基坑宽度效应对基坑稳定性影响的有限元分析  

Finite element analysis of the effect of foundation pit width on its stability

作　　者：胡敏云[1] 苟长飞 严昱翔 袁宗浩 陈娟[3] 闫自海[3] HU Min-yun;GOU Chang-fei;YAN Yu-xiang;YUAN Zong-hao;CHEN Juan;YAN Zi-hai(Zhejiang University of Technology,Hangzhou 310014,China;Wenzhou Mass Transit Railway Investment Group Co.,Ltd.,Wenzhou 325000,China;Power China Huadong Engineering Corporation Ltd.,Hangzhou 310012,China)

机构地区：[1]浙江工业大学建筑工程学院,浙江杭州310014 [2]温州市铁路与轨道交通投资集团有限公司,浙江温州325000 [3]中国电建集团华东勘测设计研究院,浙江杭州310012

出　　处：《地基处理》2020年第1期1-8,共8页Journal of Ground Improvement

摘　　要：本文结合杭州某地铁车站基坑工程,通过建立不同几何尺寸的有限元分析模型,研究了基坑宽度效应对基坑变形和稳定性的影响。首先采用有限元强度折减法计算基坑抗隆起稳定性安全系数,以此为指标提出宽窄基坑的深宽比界限值,讨论了基坑宽度对坑底隆起、地表沉降、围护墙侧向变形及内力的影响。研究结果表明:宽窄基坑呈现出不同的坑底隆起模式,随着基坑宽深比的增加,坑底最大隆起量不断增大;基坑宽度较小时,宽度效应对围护结构变形、内力及周边地表沉降影响较大,当宽深比大于2时,基坑宽度效应不再明显。In combination with a subway station excavation in Hangzhou,this paper has established a finite model with different geometric dimensions to study the effect of the width of the foundation pit on its deformation.Firstly,the finite element strength reduction method is applied to calculate the safety factor for heave-resistant stability of excavation.Based on this factor,the critical value to differentiate wide or narrow foundation pit is proposed.Secondly the effect of the width of foundation pit on basal heaves,ground settlement,lateral deflections and internal forces of retaining walls is further investigated.Numerical results show that the wide and narrow foundation pit present different deformation pattern.As the width to depth ratio increases,the maximum heave deformation continues to increase.When the width of the foundation pit is small,the width effect has significant influence on the ground settlement,the deformation and internal forces of the retaining structure.And lastly when the width to depth ratio is greater than 2,the width effect of the foundation pit has minimal influence on its stability.

关 键 词：基坑宽度 强度折减 抗隆起稳定性 数值分析 

分 类 号：TU43[建筑科学—岩土工程]