钢-UHPC连续组合梁抗弯性能试验  

Experimental Investigation on Flexural Capacity of Steel-UHPC Continuous Composite Girder

作　　者：王皓磊[1,2] 孙韬[2,3] 刘晓阳 唐宸 王解军 陈爱军[1] WANG Hao-lei;SUN Tao;LIU Xiao-yang;TANG Chen;WANG Jie-jun;CHEN Ai-jun(College of Civil Engineering,Central South University of Forestry&Technology,Changsha 410004,Hunan,China;Key Laboratory for Wind and Bridge Engineering of Hunan Province,Hunan University,Changsha 410082,Hunan,China;College of Civil Engineering,Hunan University,Changsha 410082,Hunan,China;Hunan Architectural Design Institute Co.Ltd.,Changsha 410011,Hunan,China)

机构地区：[1]中南林业科技大学土木工程学院,湖南长沙410004 [2]湖南大学风工程与桥梁工程湖南省重点实验室,湖南长沙410082 [3]湖南大学土木工程学院,湖南长沙410082 [4]湖南省建筑设计院有限公司,湖南长沙410011

出　　处：《中国公路学报》2021年第8期218-233,共16页China Journal of Highway and Transport

基　　金：国家自然科学基金项目(51508581);湖南省自然科学基金项目(2016JJ3188);风工程与桥梁工程湖南省重点实验室开放基金项目(201903)。

摘　　要：为研究钢-超高性能混凝土(Ultra-high Performance Concrete,UHPC)连续组合梁的抗弯承载能力,完成了2根大比例缩尺模型的静载试验,包括1根钢-UHPC连续组合梁和1根预应力钢-普通混凝土(Normal Strength Concrete,NC)连续组合梁,对其挠度、应力分布、裂缝发生发展模式及承载能力进行分析,并研究了钢-UHPC连续组合梁的弯矩重分布性能。同时,采用ABAQUS软件中的塑性损伤模型(CDP)进行数值模拟。结果表明:钢-UHPC连续组合梁UHPC板的名义开裂强度为普通组合梁预应力NC板的2.2倍,钢-UHPC连续组合梁的极限承载力约为普通组合梁的1.2倍;UHPC板开裂后裂缝密集、间距小,且以长度较小的微裂纹为主;UHPC板/NC板与钢梁均采用群钉连接,二者相对滑移较小,可有效形成整体共同工作;采用塑性理论计算钢-UHPC连续组合梁的抗弯承载能力,应考虑UHPC的抗拉强度,与现有组合结构规范公式相比,根据所提出方法计算得到的负弯矩区截面抗弯承载力与试验值吻合较好;考虑UHPC抗拉强度后,钢-UHPC连续组合梁负弯矩区塑性铰转动能力降低,弯矩调幅需求及有效弯矩重分布能力均明显下降。To investigate the flexural capacity of steel-UHPC continuous composite girders,static tests were conducted on two large-scale continuous composite girder specimens(including a steel-UHPC continuous composite girder specimen and a prestressing steel-NC continuous composite girder specimen).The deflection,stress distribution,crack development mode,and bearing capacity were analyzed,and the moment redistribution was studied.The concrete damage plasticity(CDP)model in ABAQUS was used to simulate the loading process of the steel-UHPC continuous composite girder.The results indicate that the nominal cracking strength of the UHPC slab of the steel-UHPC continuous composite girder is approximately 2.2times that of the prestressed NC slab of an ordinary composite girder,and the ultimate bearing capacity of the steel-UHPC continuous composite girder is approximately 1.2times than of the ordinary one.The cracks that appeared in the UHPC slab,which was dominated by microcracks of smaller lengths,were numerous and intensive.The relative slip of the composite interface is small,and the grouped stud connectors can make the UHPC/NC slab and steel girder work together integrally.Based on plastic theory,new methods for analyzing the flexural capacity of steel-UHPC continuous composite girders under hogging moments are proposed considering the tensile strength of UHPC.Compared with the standard formula,the flexural capacity of the hogging moment area obtained using the proposed method yields satisfactory predictions in comparison with the test results.By considering the tensile strength of UHPC,the rotation capacity of the plastic hinge in the hogging moment area of the steel-UHPC continuous composite girder decreased,and the need for moment amplitude adjustment and the effective moment redistribution capacity declined.

关 键 词：桥梁工程 超高性能混凝土 大比例缩尺模型试验 抗弯承载能力 钢-UHPC连续组合梁 裂缝发生发展模式 弯矩重分布 

分 类 号：U443.35[建筑科学—桥梁与隧道工程]