青岛土岩复合地层地铁隧道初支结构参数

为了对青岛地区土岩复合地层地铁隧道初支结构参数进行研究,依托青岛地铁1号线隧道工程,结合正交试验设计方法,采用FLAC3D进行数值模拟,就施工方法、锚杆长度、初支刚度、初支厚度对隧道变形的影响程度、最优初支结构参数及锚杆受力进行了分析.通过现场实测与数值计算对比,验证了数值计算的正确性.结果表明:当隧道位于强风化花岗岩地层中时,施工方法对隧道变形影响最显著,锚杆长度变化引起隧道变形不明显;采用全断面法施工,最优初期支护结构参数组合为锚杆长为2 m、初支厚度为30 cm,混凝土强度等级采用C25;拱顶上方锚杆轴向受压,可能影响锚杆发挥支护作用,主要原因是地层-锚杆间产生的相对滑移变形.研究结论对重庆、厦门等"上软下硬"地区具有一定的理论研究意义和工程使用价值.

Study on the Primary Supporting Structure Parameters of Qingdao Metro Tunnel in Soil-rock Complex Stratum

In order to study the parameters of the initial support structure of the subway tunnel in the soil-rock composite stratum in Qingdao, this paper relies on the Qingdao Metro Line 1 tunnel project, combined with orthogonal test design method, and uses FLAC 3D to carry out numerical simulation. The construction method, anchor length, initial The influence of support stiffness, initial support thickness on tunnel deformation, optimal initial support structure parameters, and anchor forces are analyzed. The comparison between field measurements and numerical calculations verifies the correctness of the numerical calculations. The research shows that when the tunnel is located in the strongly weathered granite stratum, the construction method has the most significant effect on the tunnel deformation, and changes in factors such as the length of the anchor cause the tunnel deformation to be insignificant; the full section method is used for construction, and the optimal initial support structure parameter combination is the anchor The length of the rod is 2 m, the thickness of the initial support is 30 cm, and the concrete strength grade is C25. The axial compression of the anchor above the vault may affect the support of the anchor, mainly due to the relative slip between the ground and the anchor. Shift deformation. The research conclusions have certain theoretical significance and engineering value for "upper and lower hard" areas such as Chongqing and Xiamen.