软土地质条件下竖井开挖仿真研究  

Simulation research of shaft excavation under soft soil conditions

作　　者：凌涛[1] 董志红 谢永亮 吕晓江 彭学军 LING Tao;DONG Zhihong;XIE Yongliang;LXiaojiang;PENG Xuejun(China Railway No.5 Engineering Group Co.,Ltd.,Changsha 4100001,Hunan,China;Railway No.5 Bureau Group First Engineering Co.,Ltd.,Changsha 410117,Hunan,China)

机构地区：[1]中铁五局集团有限公司,湖南长沙4100001 [2]中铁五局集团第一工程有限责任公司,湖南长沙410117

出　　处：《工程建设》2025年第3期25-30,共6页Engineering Construction

基　　金：国家自然科学基金资助项目(52074116,52004088)。

摘　　要：为了研究不同条件下竖井开挖时土体的变形情况,以长沙地铁某竖井工程为研究对象,采用有限元软件PLAXIS 3D建立模型,分析开挖后土体的沉降情况以及外部载荷大小对竖井的影响。结果表明:1)在竖井开挖过程中,土体的形变面积自上而下逐渐减小,其中地表土层的形变面积最大;2)竖井周围土壤的变形主要集中在上部土层;3)在竖直方向上,随着深度增加,土体的位移量呈现先增加后减小的趋势,当竖井底部位于黏土土质时,位移量可达最大值,约为60 mm;4)外部载荷的增加对基坑底部的影响较小,当载荷达到60 kN/m^(2)时,其影响范围扩展至竖井底部3倍宽度范围内,导致地表位移100~110 mm;当外部载荷增至80 kN/m^(2)时,最大载荷位置出现在载荷面,地表位移可达130~140 mm;5)最大位移量随载荷距离的增加而减小,当载荷距离为6 m时,载荷位置对排桩影响很小。本文研究成果可为实际竖井施工提供理论指导。In order to study the deformation of soil body during shaft excavation under different conditions,a shaft project of Changsha Metro is taken as the research object,and the finite element software PLAXIS 3D is used to establish a model,and the settlement of the soil body after excavation and the influence of external load on the shaft are analyzed.The results show that:1)During the shaft excavation,the deformation area of the soil body gradually decreases from top to bottom,and the deformation area of the surface soil layer is the largest.2)The deformation of the soil around the shaft is mainly concentrated in the upper soil layer;3)In the vertical direction,as the depth increases,the displacement of the soil body tends to increase first and then decrease.When the bottom of the shaft is located in clay soil,the displacement can reach the maximum value,about 60 mm;4)The increase of external load has little impact on the bottom of the foundation pit.When the load reaches 60 kN/m^(2),the influence range extends to 3 times the width of the bottom of the shaft,resulting in a surface displacement of 100~110 mm.When the external load increases to 80 kN/m^(2),the maximum load position appears on the load surface,and the surface displacement can reach 130~140 mm;5)The maximum displacement decreases with the increase of the load distance,and when the load distance is 6 m,the load position has little influence on the row pile.The results can provide a theoretical basis for the actual shaft construction.

关 键 词：竖井 软土 基坑开挖 三维有限元 

分 类 号：TD926.4[矿业工程—选矿]