SH波入射下阶跃基岩覆盖土层场地地面运动特征分析

发布时间：2018-05-20 16:05

本文选题：地震波 + 阶跃基岩覆盖土层场地　；参考：《防灾减灾工程学报》2017年05期

【摘要】：利用二维显式有限元场地地震反应分析程序,把不同频谱特性的地震动作为输入基岩的SH波,探讨了阶跃基岩覆盖土层场地地震动空间分布特征,重点研究了覆盖土层厚度和土层性状对场地地表加速度峰值和反应谱的影响。研究表明:对于阶跃基岩覆盖土层场地,覆盖土层厚度变化对相应区域地表地震反应有较为明显的影响,对土层厚度不变区域的地表地震反应影响不明显。土层性状对阶跃基岩覆盖土层场地地表的加速度峰值和反应谱均有重要的影响。软土和上软土下硬土组合土层场地地表的加速度峰值要比硬土场地地表上的大。软土场地中反应谱的峰值要比硬土场地中反应谱的峰值大,硬土场地反应谱峰值对应的周期较短,软土场地反应谱峰值对应的周期较长。土层性状对地震动反应谱的影响,主要体现在短周期分量上。
[Abstract]:In this paper, the seismic response analysis program of 2-D explicit finite element method is used to study the spatial distribution characteristics of ground motion in step bedrock overlying soil, taking the ground motion with different spectral characteristics as the SH wave of the input bedrock. The effects of soil cover thickness and soil layer characteristics on the peak acceleration and response spectrum of the ground surface were studied. The results show that the variation of soil cover thickness has obvious influence on the seismic response of the corresponding area for the step bedrock covering site, but it has no obvious effect on the surface seismic response in the region with constant soil thickness. Soil properties have an important effect on the peak acceleration and response spectrum of the ground surface in the step bedrock covering site. The acceleration peak of soft soil and upper soft soil composite soil is larger than that of hard soil site. The peak value of response spectrum in soft soil site is larger than that in hard soil site, the period corresponding to the peak value of response spectrum in hard soil site is shorter than that in hard soil site, and the period corresponding to the peak value of response spectrum in soft soil site is longer. The effect of soil properties on seismic response spectrum is mainly reflected in the short period component.
【作者单位】：南京工业大学土木工程学院;
【基金】：国家自然科学基金项目(51278245);国家自然科学基金项目(51308293)资助
【分类号】：TU435

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