浅埋暗挖工法转换对地表沉降的影响研究

Study on the Influence of Shallow Subsurface Excavation Method Transformation on Ground Settlement

为研究不同施工方法转换方式下开挖暗挖隧道工程对地层竖向位移的影响,本文以合肥市轨道交通3号线潜山路站—史河路站暗挖区间为工程背景,通过运用三维有限元数值分析软件Midas GTS NX建立数值模型。通过模拟分析不同转换工况对地表沉降的影响并与实际监测结果进行对比,得出如下结论:采用先CRD法后上下台阶法的转换工法施工时,可以有效地控制隧道工程初始段地表沉降。随着初始段采用CRD法施工长度的增加,沉降值逐渐降低,但降低速率逐渐减小直至基本为零。进入上下台阶法施工区段后,沉降值及影响范围进一步加大,且增加速率较快,类似隧道工程应加强该区段的监测布置范围。

For the study of shallow tunnel construction method of different conversion to the influence of surface subsidence,this paper takes Hefei City Rail Transit Line 3 Qianshan Road station to Shihe Road Station Excavation interval as the engineering background,three-dimensional finite element numerical analysis software Midas GTS NX to establish numerical model.Through the simulation analysis of different transformation conditions on the influence of surface subsidence and the actual monitoring results,the following conclusion The surface settlement of the initial section of the tunnel project can be effectively controlled when the first CRD method is used and the conversion method of the upper step method is used.With the increase of the construction length of the CRD method in the initial stage,the settlement value gradually decreases,but the reduction rate decreases gradually until almost zero.After entering the construction section of the upper and lower steps,the settlement value and the influence scope will further increase,and the rate of increase will be faster.Similar to the tunnel engineering,the monitoring layout scope of the section should be strengthened.