谢耀峰^1,2　王云球¹
　（1 河海大学交通与海洋工程学院  南京210098；2 东南大学港口航道工程系  南京210096）

[提要]  结合湛江港某码头基桩工程，对桩的负摩擦力进行试验研究。研究表明由同一根桩所测得的下拉荷载值远小于上拔荷载值。桩的负表面摩擦力在泥面以下约L/5左右处达到最大。摩擦桩的中性点位置多在0.67L处。建议的单桩下拉荷载经验公式，可供工程计算参考使用。
[关键词]  负摩擦力  下拉荷载  中性点

The test of negative skin friction along the single pile is studied,which is modeled after piles of　Zhanjiang harbor.The influence on negative skin friction along the various piles is discussed.The　mechanism and some new work laws of negative skin friction along the single pile or wharf bent piles are analyzed. The place of the maximum negative surface friction is L/5 0r so in soil. The neutral point of the friction pile is 0.67L or so in soil. An improved empirical formula is put forward for the calculation of the negative skin friction,which can be referred in project designing.
Keywords:  negative skin friction; downdrag force; neutral point

    　参  考  文  献
1．王云球，湛江港－区南二期工程桩基负摩擦力模型试验报告．河海大学，1996．
2．Auvinet G, Jhanell J. Negative skin friction on piles in Mexico city clay.ln:Proc.llth ICSMFE,1981,Ⅲ．
3．Endo M, Kawasaki T, Shibata T.  Negative skin friction acting on steel pipe in clay. In:  Proc. 7th ICSMFE, 1969,Ⅱ．