盾构施工对不同刚度桩体影响的数值分析

针对苏州轻轨一号线盾构隧道的施工情况,采用三维有限元数值模型,研究了盾构施工对不同刚度桩体的影响。计算结果表明：当盾构施工时,不同刚度桩体均偏向隧道移动,在隧道轴线处的横向位移均为最大。桩身横向位移最大值、竖向位移随桩体刚度增大而变小,桩身轴力、弯矩则随桩体刚度增大而逐渐增大,桩身最大负弯矩均出现在隧道轴线位置处。在盾构正下方穿越单桩过程中,桩身沿隧道轴向位移近似为一条直线。当桩体弹性模量为0.5 GPa时,柱顶和桩底处竖向位移相差较大;当桩体弹性模量大于0.5 GPa时,桩身竖向位移急剧增大。桩身轴力沿桩身两端大、中间小。桩身弯矩随桩体弹性模量增大而明显增大。

Numeric Analysis of the Influence of Shield Driving on Single Pile with Variable Stiffness

The numerical analysis is carried out to study the influence adjacent sheild tunnel construction on light-railway line 1 in Suzhou on the single pile with variable stiffness,The results of numerical simulationing show that the pile move toward the tunnel,the lateral deformation of the pile is greatest in the tunnel center.The pile lateral and vertical deformation becomes smaller with the pile stiffness increasing.Pile axial force and bending moment becomes greater with the increasing of the pile stiffness,the pile greatest negative bending moment is at the tunnel axis.When shield driving is below the pile,the deformation along tunnel axis is approximately a line.When pile elastic modulus is 0.5 GPa,the vertical deformation difference between pile top and bottom is greater;when pile elastic modulus is greater than 0.5 GPa the vertical deformation increases quickly.The pile axial force is great at pile top and bottom,but small at the middle. Pile bending moment becomes greater with pile stiffness increasing.