[提要]  基于9个三桩承台和15个四桩承台的模型试验，详细分析了承台的破坏形态和力学性能，以及钢纤维混凝土( SFRC)用于桩基承台的优越性；通过对SFRC桩基承台模型进行全过程材料非线性计算，分析承台的裂缝扩展情况、应力分布规律和传力机理。综合有限元计算和试验研究结果，提出了桩基厚承台的空间拉杆拱或软化桁架传力模型，为《钢纤维混凝土结构设计与施工规程》的修订提供理论支持和试验依据。
[关键词]  桩基承台  钢纤维混凝土  非线性分析  有限元

The modeling experiments on 9 three-pile caps and 15 four-pile caps specimen are carried on, the failure state, mechanic characteristic of thick piles cap and the obvious effect of adding steel fibers into concrete are analyzed in detail. In addition, a material nonlinear computation for steel fiber reinforced concrete piles cap model is also executed. The laws of cracks propagation, stress distribution and load-transferred rules are analyzed. Through concluding the finite element computing and experimental study achievements, the spatial tie-arch or softening-truss load-transferred model of piles cap are advanced, which provides theoretic support and experimental basis for corupiling the Specification for Technology of Fiber Reinforced Concrete Structures.
Keywords: pile cap;  steel fiber reinforced concrete;  nonlinear analysis; finite element