基于非极限土压力的基坑开挖引起隧道变形的计算方法  

A computational method for the lateral displacement of tunnels caused by foundation pit excavation based on non-limit earth pressure

作　　者：许四法[1] 于均辉 王哲[1] 郭丙来 XU Sifa;YU Junhui;WANG Zhe;GUO Binglai(Institute of Geotechnical Engineering,Zhejiang University of Technology,Hangzhou 310023,China)

机构地区：[1]浙江工业大学岩土工程研究所,浙江杭州310023

出　　处：《浙江工业大学学报》2024年第3期312-318,共7页Journal of Zhejiang University of Technology

摘　　要：由于基坑开挖引起邻近隧道变形,继而影响地铁在隧道中的安全运行,因此如何准确预测邻近隧道变形是个值得研究的问题。根据非极限土压力计算方法,计算基坑开挖卸荷坑壁上的土压力,利用Mindlin求解公式,获得基坑开挖阶段旁侧隧道上的附加荷载,将隧道结构看作Winkler地基梁上的Euler梁,建立弹性地基梁微分方程,给出隧道水平位移变形的解析方法。基于该方法分析了基坑开挖引起邻近隧道的水平位移。研究结果表明:随着基坑开挖深度的增加,隧道水平位移相应增加;考虑非极限土压力计算得到的隧道水平位移结果与实测值较为接近,误差总体保持在20%以内;相较于传统隧道水平位移求解方法,笔者方法更加符合实际。Foundation pit excavation causes the deformation of adjacent tunnels,which in turn affects the safe operation of subway in tunnels.Therefore,how to accurately predict the deformation of adjacent tunnels is a problem worth studying.According to the non-limit earth pressure computational method,the earth pressure on the unloading pit wall during foundation pit excavation is calculated.With the aid of the Mindlin solution,the additional load acting on the side tunnel during the excavation stage of the foundation pit is obtained.The tunnel structure is considered as a Euler beam on the Winkler foundation beam and the differential equation of the elastic foundation beam is established.An analytical method for the horizontal displacement and deformation of the tunnel is given.Based on this method,the horizontal displacement of adjacent tunnels caused by foundation pit excavation is analyzed.The results show that the horizontal displacement of the tunnel increases with the increase of excavation depth of the foundation pit.The horizontal displacement of the tunnel calculated by considering non-limit earth pressure is relatively close to the value measured,and the overall relative error is smaller than 20%.Compared with the traditional method proposed,the author method is more practical.

关 键 词：基坑开挖 隧道水平位移 非极限土压力 MINDLIN解 弹性地基梁 

分 类 号：TU432[建筑科学—岩土工程]