粗糙度对超长嵌岩桩承载特性影响的研究

Influence of Roughness on Bearing Characteristic of Super-long Rock-socketed Pile

研究目的:为探讨粗糙度对超长嵌岩桩承载特性的影响,对武汉市某大桥的桩基工程,运用有限元方法分析了不同桩侧粗糙程度下,桩基沉降量、桩侧摩擦力分布和桩身轴力分布情况,并与室内模型试验所得出的结果进行对比分析。研究结论:(1)桩侧越粗糙,桩侧摩擦力越容易发挥,桩侧摩擦力越大,相同竖向荷载作用下的桩顶沉降量越小;(2)桩顶荷载传递至周围岩土层的速率越快,传递同等水平的竖向荷载所需的传递深度越小;(3)粗糙度对桩端荷载分担比例的影响不大;(4)本研究结论可为嵌岩桩工程的设计、施工提供一定的借鉴。

Research purposes： Based on the pile foundations of a bridge in Wuhan City, the finite element method is used to study pile settlement, pile side friction distribution and axial force distribution with different pile side roughness. Then combined with the laboratory model test results, explored the roughness on the bearing characteristics of super - long rock -socketed piles. Research conclusions：The results shows that the pile side friction is easier to play as the surface of pile is rougher, for this reason the pile side friction get bigger and the pile settlement become smaller. In the same time, the rate of transfer load on pile top to the surrounding rock and soil is faster, and the depth of transfer the same level of vertical load become smaller. However, the roughness does not much affect the load proportion of pile tip. The conclusions can provide a reference for design and construction of super - long rock - socketed pile.