走滑断层错动量大小对铁路隧道结构安全性影响的数值分析

Numerical Analysis on the Effect of Strike-slip Fault Dislocation on the Structural Safety of Railway Tunnels

走滑断层错动容易使穿越活动断裂带的隧道结构遭受严重的破坏。以某铁路隧道穿越某断裂带为工程背景,采用有限差分数值模拟手段,通过分析不同走滑断层错动量下隧道结构的位移、应力和应变,对隧道结构的安全性进行评判。研究表明:走滑断层错动时,除纵向位移外,随着错动量的增加,隧道结构位移越大,且走滑断层错动对在断层区和上盘区域的隧道结构影响最大;在走滑断层错动量>0.6 m后,隧道结构应力受错动量的影响较小,且隧道结构开始破坏,随着错动量增加,破坏范围增大。

Many active faults, especially strike-slip faults, exist along the Sichuan-Tibet Railway, and it is easy for strike-slip fault dislocations to make a tunnel that passes through an active fault zone suffer serious structure damages. Taking a railway tunnel that passes a fault zone as the engineering background, this paper adopts the finite-difference numerical simulation to evaluate the safety of the tunnel structure by analyzing the displacement, stress and strain of the tunnel structure under different strike-slip fault dislocations. The research shows that: with strike-slip fault dislocation, the larger the dislocation is, the greater the displacement of the tunnel structure will be except longitudinal displacement, and the greatest impact the strike-slip fault dislocation will have on the tunnel structure in the fault area and the hanging wall area;after the strike-slip fault dislocation is larger than 0.6 m, the stress on the tunnel structure is less affected by the dislocation;After the strike-slip fault dislocation is greater than 0.6 m, the tunnel structure starts to be damaged, and the damage rage increases with the increase of the dislocation.