基于CPTU测试的桩基承载力预测新方法

New method based on CPTU data to evaluate pile bearing capacity

首先回顾了基于静力触探试验(CPT)和孔压静力触探试验(CPTU)预测桩基承载力的方法。根据连盐高速和宁常高速公路工程中的PTC、CFG和PHC桩的CPTU试验资料,提出了基于CPTU预测桩基承载力的折线法。以静载荷和高应变试验得到的桩基承载力作为参考值,评估了各种预测桩基承载力方法的有效性。结果表明,折线法比其余三种方法在预测桩基承载力方面具有更高的可靠性,具有简单、快速、多参数的优点,并且不依赖于操作者主观性的影响,值得在桩基工程中推广应用。

Several methods to determine bearing capacity of piles directly based on cone penetration test(CPT) and piezocone penetration test(CPTU) data are presented.The methods are proposed through the bearing capacity of PTC,CFG and PHC piles of Jiangsu Expressway combining CPTU data and capacities obtained from CPTU static loading tests and large strain tests.A new method to evaluate the axial capacity of pile has been proposed in which the pile unit skin friction and unit end bearing resistance are computed from the sleeve friction,excess pore water pressure and effective cone resistance.The results show that the proposed CPTU method has higher reliability than the other three methods.The new CPTU method is simple,fast and independent of all operator subjective influence.Therefore,it is notably suitable for use in pile engineering practice.