软土地基-浅基础体系地震反应数值分析  

Numerical Analysis on Seismic Response of Soft Soil-Shallow Foundation System

作　　者：田兆阳[1,2] 李平[1] 张宇东[1] 辜俊儒 TIAN Zhaoyang;LI Ping;ZHANG Yudong;GU Junru(Institute of Disaster Prevention Science and Technology,Sanhe 065201,China;Shandong Earthquake Agency,Jinan 250014,China)

机构地区：[1]防灾科技学院,河北三河065201 [2]山东省地震局,山东济南250014

出　　处：《防灾减灾工程学报》2021年第6期1228-1237,共10页Journal of Disaster Prevention and Mitigation Engineering

基　　金：地震科技星火计划项目(XH20084);河北省地震灾害防御与风险评价重点实验室开放基金项目(FZ213207)资助。

摘　　要：软土场地中的天然地基浅基础在强震作用下易产生失稳及震陷等破坏,在设计过程中充分考虑并利用其土结相互作用的影响,可以有效提高体系的抗震性能。基于OpenSees有限元计算平台,建立包含土结接触面的软土地基-浅基础二维平面应变模型,计算分析了不同地震动输入和基础上部荷载对体系地震动、基础震陷量和基底反力分布的影响,结果表明:强震作用下软土场地对地震动的放大作用减弱,但会产生大变形,因此抗震设计的重点应着眼于地基基础的大变形;上覆荷载大小对最终震陷值和震陷范围影响显著,而未改变震陷曲线间的相对形态;地震动能量的累积时间及累积速率影响软土地基-浅基础体系震陷的发展,抗震分析中应考虑场地设计地震动的有效持时和阿里亚斯强度;采用碎石桩等加固措施可改变基底压力分布形态,从而有效的提高体系的抗震性能。Shallow foundation on natural soft soil is susceptible to seismic hazards like unstability and settlement under intensive earthquake.Considering the impact of soil-structure interaction in the design process could have a positive impact on the seismic resistance of the system.This paper aims to investigate the seismic performance of the soft soil-shallow foundation system using numerical simulation method. Based on the OpenSees program,a 2-D plane-strain soft soil-shallow foundation system model containing soil-structure interface was established,and dynamic analyses with various input ground motions and upper loads were conducted. The seismic response,foundation seismic settlement,subgrade reaction under all calculated conditions were obtained and compared. The simulation result shows that:1.The amplification coefficient in soft soil weakens under strong motion,the emphasis of earthquake resistant design should aim to control the large deformation. 2.Upper loads have a significant influence on the final subsidence and the settlement area instead of the relative shape of the settlement curves. 3.The seismic settlement of soft soil-shallow foundation system relates to the accumulation time and rate of ground motion energy,which can be reflected in the effective duration and Arias intensity of the design ground motion. 4.Pertinence reinforcement methods in foundation soil like stone columns can change the distribution forms of subgrade reaction and improve seismic performance of the soft soil-shallow foundation system.

关 键 词：软土地基 浅基础 OPENSEES 抗震性能 数值模拟 

分 类 号：TU443[建筑科学—岩土工程]