外墙插入比对坑中坑基坑变形影响的敏感性分析  

Sensitivity Analysis of the Influence of External Wall Insertion Ratio on Deformation of Pit-in-Pit

作　　者：侯新宇[1] 袁娇娇[1] 蔺彦玲 HOU Xinyu;YUAN Jiaojiao;LIN Yanling(School of Civil Engineering and Architecture,Jiangsu Open University,Nanjing 210036)

机构地区：[1]江苏开放大学建筑工程学院,江苏210036

出　　处：《现代隧道技术》2018年第6期87-93,共7页Modern Tunnelling Technology

基　　金：国家自然科学基金项目(41572273);江苏省高校自然科学研究面上项目(14KJB560004);江苏省"六大人才高峰"项目(2014JZ010);江苏省"青蓝工程"优秀青年骨干教师项目(20141001)

摘　　要：文章以苏州某地铁换乘站坑中坑基坑为基本模型,采用土体卸载条件下的HS有限元模型,系统研究了外墙插入比对坑中坑基坑支护结构和基坑土体变形的影响。结果表明:随着外墙插入比增加,外墙墙身最大侧移减小,但均在30～35 mm范围内,墙脚侧向变形以线性规律增加明显;内墙顶端侧向变形以线性规律增加显著,而墙身侧向变形最值增加不明显,墙体底端无明显改变;内坑坑底隆起超过90 mm,受外墙插入比影响甚微;外坑坑底隆起超过70 mm,隆起量受外墙插入比的影响随着距离外墙减小而增加;外坑坑背土体沉降显著,距外墙14 m范围内沉降随外墙插入比增加而减小,外墙插入比为0.25时沉降量最大,14 m范围外则出现相反趋势。鉴于此,在确保坑中坑安全和环境影响前提下,确定合理的外墙插入比对坑中坑实施具有重要意义。Adopting Hardening-Soil finite element model based on soil unloading conditions,the influence of external wall insertion ratio on deformation of retaining structure and soil was studied taking the foundation pit of a metro transfer station of Suzhou metro line 1 as background.The results show that the maximum lateral displacement of external wall decreases with an increase of insertion ratio within the range of 30-35 mm,and the lateral deformation at the foot of wall increases significantly in a linear form;the lateral deformation at the top of internal wall obviously increases linearly,while the maximum of lateral wall deformation of wall body increases slowly and there is almost no change at the bottom of wail;the uplift at the internal pit bottom is more than 90 mm and it is slightly effected by the insertion ration of external wall while the uplift at the external pit bottom is more than 70 mm and it increases with an decrease of the distance away from the external wall;soil mass settlement at the back of the external pit is obvious and it decreases with an increases of insertion ratio of external wall within the range 14 m away from the external wall,and the settlement reaches the maximum when the insertion ratio of external wall is 0.25 while the tendency of settlement develops reversely when the distance from the external wall is beyond 14 m.To ensure the safety and reduce environmental impact,it is significant to determine a reasonable insertion ratio of external wall regarding the pit-in-pit excavation

关 键 词：插入比 坑中坑 变形影响 敏感性分析 HS模型 

分 类 号：U231.4[交通运输工程—道路与铁道工程]