空心楼盖板柱增强节点抗冲切性能数值分析

NUMERICAL STUDY OF PUNCHING SHEAR BEHAVIOR OF THE HOLLOW FLOOR SLAB-COLUMN REINFORCED CONNECTION

为研究现浇空心楼盖板柱增强节点的抗冲切性能,在试验研究的基础上,对纵筋配筋率、暗梁箍筋加密区间距、弯起钢筋直径进行数值分析研究。结果表明:现浇空心楼盖板柱增强节点的裂缝分布规律具有与普通双向板类似的板底"饱满X型"、板顶"椭圆形",节点的破坏形态为弯曲破坏;纵筋配筋率的增加能够提高板柱增强节点的极限承载力和刚度,但纵筋配筋率超过2.54%,极限承载力已不能明显提高。随着纵筋配筋率的增加,节点的破坏形态由弯曲破坏向冲切破坏转变;暗梁加密区箍筋间距的减小和弯起钢筋截面积的增大均可提高板柱增强节点的极限承载力,但提高不明显;现浇空心楼盖板柱增强节点的受冲切承载力可参考普通实心板柱节点的理论计算方法,计算值与试验值吻合较好。

To study the mechanical property on the RC hollow floor slab-column reinforced connections（HFS-CRC）under vertical load,on the basis of experiment,it was mainly conducted a numerical study of tension reinforcement ratio,hoop reinforcement of hidden beam and bent-up steel bar diameter.The result showed that the fracture distribution of HFS-CRC possessed of the characteristics of flexural failure,consisting of inclined cracking like＂X＂at the bottom of the floor and cracking like ellipse at the top of the floor.Although the ultimate capacity and stiffness increased as reinforcement ratio increased,the enhancement was insignificant when the reinforcement ratio was greater than 2.54%.Failure mode of HFS-CRC change from punching shear failure to flexural failure as reinforcement ratio increased.The ultimate bearing capacity could be increased as the space of hoop reinforcement of hidden beam decreased and bent-up steel bar diameter increased,but the enhancement was insignificant.The theoretical calculating method of common solid slab-column reinforced connection can provide a reference for the punching shear capacity of HFS-CRC,and the calculated results agree well with the test results.