| China is located between the Eurasian seismic belt and the circum-Pacific seismic belt,which are the two major seismic zones in the world.Because of the compression of the Pacific,Indian and Philippine plates,earthquakes occur frequently in China.Gravity dam is an important water retaining structure in water control project.Once it fails,it will cause huge loss of life and property to downstream people.Therefore,seismic dynamic analysis and seismic safety evaluation of gravity dam are very important.The influence of infinite foundation and reservoir water on the dam body must be considered in seismic response analysis and seismic safety evaluation of gravity dams.In this paper,the dam body,reservoir water and foundation are studied as a whole.The polygon finite element method based on scaled boundary finite element is adopted for dam body,and the scaled boundary finite element method is used for reservoir water and foundation.In this paper,the SBFEM model of dam-reservoir interaction,the SBFEM model of dam-foundation dynamic interaction and the polygon finite element model based on SBFE are established respectively,then the three models are coupled.Finally,the dynamic interaction calculation model of gravity dam-reservoir-foundation system is obtained.The main conclusions of this paper are as follows:(1)Through static and dynamic analysis of two-dimensional gravity dams,it can be concluded that the polygon finite element method based on scaled boundary element can be effectively applied to seismic response analysis of gravity dams,and the uniform mass matrix is more accurate when calculating the mass matrix of polygon elements.(2)When the scaled boundary finite element method is used to analyze the dam-reservoir dynamic interaction,the boundary conditions at infinity can be satisfied automatically,and only the points at the dam-reservoir interface need to be discretized,which is more accurate and less computational than the finite element method.(3)When using the scaled boundary finite element method to analyze the dynamic interaction between dam and foundation,only the points on the interface of near-field foundation and far-field foundation need to be discretized,so that the dimension of the problem can be reduced,the degree of freedom of calculation can be greatly reduced and the calculation efficiency can be improved.(4)The polygon finite element method based on scaled boundary element method is adopted for dam body and the scaled boundary finite element method for reservoir water and foundation.The dam-reservoir-foundation system developed by these two methods can be effectively applied to the dynamic interaction analysis of practical engineering. |
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