부산대학교 도서관

To ensure the safe construction of the tunnel through the fault composite stratum, relying on a domestic tunnel project, taking the surrounding rock of the tunnel in the fault zone as the research object, the three-dimensional tunnel model is established by the finite element software and combined with the on-site electronic equipment monitoring, and the mechanical response law of the tunnel structure and surrounding rock is studied. The numerical results show that the deformation laws of tunnel crown and arch waist in normal stratum and fault zone are the same. The overall deformation value of tunnel in fault section is greater than that in normal section, and the maximum deformation value appears at the rock stratum interface, which is 9.04mm and 3.49mm respectively; The tunnel uplift value is smaller at the interface than at both sides, and the maximum value appears in the fault section, which is 7.42mm; The surrounding rock within one time of tunnel excavation diameter is affected, and the deformation gradually increases from the depth of rock stratum to the vault. The existence of broken rock mass in fault zone will aggravate the deformation within this range. The maximum stress value of tunnel lining is 17.5MPa at the arch waist, 11.0MPa at the arch crown and 7.69Mpa at the arch bottom, all of which occur at the junction of fault zone and normal section rock stratum. The stress of arch crown and arch bottom lining decreases sharply from the interface along both sides, while the trend of arch waist decrease is relatively slow. The maximum lining pressure in the normal section appears at the arch waist, the maximum pressure in the fault zone appears between the arch waist and the arch shoulder, and the minimum lining pressure in both sections appears at the arch bottom. The field monitoring data show that the tunnel deformation gradually tends to be flat with time. The final change value is 0.6mm after 16 days, and no obvious deformation is detected after 24 days. The final monitoring results are consistent with the numerical simulation data. The research results provide a reference for the construction of similar composite stratum tunnels.