节理岩体力学参数对双护盾TBM卡机的影响

Influence of mechanical parameters for jointed rock masses on double-shield TBM jamming

针对双护盾TBM在节理岩体中掘进易于发生卡机等问题,进行了节理岩体力学参数对围岩与TBM接触压力的影响研究.首先,采用正交试验进行试验方案设计,利用离散元软件3DEC建立TBM在节理岩体中动态掘进模型;然后以围岩与TBM接触压力Q为指标采用3DEC进行数值模拟计算,并利用极差和方差分析研究了岩石力学参数(弹性模量、泊松比、黏聚力、内摩擦角)和节理力学参数(法向刚度、剪切刚度、节理黏聚力、节理内摩擦角)对围岩与TBM接触压力的影响;最后以正峰寺隧道为例进行算例分析.结果表明:节理岩体力学参数中弹性模量对接触压力影响极其显著,法向刚度影响非常显著,剪切刚度和黏聚力影响显著,其余参数仅是有影响但不显著.

To address the problem that double-shield TBMs are prone to jamming in jointed rock masses,the influence of mechanical parameters for jointed rock masses on contact pressure between surrounding rock and TBM is studied.First,the orthogonal test is conducted to design the test scheme,and the dynamic excavation model of TBM in jointed rock mass is established by using the discrete element software 3DEC.Then,3DEC is used for numerical simulation with the contact pressure Q between surrounding rock and TBM as the index.And the effects of rock mechanical parameters(including elastic modulus,Poisson’s ratio,cohesion,internal friction angle)and joint mechanical parameters(including normal stiffness,shear stiffness,joint cohesion,internal friction angle)on the contact pressure between surrounding rock and TBM are studied by range analysis and variance analysis.Finally,a case analysis of Zhengfensi Tunnel is conducted.Results show that the elastic modulus in the mechanical parameters of jointed rock mass has an extremely significant influence on the contact pressure,the influence of normal stiffness is very significant,the influence of shear stiffness and cohesion is significant,and the rest parameters also show influences,which are not significant.