高烈度艰险山区跨断层隧道减震层减震技术研究

Damping Shake Technology of the Shock Absorption Layer of Fault-crossing Tunnels in a Dangerous Mountainous Area with High-Intensity Earthquakes

为进一步提高高烈度艰险山区跨断层隧道的减震性能,依托丽香铁路蒙古哨隧道工程,利用有限差分数值软件FLAC^(3D)对跨断层隧道施设减震层不同模式的减震效果进行研究。研究结果表明:减震层施设于初支与围岩间,其横向位移减小4.17%、竖向位移减小14.32%、最大主应力减小47.89%、最小主应力减小25.93%、最大剪切应力减小27.74%、最小安全系数提高34.62%～59.40%;减震层施设于初支与二衬间,其横向位移减小3.72%、竖向位移减小7.73%、最大主应力减小16.11%、最小主应力减小20.21%、最大剪切应力减小20.73%、最小安全系数提高0.04%～28.38%;减震层施设于初支与围岩间的减震效果优于施设于初支与二衬间。研究成果对于跨断层隧道的减震设计及减震技术有着重要的意义。

To improve the damping performance of fault-crossing tunnels in dangerous mountainous areas with high-intensity earthquakes,based on the Menggushao tunnel engineering of Lixiang Railway,this paper used the finite differential software FLAC 3D to study the damping effect of the shock absorption layer of the fault-crossing tunnel under different setting modes.Results showed that if the shock absorption layer is set between the primary support and surrounding rock,the lateral displacement,the vertical displacement,the maximum principal stress,the minimum principal stress,and the maximum shear stress will decrease by 4.17%,14.32%, 47.89%,25.93%,and 27.74%,respectively,and the minimum safety factor will increase by 34.62%- 59.40%;If the shock absorption layer is set between the primary support and secondary lining,the lateral displacement,the vertical displacement,the maximum principal stress,the minimum principal stress,and the maximum shear stress will decrease by 3.72%,7.73%,16.11%,20.21%,and 20.73%,respectively,and the minimum safety factor will increase by 0.04%-28.38%.The damping effect of the shock absorption layer,set between the primary support and surrounding rock,is better than that set between the primary support and secondary lining.This study is of great significance for the damping design and damping shake technology of fault-crossing tunnels.