支承条件对单桩承载力影响的分析

Analysis on Effect of Bearing Capacity of Single Pile by Supporting Condition

摘要:

对比5个工程14根不同桩长的试桩成果，发现同一场地、相同桩型的试桩，因为桩长、持力层不同，导致单桩承载力有较大差异，特别是支承在软粘性土持力层的承载力明显偏低。这种差异按现有规范和有关认识无法解释，说明对单桩承载机理的认识还不够深入、全面。举例对桩端支承条件、时间效应分别加以分析表明，当桩端持力层条件较差时，用动阻力（压桩力）或用A.S.Vesic的论述可以更好地解释摩擦单桩承载力明显偏低的现象。

Abstract:

The result of pile tests on 14 piles with different lengths in 5 engineering cases shows that bearing capacity of single pile was quite different in the same construction site and with the same type of pile just because of different pile lengths and bearing stratums. The paper analyzed the conditions of bearing capacity of pile tip and time effect, when bearing capacity of pile tip was weak, lower bearing capacity of single friction pile could be reasonably explained by compressive pressure to pile or by A.S.Vesic theory.