摘要
武汉地铁正处于实现"主城成网、新城通线"目标的关键时期,地铁施工安全尤为重要。为研究偏压条件下地铁工作井(深基坑)开挖安全及井-隧相互影响,以武汉地铁19号线5标段4号井为例,首先依托工程地质勘察资料建立三维数值模型,对深基坑变形进行了数值模拟计算与分析;然后在施工过程中对深基坑周边地表沉降、围护桩深层水平位移、内支撑轴力进行了全程现场监测;最后将数值模拟结果与现场监测数据进行了对比分析,研究了偏压条件下深基坑开挖过程中的变形特征以及地铁隧道开挖对深基坑变形的影响。结果表明:(1)设计采用的"围护桩+内支撑"的深基坑支护方案能有效抵抗偏压对深基坑开挖安全的影响,能将深基坑开挖过程中的变形控制在允许范围之内;(2)偏压条件下深基坑周边的地表沉降与围护结构深层水平位移呈现出非对称变形的特征;(3)隧道的施工会使深基坑的围护结构与周边地表沉降重新发生变形,且由于偏压的影响其变形具有非对称性。
Wuhan Metro is in the critical period of achieving the goal of “Main City into a Network, New City through the Line”,and the safety of metro construction is particularly important.In order to study the excavation safety of subway working shafts and the well-tunnel interaction under biased pressure, based on the project of well No.4, Section 5 of Wuhan Metro Line 19,this paper firstly establishes a three-dimensional numerical model, calculates and analyzes the deformation of the deep foundation pit.Secondly, the paper conducts on-site monitoring of the surface settlement around the deep foundation pit, deep horizontal displacement of the enclosure pile, and axial force of inner support of the deep foundation pit during construction.Finally, the paper compares the numerical and monitoring results to investigate the deformation characteristics of the deep foundation pit during excavation and the influence of the metro tunnel excavation on deformation of the deep foundation pit under biased pressure.The results are as follows:(1)The design of support scheme of “enclosure pile + internal support”for the deep foundation pit can effectively resist the influence of bias pressure on the excavation safety of the deep foundation pit, and the deformation of the pit excavation can be controlled within the allowable range;(2)Under bias pressure, there appears asymmetric deformation of both the surface settlement surrounding the deep pit and the deep horizontal displacement of the enclosure structure;(3)Tunnel construction will cause new deformation of enclosure structure of deep foundation pit and the surrounding surface settlement which is asymmetric due to the influence of bias pressure.
作者
张宇翔
焦玉勇
荆武
钟天
黄才彬
ZHANG Yuxiang;JIAO Yuyong;JING Wu;ZHONG Tian;HUANG Caibin(Faculty of Engineering,China University of Geoscience(Wuhan),Wuhan 430074,China;Wuhan Hanyang Municipal Construction Group Co.,Ltd.,Wuhan 4300509China)
出处
《安全与环境工程》
CAS
CSCD
北大核心
2022年第1期39-46,57,共9页
Safety and Environmental Engineering
基金
国家自然科学基金重点国际(地区)合作研究项目(41920104007)
国家自然科学基金重点项目(41731284)。
关键词
地铁施工安全
偏压
工作井
隧道
数值模拟
现场监测
safety of metro construciton
biased pressure
working shaft
tunnel
numerical simulation
on-site monitoring
