钢-混凝土组合桁架梁抗弯性能试验

Experimental study on bending capacity of steel-concrete composite truss girder

为研究钢-混凝土组合桁架梁(SCCTG)的抗弯性能,对编号为CB1、CB2a、CB2b和CB3的4个试件进行试验研究和数值模拟.结果表明:SCCTG截面应变基本符合平截面假定,理论计算时可采用平截面假定,且SCCTG具有较高的极限承载能力和良好的变形性能,采用较密栓钉时可有效提高混凝土板和钢桁架的整体工作性能;当在弹性阶段时,SCCTG翼缘板的有效宽度基本不变,在塑性阶段,有效宽度有所增加,但均小于《规范》计算值,同时,试验证明混凝土受压翼缘存在较明显的剪力滞后效应,因此,设计计算时应考虑剪力滞后效应对组合梁承载力和变形的影响.

To study the bending capacity of steel-concrete composite truss girder （SCCTG）, experimental study and numerical simulation is investigated on 4 specimens, No CB 1, CB2a, CB2b and CB3. The stress distribution, load-tisplacement relationship, load-slip relationship and ultimate bearing capacity are analyzed in detail. The results show that the sectional strain comply plane section assumption. SCCTG has a higher ultimate bearing capacity and good performance of deformation. Concrete slab and the steel truss can work together better using denser pegs. In elastic stage, the effective width of the SCCTG flange plate is essentially the same. And in the plastic stage, the effective width has an increase. The test also proved there is obvious shear lag effect in the concrete compression flange. Therefore, shear lag should be considered when designing and calculating the bearing capacity and deformation of SCCTG.