基坑开挖导致邻近既有隧道变形的主动控制研究
Research on active control of deformation of existing tunnel caused by foundation pit excavation
苏栋 1张小妹 2张国涛 1雷国平 3陈湘生1
作者信息
- 1. 深圳大学 滨海城市韧性基础设施教育部重点实验室,广东 深圳 518060;深圳大学 土木与交通工程学院,广东 深圳 518060
- 2. 深圳市前海建设投资控股集团有限公司,广东 深圳 518066
- 3. 佛山大学 土木与交通学院,广东 佛山 528225
- 折叠
摘要
采用有限元分析方法对新型支撑轴力主动控制系统进行了研究,提出了一种支撑轴力设计方法;在对支撑不施加主动轴力的情况下,研究了花岗岩残积土地层中基坑开挖对既有隧道的影响,根据基坑侧边不同位置隧道在基坑开挖作用下的位移划分了基坑开挖影响区;基于提出的轴力设计方法,研究了基坑开挖过程中支撑轴力主动控制对既有隧道位移的影响规律;获得了隧道位移控制到预警值 10mm以下的临界控制比,分析了其在不同隧道位置时的分布规律.结果表明:该地层中的影响区范围相对已有研究的影响区更小;隧道位移与地连墙位移的控制比近似呈正比关系;基坑腰部 0.6 倍挖深位置附近隧道的水平位移需进行最严格的控制,靠近基坑且深度较深的区域通过水平位移控制得到的临界控制比更小,应以隧道水平位移控制为主,而远离基坑且深度较浅的区域应以隧道竖向位移控制为主;花岗岩残积土中的基坑开挖影响区以及对临界控制比的量化研究成果可为类似工程提供参考.
Abstract
Finite element analysis method was used to study a new type of active control system for the axial forces of the supports,and a design method was proposed.The influence of excavation of a foundation pit in granite residual soil layers on existing tunnels was studied without applying active axial force to the supports.The excavation impact zone of the foundation pit was divided based on the displacement of tunnels at different positions on the side of the foundation pit under the action of excavation.Based on the proposed axial force design method,a study was conducted on the influence of active control of axial forces of the supports on the displacement of existing tunnels during excavation of the foundation pit.The critical control ratio of tunnel displacement control below the warning value of 10 mm was obtained,and its distribution pattern at different tunnel positions was analyzed.The results show that the scope of the impact zone in this stratum is relatively small compared to the existing research results.The tunnel displacement is approximately proportional to the control ratio of the diaphragm wall displacement.The horizontal displacement of the tunnel near the excavation depth of 0.6 times depth of the foundation pit needs to be strictly controlled.The critical control ratio obtained through horizontal displacement control is smaller in areas close to the foundation pit and deeper,and tunnel horizontal displacement control should be the main approach.The area far from the foundation pit and shallow in depth should be mainly controlled by vertical displacement of the tunnel.The quantitative research results on the excavation impact zone of foundation pits in residual granite soil and the critical control ratio can provide reference for similar projects.
关键词
基坑/隧道位移/支撑轴力/主动控制系统Key words
foundation pit/tunnel displacement/supporting axial force/active control system引用本文复制引用
基金项目
深圳市自然科学基金项目(JCYJ20210324094607020)
国家自然科学基金项目(51938008)
广东省重点领域研发计划项目(2019B111105001)
出版年
2024
NETL
NSTL
万方数据