上部基坑开挖与内部堆载情况下盾构隧道位移的计算方法  

Calculation method of shield tunnel displacement in the case of pit excavation and in-tunnel loading

作　　者：邱士正 韩玉珍 王炳华 聂小凡 张振东 何纪忠 吕林海 王旭阳 唐坤 QIU Shizheng;HAN Yuzhen;WANG Binghua;NIE Xiaofan;ZHANG Zhendong;HE Jizhong;LYU Linhai;WANG Xuyang;TANG Kun(Nanning Rail Transit Construction Co.,Ltd.,Nanning 530022,China;Beijing Urban Construction Design&Development Group Co.,Limited,Beijing 100037,China)

机构地区：[1]南宁轨道交通建设有限公司,广西南宁530022 [2]北京城建设计发展集团股份有限公司,北京100037

出　　处：《中国矿业》2024年第9期179-185,共7页China Mining Magazine

基　　金：雄安新区建设科学技术计划项目资助(编号:2021-03,2021-07)。

摘　　要：地下结构上方大面积基坑开挖导致地下结构上浮,准确预测上浮变形是合理评估基坑开挖影响的前提条件。本文以既有地铁盾构隧道上方大面积基坑开挖为背景,基于基坑开挖附加荷载分布规律及分层总和法,将盾构隧道受基坑开挖与内部堆载情况下的响应位移分为整体上浮位移、相对上浮位移、堆载再压缩位移及特殊地质附加位移等四个部分,分别提出了隧道上浮位移的理论计算方法。为验证该计算方法,将其应用于南宁某工程的隧道上浮位移估算。计算结果与实测上浮位移的比较表明:大面积开挖导致的地层总体上浮占隧道上浮量的比例最大,而隧道内部堆载措施量在浅层开挖时限制隧道上浮的效果显著;理论计算方法更适用于预测施工完成时稳定阶段的盾构隧道上浮位移,计算结果与工程实测数据较为吻合,误差不超过10%,可为类似工程的设计及施工提供参考。Large-scale pits excavation above underground structures can lead to the uplift of these structures.Accurate prediction of the uplift deformation is a prerequisite for reasonably assessing the impact of pit excavation.This paper takes the large-scale pits excavation above existing shield tunnels of the subway as the background.Based on the distribution law of additional loads during pit excavation and the layered summation method,the response displacement of the shield tunnel under the conditions of pits excavation and internal stacking is divided into four parts:overall uplift displacement,relative uplift displacement,compression displacement due to stacking,and special geological additional displacement.The theoretical calculation method for tunnel uplift displacement is proposed separately for each part.To verify this calculation method,it is applied to estimate the tunnel uplift displacement in a project in Nanning.A comparison between the calculation and the monitor data shows that the overall uplift of the layers caused by large-scale excavation accounts for the largest proportion of the tunnel uplift,while the internal stacking measures have a significant effect on limiting the tunnel uplift during shallow excavation.The theoretical calculation method is more suitable for predicting the uplift displacement of the shield tunnel in the stable stage after the completion of construction.The calculated results are in good agreement with the measured data of the project,with an error of no more than 10%.This can provide a reference for the design and construction of similar projects.

关 键 词：基坑开挖 盾构隧道 内部堆载 位移计算 分层总和法 

分 类 号：TU459.2[建筑科学—岩土工程]