走滑断层错动作用下隧道变形的数值分析

Numerical Analysis of Tunnel Deformation under the Slip of Strike-slip Fault

活断层会造成地层错动变形,使得跨断层隧道产生错位、变形甚至坍塌,严重危害隧道的安全。文章以云南某穿越断层的隧道工程为背景,利用FLAC 3D软件建立了跨断层隧道的三维有限差分模型,分析断层倾角、断层倾向、衬砌厚度对隧道变形及应力的影响。结果表明:在走滑断层的影响下,隧道衬砌的水平位移和水平收敛在断层附近急剧变化,且衬砌水平收敛在断层位置达到峰值。衬砌在断层滑移的影响下出现了纵向拉应力,并且断层附近的衬砌出现了明显的应力集中,两侧拱腰位置具有较大的纵向拉应力。断层倾角、衬砌厚度对水平收敛的影响较小,而断层倾向对水平收敛的影响较大。研究成果可为类似的跨断层隧道结构设计提供一定的依据。

Active fault can cause strata deformation and result in deformation and even collapse of fault-crossing tunnels,which seriously endangers the safety of tunnel.In this paper,a three-dimensional finite difference model of a fault-crossing tunnel in Yunnan is established by using software of FLAC 3D.The influence of fault dip angle,fault dip direction angle and lining thickness on tunnel under the influence of fault is analyzed.The results show that:under the influence of strike-slip fault,the horizontal displacement and convergence of tunnel lining change drastically near the fault,and the horizontal convergence of lining reaches the peak at the fault.Under the influence of fault-slip,longitudinal tensile stress occurs in the lining near the fault,and obvious stress concentration occurs in the lining near the fault.The influence of fault dip angle and lining thickness on horizontal convergence is small,while the influence of fault inclination on horizontal convergence is great.The research results of this paper have certain reference significance to solve the problem of deformation of fault-crossing tunnel.