空间圆管桁架混凝土组合梁受力性能试验研究  

Experimental Study of Mechanical Behavior of Spatial Circular Steel Tube Truss and Concrete Composite Girder

作　　者：陈建兵[1,2] 陈荣[1] 李强[1] 

机构地区：[1]苏州科技学院土木工程学院,江苏苏州215011 [2]江苏省结构工程重点实验室,江苏苏州215011

出　　处：《世界桥梁》2014年第5期41-47,共7页World Bridges

基　　金：江苏省结构工程重点实验室资助课题(ZD1102);苏州市市级建设科研项目(2014-1-12)

摘　　要：空间圆管桁架混凝土组合结构是一种新型组合结构,为了解其受力特点、破坏机理、变形能力、管桁架杆件的内力分布规律及界面相对滑移等,设计制作了2根弦杆未填充混凝土的不同混凝土翼板厚度的空间圆管桁架混凝土组合梁模型试件,采用三分点对称加载,对其进行受力性能试验研究。研究表明,在对称荷载作用下,组合梁的破坏形式为弯曲破坏,同时伴随有受拉腹杆节点焊缝的强度破坏;空间圆管桁架组合梁具有良好的承载能力和变形能力,相同荷载下,混凝土板厚的组合梁的承载能力高于板薄的组合梁;组合梁破坏时,其跨中挠度约为跨径的1/200;不考虑界面相对滑移的情况下,截面应变满足平截面假定;加载前期,支点截面界面相对滑移量大于L/8截面,而加载后期,L/8截面界面相对滑移量大于支点截面;腹杆为非轴心受拉或受压杆件,且跨中位置腹杆的轴力较小,梁端位置腹杆的轴力较大。The spatial steel truss of circular steel tubes and concrete composite structure is a new type of composite structure .In order to examine its load bearing behavior ,failure mechanism , deformability ,internal force distribution law of tubular truss members and interface relative slip -page ,a spatial steel truss of circular tubes and concrete composite girder model was designed and fabricated .The model was characterized by its two chords that are not filled with concrete as well as the concrete flange plates with variable thickness .Loads were symmetrically applied at the 1/3 and 2/3 locations of the calculated span length of the girder proposed .The mechanical behavior of the model was experimentally studied .The results of the study indicate that under the action of symmetric loads ,the composite girder succumbs to bending failure ,concurrently with strength damage at the welding joints of the tensile web member nodes .The spatial tube truss composite girder exhibits good load bearing capacity and deformability .Under the same loads ,the load bear-ing capacity of the composite girder with thicker concrete slabs is superior to that with thinner ones .When the composite girder fails ,the deflection in the midspan is measured about 1/200 of its span length .Without considering the interface relative slippage ,the strain in the cross section suits the plan cross-section assumption .At the early stage of loading ,the amount of interface rela-tive slippage in the supports is greater than the L/8 of cross section ,while at the late stage of load-ing ,the L/8 cross-section interface relative slippage is greater than the cross section of the sup-port .The web members are not the axle tensile or compressive members ,and the axle force of the web members in the midspan is small and that of the web members in the ends of the girder is great .

关 键 词：空间桁架 圆管桁架 钢 - 混凝土组合梁 受力性能 试验研究 

分 类 号：TU398.9[建筑科学—结构工程]