不同开挖工法对公路隧道稳定性的影响分析

Analysis of Influence of Different Excavation Methods on Stability of Highway Tunnel

湖北省的某隧道长为1 500 m,位于软弱围岩中。为了研究不同开挖工法对其稳定性的影响,基于该隧道地质资料,利用有限元软件FLAC3D分别模拟了CD法、CRD法、台阶法和双侧壁导坑法4种工法。在考虑渗流作用的影响下,对各工法施工引起的最终沉降值、地表沉降值、拱顶沉降值及塑性区分布规律进行了研究,最后通过对比各工法所对应上述指标,综合考虑施工安全及经济性等因素,推荐双侧壁导坑法作为该隧道的施工方法。

The tunnel in Hubei is 1 500 m long and it is located in the soft surrounding rock.In order to study the influence of the excavation method,this paper uses the finite element software FLAC3D to simulate the CD method,CRD method,step method and Four kinds of side wall guide pit method.Under the influence of seepage,the final settlement value,surface settlement value,vault settlement value and plastic zone distribution law caused by each construction method were studied.Finally,the construction safety was considered by comparing the above-mentioned indicators corresponding to each construction method.For economic factors and other factors,the double-wall guide pit method is recommended as the construction method of the tunnel.