Numerical simulation of preliminary lining of large section crossing tunnels constructed with PBA method

Based on the North Gongti Road Station of Beijing Metro line 10, the construction steps and mechanism of large section crossing tunnels constructed with the pile-beam-arch(PBA) tunneling method were described.The behaviors of preliminary lining of tunnels was analyzed using FEM.The results showed that the preliminary support system of tunnels worked interactively restricted within certain area and the tunnel crown settlement decreased from junction area to both sides.With the influence of latterly constructed arch, the tunnel crown of the main tunnel jointed with the vertical tunnel manifested tensile state.The folding beam settled in the tunnel junction could diffuse the pressure of upper arch and weaken the stress concentration.The results could be a reference to design and construction of crossing tunnels constructed with PBA tunneling method.