Contrastive Research On Site Seismic Motion Numerical Simulation Methods Based On Strong Motion Observation Records

The site topographic geologic, nonlinearation and seismic motion inputs have a huge effect on the ground motion during the seismic response analysis of complex site. Numerical simulation methods have been used to predict the seismic motion of target areas for the strong earthquake observation stations can not cover all areas.The existing site response analysis models include models of one dimension equivalent linearization, two dimension linearization and three dimension linearization. Due to the difficulties in modeling of the ground motion and the fact that underground geological data are difficult to obtain, three dimension linearization analysis model has less application in engineering. Although the one dimension equivalent linearization model has been widely used for less calculated amount and easy obtained soil parameter, but it can be only used to horizontal layer and can not consider the topographic effect. The high dimension linearization can consider the hypsography changes, but there is a big difference in dealing with the nonlinear characteristics of soil. The paper has proposed a new two dimension P-SV time domain finite element methods, which can be considering the effect of two dimension sites and non-linear characteristic of siol.The studies done in the paper include:1. Based on the equivalent linearization considering the nonlinear characteristics of soil, and extending it to the two dimension P-SV time domain problem, a new two dimensional time P-SV equivalent linearization model, which can be considering the effect of two dimension sites and non-linear characteristic of soil, is proposed in the paper, and the validity and retionality of the model are verified by the numerical examples.2. With the data of test sites and earthquake records from Ashigara Valley, Japan and Turkey Flat, American, by chosing the outcropping bedrock and underground bedrock earthquake records as the seismic motion inputs, the effect of different bedrock seismic motion inputs to ground motion and the difference of simulation with analytical models have been studyed.3. The underground bedrock records are selected as the seismic inputs in the American Turkey flat site, and the seismic inputs of Japanese Ashigara Valley site are inverted from the exposed surface bedrock records. The site seismic response is analyzed to study the effects of the topographic geologic, nonlinearization, seismic motion inputs to the ground motion.4. The site response prediction work is conducted by using the data of basin structure site and earthquake records from Lower Hutt, Newlands, two dimension linearization model has been used to study the effect of basin structure to ground motion during small earthquakes. The nonlinearization effect of basin structure to ground motion and the effect of basin edge have been studyed.5. The studies done in the paper have been summarized and the research in the future are proposed.