不同桩端土承压钻孔灌注桩模型试验研究  

Model tests on bored piles under vertical load on different pile-tip soils

作　　者：刘锟[1] 赵春风[2,3] 

机构地区：[1]上海市政工程设计研究总院(集团)有限公司,上海200092 [2]同济大学岩土及地下工程教育部重点实验室,上海200092 [3]同济大学地下建筑与工程系,上海200092

出　　处：《岩土工程学报》2011年第3期490-495,共6页Chinese Journal of Geotechnical Engineering

基　　金：国家自然科学基金项目(40972180);上海市重点学科建设项目(B308)

摘　　要：通过模型试验研究不同桩端土对承压钻孔灌注桩承载特性的影响。模型试验中,结合软土地区灌注桩穿越土层的特点选择桩周桩端土,采用裹膜预制预埋的方法设置模型桩,以消除桩身粗糙程度、桩径等因素差异的影响,并一定程度上模拟灌注桩成孔卸载过程;通过静载试验得到6根试桩的试验数据,就桩端土对桩侧摩阻力的影响进行了重点介绍;建立桩侧摩阻力与桩土相对位移之间的关系,并由归一化处理使得桩端土对桩侧摩阻力的影响得到量化解决。结果表明:模型试验研究桩端土对灌注桩承载特性影响的方法可行,解决不同情况下桩端桩周土对灌注桩承载性能的影响,仍需大量试验和工程实践验证。The primary goal of this research is to study the influences of different pile-tip soils on the bearing characters of bored piles.Soils laid around and under piles are selected based on characteristics of strata passed through by bore piles in soft soil.Prefabricated model piles are pre-installed onto the pile-tip soils with film around them to remove influences induced by differences in coarse degree and diameter of piles,and to produce unloading effect on piles.Test data are gained after static loading tests on six model piles,and the influences on side resistance are discussed.Relations between side resistance and relative displacement are established and normalized to quantitatively solve the problem.It is concluded that the model tests on the influences of different pile-tip soils on the bearing characters of bored piles are valid,and more test data and project practice are needed to solve this problem thoroughly.

关 键 词：灌注桩 桩端土 模型试验 桩侧摩阻力 桩土相对位移 

分 类 号：TU473[建筑科学—结构工程]