柱帽处施工冷缝对无梁楼盖承载安全性影响的数值模拟分析

Numerical Immitation Analysis of the Influence of Cold Construction Joints at Column Cap on Bearing Safety of Flat Slab Floors

近年来,无梁楼盖作为地下室结构顶板得到了越来越多的应用。无梁楼盖作为地下室顶板,尤其是住宅的地下室顶板的主要优势在于其经济性。文章主要研究在均匀堆载和不均匀堆载下,无梁楼盖的受力特点及破坏模式。通过利用ABAQUS的粘结单元来模拟柱帽处施工冷缝对无梁楼盖承载力的影响。结果表明:无梁楼盖的柱帽托板与顶板之间分次浇筑(设施工冷缝)和一次性整体浇筑的两种施工方式对无梁楼盖的受力没有太大影响。但施工缝的接触面还是承担很大的摩擦力;分析表明超载是结构损伤的最直接原因;设计中应考虑适当提高抗冲切安全度。

Nowadays,Flat slab floors are widely used in top slab of basement structure.The main advantage of flat slab floor is more economic and efficient than other type of floors.This paper devoted to investigating the mechanical characteristics and failure mode of the flat slab floors under symmetrical and asymmetrical stack load.With the help of the cohesive element in software ABAQUS,construction cold joints between the column cap and the slab was simulated and studied on the influence of bearing capacity of flat slab floors.The results showed that,there is no huge impact on the bearing capacity of flat slab floors between the one-time entire concrete pouring and the multi-time concrete pouring of the column cap and slab.However,the interface of construction joint undertook great frictions.The overloading is the direct reason causing the damage of beamless slab.Designers should also consider to raise the punching shear safety.