高地应力断层带超大断面隧道施工设计

Construction Design for Super-large Section Tunnels in Fault Zone with High Geotress

柿子园隧道合分修过渡段开挖面积达345 m^(2),且该段穿越王家坪1号断层,存在高地应力。为解决穿越高地应力断层带的超大断面隧道面临的初期支护变形、二次衬砌开裂等修建难题,根据地质情况,采用数值模拟和工程类比相结合的方法,对隧道断面形状进行比选,确定结构支护参数,并提出一种新的施工方法。实践表明,该工法能解决柿子园隧道施工难度大、变形不易控制等问题。

The excavation area of the transition section of combined and separate construction in the Shiziyuan Tunnel is 345 m^(2),and this transition section passes through Wangjiaping No.1 fault with high geostress.In order to solve construction problems faced by super-large section tunnel crossing the fault zone with high geostress,such as primary support deformation and secondary lining cracking,a combination of numerical simulation and engineering analogy is used based on geological conditions to compare and select the tunnel section form,determine structural support parameters,and propose a new construction method.Practice shows that this construction method can solve problems such as difficulty in tunnel construction and difficulty in controlling deformation.