Nonlinear Response Analysis Method Of One-Dimensional Soil Layer Based On Principle Of Effective Stress

Large amount of earthquake damage surveys and strong eismic observation results show that site condition has important influence on ground motion. Thereinto, seismic response of soil layer is the key problem in the study of ground motion. At present, the common method of seismic response analysis of soil layer is one-dimensional seismic response method of soil layer based on equivalent linearization method. With the deficiency and imperfection of equivalent linearization method, especially it can't consider the infection of the pore water pressure .this paper also develops research on one-dimensional seismic response analysis of soil layer, specifically shown as follows:1. The research status on one-dimensional seismic response method of soil layer is simply summarized; especially several stress-strain models and characteristic in common use are introduced. The function of pore water pressure in the analysis of seismic response is discussed, and several common methods of pore water pressure are introduced.2. The basic principle and compute flow of one-dimensional seismic response analysis program of equivalent linearization which is used worldwide at present are introduced; the advantages and disadvantages of this method are also simply analyzed.3. This paper puts forward the nonlinear response analysis method of soil layer based on principle of effective stress, with introducing the constitutive model,pore pressure model and modified method of shear modulus. As for the disposal of boundary condition, the multi-transmission boundary condition and viscosity boundary condition are introduced and simply analyzed.4.Based on the method presented in this paper, the nonlinear computational analysis program is compiled, and calculate one-dimensional seismic response of soil layer about with pore water and without pore water . And the results obtained by numerical computation are compared with the results obtained by equivalent linearization method in the same condition of soil layer. Numerical experiments demonstrate that this method can not only express the nonlinear characteristic of soil but also consider the influence of pore water in dynamic response analysis of soil layer, so as to simulate the actual condition of soil layer better. At last, all the works done in this paper are summarized, and further research direction in this area is discussed.