悬链线钢管混凝土单管拱破坏试验研究  

Experimental study on failure of concrete filled steel tubular arch with catenary

作　　者：刘增武 王邵锐[1] 辛景舟 周建庭[1,2] 李英斌 LIU Zengwu;WANG Shaorui;XIN Jingzhou;ZHOU Jianting;LI Yingbin(School of Civil Engineering,Chongqing Jiaotong University,Chongqing 400074;State Key Laboratory of Mountain Bridge and Tunnel Engineering,Chongqing Jiaotong University,Chongqing 400074)

机构地区：[1]重庆交通大学土木工程学院,重庆400074 [2]重庆交通大学山区桥梁及隧道工程国家重点实验室,重庆400074

出　　处：《铁道科学与工程学报》2023年第8期2961-2973,共13页Journal of Railway Science and Engineering

基　　金：广西重点研发计划项目(桂科AB22036007);重庆市自然科学基金资助项目(cstc2019jcyj-cxttX0004,cstc2020jcyj-msxmX0532);国家自然科学基金青年基金资助项目(51608080);重庆市自然科学基金面上项目(cstc2021jcyj-msxm2491)。

摘　　要：为探究悬链线钢管混凝土拱的力学性能,依托净跨径95 m的单管混凝土拱桥—瓦石窝大桥,开展1︰16的缩尺模型试验。开展2根钢管混凝土悬链线拱面内单点加载试验,试验拱跨度为5.938 m,矢跨比为1/3.5,拱轴系数为1.5,加载工况分别为拱顶加载和四分点加载。试验结果表明:拱顶和1/4加载工况下,拱的破坏模式均为四铰破坏;2种加载工况下,拱加载点处外部变形较大,但未发生局部屈曲现象。在达到极限荷载的55%后,拱肋钢管开始对核心混凝土产生约束作用,钢管对核心混凝土的约束效应比抛物线拱要提前发挥作用。L/4加载工况下拱的变形和应变均大于拱顶加载工况,说明L/4加载工况更不利。另外,利用ANSYS梁单元法对悬链线钢管混凝土拱进行了参数扩展分析,分析了不同加载方式、拱轴系数、矢跨比,以及含钢率对拱极限承载力的影响。结果表明:不同加载方式、矢跨比、含钢率对拱的承载能力影响较大,拱轴系数影响较小。随着含钢率和矢跨比的增大拱的承载力相应增加。研究成果可以增补钢管混凝土拱承载力试验库和为工程设计提供借鉴,同时也为悬链线钢管混凝土拱的理论计算铺垫基础。In order to explore the mechanical properties of the catenary concrete-filled steel tube arch bridge,a 1︰16 scale model test was carried out based on the single tube concrete arch bridge-washiwo bridge with a net span of 95 m.Two concrete-filled steel tubular catenary arch plane single point loading tests were conducted.The test arch span was 5.938 m,the rise span ratio was 1/3.5,and the arch axis coefficient was 1.5.The loading conditions were vault loading and quarter point loading respectively.The test results show that the failure mode of the arch is four hinge failure under the condition of vault and quarter load;Under the two loading conditions,the external deformation of the arch at the loading point is large,but there is no local buckling.After reaching 55%of the ultimate load,the steel pipe of the arch rib begins to restrain the core concrete,and the restraining effect of the steel pipe on the core concrete is earlier than that of the parabolic arch.The deformation and strain of arch under l/4 loading condition are greater than that under vault loading condition,indicating that l/4 loading condition is more unfavorable.In addition,the parameter expansion analysis of catenary concrete-filled steel tubular arch was carried out by using ANSYS beam element method,and the effects of different loading methods,arch axis coefficient,rise span ratio,and steel ratio on the ultimate bearing capacity of the arch were analyzed.The results show that different loading methods,rise span ratio and steel ratio have great influence on the bearing capacity of the arch,and the arch axis coefficient has little influence.With the increase of steel ratio and rise span ratio,the bearing capacity of arch increases correspondingly.The research results can supplement the bearing capacity test library of concrete-filled steel tube arch and provide reference for engineering design,and also pave the foundation for theoretical calculation of catenary concrete-filled steel tube arch.

关 键 词：钢管混凝土 悬链线拱 破坏试验 单点加载 破坏模式 

分 类 号：U445.35[建筑科学—桥梁与隧道工程]