Study On Adjacent Partition And Load Calculation Method Of Subway Tunnel Construction In Horizontal Layered Rock Stratum

The development and utilization of underground space has become a new direction of contemporary urban development.Due to various reasons,small clear distance tunnels are more and more appearing in cities,and their proximity forms are becoming more and more,and the distance between adjacent tunnels is getting smaller and smaller.China is vast and widely distributed in stratified rock strata,and it will inevitably involve stratified rock formations in the process of subway construction.It is of great significance for the development of subway in our country to carry out the research on the adjacent partition and load calculation method of subway tunnel construction in horizontal layered rock formation.This paper,based on the section tunnel of line five of Chongqing rail transit,mainly carried out the following research.(1)Under the horizontal stratified rock stratum,based on the determination of the peak velocity of the particle,the rock,structure surface,explosive and air model are established by ANSYS/LS-DYNA software,the damage range of the tunnel excavation by drilling and blasting is obtained.Based on the Griffith strength criterion,the damage scope of TBM tunnel excavation is obtained by using FLAC3 D software.Referring to the measured values of damage zone parameters of similar engineering,the physical and mechanical parameters of surrounding rock in fractured zone and fractured area are determined.(2)Based on the damage of the surrounding rock and based on the Mole Kulun yield criterion,four adjacent subareas of the deep and shallow buried strata of the horizontal layered rock are determined by the existing drilling and blasting tunnel and the TBM tunnel.The superposition of near impact under multi hole tunnels is studied,and the influence zoning under multi hole conditions is determined.(3)In this paper,the cohesive force,friction angle and thickness of horizontal stratiform rock are corrected by summarizing the previous conclusions,and the calculation method of subway interval tunnel load on the horizontal layered rock stratum based on the adjacent zoning is given.(4)Based on the damage of surrounding rock,the influence of the dynamic load of subway train on the soil layer and the new tunnel is studied under the horizontal stratiformrock stratum.