钢纤维混凝土二桩厚承台的试验研究  

Experimental research on steel fiber reinforced concrete two-pile thick caps

作　　者：孙成访[1] 谷倩[2] 彭少民[2] 

机构地区：[1]东莞理工学院城市学院,广东东莞523106 [2]武汉理工大学土木工程与建筑学院,湖北武汉430070

出　　处：《建筑结构学报》2010年第2期117-124,共8页Journal of Building Structures

基　　金：国家规程<钢纤维混凝土结构设计与施工规程>修订项目;武汉青年科技晨光计划项目(20035002016-30)

摘　　要：为了研究钢纤维增强混凝土(SFRC)二桩厚承台的传力机理和破坏模型,以及钢纤维在混凝土二桩厚承台中的作用,对30个混凝土和钢纤维混凝土二桩承台进行了静力加载试验和非线性有限元分析,探讨了钢纤维混凝土二桩厚承台的开裂荷载、极限荷载、裂缝开展、承台内部应变分布、钢筋应力分布等力学性能。结果表明:钢纤维的掺入能有效提高混凝土承台的开裂荷载和极限荷载,阻碍裂缝的发展,降低承台的厚度;钢纤维混凝土二桩厚承台破坏形态为冲切破坏,其传力模型符合拉杆拱模型或桁架模型。提出了基于桁架模型的钢纤维混凝土二桩厚承台承载力设计计算公式,其计算值与试验值吻合较好。该研究成果可为有关规程的编制及实际工程的应用提供参考。In order to study load-transfer mechanism and the failure mode of the steel fiber reinforced concrete （SFRC） two-pile thick caps, and the effect of the steel fiber on reinforced concrete two-pile thick caps, thirty model specimens were tested under static loading and analyzed by nonlinear finite element method. This paper discusses the mechanical behavior such as cracking load, limit load, distribution of strain inside caps and stress of the bars on the bottom of SFRC two-pile caps. The results indicate that steel fiber can increase the cracking load and limit load of the reinforced concrete pile caps, hinder the further growth of cracks, thus the thickness of the reinforced concrete pile caps may be reduced. The failure mode of SFRC two-pile thick caps is punching damage, and the load-transfer mechanism can be explained well by arch-and-tie or truss models. An equation for predicting the bearing capacity of SFRC two-pile thick cap based on truss model is proposed and the calculation results agree well with the experimental results. The research results provide references for compiling the guidelines or codes to guide engineering design practice.

关 键 词：钢纤维混凝土 二桩厚承台 破坏模型 静载试验 非线性分析 承载力 

分 类 号：TU473.1[建筑科学—结构工程] TU317.1[建筑科学—土工工程]