Research On Equivalent Dynamic Analysis Method Considering Interaction Effect Of Foundation And Fault

In China,a large number of engineering constructions' foundations are influenced by the dynamics.For the foundation under dynamic load,the interaction between ground and fault should be considered in the design and analysis of vibration to meet the requirements of safety,applicability and economy,as well as to ensure the safe and stable operation of the structure and equipment supported by the foundation.How to consider the influence of fault on foundation in foundation design and get the equivalent mode of interaction between ground and foundation are of great practical significance.This paper has reviewed the existing calculation methods of the interaction between fault and foundation.Among them,the method of coupling analysis between the semi-infinite domain of foundation with artificial boundary applied on the finite range of foundation and the engineers can calculate and analyze by using the commonly used finite element software.This method only needs to use the spring-damper element of the finite element software to apply viscoelastic artificial boundary,but this method still has the limitation of large amount of calculation and certain limitations for engineer's modeling.Based on the wave theory,this paper deduces the motion equation and definite solution condition of the coupled system of fault and foundation,uses the weighted residual method to solve the motion equation of the coupled system of fault and foundation,obtains the expression of additional stiffness of foundation through discussion and simplification,and obtains the effect of additional stiffness on foundation by equivalent foundation.Since the expression of additional stiffness involves the stiffness matrix of the foundation in the infinite domain,this paper also introduces the infinite element method to deduce the stiffness of the foundation element in the two-dimensional case,and obtains the additional stiffness matrix of the foundation through MATLAB calculation.The spring element in the finite element software is applied to the coupling interface of the foundation to express the additional stiffness of the foundation.