Deng Gao , Yusheng Shen , Pengfa Zhou , Andi Gou , Mingyu Chang , Jun Dong , Kang Wu
{"title":"Failure mechanism of deep-buried and large cross-section subway station tunnel: Geo-mechanical model test and numerical investigation","authors":"Deng Gao , Yusheng Shen , Pengfa Zhou , Andi Gou , Mingyu Chang , Jun Dong , Kang Wu","doi":"10.1016/j.tust.2024.106148","DOIUrl":null,"url":null,"abstract":"<div><div>In some megacities, urban subway and municipal engineering are developing in the tendency of large cross-section and great buried depth, which brings a series of challenges to the design and construction of underground engineering. The mechanical characteristics and failure mechanism of tunnels have been paid more and more attention. Based on Xietaizi Subway Station tunnel in Chongqing, China, the paper carried out a geo-mechanical model test to simulated partial excavation processes of the large cross-section tunnel, integrating the resultant disturbances from partial excavation. The deformation and stress characteristics of the tunnel under different buried depths are analyzed, and the failure mechanism of large cross-section tunnel lining is investigated. The reliability of the research results is verified by the geo-mechanical model test and numerical simulation. The results indicate that under the pressure of the surrounding rock, the tunnel lining adjusts its internal forces primarily through deformation before transitioning to cracking, and retains earing capacity after the first crack appears. The tunnel structure experiences a process characterized by ‘elasticity-plasticity-injury-failure’. The tunnel section exhibits a ‘flattening’ deformation trend. The invert cracks are primarily distributed within a range of 0.5 times the tunnel span, while the vault cracks are mainly concentrated at the mid-span. Ultimately, the tunnel structure is compromised by the fracture of the invert’s middle section.</div></div>","PeriodicalId":49414,"journal":{"name":"Tunnelling and Underground Space Technology","volume":null,"pages":null},"PeriodicalIF":6.7000,"publicationDate":"2024-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Tunnelling and Underground Space Technology","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0886779824005662","RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"CONSTRUCTION & BUILDING TECHNOLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
In some megacities, urban subway and municipal engineering are developing in the tendency of large cross-section and great buried depth, which brings a series of challenges to the design and construction of underground engineering. The mechanical characteristics and failure mechanism of tunnels have been paid more and more attention. Based on Xietaizi Subway Station tunnel in Chongqing, China, the paper carried out a geo-mechanical model test to simulated partial excavation processes of the large cross-section tunnel, integrating the resultant disturbances from partial excavation. The deformation and stress characteristics of the tunnel under different buried depths are analyzed, and the failure mechanism of large cross-section tunnel lining is investigated. The reliability of the research results is verified by the geo-mechanical model test and numerical simulation. The results indicate that under the pressure of the surrounding rock, the tunnel lining adjusts its internal forces primarily through deformation before transitioning to cracking, and retains earing capacity after the first crack appears. The tunnel structure experiences a process characterized by ‘elasticity-plasticity-injury-failure’. The tunnel section exhibits a ‘flattening’ deformation trend. The invert cracks are primarily distributed within a range of 0.5 times the tunnel span, while the vault cracks are mainly concentrated at the mid-span. Ultimately, the tunnel structure is compromised by the fracture of the invert’s middle section.
期刊介绍:
Tunnelling and Underground Space Technology is an international journal which publishes authoritative articles encompassing the development of innovative uses of underground space and the results of high quality research into improved, more cost-effective techniques for the planning, geo-investigation, design, construction, operation and maintenance of underground and earth-sheltered structures. The journal provides an effective vehicle for the improved worldwide exchange of information on developments in underground technology - and the experience gained from its use - and is strongly committed to publishing papers on the interdisciplinary aspects of creating, planning, and regulating underground space.