaluate the effectiveness of the GeoMeltR SPVTM process to treat waste contained in vertical pipe units (VPUs) and caissons that were used for the disposal of remote handled transuranic wastes located at Hanford's 618-10 and 618-11 burial grounds. This project is being performed for the US Department of Energy (DOE) for use at the Hanford site and other DOE installations. The Phase I evaluation determined that removal and treatment of the 618-10/11 VPUs are beyond what can be safely accomplished using conventional excavation methods. Accordingly, a careful stepwise non-intrusive delineation approach and treatment using the GeoMeltR SPVTM technology, followed by removal, characterization, and disposal of the resulting inert vitrified mass was identified as the preferred alternative. Phase II of the project, which started in July 2004, included a full-scale non-radioactive demonstration of AMEC's GeoMeltR SPVTM process on a mock VPU configured to match the actual VPUs. The non-radioactive demonstration (completed in May 2005) was performed to confirm the approach and design before proceeding to a radioactive ('hot') demonstration on an actual VPU. This demonstration took approximately 130 hours, processed the entire mock VPU, and resulted in a vitrified monolith weighing an estimated 90 tonnes. [1] Plans for a radioactive demonstration on an actual VPU are being developed for CY 2006. In addition to demonstrating GeoMeltR SPVTM, delineation techniques are being evaluated as

  15. 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

  16. 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.

  17. 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

  18. Hazardous chemical and radioactive wastes at Hanford

    International Nuclear Information System (INIS)

    The Hanford Site was established in 1944 to produce plutonium for defense. During the past four decades, a number of reactors, processing facilities, and waste management facilities were built at Hanford for plutonium production. Generally, Hanford's 100 Area was dedicated to reactor operation; the 200 Areas to fuel reprocessing, plutonium recovery, and waste management; and the 300 Area to fuel fabrication and research and development. Wastes generated from these operations included highly radioactive liquid wastes, which were discharged to single- and double-shell tanks; solid wastes, including both transuranic and low-level wastes, which were buried or discharged to caissons; and waste water containing low- to intermediate-level radioactivity, which was discharged to the soil column via near-surface liquid disposal units such as cribs, ponds, and retention basins. Virtually all of the wastes contained hazardous chemicals as well as radioactive constituents. This paper focuses on the hazardous chemical components of the radioactive mixed waste generated by plutonium production at Hanford. The processes, chemicals used, methods of disposition, fate in the environment, and actions being taken to clean up this legacy are described by location

  19. Construction of Monju

    International Nuclear Information System (INIS)

    The construction works was started in January, 1983. The main works can be divided into (1) the construction of the roads to the site including the repair of the prefectural road, (2) the preparation of the land for temporary installation outside the site, (3) the creation of the site, the excavation for building foundations, the change of the stream in the site, and the land side works of water intake and discharge facilities, (4) the sea area works of bank revetment, breakwaters and unloading quay, and (5) the manufacture of caissons and blocks in the Technoport Fukui about 60 km distant from the site. The main buildings are those for the reactor, reactor auxiliaries, maintenance and waste treatment, diesel engines, and the turbine. The aseismatic structure, the coolant temperature if it leaks were the main considerations. The manufacture, transport and installation of machinery and equipment are reported. The sodium of about 1700 t was imported from France. The MOX fuel for initial charge was produced, and the pellets were filled smoothly. (K.I.)

  20. 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)

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

    Directory of Open Access Journals (Sweden)

    Wu-Jian Long

    2014-10-01

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

  2. 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.

  3. 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.

  4. Works of shifting discharge facilities in construction for adding No.3 and No.4 plants to Oi Nuclear Power Station

    International Nuclear Information System (INIS)

    At present in Oi Power Station, No.1 and No.2 plants of 1175 MWe output each are in operation, but in order to stabilize electric power supply for a long period, Kansai Electric Power Co., Inc. earnestly advances the construction works for adding No.3 and No.4 plants of each 1180 MWe output PWR. No.3 plant is expected to begin the operation in October, 1991, and No.4 plant in August, 1992. The works for creating the site were started in July, 1985, and the flat land of about 60,000 m2 and the reclaimed land of about 80,000 m2 were prepared. Subsequently, the main construction works were started in May, 1987, and the rate of general progress was 21 % in No.3 plant and 2 % in No.4 plant as of the end of October, 1988. Due to the addition of No.3 and No.4 plants, the quantity of condenser cooling water discharge increases to 318 m3/s from 150 m3/s at present, therefore, the bank having discharge holes is shifted from the present position about 100 m toward sea. As to the problems, the shifting works in flowing water, the method of shifting, the examination on lifting caissons and culverts, the trial construction of chemical anchors and so on were investigated. The execution of the shifting works is reported. (K.I.)

  5. Behaviors of protective bank and reclaimed ground of artificial island type nuclear power station at the time of earthquakes

    International Nuclear Information System (INIS)

    The protective banks arranged around an artificial island type nuclear power station and the reclaimed ground behind them are the important structures for ensuring the safety of nuclear reactor facilities and others, therefore, the establishment of the technology for evaluating their aseismatic safety becomes a subject. In this research, in order to grasp the change of ground characteristics at the time of the occurrence of liquefaction and the dynamic interaction of structures and reclaimed ground, caisson type protective banks and the ground behind them were modeled, and the centrifugal loading model experiment was carried out. Next, by the FEM analysis using effective stress method, the numerical simulation of this experiment was performed, and it was shown that this analysis method is the effective technique for evaluating the displacement of protective banks, and the liquefaction and the residual subsidence of ground. The experimental method and the analysis of the experimental results of the model vibration experiment are reported. The analysis technique using the effective stress analysis code STADAS is explained. The numerical simulation of the experimental results is reported on the analysis model, the values of the properties used and the results. (K.I.)

  6. Port construction works in the Sendai Nuclear Power Station

    International Nuclear Information System (INIS)

    Sendai Nuclear Power Station is the second nuclear power station of Kyushu Electric Power Co., Inc., with two PWR plants of 890 MW each, and the operation of No.1 plant will be started in July, 1984, and that of No.2 plant in March, 1986. The civil engineering works for both plants were started in June, 1978, and March, 1981, respectively, and the rate of progress as of the end of September, 1982, was 97 % and 66 %, respectively. In the construction of this power station, the port facility was provided for the transport of construction materials and spent fuel, and for the intake of condenser cooling water. In order to make the construction by dry work, the double cofferdam structures with steel sheet piles were made offshore. The use of the wharf was started in March, 1980, though typhoons hit the area several times, and the dredging in the port was completed in May, 1982. The outline of the plan of this power station, the state of affairs before the start of construction, the outline of the port construction works, the topography, geological features and sea conditions, the design of the port such as breakwaters, unloading wharf and water intake, the manufacture and installation of caissons, dredging, and the temporary cofferdam works for water intake are described. (author)

  7. 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.)

  8. 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.

  9. 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».

  10. 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...

  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. Status of outdoor radioactive contamination at the Hanford Site

    International Nuclear Information System (INIS)

    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 km2, the radioactively contaminated area is only about 36 km2 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 km2 are posted as surface contamination and 10 km2 are posted as underground contamination

  13. 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

  14. 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

  15. 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

  16. 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

  17. Dynamic motions of floating nuclear plants (FNP) due to waves and earthquakes and feasibility studies on the FNP

    International Nuclear Information System (INIS)

    This report has summarized results on feasibility studies on floating nuclear plants (FNP). To extend siting options of the nuclear plants, the FNP is one of the most promising plants next to a siting technology on a man-made island because the FNP is effectively isolated from horizontal earthquake motions and designing plants is expected to be standardized irrelevant to ground conditions. One idea among those on the FNP is that the floating body is moored in a calm basin protected by breakwaters. Technical tasks on dynamic response of the floating body due to waves, wind and earthquakes were investigated using both physical model tests and numerical simulation models. It is required for the breakwaters to reduce a wave height inside the basin to 1.0 m. To reduce transmitted waves through the breakwater to a certain limited level under which the FNP's response to the waves is accepted, conventional rubble mound breakwaters do not function. Additional facilities such as sheet-pile type structure are required at the shallow water region. In deeper water sea, a caisson type breakwater work well to prohibit the transmitted waves. 2-D numerical simulation model was developed to estimate the wave motions in and near the breakwater. Dynamic motion of the FNP in short-crested waves joined to a dolphin-link mooring system was investigated using numerical simulation and physical model tests with multi-directional wave makers. Wind force acting the power plant was included together with the wave force. It is confirmed that under the design forces a magnitude of the FNP dynamic motion was smaller than the limited one to operate the nuclear plant. Displacement of the mooring system and its force were also smaller than the limited conditions. Because vertical earthquake motions on the FNP are almost the same as the ground motion, pneumatic chambers at the bottom of the barge are installed. It is evaluated by the solution that high frequency vertical acceleration greater than 1

  18. 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

  19. 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

  20. 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.

  1. 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.

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

    Directory of Open Access Journals (Sweden)

    Hlaweniczka, Kurt

    1978-09-01

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

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

  3. 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.

  4. 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

  5. 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.

  6. 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

  7. 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

  8. 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.

  9. 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

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

    Directory of Open Access Journals (Sweden)

    S. N. Leonovich

    2015-12-01

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

  11. 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.

  12. 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

  13. Detailed characterization and preliminary adsorption model for materials for an intermediate-scale reactive-transport experiment

    Energy Technology Data Exchange (ETDEWEB)

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

    1994-12-31

    An experiment involving migration of fluid and tracers (Li, Br, Ni) through a 6-m-high x 3-m-dia caisson Wedron 510 sand, is being carried out for Yucca Mountain Site Characterization Project. Sand`s surface chemistry of the sand was studied and a preliminary surface-complexation model of Ni adsorption formulated for transport calculations. XPS and leaching suggest that surface of the quartz sand is partially covered by thin layers of Fe-oxyhydroxide and Ca-Mg carbonate and by flakes of kaolinite. Ni adsorption by the sand is strongly pH-dependent, showing no adsorption at pH 5 and near-total adsorption at pH 7. Location of adsorption edge is independent of ionic strength and dissolved Ni concentration; it is shifted to slightly lower pH with higher pCO2 and to slightly higher pH by competition with Li. Diminished adsorption at alkiline pH with higher pCO2 implies formation of dissolved Ni-carbonato complexes. Ni adsorption edges for goethite and quartz, two components of the sand were also measured. Ni adsorption on pure quartz is only moderately pH-dependent and differs in shape and location from that of the sand, whereas Ni adsorption by goethite is strongly pH-dependent. A triple-layer surface-complexation model developed for goethite provides a good fit to the Ni-adsorption curve of the sand. Based on this model, the apparent surface area of the Fe-oxyhydroxide coating is estimated to be 560 m{sup 2}/g, compatible with its occurrence as amorphous Fe-oxyhydroxide. Potentiometric titrations on sand also differ from pure quartz and suggest that effective surface area of sand may be much greater than that measured by N{sub 2}-BET gas adsorption. Attempts to model the adsorption of bulk sand in terms of properties of pure end member components suggest that much of the sand surface is inert. Although the exact Ni adsorption mechanisms remain ambiguous, this preliminary adsorption model provides an initial set of parameters that can be used in transport calculations.

  14. Ship operation and failure mode analysis using a maneuver simulator

    Science.gov (United States)

    Cabrerizo-Morales, Miguel Angel; Molina, Rafael; de los Santos, Francisco; Camarero, Alberto

    2013-04-01

    In a ship or floating structure operation the agents that contribute to the systems behaviour are not only those derived from fluid-structure interaction, but also the ones linked to mooring-control line set-up evolution and human interaction. Therefore, the analysis of such systems is affected by boundary conditions that change during a complete operation. Frequently, monitoring techniques in laboratory (model) and field (prototype) are based in different instrumental techniques adding difficulty to data comparison and, in some cases, inducing precision and repeatability errors. For this reason, the main aim of this study is to develop the methods and tools to achieve a deep knowledge of those floating systems and obtain capabilities to optimize their operationally thresholds. This abstract presents a methodology and an instrumental system applicable both in field and laboratory: SRECMOCOS Project (Small scale REal-time Caisson MOnitoring and COntrol System). SRECMOCOS compiles three modules. For the monitoring and control of the structure it has been developed a synchronized open and modular microcontroller-based electronic system that comprises sensors, to monitor agents and reactions, and actuators to perform pertinent actions after processing the sensors' data. A secondary objective has been to design and implement a global scaled simulator (1:22), at the 3D basin of The Harbour Research Lab at Technical University of Madrid, in which climatic agents and those derived from the rig/maneuvering setup and the structural design were included. The particular case of Campamento's drydock, in Algeciras Bay (Spain), has been used to apply and validate the methodology. SRECMOCOS Project conjugates control, monitoring and wireless communication systems in a real time basis, offering the possibility to register and simulate all the parameters involved in port operations. This approach offers a step forward into a monitoring strategy to be included in monitoring

  15. 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。

  16. 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。

  17. Detailed characterization and preliminary adsorption model for materials for an intermediate-scale reactive-transport experiment

    International Nuclear Information System (INIS)

    An experiment involving migration of fluid and tracers (Li, Br, Ni) through a 6-m-high x 3-m-dia caisson Wedron 510 sand, is being carried out for Yucca Mountain Site Characterization Project. Sand's surface chemistry of the sand was studied and a preliminary surface-complexation model of Ni adsorption formulated for transport calculations. XPS and leaching suggest that surface of the quartz sand is partially covered by thin layers of Fe-oxyhydroxide and Ca-Mg carbonate and by flakes of kaolinite. Ni adsorption by the sand is strongly pH-dependent, showing no adsorption at pH 5 and near-total adsorption at pH 7. Location of adsorption edge is independent of ionic strength and dissolved Ni concentration; it is shifted to slightly lower pH with higher pCO2 and to slightly higher pH by competition with Li. Diminished adsorption at alkiline pH with higher pCO2 implies formation of dissolved Ni-carbonato complexes. Ni adsorption edges for goethite and quartz, two components of the sand were also measured. Ni adsorption on pure quartz is only moderately pH-dependent and differs in shape and location from that of the sand, whereas Ni adsorption by goethite is strongly pH-dependent. A triple-layer surface-complexation model developed for goethite provides a good fit to the Ni-adsorption curve of the sand. Based on this model, the apparent surface area of the Fe-oxyhydroxide coating is estimated to be 560 m2/g, compatible with its occurrence as amorphous Fe-oxyhydroxide. Potentiometric titrations on sand also differ from pure quartz and suggest that effective surface area of sand may be much greater than that measured by N2-BET gas adsorption. Attempts to model the adsorption of bulk sand in terms of properties of pure end member components suggest that much of the sand surface is inert. Although the exact Ni adsorption mechanisms remain ambiguous, this preliminary adsorption model provides an initial set of parameters that can be used in transport calculations

  18. 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

  19. 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

  20. 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

  1. 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

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

    International Nuclear Information System (INIS)

    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

  3. 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)

  4. 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

  5. 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

  6. 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

  7. MR imaging of the hip

    International Nuclear Information System (INIS)

    abnormalities shown with MR arthrography. Only the accurate detection of these lesions may allow early therapeutic intervention and, therefore relief of pain, and prevent or delay the development of arthritis. Avascular necrosis (AVN) also known as (ischemic) osteonecrosis, or aseptic osteonecrosis is a condition resulting from insufficient blood supply to the richly vascularized subchondral bone. AVN may be idiopathic, but is often secondary to trauma, exogenous steroid use or Cushing syndrome, alcoholism, pancreatitis, HIV, Gaucher, rheumatoid arthritis, Caisson's disease, etc. Symptoms are very much dependent on subchondral location. On T1-weighted images a low signal intensity line of demarcation is seen in over 90% of cases. On T2-weighted sequences a high signal intensity line appears within the low signal intensity in the majority of cases. This is referred to as the double line sign. This highly specific sign for AVN is secondary to a combination of factors including chemical shift artifact, presence of granulation tissue and sclerosis. The double line sign may be absent in early AVN. The signal intensity of the central zone may look like fat (early AVN), blood (rare), edema (not specific), or fibrotic tissue (advanced AVN). Marrow edema can also be seen in transient osteoporosis, osteomyelitis, and secondary to occult (subchondral) fractures or tumors like osteoid osteoma, osteoblastoma and chondroblastoma. The relationship between transient osteoporosis and AVN is controversial. Patients with edema without initial demarcation that develop AVN have subchondral abnormalities in the initial phase. Not rarely avascular necrosis is bilateral. The size of the necrotic area is the most important prognostic factor. When the necrotic volume is small, patients often are asymptomatic and collapse or fractures are uncommon. MRI is the most sensitive imaging modality in the early detection of AVN. The reported MR sensitivities of 85-97 % are superior to those of bone scintigraphy

  8. 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

  9. 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