Y型沉管灌注桩及其承载特性

对Y型沉管灌注桩技术原理予以介绍,针对工程界对Y型桩有别于传统桩型的反拱曲面是否存在摩阻弱化效应的忧虑进行圆形桩、Y型桩现场对比试验。试验结果表明:Y型桩承载力的增加与侧表面积的增加效果同样明显,反拱曲面尽管可能存在摩阻不均匀发挥的特性,但未发现其异形摩阻弱化效应。结合三个工程实例的静荷载检测结果,对Y型沉管灌注桩的承载特性进行分析;针对Y型桩有别于传统桩型的过度充盈反而削减承载力的特点,提出在计算Y型桩极限承载力时引入充盈折减系数,并对求解充盈折减系数的方法予以介绍。

THE Y-SHAPED VIBRO-PILE AND LOAD BEARING CHARACTERISTICS

Firstly,the technique principle of Y-shaped vibro-pile is introduced.It is concluded that the skin friction characteristic of both positive circular arc surface and inverse arc surface is basically the same,which is validated by the contrast of static load test between circular pile and Y-shaped vibro-pile.Although the asymmetry is likely,the skin friction of inverse arc surface is not reduced.Combining with the three practical projects,the load bearing characteristics and working mechanism of Y-shaped vibro-pile are studied.The fullness depreciation coefficient is brought forward and analyzed in calculating ultimate bearing capacity aiming at the characteristic of Y-shaped vibro-pile,and its physical meaning and calculation method are also introduced.