Research on Action Mechanism in Unsymmetrical Pressure for Middle Wall of Double-Arched Tunnel

Based on the finite element analysis of double-arched tunnel under terrain partial pressure and construction progress partial pressure separately,the deformation and mechanics of middle wall of double-arched tunnel are mainly analyzed in this paper.It is proposed in this paper that the bottom section of middle wall should be the controlled section for the design.Since the flexural and shear at the bottom section is larger than other parts. In addition,it is important to note that the middle wall is represented a remarkable change in the slope 1:1.4 nearby under the terrain partial pressure alone.When the slope is higher than 1: 1.4,the flexural and shear grows significantly.Therefore,it should be avoid exceeding this slope in design.