Safety Construction Technologies for Large-Cross-Section Tunnel in Steep and Weak Geological Strata During Exit Tunneling
The Qingfeng Tunnel,part of the Kang-Yu High-Speed Railway,is situated on a steep slope at its outlet,necessita-ting an exit tunnelling approach from within tunnel outward.Based on the topographical and engineering geological characteristics of the tunnel exit section,a construction scheme employing the three-step method with advanced support provided by small grouting pipes was developed.Three-dimensional numerical simulations were conducted to analyze the deformation and stress conditions of the support system under various construction scenarios,thereby verifying the feasibility of the exit tunneling scheme.Monitoring results of vault settlement and steel frame stresses during the exit tunneling process demonstrate that the adopted construction method effectively ensures the safety and stability of the Qingfeng Tunnel during its exit phase.
万方数据
维普
