摘要
为改善波形钢腹板组合梁负弯矩区受力性能,避免波形钢腹板剪切屈曲以及受压翼缘局部屈曲,提出波形钢腹板内衬混凝土形成组合构造的措施。通过设计具有不同弯、剪比参数的2个试件,开展波形钢腹板内衬混凝土组合梁模型试验,研究其承受弯矩与剪力共同作用下的力学性能,明确不同弯、剪比对极限承载能力以及失效模式的影响,建立弯、剪共同作用的相关方程。试验结果表明:试件的破坏模式为明显的弯、剪耦合破坏,内衬混凝土出现弯曲、剪切2类主裂缝;弯剪比对试件未开裂截面抗剪刚度影响较小,但对初始开裂后试件抗剪刚度影响较大;弯剪比增大,试件开裂荷载减小,结构的延性增加;在弯、剪共同作用下,未开裂截面应变基本满足平截面假定,但受拉区混凝土开裂后,相应区域波形钢腹板由于"折叠效应"应变较小,平板段几乎为0,斜板段由于混凝土的挤压作用应变不为0。最终依据模型试验与数值模拟结果,建立弯、剪共同作用下波形钢腹板内衬混凝土组合梁承载力评价准则,为今后的设计提供参考。
In order to improve the mechanical performance of composite girder with corrugated steel webs under hogging moment and avoid the shear buckling of the corrugated webs and local buckling of compressive flange,measures of concrete-encased composite girder with corrugated steel webs were proposed.Two specimens with different flexure shear ratios were designed and model tests on concrete-encased composite girders with corrugated steel webs were conducted to investigate the mechanical performance under combined shear force and bending moment,understand the effects of flexure shear ratios on the ultimate load-carrying capacity and failure modes,and establish correlation equations under shear force and bending moment.The results show that composite girders are failed due to the interaction of flexural and shearing forces and both flexural cracks and shear cracks appear on encased-concrete.The flexure shear ratio hasaslight effect on the shear stiffness of un-cracked section,but a large effect on the shear stiffness after concrete crack.With the increase of flexure shear ratio,the cracking load decreases,but the structural ductility increases.In addition,the un-cracked sections satisfy the assumption of plane section under shearing and flexural loads.However,after concrete crack in the tensile region,the strain of corrugated web at the corresponding positions becomes small on account of＂accordion effect＂.The strain is almost zero in flat plate areas but recognizable strain in skew plates is not zero because of the compression of concrete.Finally,based on model test and numerical simulation results,load-carrying capacity evaluation rules of concrete-encased composite girder with corrugated steel webs under shearing and flexural loads are established,to provide a reference for further designs.
作者
贺君
刘玉擎
吕展
李传习
HE Jun LIU Yu-qing LU Zhan LI Chuan-xi(School of Civil Engineering and Architecture, Changsha University of Science ~ Technology, Changsha 410114, Hunan, China Department of Bridge Engineering, Tongji University, Shanghai 200092, China Department of Civil and Environmental Engineering, Imperial College London, London SW7 2AZ, UK)
出处
《中国公路学报》
EI
CAS
CSCD
北大核心
2017年第7期94-100,143,共8页
China Journal of Highway and Transport
基金
国家重点基础研究发展计划("九七三"计划)项目(2015CB057701)
国家自然科学基金项目(51308070
51408070)
桥梁工程湖南省高校重点实验室开放基金项目(13KA04)
长沙理工大学土木工程创新性项目(13ZDXK04)
山西省应用基础研究计划项目
关键词
桥梁工程
波形钢腹板
模型试验
弯、剪性能
内衬混凝土
bridge engineering
corrugated steel web
model test
flexural and shearing performance
encased concrete
