考虑管参与工作的圆管式空心板截面承载力试验与理论研究

Experimental and Theoretical Study on Bearing Capacity of Cross-section of Hollow Slab with Tubular Cavities Considering Function of Tubes

为深入掌握内置GBF高强薄壁管的圆管式空心板结构性能,研究了这类结构中GBF高强薄壁管是否参与结构受力的问题。首先通过试验实测了圆管式空心板截面承载力,然后根据薄壁管的实际受力状况对截面承载力进行了较精确地理论分析,推导了考虑管参与受力的截面承载力计算公式。研究表明:在承载力极限状态下当混凝土受压区高度满足一定条件时,GBF高强薄壁管将参与结构受力从而一定程度上提高了结构的截面承载力;根据截面受力状况的不同,该类空心板截面承载力的准确计算需要分2种情形考虑;在设计中仅将GBF高强薄壁管视为成孔内模是不当的,应充分考虑其对结构极限承载力的影响。

In order to deeply master the structural performance of hollow slabs with tubular cavities which placed GBF high-strength thin-wall pipes inside, the problem whether GBF high-strength thin-wall pipes inside this kind of structure take part in structural behavior was studied. First, the experiment was conducted to measure the bearing capacity of cross-section of the hollow slab. Then, the bearing capacity of cross- section was theoretically and precisely analyzed according to real force condition of thin-wall pipes, and the calculation formula of bearing capacity of cross-section considering the function of the pipes was derived. It is shown that （ 1 ） when the height of concrete compressive area satisfies a certain condition, GBF high-strength thin-wall pipes will take part in structural behavior so that the bearing capacity of cross-section of the structure will be improved to a certain degree in ultimate status of bearing capacity; （2） the accurate calculation of bearing capacity of this kind of hollow slab should be considered by two conditions according to section stress status; （3） it is inappropriate to regard GBF high-strength thin-wall pipes as pore-forming internal mold, its influence on the structural ultimate bearing capacity should be considered adequately.