全装配式RC楼盖横板向传力性能试验研究及理论分析

Experimental study and theoretical analysis of force transmission performance in orthogonal slab laying direction of untopped precast RC floor

为研究分布式连接全装配RC楼盖(DCPCD)横板向传力性能,完成了8个对边简支试件的竖向静载试验。基于共轭法提出了DCPCD横板向刚度的计算方法,并研究了板缝数量、板缝连接件数量、楼盖跨度和横板向与顺板向刚度比等参数对DCPCD横板向传力性能的影响。结果表明:DCPCD试件的板缝连接件受力性能良好,可有效地传递横板向弯矩和剪力,并能较好地协调相邻预制板的变形;基于共轭法的DCPCD横板向刚度计算方法的精度比最小截面刚度法和折线变形法高;减少板缝数量、增加板缝连接件数量均可有效改善楼盖横板向的传力性能,提高楼盖的竖向承载力和刚度;基于楼盖承载力与振动舒适度的要求,建议四边简支楼盖横纵向刚度比的取值范围为0.3~0.75。

In order to investigate the force transmission performance in orthogonal slab slaying direction(OSLD)of discretely connected precast RC floor diaphragm(DCPCD),the vertical static load tests consisting eight specimens under the consition of opposite sides simply supported were conducted.Based on the conjugate method,the calculation method of stiffness in OSLD of DCPCD was put forward,and the influence of the number of slab joints,the number of slab joint connectors,the span of floor and the stiffness ratio in OSLD and slab laying direction(SLD)on the force transmission performance of DCPCD was investigated.The results show that the slab joint connectors of DCPCD have good working performance,it can effectively transmit the bending moment and shear force in OSLD,and it can better coordinate the deformation between adjacent precast slabs.The stiffness calculation method in OSLD of DCPCD based on conjugate method theory has higher calculation accuracy than the minimum section stiffness method and folded line deformation method.Reducing the number of slab joints and increasing the number of slab joint connectors can effectively improve the force transmission performance in OSLD of the floor,and improve the vertical bearing capacity and stiffness of the floor.Based on the requirements of floor bearing capacity and serviceability,it is suggested that the stiffness ratio in OSLD and SLD of floor simply supported on four sides is 0.3~0.75.