盾构隧道沉降下整体道床变形及层间脱空分析  

Deformation and Interlayer Disengaging Analysis of Monolithic Track Bed under the Shield Tunnel Settlement

作　　者：彭华[1] 梁延科 蔡小培[1] 马文辉[1] PENG Hua, LIANG Yan- ke, CAI Xiao- pei, MA Wen- hui(Beijing Jiaotong University, Beijing 100044, Chin)

机构地区：[1]北京交通大学,北京100044

出　　处：《铁道工程学报》2018年第1期95-99,105,共6页Journal of Railway Engineering Society

基　　金：北京市自然科学基金委员会-北京市科学技术研究院联合项目(L150003);国家自然科学基金项目(51578053;51778050;51478032)

摘　　要：研究目的:盾构隧道管片沉降引起的整体道床脱空已成为影响地铁安全运营的重要因素。为揭示盾构隧道管片沉降下整体道床力学特性,建立轨道-整体道床-管片衬砌空间耦合有限元模型,并依托北京机场线T2支线东、西两侧线路的管片实际沉降监测数据,分析道床脱空下整体道床的变形以及破坏特征。研究结论:(1)当管片发生局部沉降,沉降波谷位于伸缩缝处时,道床上表面在沉降起始处出现开裂,道床底部两侧小范围会出现开裂;沉降波谷位于两伸缩缝中间位置时,道床上表面会出现大范围的开裂现象,且出现在管片沉降的起始位置,道床底部两侧及管片沉降波谷处会出现开裂现象;(2)当管片发生连续沉降,在两个沉降区的波谷都不位于伸缩缝处时,道床底部会出现大范围的开裂,道床上表面所受拉应力比较小,不会出现开裂;在其中一个管片沉降区的波谷位于伸缩缝处时,道床的两侧小范围会出现开裂,道床上表面会出现大范围的开裂;(3)该研究成果对地铁盾构隧道的养护维修具有一定的借鉴价值。Research purposes： Disengaging of monolithic track bed caused by shield tunnel settlement has become an important factor affecting the safety of subway operation. To reveal the mechanical characteristics of monolithic track bed under shield tunnel settlement, a spatial coupling finite element model for a track - track bed - segment lining system is established. Based on the segment settlement monitoring data of Beijing Subway Airport Line T2, the deformation and failure characteristics of monolithic track bed are analyzed under disengaging of it. Research conclusions： （ 1 ） When wave trough of local settlement at the expansion joint occurs in segment, fractures appear on the surface of the track bed at the settlement starting point, as well as two sides of the track bed bottom. When settlement trough is located in the middle of two expansion joints, a large scale of cracking phenomenon appears on the surface of track bed at the settlement starting point, while cracks appears on both sides of the bottom of the track bed and the track bed at settlement trough. （2） When the segment is in continuous settlement, and two subsidence troughs are not located in the expansion joint, the crack will appear at the bottom of a large range of bed surface, and tension stress is relatively small, without cracking. When the trough of one segment settlement area is located at the expansion joint, there will be cracking on both sides of the track bed, and a wide range of cracking on the surface of the ballast. （3） The research achievement has a certain value of reference for the maintenance in the shield tunnel of metro.

关 键 词：管片沉降 整体道床 力学特性 有限元分析 伸缩缝 

分 类 号：U216.3[交通运输工程—道路与铁道工程]