The Research On Analysis Method Of Soil-structure Dynamic Interaction

The dynamic soil-structure interaction (SSI) research is a front subject in the field of current civil engineering. Dynamic SSI has favorable or unfavorable effect on the structure's seismic response. So carrying out dynamic SSI analysis has double significance: guaranteeing the structural safety and saving construction investment. However, only with the existed theory research results, we can't confirm whether soil-structure interaction has advantageous effect on the structure's seismic response or not because of the complexity of the dynamic SSI analysis. So, the theoretical research needs to strengthen and strengthen further. After consulting a large number of references, the following aspects of this research are studied in this paper:1. The effect of confining pressure caused by soil gravity on the ultimate resistance of soil is considered. And then, the relationship between the ultimate resistance and the depth of soil is obtained based on the Mohr-Coulomb failure criterion; a hyperbolic function is proposed to describe this relationship. The characteristics of some types of p-y curves are investigated, and the hyperbolic p-y curve is adopted. According to the hyperbolic p-y curve, the stiffness coefficient of soil can be derived, and a non-linear dynamic differential equation is founded and its difference solution is presented. In order to facility engineering application, a simplified pile model is proposed. The simplified model divides the pile into embedded and free cantilever segments and the non-linear properties of pile are taken into account by modifying the length of free cantilever segment. Numerical example demonstrates the necessity of non-linear analysis and the feasibility of the difference solution and simplified solution.2. Adopted simplified pile model and multi-segment beam element model, the seismic response of a frame structure supported by some isolated piles is analyzed by time history analysis method. And then laws of the SSI effect on structural seismic response are summarized based on a large number of numerical analysis results.3. Simulation of infinite soil media is a key topic of time history analysis of the soil-structural system's seismic response by numerical analysis method such as finite element method. A consistent artificial boundary formula which simulate P-wave propagate to infinite media in plane is deduced. Numerical analysis method is adopted to analyze wave propagating in plane and the result precision of the consistence boundary is compared with that of the Visco-elastic boundary. Comparisons...