软弱夹层对地表加速度峰值的影响

Effect of soft strata on peak acceleration of ground motion

软弱夹层对地震反应的影响众所周知,根据实际工程情况,软弱夹层定义为:当某土层剪切波速Vs与上下相邻两层剪切波速Vs/Vs-1≤0.80,且Vs/Vs+1≤0.85时,该层就是软弱夹层.根据天津实际情况,利用目前工程上所广泛应用的场地地震反应分析的一维等效线性化波动方法,计算了不同场地剖面在3种不同频谱地震动作用下的地表加速度峰值.分析研究了不同埋深的软弱夹层对地表加速度峰值的影响,获得了一些有意义的结论.

The influence of soft strata on the seismic response is known to all. Based on actual engineering circumstance, the soft strata is defined as that ： When the shear wave velocity of the soil layer is Vs and Vs/Vs-1≤0. 80 ＆ Vs/Vs＋1 ≤0. 85, the layer is a soft strata. Based on the actual circumstance of Tianjin, the ground peak accelerations of different soil constructions are calculated under three different frequency earthquake inputs by the equivalent linearization and wave propagation method for the earthquake response analysis of the soft strata. The effect of the depth of the soft strata on ground peak acceleration is analyzed, and some conclusions with realistic significance are drawn.