（1 南通大学交通学院，南通 226019；2 东南大学土木工程学院，南京 210096；3 河海大学港口海岸与近海工程学院，南京 210098）

［摘要］通过群桩负摩擦力室内模型试验，探讨负摩擦力的群桩效应。结果表明：桩身轴力随着土载的增大而逐步增大，砂土固结完成后，随土载增大桩中性点位置逐步下移，最终基本位于距桩顶0.8～0.9倍桩长处；负摩擦力群桩效应系数随着桩间距的增大而增大，当桩间距达到6倍的桩外径时，群桩效应系数接近1.0。

［关键词］负摩擦力; 群桩效应系数; 模型试验

中图分类号：TU473.1      文献标识码：A      文章编号：1002-848X(2014)17-0072-03

Experimental study on the group piles effect coefficient of negative skin friction in sand

Miao Yun1, Dai Guoliang2, Huang Ting3

 (1 Transportation College, Nantong University, Nantong 226019, China; 2 Department of Civil Engineering, Southeast University, Nanjing 210096, China; 3 College of Harbour, Coastal and  Offshore Engineering, Hohai University, Nanjing 210098, China )

Abstract: The group piles effect of negative skin friction was discussed through the indoor model test. Results show that axial force of the pile increases gradually with the increase of the soil load. After the concretion of the soil, the location of the neutral point of the pile  moves down gradually with the increase of the soil load and  locates in the 80% to 90% of the total pile length from the pile top eventually. The group piles effect coefficient of negative skin friction increases with the increase of pile spacing and it is close to 1.0 when the pile spacing reaches as long as 6 times of the pile outer diameter.

Keywords: negative skin friction; group pile effect coefficient; model test

*国家科技支撑计划项目（2011BAG07B01），973计划资助项目（2013CB036304）。

作者简介：缪云，硕士，助教，Email：miaoyun@ntu.edu.cn。

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