【摘要】 沉积河谷对地震动具有显著的放大效应,而软夹层的存在对其放大程度具有较大影响。采用一种高精度有限元-间接边界积分方程耦合方法,对P、SV和Rayleigh波入射下含软夹层层状沉积谷地地震响应进行计算分析。分析表明,软夹层的影响规律依赖于入射波的波型、频率和角度、软夹层的厚度和埋深等因素。整体上看,对于地表位移,较低频率地震波入射下,软夹层的放大效应比较明显,且较厚夹层在浅埋情况下的放大作用更为显著;对高频波入射则主要表现为减震效应。对于地表加速度,软夹层主要表现出降幅作用,降低幅度可达30%。另外,总体上软夹层对于P波的影响要大于对SV波的影响。更多还原

【Abstract】 Sedimentary valley has significant amplification effect on ground motion,and the existence of the soft interlayer has a great influence on the amplification effect. The seismic responses of layered sedimentary valley containing soft interlayer under P,SV and Rayleigh waves incidence are calculated and analyzed by a highly accurate finite element-indirect boundary integral coupling method. Numerical results illustrate that the influence features of the soft interlayer on the ground motion of the valley strongly depend on the incident frequency and angle,soft layer’s thickness and buried depth. On the whole,As for the earthquake displacement amplitude,soft interlayer has a marked amplification effect,which seems more obvious for low frequency waves and thick soft layer with shallow depth; while for high frequency waves,the effect of vibration reduction may be more dominant. As for the ground surface acceleration,the soft interlayer mainly shows deamplification effect,which can be up to 30%. In Addition,the effect of soft interlayer seems more significant for P waves incidence than that of SV waves incidence.更多还原