腹板开洞钢-混凝土连续组合梁受剪性能试验研究

为研究腹板开洞连续组合梁的受剪性能,以配筋率和混凝土板厚为变量参数,对5根腹板开洞连续组合梁进行了两点单调对称集中加载试验,采用剪力分离方法对应变试验数据进行计算,得到组合梁钢梁和混凝土板承担的剪力.试验结果表明:腹板开洞不仅降低了连续组合梁的刚度和承载能力,而且引起洞口区域混凝土板和钢梁截面的竖向剪力重分布,剪力主要通过洞口上方的混凝土板来承担,占到总剪力的 85%~90%;洞口区域不再符合平截面假定,最终连续组合梁洞口发生剪切破坏,组合梁丧失承载能力;增加混凝土板厚度和截面配筋率可以提高连续组合梁的承载和变形能力,并可以用来进行洞口区域的补强. 

Experimental Study on Shear Bearing Behavior of Continuous Steel-Concrete Composite Beams with Web Openings

In order to investigate the shear bearing behavior of continuous steel-concrete composite beams with web openings, five continuous composite beams with web openings under two monotonic symmetric concentrated loads were tested using the thickness and reinforcement ratio of slabs as variables. The shear separation method was introduced to calculate the shear stress borne by concrete slabs and steel beams of composite beams. The test results show that web openings not only decrease the stiffness and ultimate load-carrying capacity but also give rise to the redistribution of vertical shear force of steel beams and concrete slabs; that is, the concrete slab bears 85%-90% of the total cross-section shear at the web opening region. The plane hypothesis is not valid in the web opening area. The failure mode is the shear failure of concrete slab in the region near the opening. In addition, the ultimate load-carrying capacity and deformability of continuous composite beams can be increased by increasing the thickness and reinforcement ratio of a concrete slab, which can be used for enhancement of the web opening area.