考虑多因素影响的双侧壁导坑法施工参数研究

Research on construction parameters of double side heading method considering multiple factors

针对双侧壁导坑法施工参数优化研究通常采用单因素分析存在一定片面性的问题,以重庆轨道交通9号线(地铁)一期工程五里店地铁车站隧道为研究背景,选取临时支撑半径、中岩墙厚度、开挖进尺3个施工参数作为影响因素,以拱顶最大竖向位移和边墙最大水平位移作为计算指标,应用FLAC^(3D)有限差分软件进行数值模拟分析。研究结果表明:通过多因素分析得出的施工参数最优组合为临时支撑半径23.0 m、中岩墙厚度9.0 m、开挖进尺0.75 m;以多因素分析结果为基础的回归法反分析得出的施工参数最优组合为临时支撑半径24.0 m、中岩墙厚度8.0 m、开挖进尺0.8 m;通过对比3组最优施工参数组合的拱顶最大竖向位移和边墙最大水平位移,得出以多因素分析结果为基础采用回归法反分析得到的施工参数更具优越性。

The construction parameter optimization research of the double-side heading method usually adopts single factor analysis,which has certain limitations.The research took the Wulidian Subway Station Tunnel Project as the research background,which is one of the first phase projects of Chongqing Rail Transit Line 9.The radius of temporary support,the thickness of the middle rock wall,and the excavation footage were used as influencing factors,and the maximum vertical displacement of the vault and the maximum horizontal displacement of the side wall were used as the calculation indicators.The finite difference software FLAC^(3D) was used to carry out multi-factor numerical simulation analysis.The results showed that the optimal combination of construction parameters obtained by multi factor analysis were that temporary support radius was 23.0 m,medium rock wall thickness was 9.0 m and excavation footage was 0.75 m;the optimal combination obtained by the back analysis of regression method based on the results of multi factor analysis that temporary support radius was 24.0 m,medium rock wall thickness was 8.0 m and excavation footage was 0.8 m.By comparing the maximum vertical displacement of the arch crown and the maximum horizontal displacement of the side wall of the three groups of optimal construction parameters,it was concluded that the construction parameters obtained by regression back analysis based on the results of multi factor analysis have more advantages.