Analysis on the Influence of Surface Buried Depth on the Deformation of Long-span Metro Tunnels
Taking the shallow buried long-span subway tunnel with medium rock column as the background,the finite element numeri-cal analysis method is used to analyze the change characteristics of vertical and horizontal displacement of subway tunnel under differ-ent buried depths.The following conclusions are drawn:(1)With the increase of surface buried depth,the cumulative values of surface settlement,vault settlement and peripheral convergence will gradually increase.There is pressure arch effect in underground engineering construction,when the surface buried depth is greater than 1.5D(D is the tunnel excavation span),the relative change rate of displace-ment decreases significantly.(2)In the range of 1D～2D buried depth,the maximum values of surface center settlement,vault settle-ment and peripheral convergence increased from-7.13,-11.28,3.57 mm to-12.73,-22.3,5.64 mm,respectively,with a rela-tive increase of 78.54%,97.7%and 57.98%.The vertical displacement is most affected by the depth of the ground.(3)The relative change rate of 10%is used as the basis for the stability of displacement and deformation,so the second lining has an obvious effect on stabilizing the deformation in the cavity.The change of burial depth has no effect on the relative change rate of displacement around the hole.
subway tunnelnumerical simulationreserved middle rock pillar methodland subsidencehole surrounding deformation
NETL
NSTL
万方数据
维普
