PBL加劲型矩形钢管混凝土桁架受弯性能试验  

Experiment on Flexural Behaviour of Rectangular Concrete Filled Steel Tubular Truss Stiffened with PBL

作　　者：高诣民[1] 刘永健[1] 姜磊[1] 刘君平[2] 刘欣昊 

机构地区：[1]长安大学公路学院,陕西西安710064 [2]福州大学土木工程学院,福建福州350116

出　　处：《建筑科学与工程学报》2017年第5期171-180,共10页Journal of Architecture and Civil Engineering

基　　金：国家自然科学基金项目(51378068);国家重点研发计划资助(2016YFC0701202);中央高校基本科研业务费专项资金项目(310821175015)

摘　　要：通过3片开孔钢板(PBL)加劲型矩形钢管混凝土桁架和1片矩形钢管混凝土桁架受弯性能试验,研究主管内设PBL及节点支主管宽度比β对桁架破坏模式、支主管应变变化和极限承载力的影响,对桁架竖向挠度限值进行分析,并探讨节点变形对桁架整体变形的影响。结果表明:矩形钢管混凝土桁架和PBL加劲型矩形钢管混凝土桁架均发生节点破坏,主管内设PBL改变了管内混凝土的开裂模式,有效限制了混凝土裂缝发展,使钢管与混凝土更好地协同受力;矩形钢管混凝土桁架和β分别为0.5,0.75,0.875的PBL加劲型矩形钢管混凝土桁架的节点变形占桁架整体变形比例分别为33.43%,24.44%,23.69%和21.44%,PBL有效限制受拉支管处主管的外凸变形,使节点变形占桁架整体变形比例减小,提高节点承载力,但对受压支管处主管变形基本无影响;对于矩形钢管混凝土和PBL加劲型矩形钢管混凝土组合桁梁桥竖向挠度限值可参考《公路钢结构桥梁设计规范》(JTG D64—2015)取为桁架全长的1/500。Through flexural experiment on 3 rectangular concrete filled steel tubular trusses stiffened with PBL and 1 rectangular concrete filled steel tubular truss, the influences of PBL set inside main pile and width ratio β of main pile and branch pipe on the failure modes of trusses, strains of main pile and branch pipe, and ultimate bearing capacity were studied. The limiting values of vertical deflection of trusses were analyzed, and the influence of joint deformation on overall deformation of truss was discussed. The results show that joint failures occur in rectangular concrete filled steel tubular truss and rectangular concrete filled steel tubular trusses stiffened with PBL. The PBL set inside the tube can change the crack mode of concrete, the crack development is limited, and the steel tube and concrete work better together. The proportion of joint deformation of rectangular concrete filled steel tubular truss and rectangular concrete filled steel tubular trusses stiffened with PBL （β=0.5, 0.75 and 0. 875） in overall deformation of trussare 33.43%, 24.44%, 23.69% and 21.44% respectively. The convex deformation of main pile at the region of tension branch pipe is effectively limited by PBL. The proportion of joint in overall deformation of truss deformation decreases, and the bearing capacity of joint is improved. The PBL has no effect on the deformation of main pile at the region of compression branch pipe. For the rectangular concrete filled steel tubular truss bridge and rectangular concrete filled steel tubular truss bridge stiffened with PBL, the limiting value of vertical deflection is 1/500 of truss overall length according to Specifications for Design of Highway Steel Bridge （JTG D64-- 2015）.

关 键 词：桥梁工程 PBL加劲型矩形钢管混凝土桁架 受弯试验 破坏模式 竖向挠度限值 节点变形 整体变形 

分 类 号：U443.35[建筑科学—桥梁与隧道工程]