综合管廊近接地铁线施工对既有隧道的影响研究

Study on the Influence of Adjacent Construction of Integrated Pipe Gallery Foundation Pits on Existing Subway Tunnels

为探明超长条形基坑近接既有地铁隧道开挖时需采取何种加固措施及处理范围。基于昆明地区某综合管廊基坑近接既有地铁线开挖的实际工程进行数值仿真分析,并将分析结果与现场监测数据进行对比。研究结果表明:基坑底预加固和隔离加固均对隧道变形抑制效果显著;在不考虑预加固措施施工扰动影响的前提下,预加固处理对隧道结构的受力影响较小;隧道结构的竖向变形模拟结果相对实测值偏差较小,模拟结果对实际工程有较强的指导意义。基于研究结果,针对软土地区综合管廓基坑近接既有地铁隧道开挖的情况,给出预加固方法及处理范围的若干建议,为同类工程设计、施工提供有益参考。

In order to find out what reinforcement measures and treatment scopes are required when the long strip foundation pit adjacent to existing tunnels s excavated.Based on the simulation analysis of the excavation of an integrated pipe gallery foundation pit adjacent to existing subway tunnels in Kunming,the analysis results are compared with monitoring data.The results show that both the pre-reinforcement of foundation pit bottom and the isolation reinforcement of the foundation pit have a significant effect on the suppression of tunnel deformation;when construction disturbance of pre-reinforcement measures are not considered,the pre-reinforcement treatment will have less influence on the stress of the tunnel structure;the deviation of the simulation results of the vertical deformation of tunnel from the actual measured values is small,and the simulation results have a strong guiding significance for the actual project.Based on the results of the study,some suggestions of the pre-reinforcement method and the treatment range are given for the long strip foundation pit excavation adjacent to existing tunnels in soft soil area,which provides a useful reference for the design and construction of similar projects.