With better understanding of the quality and physico-mechanical properties of rocks of dam foundation,and the physico-mechanical properties and structure design of arch dam in association with the foundation excavatio...With better understanding of the quality and physico-mechanical properties of rocks of dam foundation,and the physico-mechanical properties and structure design of arch dam in association with the foundation excavation of Xiluodu arch dam,the excavation optimization design was proposed for the foundation surface on the basis of feasibility study.Common analysis and numerical analysis results demonstrated the feasibility of using the weakly weathered rocks III1and III2as the foundation surface of super-high arch dam.In view of changes in the geological conditions at the dam foundation along the riverbed direction,the design of extending foundation surface excavation area and using consolidating grouting and optimizing structure of dam bottom was introduced,allowing for harmonization of the arch dam and foundation.Three-dimensional(3D)geomechanics model test and fi nite element analysis results indicated that the dam body and foundation have good overload stability and high bearing capacity.The monitoring data showed that the behaviors of dam and foundation correspond with the designed patterns in the construction period and the initial operation period.展开更多
The 285.5 m-high Xiluodu Arch Dam is located in a seismic region along the Jinsha River in China, where the horizontal components of peak ground accelerations for design and checking earthquakes have been estimated to...The 285.5 m-high Xiluodu Arch Dam is located in a seismic region along the Jinsha River in China, where the horizontal components of peak ground accelerations for design and checking earthquakes have been estimated to be 0.355 g and 0.423 g, respectively( g is the gravitational acceleration). The ground motion parameters of design and checking earthquakes are defined by exceedance probabilities of 2% over 100 years and 1% over 100 years, respectively. The dam shape was first selected and optimized through static analysis of the basic load combinations, and then adjusted after taking into account the seismic loads. The dam should be operational during and after the design earthquake with or without minor repairs, and maintain local and global stabilities during an extreme earthquake. Both linear elastic dynamic analysis and nonlinear dynamic analysis considering radiation damping, contraction joints, and material nonlinearity were conducted to assess the stress in the arch dam.The dynamic analysis shows that the maximum dynamic compressive stresses are less than the allowable levels, while the area with tensile stress over the limit is less than 15% of the dam surface and the maximum contraction openings range from 10 mm to 25 mm. The arch dam has sufficient earthquake-resistance capacity and meets the safety requirements. Nevertheless, steel reinforcement has been provided at the dam toe and in the zones of high tensile stress on the dam surface out of extra precaution.展开更多
Because of good quality of compressive resistance, the hyperbolic arch dam is being increasingly applied to engineering projects. In order to satisfy the needs of compressive resistance under the conditions of high wa...Because of good quality of compressive resistance, the hyperbolic arch dam is being increasingly applied to engineering projects. In order to satisfy the needs of compressive resistance under the conditions of high water pressure, a stress analysis is required for the dam. During the stress analysis process however, due to the complexity of the three-dimensional modeling, it is very hard to form a model. Therefore, the stress analysis process is a barrier for the arch dam. In this article, based on the research of the new line-type arch dam, a mathematical model in different degree of convexity conditions of the dam is established; using the C ＋ ＋ language program, a computer three-dimensional model simulation is realized on AutoCAD. The accurate three-dimensional model is providing a finite element optimization design of the involute hyperbolic arch dam for the next step.展开更多
Because of its good condition with mechanics, logarithmic spiral double curve arch bam has been widely used in the practical engineering. The introduction of a new method in how to divide transverse joint in arch dam ...Because of its good condition with mechanics, logarithmic spiral double curve arch bam has been widely used in the practical engineering. The introduction of a new method in how to divide transverse joint in arch dam will be given and the further research of its calculation has been done. The C＋＋ is used in electronic procedure and the 3D simulation has been finished with AutoCAD, which will provide the object model for computer simulation of the arch dam and the division of finite element mesh. Meanwhile, this method in dividing the transverse joint in arch dam also can be taken as the calculated basis for the design and calculation of arch dam, construction lofting and the calculation of the work amount.展开更多
文摘With better understanding of the quality and physico-mechanical properties of rocks of dam foundation,and the physico-mechanical properties and structure design of arch dam in association with the foundation excavation of Xiluodu arch dam,the excavation optimization design was proposed for the foundation surface on the basis of feasibility study.Common analysis and numerical analysis results demonstrated the feasibility of using the weakly weathered rocks III1and III2as the foundation surface of super-high arch dam.In view of changes in the geological conditions at the dam foundation along the riverbed direction,the design of extending foundation surface excavation area and using consolidating grouting and optimizing structure of dam bottom was introduced,allowing for harmonization of the arch dam and foundation.Three-dimensional(3D)geomechanics model test and fi nite element analysis results indicated that the dam body and foundation have good overload stability and high bearing capacity.The monitoring data showed that the behaviors of dam and foundation correspond with the designed patterns in the construction period and the initial operation period.
基金supported by the Program of Study on the Standard of Overall Safety Control of High Arch Dam of PowerChina Co.,Ltd.(Grant No.DJ-ZDXM-2014-19)
文摘The 285.5 m-high Xiluodu Arch Dam is located in a seismic region along the Jinsha River in China, where the horizontal components of peak ground accelerations for design and checking earthquakes have been estimated to be 0.355 g and 0.423 g, respectively( g is the gravitational acceleration). The ground motion parameters of design and checking earthquakes are defined by exceedance probabilities of 2% over 100 years and 1% over 100 years, respectively. The dam shape was first selected and optimized through static analysis of the basic load combinations, and then adjusted after taking into account the seismic loads. The dam should be operational during and after the design earthquake with or without minor repairs, and maintain local and global stabilities during an extreme earthquake. Both linear elastic dynamic analysis and nonlinear dynamic analysis considering radiation damping, contraction joints, and material nonlinearity were conducted to assess the stress in the arch dam.The dynamic analysis shows that the maximum dynamic compressive stresses are less than the allowable levels, while the area with tensile stress over the limit is less than 15% of the dam surface and the maximum contraction openings range from 10 mm to 25 mm. The arch dam has sufficient earthquake-resistance capacity and meets the safety requirements. Nevertheless, steel reinforcement has been provided at the dam toe and in the zones of high tensile stress on the dam surface out of extra precaution.
基金Supported by Postgraduate Education Innovation Fund of Chongqing Jiaotong University
文摘Because of good quality of compressive resistance, the hyperbolic arch dam is being increasingly applied to engineering projects. In order to satisfy the needs of compressive resistance under the conditions of high water pressure, a stress analysis is required for the dam. During the stress analysis process however, due to the complexity of the three-dimensional modeling, it is very hard to form a model. Therefore, the stress analysis process is a barrier for the arch dam. In this article, based on the research of the new line-type arch dam, a mathematical model in different degree of convexity conditions of the dam is established; using the C ＋ ＋ language program, a computer three-dimensional model simulation is realized on AutoCAD. The accurate three-dimensional model is providing a finite element optimization design of the involute hyperbolic arch dam for the next step.
基金Supported by Postgraduate education innovation fund of Chongqing Jiaotong University 2010
文摘Because of its good condition with mechanics, logarithmic spiral double curve arch bam has been widely used in the practical engineering. The introduction of a new method in how to divide transverse joint in arch dam will be given and the further research of its calculation has been done. The C＋＋ is used in electronic procedure and the 3D simulation has been finished with AutoCAD, which will provide the object model for computer simulation of the arch dam and the division of finite element mesh. Meanwhile, this method in dividing the transverse joint in arch dam also can be taken as the calculated basis for the design and calculation of arch dam, construction lofting and the calculation of the work amount.
