The pedestrian cross passage is an important passage set between two long tunnels for personnel escape.It is usually constructed by mining method,mechanical method or freezing method,which is difficult and risky.Taking the pedestrian cross passage of Qilianshan Road large section rectangular pipe jacking tunnel in Shanghai as the background project,the design scheme of deep foundation pit support constructed by conventional open excavation method is studied.The foundation pit support adopts bored piles combined with double row high-pressure jet grouting pile waterproof curtain.MJS isolation reinforcement measures are adopted near the pipe jacking side and also used as water stop.The pit bottom is reinforced with high-pressure jet grouting piles.The GTS NX finite element software is used to simulate the process of foundation pit excavation,and combined with the monitoring data,the influence of foundation pit excavation on pipe jacking is analyzed.The research results show that the enclosure scheme adopted in the project is safe and reliable,and the impact on pipe jacking is controllable.The deformation trend of pipe jacking is to shift to the side of the foundation pit and lift vertically.The horizontal deformation,horizontal and vertical convergence of pipe jacking are small,but the upward deformation is large.It is recommended to take temporary weighting measures.The research results can provide reference for the implementation of similar cross passage projects in the future.
NETL
NSTL
万方数据
