水下浅埋盾构隧道接缝渗漏时围岩沉降分区  

Settlement Zoning of Surrounding Rock in Case of Joint Leakage of Underwater Shallow⁃buried Shield Tunnel

作　　者：吴春晓 王孟伟 曾榕凯 李云龙 路平[1] 张友良 WU Chunxiao;WANG Mengwei;ZENG Rongkai;LI Yunlong;LU Ping;ZHANG Youliang(School of Civil Engineering and Architecture,Hainan University,Haikou 570228,China;School of Civil Engineering,Beijing Jiaotong University,Beijing 100044,China)

机构地区：[1]海南大学土木建筑工程学院,海口570228 [2]北京交通大学土木建筑工程学院,北京100044

出　　处：《铁道建筑》2023年第2期94-98,共5页Railway Engineering

基　　金：国家自然科学基金(51868017);海南省基础与应用基础研究计划高层次人才项目(2019RC079);海南省自然科学基金(522CXTD510)。

摘　　要：针对水下浅埋盾构隧道接缝渗漏问题,开展多组模型试验。通过改变渗漏位置、压力水头两项参数对地表沉降、渗漏量和地层应力进行分析,结合模型试验结果对理论椭球分区法进行修正,并对隧道渗漏后的围岩沉降进行分区。结果表明:压力水头增加,漏缝处埋深越浅,发生渗漏时地表沉降增量越大;渗漏量和平均有效主应力曲线均可划分为初始阶段、漏砂漏水阶段和收敛阶段;收敛阶段土拱稳定,不漏砂只漏水且平均有效主应力基本恢复至漏砂前;依据砂粒运动特征将隧道围岩沉降分为侵蚀区、位移区和稳定区,经偏移修正和曲线修正后侵蚀区和位移区的水平向长度与压力水头、漏缝处埋深正相关;压力水头增量相同时,漏缝处埋深越大,侵蚀区水平向长度受压力水头增加的影响越明显;压力水头越大,侵蚀区水平向长度受渗漏位置变动影响越明显。Aiming at the problem of joint leakage of underwater shallow-buried shield tunnel,several sets of model tests were carried out.By changing the two parameters of leakage location and pressure head,the surface settlement,leakage amount and formation stress were analyzed,and the theoretical ellipsoid zoning method was modified based on the model test results,and the surrounding rock settlement after tunnel leakage was zoned.The results show that with the increase of pressure head,the shallower the buried depth of the leakage joint is,the larger the increment of surface settlement is when the leakage occurs.The leakage amount and the average effective principal stress curve can be divided into the initial stage,the sand and water leakage stage and the convergence stage.In the convergence stage,the soil arch is stable,there is only water leakage without sand leakage,and the average effective principal stress is basically restored to that before the sand leakage.According to the characteristics of sand movement,the surrounding rock settlement of the tunnel is divided into erosion zone,displacement zone and stable zone.After offset correction and curve correction,the horizontal length of the erosion zone and displacement zone is positively related to the pressure head and the buried depth of the leakage joint.When the increment of pressure head is the same,the greater the buried depth of the leakage joint,the more obvious the influence of the increase of the pressure head on the horizontal length of the erosion zone will be.The greater the pressure head is,the more obvious the influence of the change of the leakage position on the horizontal length of the erosion zone will be.

关 键 词：盾构隧道 沉降分区 模型试验 渗漏位置 压力水头 土拱 沉降槽 渗漏量 

分 类 号：U45[建筑科学—桥梁与隧道工程]