地铁旁穿桥梁桩基础数值模拟

Numerical Analysis of Tunnel Running through Bridge Pile Foundation

以大连地铁旁穿高架桥桩基础为背景，利用有限元软件 MIDAS/GTS 建立了三维数值模型，研究了隧道施工过程桩的内力和位移的变化规律。分析结果表明：桩顶竖向沉降值最大；桩的水平位移先增大，后减小，由正值逐渐变为负值；隧道周围土体的损失使桩周土层发生沉降，产生负摩阻力，使桩的轴力在10~15 m 处变化很大；沉降槽内，地表隧道中线处沉降值最大，离中心越远其值越小。

Based on the background of Dalian subway running through bridge pile foundation, a 3d numerical model is built by the finite element software MIDAS/GTS in order to research the laws of the internal force and the displacement of the pile and soil during the Construction process. The outcome reflects that the sedimentation value of the top of the pile is bigger than others. Because the bigger thrust about the shield machine, the horizontal displacement of the pile is increasing at first and decreasing at last from a positive into a negative. Because of the loss of the soil, the soil beside the pile collapses and causes strong friction force. The surface sedimentation value which is near the central line of the tunnel is bigger than other place. This paper is of good reference roles in the similar underground engineering in Dalian.