软土地区某场地扩底桩原型现场对比试验研究

为了解软土地区钻孔扩底灌注桩的工作机理,研究了申嘉湖杭高速公路练杭支线某场地扩底桩与直桩的竖向静荷载对比试验。通过对现场测试结果的分析,探讨钻扩桩的承载特性和竖向承载力,讨论单桩竖向承载力与桩侧摩擦力、桩端阻力的关系及发挥特性。研究结果表明,在软土地区应用扩底桩是完全可行的,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;研究结果还表明,软土地区扩底桩工作机理与其他地区略有不同。

COMPARATIVE IN-SITU EXPERIMENT STUDY ON PEDESTAL AND NORMAL PILES OF A SET IN SOFT SOILS

In order to get working mechanism of pedestal piles in soft soils, a group of field vertical loading tests were performed on pedestal and normal piles at a site in soft soils to make comparative study.This paper analyzes the testing information, and explore the bearing characteristic and capacity of pedestal piles, discuss the working process of pile vertical bearing capacity,also relations between lateral friction force、the force at the end of the pile and pile vertical bearing capacity. The study indicates that pedestal pile could work very well in soft soils,and the pedestal pile could bring potential bearing capacity of the supporting layer into full play and remarkably enhance the pile's bearing capacity and reduce the settlement.The study indicates that working mechanism of pedestal piles in soft soils is somewhat different with that in other soils.