大纵坡隧道复合式TBM掘进推力对管片结构的力学响应分析

TBM在进行大纵坡隧道上坡施工时的掘进推力控制不当,易造成管片错台、上浮甚至结构失稳等问题,因而研究大纵坡隧道TBM掘进推力对管片结构的力学响应具有重要的工程意义。本文以重庆轨道交通9号线刘家台始发井～鲤鱼池站区间坡度为3.9%的复合式TBM隧道施工为例,采用基于荷载-结构法的隧道纵向梁-弹簧模型和数值模拟法,分析了复合式TBM在大纵坡隧道掘进过程中不均匀千斤顶推力作用下产生的附加作用力特征,探究了管片结构在附加作用力影响下内力分布规律及其变形的薄弱区域,以及管片结构变形甚至破坏的表征,从而寻求具体控制TBM施工掘进推力的有效措施。研究成果可为规范大纵坡隧道TBM施工中的推力分区和选值提供借鉴。

Mechanical Response Analysis of Tunneling Thrust to Segment Structure in Large Longitudinal Slope Composite TBM Construction

The inappropriate control of TBM driving thrust during the construction of large longitudinal slope tunnels can easily lead to the problems of segment staggering, floating and even structural instability. Therefore, it is of great engineering significance to study the mechanism of TBM driving thrust in large longitudinal slope tunnels. Taking the construction of a composite TBM tunnel with a slope of 3.9% between Liujiatai initial well and Liyuchi Station of Chongqing Rail Transit Line 9 as an example, this paper used the load structure method and numerical simulation method based on the longitudinal beam-spring model of the tunnel to analyze the additional actions of the composite TBM under the uneven jack thrust during the excavation of the tunnel with a large longitudinal slope. With the force characteristics, the distribution law of internal force and the weak area of deformation of segment structure under the influence of additional force, as well as the characterization of deformation and even failure of segment structure are explored, so as to seek effective measures to control the driving thrust of TBM construction. The research results can provide a reference for the regulating thrust zoning and selection in TBM construction of large longitudinal slope tunnel.