Simulation Of Factors Affecting Stability Of Intersect Tunnel By Tunnel Construction

Aiming at solving engineering stability problems of intersect tunnel by tunnel construction, the basic theory of stress field in tunnel construction, failure mechanism of wall rock and its classification standards, affecting judgment criterion and partition standard. Based on ABAQUS specific finite element software, stability influence of double tunnels excavation construction at the highway from Conghua to Dongguan was obtained from simulation analyses. Main research contents are as follows:(1) Based on geological data of engineering areas and geological conditions of tunnel cross section, stability assessment and classification of wall rock were conducted. Physical and mechanical parameters of tunnel and wall rock were determined.(2) Based on the actual engineering conditions, a three-dimensional finite element model by ABAQUS software was developed. Simulations on different parameters of wall rock were conducted. It was concluded that different parameters of wall rock influenced the calculation results of tunnel lining.(3) Simulations of the left and right road tunnel excavation process were performed. Deformation and stress of wall rock were obtained. Incidental tensile stress and its regularities of distribution caused by excavation of the watering cross section were gained. The location of maximum tension and compressive stress was found respectively.(4) The final deformation of tunnel wall rock in cross section was gained by calculations. The locations of maximum tension and crushing stress were found. Comparison between the maximum tension and compressive stress results and the tensile compressive strength of watering tunnel lining was conducted to determine its stability.(5) Considering excavation section by section, the actual excavation process of supporting after excavation immediately of tunnel was simulated. The results of deformation and stress of wall rock by excavation section by section were acquired. The typical section and main feature points were selected. Each point stress and deformation curve along with excavation steps was gained to summary the regularities of stress and deformation.(6) According to the results of the finite element numerical structure analyses and safety evaluations of watering tunnel, some specific advices were given in this study.