断层破碎带倾角对复合地层开挖面极限支护力的影响  

Influence of the Inclined Angle of Fault Fracture Zone on Limit Support Pressure of the Excavation Face of Shield Tunnel in Composite Stratum

作　　者：李章林 蒋鹏程 何国军 张孟喜[2] 赵慧玲 Li Zhanglin;Jiang Pengcheng;He Guojun;Zhang Mengxi;Zhao Huiling(Shanghai Tunnel Engineering Co.,Ltd.,Shanghai,200032,P.R.China;School of Mechanics and Engineering Science,Shanghai University,Shanghai,200444,P.R.China)

机构地区：[1]上海隧道工程有限公司,上海200032 [2]上海大学力学与工程科学学院,上海200444

出　　处：《地下空间与工程学报》2025年第1期225-235,共11页Chinese Journal of Underground Space and Engineering

基　　金：国家自然科学基金(52078286);上海隧道工程有限公司科研项目(2020-SK-13)。

摘　　要：为分析大直径盾构穿越断层破碎带对开挖面稳定的影响规律,总结了开挖面在盾构穿越断层破碎带前后的失稳特征,改进了包含断层破碎带的复合地层开挖面楔形体-棱柱体模型,推导了考虑断层破碎带影响的“上软下硬”复合地层开挖面极限支护力理论计算公式。结合工程实例进行了相关理论计算,揭示了大直径盾构穿越含断层破碎带前后交界面的过程中含复合地层的开挖面极限支护力受断层破碎带倾角影响的变化规律。结果表明:通过对黏聚力和内摩擦角的参数敏感性分析,开挖面范围内各土层黏聚力和内摩擦角的增大均能有效地减小极限支护力的大小,验证了改进的极限平衡分析模型的可靠性;开挖面极限支护力随着断层破碎带倾角的递增表现出增大的趋势;对应于破碎带倾角60°、70°、80°、90°,前交界面的临界长度范围始末造成了极限支护力分别增加88.4%、91.2%、92.9%、93.6%,后交界面的临界长度范围始末造成了极限支护力分别减小51.1%、53.1%、55.6%、56.3%。研究成果对大直径盾构穿越含断层破碎带的复合地层的施工控制措施的调整具有参考价值。In order to analyze the influence of large-diameter shield tunnel crossing the fault fracture zone on the stability of the excavation face,the instability characteristics of the excavation face before and after the shield tunnel crossing the fault fracture zone are summarized.The wedge-prism model of the excavation face of the composite stratum including the fault fracture zone is improved,and the theoretical calculation formula of the limit support pressure of the excavation face of the composite stratum defined as"soft on top and hard on bottom"is deduced by considering the influence of the fault fracture zone.Combined with engineering examples,this paper carries out relevant theoretical calculations,and reveals the changing rule of the limit support pressure influenced by inclined angle of fault fracture zone during the process of large-diameter shield tunnel crossing the front and back interfaces of the fault-bearing fractured zone.The results show that:Through sensitivity analysis of the parameters of cohesion and internal friction angle,it was found that increasing the cohesion and internal friction angle of each soil layer within the excavation surface can effectively reduce the size of the limit support pressure,which effectively verifies the reliability of the improved limit equilibrium analysis model.The limit support pressure of the excavation surface shows angles of the fracture zone of 60°,70°,80°,and 90°,the beginning and end of the critical length range of the front interface respectively resulted in an increase of 88.4%,91.2%,92.9%,and 93.6%in the limit support pressure,and that of the rear interface resulted in a decrease of 51.1%,53.1%,55.6%,and 56.3%in the limit support pressure respectively.The researchresults have a certain reference value for the adjustment of the controlled construction measures for large-diameter shield crossing composite formations containing fault fractured zones.

关 键 词：大直径盾构 极限平衡分析模型 断层破碎带倾角 破碎带交界面 极限支护力 

分 类 号：U451[建筑科学—桥梁与隧道工程]