Study on the Impact of Composite Stratum Pile Foundation Penetration on Existing Tunnels
Most studies on the impact of pile foundation penetration construction on existing tunnels primarily consider the effects of soil extrusion on the surrounding soil and adjacent buildings,often focusing on a single stratum.However,the impact of pile construction on nearby existing tunnels in composite geological conditions is more complex.Based on the composite strata conditions of a site in Qingdao with soft upper layers and hard lower layers,three methods:circular hole expansion theory,indoor model testing,and ABAQUS numerical simulation-were employed to analyze the effect of pile foundation penetration on the existing tunnel.The results show that the findings from all three methods are highly consistent.The farther the distance from the pile foundation,the smaller the horizontal displacement and radial stress on the surface,both of which exhibit an exponential decay pattern.The distribution of additional bending moments in the circumferential direction of the tunnel during pile driving shows a trend where the top and bottom of the tunnel move away from the center point,while the left and right ends approach the center point.The top and bottom of the tunnel bend outward,and the left and right sides bend inward.The phenomenon becomes more pronounced as the distance between the pile and tunnel decreases.The arch waist of the tunnel structure tends to move away from the pile foundation in the horizontal direction,while the arch crown shows an upward displacement in the vertical direction.As the distance between the pile and tunnel increases,both horizontal and vertical displacements decreases significantly.The influence range of single pile sinking on tunnel displacement is from 0 to 1.5D(where D is the diameter of the tunnel).
国家科技期刊平台
NSTL
万方数据
