负弯矩下部分充填式窄幅钢箱-混凝土组合梁刚度分析  

Stiffness analysis of partially filled narrow steel box-concrete composite beams under negative bending moment

作　　者：罗小均 郑艳[1,3] LUO Xiaojun;ZHENG Yan(College of Civil Engineering and Architecture,Guilin University of Technology,Guilin 541004,China;Hunan Urban Construction College,Xiangtan 411100,China;Guangxi Key Laboratory of Geomechanics and Geotechnical Engineering,Guilin 541004,China)

机构地区：[1]桂林理工大学土木与建筑工程学院,广西桂林541004 [2]湖南城建职业技术学院,湖南湘潭411100 [3]广西岩土力学与工程重点实验室,广西桂林541004

出　　处：《湘潭大学学报（自然科学版）》2023年第2期86-97,共12页Journal of Xiangtan University(Natural Science Edition)

基　　金：国家自然科学基金(52068012);广西自然科学基金项目(2020GXNSFAA159003)。

摘　　要：为探究部分充填式窄幅钢箱-混凝土组合梁在负弯矩作用下的界面滑移及混凝土翼板开裂对梁截面刚度的影响,对3根不同配筋率及剪力连接程度的试验梁进行了反向加载试验,得到了试验梁的抗弯承载力、荷载-跨中挠度曲线、荷载-最大裂缝宽度曲线以及荷载-界面滑移曲线,并分析其破坏形态、滑移和刚度变化等规律.基于等效刚度法,建立了负弯矩下考虑滑移效应和混凝土翼板开裂影响的组合梁挠度解析式.结果表明,根据文中公式算得的组合梁跨中挠度计算值比不考虑滑移及完全忽略开裂混凝土贡献的换算截面法精度更高.分阶段考虑滑移和混凝土翼板开裂影响能较好地反映正常使用阶段的组合梁截面刚度的变化特点,可以为连续组合梁负弯矩区刚度计算提供依据.In order to explore the influence of interface slip and concrete cracking on the section stiffness of partially filled narrow steel box-concrete composite beams under negative bending moment,reverse loading tests were carried out on three specimens with different reinforcement ratios and shear connection degrees.The flexural capacities,load-mid span deflection curves,load-maximum crack width curves and load-interface slip curves of the specimens were obtained,and the failure modes,slip and stiffness changes were analyzed.Based on the equivalent stiffness method,the deflection analytical formula of composite beam considering the influence of slip effect and concrete cracking under negative bending moment was established.The results show that the calculated mid-span deflection of the composite beam calculated according to the formula in this paper is more accurate than the converted section method without considering slip and completely ignoring the contribution of the concrete in tension zone.Considering the influence of slip and concrete cracking in stages can better reflect the change characteristics of the section stiffness of composite beams in normal use stage,which can provide a basis for the calculation of the stiffness of negative moment zone stiffness of continuous composite beams.

关 键 词：组合梁 滑移 开裂 挠度 抗弯刚度 

分 类 号：TU398.9[建筑科学—结构工程]