摘要
为了研究在盾构下穿对既有隧道结构以及地表产生的影响,以南大干线电力隧道下穿广州地铁2号线工程为研究对象。基于ABAQUS有限元软件建立了隧道下穿地铁线路的三维模型,考虑在盾构支护力以及注浆压力的影响下,探究了新建隧道施工对地表沉降以及既有地铁线路的位移、应力的影响。结果表明:正交下穿施工过程中既有地铁线路位移主要以纵向沉降为主,对隧道管片轴向应力影响较大;地表沉降槽并没有因既有结构的存在而发生变化,沉降曲线基本符合正态分布;随着支护应力以及注浆的增大,既有线路的沉降量会减小,但是地表沉降量并不是单一递减。因此,在盾构施工过程中,设置合理的掌子面支护力以及注浆压力是保证施工开挖以及既有线路安全的关键,要引起最够的重视。
In order to analyze the influencing factors of tunnel excavation on the existing tunnel structure and ground surface in the process of shield tunneling,this paper takes the power tunnel of Nanda Highway as an example,a threedimensional model of the tunnel underpass Guangzhou Metro Line 2 was developed.Based on ABAQUS finite element software,a three-simulation of the underpass construction process is carried out.Considering the different support pressure and grouting force,an exploration is applied for the influence of the new tunnel excavation on the surface settlement and the displacement and stress of the existing line.The results show that the displacement of the existing metro line in the process of orthogonal underpass construction is mainly the longitudinal settlement,and it has great influences on the axial stress of the tunnel segment,which will lead to the longitudinal bending moment of the tunnel lining;the surface settlement groove just changed a little due to the existence of the existing structure,and the displacement curve basically conforms to the normal distribution of Gauss curve;with the increase of support stress and grouting,the settlement of existing lines will decrease,but the surface settlement is not a single decline trend.Therefore,in the process of shield construction,a reasonable face support pressure and grouting force is a key to ensure the safety of excavation and existing subway lines,which should be paid more attention.
作者
李京承
余航飞
LI Jingcheng;YU Hangfei(China Railway 16st Bureau Group Road&Bridge Engineering Co.,Ltd.,Beijing 101500,China;School of Highway Engineering,Chang’an University,Xi’an,Shaanxi 710064,China)
出处
《水利与建筑工程学报》
2020年第5期109-114,共6页
Journal of Water Resources and Architectural Engineering
关键词
隧道交叉
既有隧道
支护力
注浆压力
数值模拟
tunnel overlapping
existing tunnel
support pressure
grouting forces
numerical simulation
