宽度效应对软土基坑抗隆起稳定性影响的数值模拟研究  

Numerical simulation study on the infl uence of width eff ect on basal heave stability of soft soil foundation pit

作　　者：付士崇 FU Shichong(China Railway SIYUAN Survey and Design Group Co.,Ltd.,Wuhan,430063)

机构地区：[1]中铁第四勘察设计院集团有限公司交通院,武汉430063

出　　处：《铁道勘测与设计》2025年第1期92-97,共6页Railway Survey and Design

摘　　要：通过数值模拟方法探究宽度效应对软土基坑抗隆起稳定性的影响。研究发现,随着基坑宽深比的增大,抗隆起稳定安全系数Fs逐渐趋于稳定。提出软土地基宽窄基坑划分的新方法,并进行理论分析。结果表明,以强作用区边界延伸至坑底平面与对侧围护结构交点为界,坑底隆起可以分为两种破坏模式。第一种破坏模式中,强作用区的潜在滑移线不对另一侧围护结构产生影响。基坑宽深比减小,Fs保持稳定。第二种破坏模式中,强作用区的潜在滑移线开始碰到对侧围护结构。受对侧围护结构和土体的影响,Fs迅速增大。最后建立示例基坑模型,应用所提出方法对其进行宽窄基坑划分。The influence of width effect on the basal heave stability of soft soil foundation pit is explored by numerical simulation.It is found that the factor of safety gradually reaches a steady state as the width-to-depth ratio of the foundation pit increases.A new method for the division of wide and narrow foundation pits in soft soil foundation is proposed and analyzed theoretically.The results show that the bottom heave can be divided into two failure modes with the boundary of the strong action zone extending to the intersection of the bottom plane and the opposite retaining structure.In the first failure mode,the potential slip line of the strong action zone does not affect the other side of the retaining structure.The width-depth ratio of the foundation pit decreases,and the safety factor remains stable.In the second failure mode,the potential slip line of the strong action zone begins to hit the opposite side of the retaining structure.The safety factor increases rapidly due to the influence of the opposite retaining structure and soil.Finally,an example foundation pit model is established,and the proposed method is used to divide the wide and narrow foundation pits.

关 键 词：软土基坑 抗隆起稳定 宽度效应 破坏模式 有限元分析 

分 类 号：TU7[建筑科学—建筑技术科学]