Roof collapse mechanism of weak surrounding rock for deep-buried tunnels under high geostress conditions

作     者：ZHANG Qi GUO Xiaokang YAN Zhiguo LEI Zhongdai SHEN Yixin ZHANG Qi;GUO Xiaokang;YAN Zhiguo;LEI Zhongdai;SHEN Yixin

作者机构：School of Civil EngineeringSoutheast UniversityNanjing 211189China Department of Geotechnical EngineeringTongji UniversityShanghai 200092China 

出 版 物：《Journal of Mountain Science》 (山地科学学报（英文）)

年 卷 期：2024年第21卷第7期

页      面：2408-2426页

核心收录：

学科分类：0830[工学-环境科学与工程（可授工学、理学、农学学位）] 081406[工学-桥梁与隧道工程] 08[工学] 0814[工学-土木工程] 082301[工学-道路与铁道工程] 0823[工学-交通运输工程] 

基　　金：supported partially by the National Natural Science Foundation of China(42277158 41972277 and U1934212) 

主　　题：Geostress Deep-buried tunnels Collapse mechanism Pressure arch Limit analysis HoekBrown criterion 

摘      要：High geostress,a typical attribute of tunnels located at significant depths,is crucial in causing stress-induced failure and influencing the stability of the tunnel *** study developed an analytical method for the failure mechanism that occurs in deep-buried tunnel roofs,taking into account the influence of *** limit analysis theory was utilized for deriving analytical solutions about the geometry of the collapsing surface and the limit supporting *** collapsing surface obtained by the analytical solution was validated by the findings of the physical model test,which shows a high level of agreement with the actual *** extensive investigation was done to explore the effects of the lateral pressure coefficients,the tunnel buried depth,the geological conditions of the surrounding rock,the long-short axis ratio,and the size of the tunnel *** findings indicate that an increase in the lateral pressure coefficient from 0.5 to 1.5 results in a reduction in the height of the collapsing zone by 2.08 m and the width of the collapsing zone by 1.15 m,while simultaneously increases the limit supporting pressure by 18.9%.The proposed upper bound method accurately determines the limit supporting pressure and the geometry of the collapsing surface,which aligns well with the results acquired through numerical modelling and on-site monitoring in actual engineering *** proposed analytical method can serve as a reference for similar crown failure issues of deep-buried tunnels.