哈尔滨城市地铁大断面隧道施工稳定性分析

Analysis on construction stability of large section tunnel of Harbin City Metro

以哈尔滨城市地铁隧道施工为工程背景,基于区域地质条件,构建了有限元数值模型,分析双侧壁导坑法和交叉中隔墙法(CRD法)施工过程围岩变形和受力变化规律,结合现场监测手段,分析大断面隧道的施工方法及其稳定性。结果表明:弱围岩区域隧道施工,无论是隧道变形总量还是施工引起的地表沉降,双侧壁导坑法均比CRD法有优势,且应力变化、最大应力值均较小,围岩主应力分布也较均匀,而CRD法仅在隧道变形收敛有优势;通过分析现场监测数据可知,施工的先后顺序会影响变形,后开挖的断面会影响先开挖的,使用双侧壁导坑法也能够很好的满足施工的变形控制标准。

Based on the engineering background of Harbin Metro Tunnel and regional geological conditions,this paper constructs a regional numerical model,analyses the deformation and the stress variation of surrounding rock during the construction in double side drift method and Cross Diaphragm(CRD) method. It also analyses the construction method and stability of large cross-section tunnel combining with on-site monitoring means. The results show that the tunnel construction in the weak surrounding rock area,whether it is the total deformation of tunnel or the ground settlement caused by construction,the double side drift method has advantages over the CRD method,and the stress change and maximum stress value are smaller,the principal stress distribution of surrounding rock is uniform. The CRD method only has an advantages in tunnel deformation convergence;By analyzing the field monitoring data,it can be seen that the sequence of construction affects the deformation,after the excavation of the section has an effect on the first excavation. The double side drift method can meet the deformation control standard of the construction.