基桩竖向抗压承载力动静试验结果分析研究

Analysis on the dynamic and static testing results of the vertical bearing capacity of pile

本文通过对同一工程的基桩竖向抗压承载力的高应变法测试和静载试验结果的分析,指出工程基础的设计选型和施工工艺的选取应充分考虑场地特殊地质条件的影响,计算取值应是成桩后实际状态的合理取值,否则设计错误,造成工程损失。本文同时也指出了在检测过程中应注意检测方法的选择问题,对Q-s曲线呈现缓变型的摩擦灌注桩不适宜用高应变法检测,特别是出现单击贯入度大,桩底同向反射峰明显而且肥大时,不可用常规的桩—土模型进行计算分析;对于桩身或(和)桩端位于遇水易软化层的摩擦桩,静载荷试验适宜采用慢速维持荷载法,快速维持荷载法可能会得出错误的结论。

This paper presents the analysis of the vertical bearing capacity of foundation pile of high-strain dynamic testing and static load testing results, pointing out that the design of the project basis selection and the selection of the construction process should take full account of the special geological condition, the vertical bearing capacity of pile should be calculated on the reasonable value of the actual state, or design errors, resulting in loss of work. The paper also pointes out that we shouid note the choice of testing methods in the testing process. It is inappropriate to adopt high-strain method for the friction pile with a slowly varying Q-s curve. In particular, when the single penetration is large and the reflection peak at the end of pile in the same direction is hypertrophy and clear, conventional pile-soil model can＇ t be used to calculate and analyse. When the friction pile ends on the bearing stratum for the soft rock with water- softening characteristics, only slow-static-load testing can be used and fast method may lead to wrong conclusions.