静压桩荷载传递与承载性状试验研究

依托某实际工程 ,在对桩-土体系荷载传递机理分析的基础上 ,研究了现场静力压桩试验和载荷试验过程中桩侧阻力的变化规律及其承载特性.结果表明 :在竖向压力作用下静压桩穿越不同的土层时 ,需同时克服土体对桩侧阻力和端阻力作用 ,不同阶段桩顶荷载作用时的端阻和侧阻的发挥性状不同 ;随着压桩荷载增加 ,桩身上部摩阻力先于下部发挥作用 ,较先进入极限状态 ,体现了其异步性 ,桩基设计时桩身中上部应适当加强 ;地基土自身的强度会随地基土水环境的变化而改变 ,对桩侧摩阻力和桩端阻力发挥影响显著 ;正常工作阶段 ,桩基大都处于弹性变形阶段 ,然而超出此范围后 ,桩基破坏大都表现为沉降或不均匀沉降.

Experimental Research on Loading Transfer and Bearing Characteristics of a Jacked Pile

Based on one real construction project and analysis of pile-soil system load transfer mechanism ,variety laws of pile side resistance during the process of loading test and static pressed pile were analyzed .The results are as follows:Under vertical pressure and passing through different soil layer ,jacked pile need to overcome pile tip resistance and pile side resistance from soil .In the different stage of pile top load action ,pile tip resistance and pile side resistance work in different character properties .With load increasing ,frictional resistance firstly develops in the upper part of pile .The upper part firstly goes into limit state which shows asynchronism .therefore when design piles ,the upper part should be strengthened .The strength of foundation soil itself will change along with the alternation of water and soil environment which affects the development of the pile tip resistance and pile side resistance observably .During the normal working stage ,the pile is mostly in elastic deformation stage ,and it then exceeds this stage .The failure of pile foundation is mostly caused by uneven settlement .