Analyze On The Seismic Response Of Soil Slope Based On The Multi-point Input Method

Earthquake is a complex time and space process.Generally speaking,the seismic response analysis assumes that on the contact surface of the research objectives,each points ground motion parameters are completely consistent,that is single-point input.For that seismic wave in the communication process has traveling wave effect and site effect,different points ground motion parameters are not exactly the same,even completely different.If we just consider the single-point input,it may not match the reality and cause big difference,so it is necessary to make some research on the multi-point input.In this paper,we take the two-dimensional soil slope as an example,considering the multi-point input to explore seismic response analysis,compare the single-point seismic input and the multi-point input so as to provide reference for the seismic design of the slope.The main work of this research is:(1)Summarize the previous research results of the ground motion synthesis and ground motion input methods,choose the correct method to form multi-point seismic acceleration time history.(2)Design the two-dimensional rock soil slope model,considering single-point input and multi-point input to analysis soil seismic response,safety coefficient,plastic zone distribution,the principal stress extreme characteristics.(3)To investigate the influence of single-point input and multi-point input on the safety factor of the soil slope model with the changes of the slope angle and the slope height.This paper adopts the ground motion synthesis method with general slice method,considering the effect of different wave input applied on soil slope of each strip earthquake acceleration time history,researches shows that the multi-point ground motion input is more safe than single-point ground motion input,behaving as the follows:(1)In the soil seismic response analysis,the peak acceleration and peak velocity of multi-point input are much greater than the single-point input,the occurring time is also earlier;(2)In the principal maximum stress distribution,multi-point input under the maximum principal stress value is greater than the single-point input,which is about 10%;(3)In the plastic distribution area,the performance of multi-point effect that performed the stretching of the upper and the lower part of the pure shear failure is more obvious;(4)The safety factor of multi-point input value is smaller than that of single-point input,almost 7%;To sum up,multi-point ground motion should be taken into the seismic design.