特大桥主塔桩基承载性状及其岸坡稳定性数值分析

Numerical analysis of bearing behavior and bank slope stability of main tower pile foundation of grand bridge

桥梁荷载作用下,岸坡中桥梁主塔桩基承载性状复杂,也使岸坡稳定性发生变化。本文以乌江特大桥遵义岸岸坡和桥墩基础为例,采用有限差分法和强度折减法,对桥墩桩基与地基相互作用及岸坡稳定性进行数值模拟。结果表明:(1)桥梁荷载作用下,岸坡中位移主要发生桩基顶部且集中在靠近河流一侧桩顶上,桩周岩土体中的位移主要发生在靠近河流一侧桩基;(2)桩基位置不同轴力差异明显,表明发挥了群桩效应;(3)岸坡的安全系数在工程完成后为2.59。

Under the load of the bridge, the bearing behavior of the main tower pile foundation in the bank slope is complex, and the stability of the bank slope will change accordingly. With Zunyi bank slope and pier foundation of Wujiang Grand Bridge as the example, a numerical simulation is carried out in this paper for the interaction between the pile foundation and the foundation as well as the stability of bank slope, with the finite difference method and the strength reduction method. The results show that:(1) Under the load of the bridge, the displacement in the bank slope mainly occurs at the top of the pile foundation and is concentrated on the pile top near the river side, and the displacement in the soil-rock mass around the pile mainly occurs on the pile foundation near the river side.(2) The difference in axial force is dependent on the location of the pile foundation, which indicates that the group pile effect is exerted.(3) The safety factor of the bank slope is 2.59 after the project is completed.