Face stability analysis of large shield-driven tunnel in rock-soil interface composite formations

作     者：Xiaobin Ding Kang Li Yuxuan Xie Shuzhuo Liu 

作者机构：School of Civil Engineering and TransportationSouth China University of TechnologyGuangzhou 510641China Guangdong Provincial Key Laboratory of Modern Civil Engineering TechnologySouth China Institute of Geotechnical EngineeringGuangzhou 510650China 

出 版 物：《Underground Space》 (地下空间（英文）)

年 卷 期：2022年第7卷第6期

页      面：1021-1035页

核心收录：

学科分类：08[工学] 0814[工学-土木工程] 

基　　金：financially supported by Guangdong Provincial Key Laboratory of Modern Civil Engineering Technology(2021B1212040003) National Natural Science Foundation of China(Grant No.41827807). 

主　　题：Tunnel Stability Limit support pressure RSI composite formations 3D failure mechanism 

摘      要：A new 3D log-spiral model(LS-M model)is proposed to determine the minimal support pressure on the tunnel face of a large shielddriven tunnel in rock-soil interface(RSI)composite formations.In the proposed LS-M model,we define the RSI angle ω and use a new approach to calculate the equivalent tunnel face area,which provides a collapse zone with more realistic geometry than the traditional wedge model.And it has acceptable accuracy with simpler implementation than limit equilibrium analysis.Comparing with previous studies and 3D numerical analysis,it indicates that:(i)the LS-M results agree well with others in full-soil formations on the variation patterns of minimum support pressure and stability coefficients N_(c) and N_(γ);(ii)the critical RSI angle ω_(cr),which is predominantly influenced by soil cohesion,increases with the soil property values;(iii)the limit support pressure starts to increase with ω only when ωω_(cr);(iv)the peak support pressure occurs at lower C/D with a lower ω;(v)ω can only affect stability coefficients N_(c) and N_(γ) when ω and the friction angle are relatively small,while N_(s) is substantially influenced by RSI angle ω.