The Seismic Response Analysis Of Karst Site

The seismic response analysis is very important to determine the ground motion parameter of karst site. Because of the complexity of the karst site, the conventional site analytical analysis method is difficult to adapt to solve the seismic response analysis of karst site. The laboratory test is difficult to achieve the overall analysis of the karst site. Which increase the difficulty to determine ground motion parameters of karst site. To analysis the change rule of surface ground motion parameters of karst site, which in the reasonable scope to determine the calculation formula of main surface ground motions for a single hole in karst site. Based on the basic theory of dynamic finite element. First of all, from the contrast analysis of seismic response of the karst site and the ordinary site, then use ABAQUS software to establish two site of calculation model. Analysis the existence of soil hole influence to the seismic response of karst site, then to determine the main factors and its reasonable scope affecting to the seismic response of karst site. To determine the level value of the main factors based on the orthogonal theory, using MATLAB fitting method to quadratic regression analysis, to study the mainly site motion parameter change rule on the surface of karst site, which in the reasonable scope to determine the calculation formula of main surface ground motions for a single hole in karst site.The main work is as follows:(1)Summarizes the basic method to analysis seismic response of karst site and the characteristics of karst site.Then Summarizes the soil dynamic constitutive research status and the artificial boundaries research status,inversion calculate the selection of seismic wave.(2) Using ABAQUS software to establish karst site and ordinary site model,Calculate the soil hole influence effect to the site motion parameters of karst site.The result is the velocity and displacement effect is relatively small but the relatively of acceleration is big.The soil hole influence to the acceleration should be attention to.(3) This paper expounds the basic theory and the implementation steps of the orthogonal experiment. By using orthogonal test table,analysis the main factors affecting the surface of the site motions,selected the orthogonal table of L16(45), determine the reasonable level,arranged the finite element orthogonal experiment of 5 factors 4 levels.Determine the parameters models of 32 groups.(4) Using MATLAB software to analysis the quadratic regression which based on the finite element calculation 32 groups results. It is concluded that the formula of the site parameter between the main influence factors.