微型桩加固公路路肩数值模拟分析

Numerical Simulation Analysis of Road Shoulder Strengthened by Micro-piles

为研究重型汽车运行过程中引起的振动荷载对路基稳定性的影响,采用有限差计算软件建立了重型汽车运行条件下高级公路路基三维仿真模型,重点对其动力响应及桩的支护效应进行分析.结果表明:随着测点与振源水平距离的增加,测点峰值加速度逐渐减小;与无微型桩加固路堤相比,路肩用微型桩加固后,地表各测点的竖向振动峰值加速度衰减的相对较快;当桩径和桩长一定时,随着桩间距的增大,路基面上各测点的竖向位移也相应增大,且重车荷载激励作用处竖向位移最大;同时,随着测点与振源水平距离的增加,路基表面竖向位移逐渐减小.当桩径4m,桩长3m时,桩身最大动弯矩基本位于桩顶以下2m处,并且达到最大动弯矩后,微型桩桩身动弯矩随埋深的增加而逐渐减小.

In order to study the dynamic response of the vibration load caused by the heavy-duty vehicles operation to the subgrade,a three-dimensional simulation model of the advanced highway subgrade under heavy-duty vehicles operating conditions was established by using the finite difference calculation software.The dynamic response and the support effect of the piles were analyzed.The results show that with the increase of the horizontal distance between the measuring point and the vibration source,the peak acceleration gradually decreases.Compared with the roadbed without the micro-piles reinforcement,the vertical vibration acceleration of the ground surface is attenuated after the road shoulder is reinforced with the micro-piles.When the pile’s diameter and the pile’s length are fixed,as the pile’s spacing increases,the vertical displacement of each measuring point on the subgrade surface increases correspondingly,and the vertical displacement of the heavy vehicle load excitation action is maximum.As the horizontal distance from the vibration source increases,the vertical displacement of the subgrade surface gradually decreases.When the pile’s diameter is 4m and the pile’s length is 3m,the maximum bending moment of the pile’s body is basically located 2m below the pile top,and after reaching the maximum bending moment,the bending moment of the micro pile’s body gradually decreases with the increase of the buried depth.