钻孔扩底桩原型对比试验研究

COMPARATIVE EXPERIMENT STUDY ON PEDESTAL PILES

为选择合理的桩基础形式,结合静荷载试验对一大型建筑场地同一地质条件下相同桩径的钻孔扩底桩和不扩底桩进行桩身轴力和桩侧阻力测试,以确定单桩竖向承载力设计参数。通过对测试资料的分析,对比两种桩型桩身轴力、桩侧摩阻力以及桩端阻力分布特征,探讨两种桩桩侧摩阻力、桩端阻力的发挥过程,研究两种桩荷载–沉降特性。研究结果表明,扩底桩能够充分发挥持力层的承载潜力,对提高单桩承载力、减小桩体沉降效果显著。

In order to choose a rational form of pile foundation for a large-size construction yard, the shaft force and lateral friction force of the pile with the static load test for the same diameter pedestal piles and the normal piles under the same geologic condition are tested to confirm the design parameter of the pile vertical bearing capacity. This paper analyzes the testing information, and contrasted distributing-characteristic of shaft force and lateral friction force and the force at the end of the pile of the two different pile types, discusses the working- process of the lateral friction force and force at the end of the pile. The load-settlement- characteristic of the pedestal piles and the normal ones is researched. The study indicates that the pedestal pile could bring potential bearing capacity of the supporting layer into play. It could remarkably enhance the pile＇s bearing capacity and reduce the settlement.