多工法组合下隧道开挖对地层的扰动影响分析

Analysis of Disturbance Influence of Tunnel Excavation on Stratum under the Combination of Multiple Construction Methods

文章运用有限元方法,模拟了台阶法、CD法和CRD法等组合工法应用于隧道开挖的工况,分析了不同工法组合开挖下隧道施工对地层的扰动影响。结果表明:工法纵向组合施工影响程度大于并行组合施工影响程度;工法纵向组合施工时,从小断面过渡向大断面施工比大断面过渡向小断面施工地层沉降位移要稍小;并行组合施工时,地层沉降值近似于两隧洞开挖引起的地层沉降值在对应位置的叠加,以大洞作为隧道开挖先行洞有利于控制施工扰动变形。

In this paper, the finite element method is used to simulate the working conditions of the application of combined construction methods such as benching tunneling method, CD method and CRD method in tunnel excavation, and the disturbance influence of tunnel construction on stratum under different combined construction methods is analyzed. The results show that the influence degree of longitudinal combined construction is greater than that of parallel combined construction. In longitudinal combined construction, the stratum settlement displacement of transition from small section to large section is smaller than that of transition from large section to small section construction.During the parallel combined construction, the stratum settlement value is similar to the superposition of the stratum settlement value caused by the excavation of the two tunnels at the corresponding position. Taking the large tunnel as the first tunnel of tunnel excavation is beneficial to control the construction disturbance deformation.