北京地铁盾构隧道渗漏病害成因及对管片结构的影响研究
Study on Causes of Leakage in Beijing Metro Shield Tunnel and Its Influence on Segment Structure
张成平 1王李斌 1唐海栋 1彭华 1李宇杰 2牛晓凯3
作者信息
- 1. 北京交通大学土木建筑工程学院,北京 100044
- 2. 北京市地铁运营有限公司,北京 100044
- 3. 北京市政路桥科技发展有限公司,北京 100037
- 折叠
摘要
为揭示城市盾构隧道渗漏病害的形成机制,对北京地铁部分盾构隧道渗漏病害的主要类型、位置及程度进行统计分析.通过现场检测、地质雷达及内窥镜探测等手段,探究盾构隧道渗漏病害机制及成因,并通过数值模拟研究管片接缝渗漏时的地层变形规律及管片结构内力特征.研究表明:1)盾构管片接缝渗漏为主要的盾构隧道渗漏类型,占比超过 60%,渗漏发生的位置集中在拱顶,以滴漏为主.2)盾构隧道渗漏水的主要内因是管片接缝处的不均匀变形,主要外因是地下水迅速升高导致存在渗漏隐患的隧道位于水位以下;同时,隧道周边地层更易形成富水体,增大了隧道渗漏病害的发生概率.3)盾构管片接缝处渗漏位置越靠近拱底,渗漏越严重,渗漏附近地层孔隙水压力消散的数值、最终达到稳定时的地表沉降越大.4)接缝局部渗漏导致的管片结构椭圆化变形较小,更易使结构出现向下且倾向渗漏点位方向的偏移;另外,渗漏位置变化相比渗漏程度对管片结构内力的影响大.
Abstract
To reveal the formation mechanism of urban shield tunnel leakage,the authors analyze the main types,locations,and leakage degrees of shield tunnel in some operating lines of Beijing metro.Furthermore,the mechanism and causes of shield tunnel leakage are explored using field observation,geological radar,and endoscope detection.Finally,numerical simulation is used to study the formation deformation rules and internal force characteristics of the segment structure when different leakage degrees and leakage locations occur at the segment joints.The research results show that:(1)The leakage of shield segment joints accounts for more than 60%of the primary leakage type,and the location of leakage is concentrated in the crown,with dripping and leakage being the leading cause.(2)The main internal cause of water leakage in shield tunnels is the uneven deformation of segment joints.The main external cause is the rapid rise of groundwater,resulting in some tunnels with potential leakage located below the water level.The strata around the tunnel are more likely to form water-rich bodies,increasing the risk of leakage.(3)The more severe the leakage at the shield segment joints and the closer the leakage location is to the arch bottom,the greater the dissipation value of the pore water pressure in the formation near the leakage point and the greater the surface settlement when it finally reaches stability.(4)Joints local leakage will result in minor elliptical deformation of the segment,and the overall structure will shift downward and toward the direction of the leakage point.In addition,changing in leakage location has a more significant impact on the internal force of the segment structure than the degree of leakage.
关键词
地铁盾构隧道/渗漏病害/现场检测/地质雷达/内窥镜探测/地层变形/管片内力Key words
metro shield tunnel/leakage disease/field test/geological radar/endoscope detection/ground deformation/segment internal force引用本文复制引用
基金项目
北京市科技计划课题(Z221100005222029)
出版年
2024
NETL
NSTL
万方数据