牛湖山大断面公路隧道稳定性数值分析

Numerical analysis of the stability of Niuhushan large section highway tunnel

牛湖山隧道位于惠深高速公路,为双向六车道分离式隧道,设计拟定开挖方式为双侧壁导坑.为了验证设计的开挖方式是否合理可行,选取隧道右线洞口段一典型横断面,运用FLAC2D建立数值计算模型,分析了隧道开挖且支护后最终的围岩位移、应力以及初期支护内力,确定了双侧壁导坑是适合该类地质条件下大断面隧道的开挖施工方法,为以后类似的大跨度隧道的设计和施工提供了参考.

Niuhushan Tunnel which is located in the Huishen highway is three lanes in each of the two separated holes on both sides. The method of excavating is designed by double-side-waU drift. In order to prove whether the excavation way is rational or feasible, a representative section is chosen as an example and a numerical model is built by using of FLAC2D. From the analysis of the displacement of the surrounding rock, the stress of the surrounding rock and the internal forces of the supporting structures in the tunnel, it is confirmed that excavating by double-side-wall drift is a feasible excavation construction method for the large section tunnel under this kind of geological condition. This can be meaningful to the design and construction of the large section highway tunnel.