Numerical Analysis on Mutual Influences in Urban Subway Double-Hole Parallel Tunneling

mutual influence of the double-hole tunnel evacuation of urban subways is one of key issues involving the subway construction safety. The asynchronous one-direction evacuation, synchronous one-direction evacuation and opposite evacuation methods are frequently used in double-hole tunnel evacuation. This paper establishes three-dimensional numerical model by using the finite element analysis software MIDAS/GTS v2.01 and mainly studies the mutual influences of tunnels in the asynchronous one-direction evacuation and synchronous one-direction evacuation. The following conclusions are concluded based on computing. The preliminary conclusion is that the influential distance between the evacuation section of two tunnels is 3D (D is the tunnel diameter) in the parallel tunnel asynchronous evacuation, namely when the lagging distance is more than 3D, the lagging evacuation tunnel will not affect the advance evacuation tunnel section. The asynchronous evacuation of the vertical distribution tunnel is divided into the up tunnel first evacuation and down tunnel first evacuation. For up tunnel first evacuation, the influence range of the lagging distance is 5D. For down tunnel first evacuation, the influence range of the lagging distance is 1D. For up tunnel first evacuation on the slope, the influence range of the lagging distance is 5D. On the whole, the influence of two tunnels in up tunnel first evacuation is bigger than it in down tunnel first evacuation. The numerical analysis results will have important theoretical meaning and application value for building technology of the parallel double-hole tunnel.

This creative work has been published under the Creative Commons Attribution 4.0 International (CC-BY 4.0) license which allows copying, and redistribution as well as adaptation of the original work provided appropriate credit is given to the original author and the conditions of the license are met.