Study of Mechanical Behavior During Construction of Large-span Neighborhood Tunnel

For the large-span neighborhood tunnel in weak surrounding rock,because of the poor engineering properties of the weak rock and more courses in tunnel construction,the stability of surrounding rock of the tunnel is significantly affected by the disturbance from the constructing process,and directly influenced by the clear spacing of tunnel,so it is worth analyzing the effect of the clear-distance to the construction mechanical behavior neighborhood tunnel for with large span in weak surrounding rock,which carries practical significance on the certainty of the minimum spacing.With the illustration of the large span and minimum spacing West Bank Tunnel,taking V-grade rock surrounding tunnel as the study object,this essay analyzes the influence of different clear distances of tunnels on the stress,deformation and distribution of plastic zone of tunnel surrounding rock by ANSYS numerical simulation.It also draws the conclusion that the minimum spacing of this kind of tunnel is no less than 0.45times of single-tunnel span,which is of some guiding significance on the selection of the clear distance in large-span neighborhood tunnel in weak surrounding rock.