粉细砂地层盾构机姿态突变判断方法  

Mutation judgement methods for shield tunneling through fine silt stratum

作　　者：钟小春[1] 易斌斌 竺维彬 刘健美 ZHONG Xiaochun;YI Binbin;ZHU Weibin;LIU Jianmei(College of Civil and Transportation Engineering,Hohai University,Nanjing 210098,China;Guangzhou Metro Group Co.Ltd.,Guangzhou 510220,China;Guangzhou Metro Design&Research Institute Co.Ltd.,Guangzhou 510010,China)

机构地区：[1]河海大学土木与交通学院,江苏南京210098 [2]广州地铁集团有限公司,广东广州510220 [3]广州地铁设计研究院股份有限公司,广东广州510010

出　　处：《华中科技大学学报（自然科学版）》2023年第7期42-47,共6页Journal of Huazhong University of Science and Technology(Natural Science Edition)

基　　金：国家自然科学基金面上项目(52178387,51678217).

摘　　要：基于某地铁安全事故,采用有限元软件Midas GTS,建立盾构姿态有限元法(FEM)模型,探讨由盾尾渗漏引起的尾盾底部掏空和由开挖面坍塌引起的前盾顶部空洞对于盾构姿态的影响.结果表明:盾尾渗漏使盾尾壳体失去了周围地基的有效约束作用,是盾构机姿态发生突变的主要因素,而开挖面坍塌则加速了盾构机姿态发展过程;盾构姿态变化有线性缓慢增长和非线性快速增长突变两个阶段,盾构机姿态突变时盾尾掏空范围在3.5 m左右;根据地质条件和盾构掘进工程风险确定盾构姿态控制的盾尾允许下沉值,再根据拟合的盾尾下沉量与前盾顶部空洞和尾盾掏空范围的曲面函数,可获得盾构机姿态突变临界发生条件即前盾顶部空洞和尾盾掏空范围的相关曲线,位于该曲线的下方区域认为是稳定安全的,位于该曲线上方区域则认为是不稳定不安全的.Based on a subway safety accident,a finite element software Midas GTS was used to establish a shield posture finite element modeling(FEM)model,the impact of the bottom hollowing of the tail shield caused by leakage at the shield tail and the top cavity of the front shield caused by excavation surface collapse on the shield posture was explored.The results showed that the leakage of shield tail causes the shield tail shell to lose the effective constraint of the surrounding foundation,which is the main factor for the sudden change of shield machine attitude.Meanwhile,the collapse of excavation surface accelerates the change of shield attitude.There are two stages in the change of shield attitude,such as linear slow growth stage and nonlinear rapid growth stage.The hollowing range in the bottom of shield tail is about 3.5 m when attitude of shield machine mutates suddenly.The allowable subsidence of the shield tail under the control of shield attitude is determined according to the geological conditions and the engineering risk of shield tunneling,and then the critical occurrence conditions of shield attitude mutation is obtained by fitting the surface function of shield tail subsidence with the cavity at the top of the shield head and the hollow in the bottom of shield tail.The area below the curve of the relationship of the shield tail subsidence between the cavity at the top of the shield head and the hollow in the bottom of shield tail is considered to be stable and safe,and the area above the curve is considered to be unstable and unsafe.

关 键 词：细粉砂地层 盾构姿态 姿态突变 盾尾渗漏 判断方法 

分 类 号：TU94[建筑科学—建筑技术科学]