填海场地软弱夹层的地震响应特征分析

Seismic Response Characteristics Analysis of Weak Interlayer in Reclamation Site

基于深圳市前海自贸区填海场地某一典型的含软弱淤泥夹层钻孔剖面,对填海场地中软弱夹层的厚度和埋深对地面运动特性的影响进行分析。将原软弱夹层按2 m、4 m、6 m、8 m、10 m厚度,0 m(地表)、5 m、10 m、15 m、20 m、30 m、45 m(层底)埋深,构造出35个土层模型。利用土层一维等效线性化分析方法对上述35个土层模型进行不同超越概率地震动输入下的地震反应分析,结果表明:当输入地震动一定时,随着软弱夹层埋深的增加,地表加速度峰值放大倍数k逐渐减小,埋深超过一定深度后,k值小于1;随着软弱夹层的厚度增大,加速度峰值放大倍数k先增显大后减小;随着输入地震动的增大,各工况下地震地表加速度峰值放大倍数k相应都减小,地表加速度峰值减小明显。

Based on the profile of a typical soft clay interlayer in the reclamation area of Qianhai Free Trade Zone in Shenzhen, the influence of the thickness and depth of the weak interlayer on the ground motion characteristics is analyzed. 35 soil layers were constructed according to the thickness and depth of the weakinterlayer, where the thickness is divided into 2 m, 4 m, 6 m, 8 m, 10 m, and the buried depth is divided into 0 m （surface）, 5 m, 10 m, 15 m, 20 m, 30 m, 45 m （bottom） . Based on seismic response analysis of the above 35 soil model with different transcendental probability ground motion using soil one-dimensional equivalent linearization method, the results show that when the input ground motion is constant, with the increase of the depth of the weak interlayer, the ground acceleration peak magnification k decreases gradually, and when the buried depth exceeds a certain depth, the k value is less than 1; vdth the increase of the thickness of the weak interlayer, the peak acceleration magnification k increased significantly and then decreases; with the increase of input ground motion, the magnification k decreases in each case, and the peak value of ground acceleration decreases obviously.