摘要
基坑开挖引起的地表沉降和围护结构变形是影响地下铁道快速安全施工的重要因素,而目前基坑周边土体位移场多采用经验方法来确定,缺乏简单准确的理论计算方法。基于形状系数概念,采用理论推导的方法,通过"源—汇"理论求出基坑开挖产生的任意点处位移,用开挖面形状系数和开挖面位移来表征基坑周边土体位移场公式,形状系数的大小只与基坑开挖面变形和土体点相对空间位置有关。并利用残余应力法对基坑底面隆起进行修正,将围护结构水平变形简化为正、反向转动和挠曲3种模式的叠加组合,提出土体位移场理论公式。本文公式的计算结果与实际值相近,该公式可用于基坑开挖引起变形的预测。
The surface settlement and the deformation of the retaining structure caused by the excavation of the foundation pit are important factors that affect the rapid and safe construction of the underground railway.At present,the displacement field of the soil around the foundation pit is mostly determined by empirical methods,and there is a lack of simple and accurate theoretical calculation methods.Based on the concept of shape factor,this paper adopts the method of theoretical derivation to obtain the displacement at any point caused by the excavation of the foundation pit through the“source-sink”theory,and uses the shape factor of the excavation surface and the displacement of the excavation surface to characterize the surrounding soil of the foundation pit.In the displacement field formula,the size of the shape factor is only related to the deformation of the excavation surface of the foundation pit and the relative spatial position of the soil points.The residual stress method was used to correct the uplift of the bottom surface of the foundation pit,and the horizontal deformation of the enclosure structure was simplified to the superposition combination of three modes of forward and reverse rotation and deflection,and the theoretical formula of the soil displacement field was proposed.The calculation results of the formula in this paper is close to the actual values,and the formula can be applied to predict the deformation induced by foundation pit excavation.
作者
周佳媚
樊霁
周生波
Zhou Jiamei;Fan Ji;Zhou Shengbo(Key Laboratory of Transportation Tunnel Engineering,Ministry of Education,Southwest Jiaotong University,Chengdu 610031,P.R.China;School of Civil Engineering,Southwest Jiaotong University,Chengdu 610031,P.R.China;Beijing Urban Construction Design and Development Group Co.,Ltd.,Beijing 100037,P.R.China)
出处
《地下空间与工程学报》
CSCD
北大核心
2021年第S02期814-820,共7页
Chinese Journal of Underground Space and Engineering
基金
国家重点研发计划项目子课题(2019YFC0605104)
关键词
形状系数
基坑
位移场
shape factor
foundation pit
displacement field
作者简介
周佳媚(1973—),女,四川都江堰人,博士,教授,主要研究方向为地下工程设计、施工。E-mail:tmzjm@home.swjtu.edu.cn
