地下水对软土盾构隧道施工的影响规律分析  

Numerical Analysis on the Impact of Groundwater on Shield Tunnel Construction under Soft Soil

作　　者：林志斌[1,2] 李元海[1,2] 赵耀强[1,2] 时林坡[1,2] 

机构地区：[1]中国矿业大学深部岩土力学与地下工程国家重点实验室,江苏徐州2210082 [2]中国矿业大学力学与建筑工程学院,江苏徐州2210082

出　　处：《地下空间与工程学报》2012年第2期375-381,389,共8页Chinese Journal of Underground Space and Engineering

摘　　要：潜水和承压水是地铁软土区间盾构隧道施工过程中的主要危险源,为研究潜水水位变化和承压水水压变化对区间隧道施工的影响,采用FLAC3D软件,选用修正剑桥模型,对不同潜水水位和承压水头作用下盾构隧道的地表沉降、衬砌内力等进行分析。研究结果表明,当隧道洞身全部位于地下水中时:(1)潜水条件下,考虑渗流时地表最大沉降量比不考虑渗流时增大约50%;盾构隧道最大地表沉降与潜水水位呈线性关系;(2)承压水条件下,考虑渗流时地表最大沉降量比不考虑渗流时增大约10%,盾构隧道最大地表沉降与承压水头不成线性关系,随着承压水头的增大,地表最大沉降的增长速率越来越大;(3)潜水水位从-6.8 m变化到-2.8 m及承压水头从8 m变化到12 m的过程中,隧道衬砌管片弯矩和轴力随着潜水水位的升高或承压水头的增大而逐渐减小。Phreatic water and confined water are the two main danger sources for constructing shield tunnel in soft soil layer strata.In order to research the influence of phreatic water level changes and confined water head changes on construction of shield tunnel,FLAC3D software and Cam-Clay model is used to analyze the ground settlement and internal force of tunnel lining under varying phreatic water level or varying confined water head.The results show that when the tunnel is located below the groundwater level：（1） In case of phreatic water condition,the maximum settlement value considering the seepage is 50% more than that without considering the seepage,and the maximum ground settlement of shield tunnel is in linear relationship with the groundwater level;（2） In case of confined water condition,the maximum settlement value considering the seepage is 10% more than that without considering the seepage,and the maximum ground settlement of shield tunnel is not in linear relationship with the confined water head,with the increase of confined water head,the increasing rate of maximum ground settlement is growing;（3） During the changing process of phreatic level from-6.8m to-2.8m and confined water head from 8m to 12m,the moment and axial force of tunnel lining segment increase gradually with the decline of water level as well as the rise of water head.

关 键 词：软土 盾构隧道 渗流 潜水 承压水 

分 类 号：TU46[建筑科学—结构工程]