深厚软土场地中透镜体对上部结构地震响应的影响

发布时间：2018-01-16 15:11

本文关键词：深厚软土场地中透镜体对上部结构地震响应的影响　出处：《地震工程与工程振动》2016年05期 　论文类型：期刊论文

【摘要】：工程场地中透镜体对地震动具有重要影响,但目前对该问题的研究比较少,尤其是深厚软土场地中的透镜体问题还鲜有研究。本文采用有限元-间接边界元耦合法,建立非线性土-结构动力相互作用模型,并对方法计算精度进行了验证。论文首先比较了弹性基岩模型和刚性基岩模型的差别,建议采用更接近实际的弹性基岩模型研究深厚软土场地中的透镜体问题。然后在考虑场地土体和透镜体介质非线性的基础上,系统地研究了深厚软土场地中透镜体宽度、厚度和埋深对上部结构地震响应的层间位移角、加速度及基底剪力的影响。研究表明,透镜体的存在可能会明显改变上部结构的动力响应,上部结构的动力响应可能会明显放大。透镜体宽度、厚度和埋深对结构动力响应均有很大影响。
[Abstract]:The lens in the engineering site has an important effect on the ground motion, but there are few researches on the problem at present. In this paper, the nonlinear soil-structure dynamic interaction model is established by using the finite element and indirect boundary element coupling method. The accuracy of the method is verified. Firstly, the difference between elastic bedrock model and rigid bedrock model is compared. It is suggested that a more practical elastic bedrock model be used to study the lenticular problem in the deep soft soil, and then on the basis of considering the nonlinearity of the site soil and the lenticular medium. The effects of lens width, thickness and depth on the interlayer displacement angle, acceleration and base shear force of the superstructure are systematically studied. The dynamic response of the superstructure may be obviously changed by the existence of the lens, and the dynamic response of the superstructure may be enlarged obviously. The width, thickness and depth of the lens have great influence on the dynamic response of the structure.
【作者单位】：天津大学水利工程仿真与安全国家重点实验室;天津大学建筑工程学院土木工程系;华东交通大学土木建筑学院;
【基金】：国家自然科学基金项目(51578372)~~
【分类号】：TU435
【正文快照】： 引言透镜体在冲积平原地区是一种常见的局部场地,透镜体尺寸小的十数米,大的数百米。可以设想,工程场地中透镜体对上部结构有显著的影响。如1976年唐山地震中,唐山市乐亭县姚圈村一民房整体沉入地下,震陷达4 m多,原因是地基1.9 m处的饱和砂土透镜体液化,造成地基承载力失效。

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