圆管式无柱帽空心无梁楼盖的试验研究

Experimental study of tubular voided flat plate floor

圆管式无柱帽空心无梁楼盖的孔道是单向的,使楼板在两个方向的截面不一样,因此需要研究它的受力性能和设计方法。柱网4m×4m,每侧挑出0.5m,板厚135mm的试验模型,在竖向均布荷载下的试验表明,该板受力全过程分为未裂、裂缝、破坏三个阶段,有足够的承载能力,竖向位移呈“拉网形”,柱顶板面处首先开裂和屈服,孔道对板中央处的板底裂缝有影响,顺孔道方向的裂缝宽度比另一方向的大。用弹性有限元分析了竖向均布荷载下,9m×9m柱网的实心无梁楼盖和圆管式空心无梁楼盖的中间板区格,计算结果表明,两者各截面弯矩及板带弯矩的差别不大。建议对竖向均布荷载作用下的圆管式无柱帽空心无梁楼盖也可象实心板的那样采用等效框架设计法,圆管应沿平行于板区格的长跨方向布置,每段圆管的长度不宜不大于1m,管间净距和管端净距分别不宜大于50mm和80mm。

Since the hole passages in the tubular voided flat plate floor are o ne way in the same direction and the cross sections in two directions are differ ent, it has the necessity to study its mechanic behavior and design method. The column grid of the test model is 4m×4m and the cantilever length from the colum n axis on each side of the test model is 0.5m. The thickness of the flat plate i s 135mm. Under uniformly distributed load,the test results showed that the whol e process can be divided into three stages, namely no cracking stage, cracking s tage and failure stage, the load carrying capacity is enough, the deflection sha pe of whole plate likes a ‘recovering fishing net’, the first cracking and yie lding section are at the top surface of the plate on the top of each column, and the influence of hole passages on bottom cracks is evident that the crack width s along the hole passages are bigger than those along the other direction. By me ans of the elastic finite element analysis method, the moment distributions in t he interior panel of the solid and tubular voided flat plate floor with 9m×9m c olumn grid subjected to uniformly distributed load are given out. The calculatio n results showed that the differences in both the section moment and the plate s trip moment of the two types of floors are not large. The paper suggests that un der the uniformly distributed load, the equivalent frame design method can also be used in the tubular voided flat plate floor as using in the solid plate floor . All the tubes should be put along the direction in the long space of the plate , the length of each tube is not longer than 1m, and the net distance between th e ends and the adjacent tubes should not be larger than 80mm and 50mm respective ly.