木寨岭隧道地应力特征及对隧道变形影响的研究

摘要

为解决高地应力引起的隧道施工大变形,采用有限元多元回归分析和神经网络对有限原位地应力测试结果的地应力值进行拓展,分析整座隧道绝大部分地段的侧压力系数均大于1以及隧道轴线方向的地应力最大和构造应力为主的地应力场特征.结合木寨岭隧道炭质板岩情况,通过FLCD数值计算,得出高地应力对隧道采用三台阶法施工变形的水平影响范围为2～3倍洞径,并且隧道中台阶位置是应力释放的主要阶段,也是引起变形的主要阶段,为后续施工提供一定的指导.%The ground stress values measured in the limited in-situ ground stress tests are expanded by means of FE multiple element regression analysis and neural network.The characteristics of the ground stress field are analyzed.The conditions of carbonaceous slate of Muzhailing tunnel is analyzed by means of FLCD numerical calculation.Conclusions drawn are as follows:1) The horizontal influencing range of the high ground stress on the deformation of tunnel constructed by 3-bench excavation method is about 2 to 3 times of the tunnel diameter.2) The middle bench,is the main stressreleasing phase and also the main deformation-inducing phase.