Study On Analytic Solution Of Seismic Response With Single Ground Fissure In Horizontal Layered Soil

The numerical solution of seismic response analysis in horizontal layered soil sites is developed with the improvement of computer technology,but the development of analytic solution is very slow,and can only be applied in the case that model is simple enough and condition is ideal sufficient,especially the analytic solution under the condition of ground fissure site is very rare.Combined with elastic wave theory,,this paper try to research based on the existing ground fissures and induce an analytic solution of seismic response under the ground fissure sites.Through calculation and comparison, the results show that:1.The seismic response of horizontal layered site was solved by shear beam method and lumped mass method,the results are similar to the finite element method,the response of the soil layer to the seismic wave is amplified.The results are influenced by the number of layers,the weak soil layer,the damping ratio and so on.2.In the form of sine wave,the seismic wave response in the surface of the single layer and the multi-layer sites without ground fissures is amplified.And the seismic response of the low frequency wave is more obvious,when the sine wave frequency is close to the fundamental frequency of the soil layer, the seismic response is the largest;the rationality of wave analytic solution is proved in this paper because of the similar to the literature solution.3.In the form of sine wave,the seismic response in the surface of the site with single ground fissure is also amplified based on wave analytic solution,and the amplification effect is more remarkable, far more than free field.Besides,the amplification effect of low frequency wave is higher than high frequency wave.There are obvious differences on the physical and mechanical properties between upside and downside of the ground fissure,so the upper amplification effect is greater than the lower. Along with the increase of the distance to ground fissure,the amplification effect both upside and downside decreases gradually.