盾构隧道内堆载对基坑开挖引起的隧道上浮量的控制效果研究  

Study on control effect of pile load in shield tunnel on tunnel floating caused by foundation pit excavation

作　　者：魏纲 周烨波 王哲[3] 翁家华 WEI Gang;ZHOU Yebo;WANG Zhe;WENG Jiahua(Key Laboratory of Safe Construction and Intelligent Maintenance for Urban Shield Tunnels of Zhejiang Province,Hangzhou City University,Hangzhou 310015,China;Zhejiang Engineering Research Center of Intelligent Urban Infrastructure,Hangzhou City University,Hangzhou 310015,China;Institute of Geotechnical Engineering,Zhejiang University of Technology,Hangzhou 310014,China)

机构地区：[1]浙大城市学院浙江省城市盾构隧道安全建造与智能养护重点实验室,浙江杭州310015 [2]浙大城市学院城市基础设施智能化浙江省工程研究中心,浙江杭州310015 [3]浙江工业大学岩土工程研究所,浙江杭州310014

出　　处：《中南大学学报（自然科学版）》2024年第7期2727-2736,共10页Journal of Central South University:Science and Technology

基　　金：浙江省基础公益研究计划项目(LGF22E080012)。

摘　　要：基坑开挖会引起下卧盾构隧道产生上浮,隧道内堆载可以有效控制上浮量。本文采用两阶段方法,推导隧道内堆载措施下基坑开挖引起的盾构隧道上浮量计算公式。首先,基于影像源法计算基坑开挖坑底隆起引起的隧道附加应力,采用能够考虑土质条件的方法计算得到隧道内堆载引起的隧道附加应力,叠加得到总的附加应力;其次,采用转动与错台协同模型计算得到隧道受力与变形;使用Midas有限元软件对具体工况进行三维建模,并将隧道纵向隆起量数值模拟结果与公式计算结果进行对比。研究结果表明:本文方法计算结果与有限元模拟结果较吻合,验证了本文方法的合理性;假设基坑开挖长度为L,最佳堆载范围为距离堆载中心±L/3范围内,超出最佳范围时堆载控制效果减弱;土体内摩擦角对隧道变形影响较大,土体内摩擦角越小,堆载对隧道变形的控制效果越好。The excavation of foundation pit will cause the floating of the underlying shield tunnel,and the loading in the tunnel can effectively control the floating.Using the two-stage method,the formula for calculating the floating of shield tunnel caused by the excavation of foundation pit with the stacking measures in tunnel was derived in this paper.Firstly,the image source method was used to calculate the tunnel additional stress caused by the bottom uplift of foundation pit excavation.The method that can consider the soil condition was used to calculate the tunnel additional stress caused by the load in the tunnel,and the total additional stress was superimposed.Secondly,the force and deformation of the tunnel were calculated by using the cooperative model of rotation and staggered platform.Midas finite element software was used to model the specific working conditions,and the numerical simulation results of tunnel longitudinal bulge were compared with the formula calculation results.The results show that the calculated results of the proposed method are in good agreement with the finite element simulation results,which verifies the rationality of the proposed method.It is assumed that the excavation length of the foundation pit is L,and the optimal load range is within±L/3 from the load center.The control effect is weakened when the optimal load range is exceeded.The soil internal friction angle has great influence on tunnel deformation.The smaller the soil internal friction angle,the better the control effect of pile load on tunnel deformation.

关 键 词：基坑工程 盾构隧道 隧道内堆载 影像源法 附加应力 

分 类 号：TU473[建筑科学—结构工程]