(中国建筑科学研究院地基基础研究所,北京 100013)

［摘要］通过对带承台单桩、群桩模型试验承载性状的分析，说明带承台单桩的承载性状与群桩的承载性状并不完全相同，不能将带承台单桩的试验结果简单地推广到群桩的设计计算中去。在带承台单桩试验中，发现带承台单桩的极限承载力大于单桩与平板极限承载力之和而在复合群桩试验中，复合桩基的极限承载力则大大小于各单桩与平板极限承载力之和。结合现场大型群桩模型试验结果及现行规范阐述了复合桩基的承载性状。

［关键词］复合桩基；承台效应；带台单桩；基底土反力

Research on composite pile foundation bearing capacity behaviorWang Tao(China Academy of Building Research, Beijing 100013, China)

Abstract:The bearing capacity behaviors of single pile with cap and group piles foundation  are analyzed in order to explain the differences between them.The bearing capacity test result of single pile with cap cannot be beought simply into group piles foundation design calculation. The ultimate bearing capacity of single pile with cap is larger than the sum of the ultimate bearing capacity of single pile and plate. While in composite group piles test, the conclusion that ultimate bearing capacity of composite pile foundation is smaller than the sum of ultimate bearing capacity of all single piles and plates is obtained.

Composite pile foundation bearing capacity behavior is explained by large scale model tests insite results and present standard.

Keywords:composite pile foundation; pile cap effect; foundation pile with the cap; subsoil back pressure

*建设部科技项目(0697-07-02)。