负摩阻力作用下桩基中性点位置、下拽力及下拽位移与时间的关系

Relationship of neutral point position, dragload or downdrag of pile versus time under negative skin friction

介绍桩基负摩阻力产生及发展过程;针对中性点位置、下拽力及下拽位移与时间之间的关系,提出关系拟合预测曲线模型,并与现场工程实测结果进行对比分析,探讨曲线模型参数的物理意义。研究结果表明:提出的曲线模型计算结果与实测结果吻合良好,从而验证该模型的准确性和可靠性,为进一步研究桩基负摩阻力特性及其设计和计算提供参考依据。

The develop process of negative skin friction of pile was briefly introduced. The relationship curves models for neutral point position versus time, dragload versus time, and downdrag versus time were developed. The curve model results were comparatively analyzed with field test results;and the physical meanings of parameters were discussed and analyzed. The results show that the results obtained by curves models fit well with those of field test results, which verifies the accuracy and reliability of curves models developed in this paper. The results also provide a reference for further study of the characteristics of negative skin friction and its design and calculation.