下穿重载公路隧道变形模拟分析

Simulated Analysis of the Deformation of the Tunnel Undercrossing a Heavy-Loaded Highway

鹰窝山隧道浅埋段下穿以运煤车辆为主的锦赤公路。车辆超载现象严重,隧道围岩为全风化花岗岩,围岩稳定性极差。在隧道施工过程中必须保证公路正常运营,施工难度大。基于现场试验获得了围岩物理力学参数,采用数值方法对施工方案进行了三维数值模拟,计算结果和隧道变形结果均表明,所采用下穿公路的隧道施工方案是合理的,保证了隧道施工安全和下穿公路的安全。

The shallow section of the Yingwoshan Tunnel under-crosses the Jinzhou-Chifeng Heavy-loaded Highway with the main traffic of coal-transporting trucks.As the trucks are mostly overloaded,and the surrounding rock of the tunnel is of completely weathered granite,the stability of the surrounding rock is extremely poor.Since the normal operation of the highway has to be ensured during the construction of the tunnel,it is very difficult to perform the construction.Upon the basis of the in-situtests from which the physical and mechanical parameters are obtained,a three-dimensional numerical simulation model is established to simulate the excavation scheme for the tunnel.Both the calculated result and the field-monitored result of the deformation of the tunnel show that the adopted construction scheme is suitable and both the safe construction of the tunnel and the safe operation of the Jinzhou-Chifeng Highway can be ensured.