踮脚和跳跃荷载下四边简支全装配式RC楼盖振动特性试验研究

为研究分布式连接全装配RC楼盖(简称全装配楼盖)竖向动力特性与人致激励响应规律，进行了2个全装配楼盖和1个现浇楼盖在四边简支条件下的动力试验，并施加了多种人致振动激励，分析了楼盖在踮脚和跳跃荷载下的振动特性。结果表明：全装配楼盖的自振频率小于现浇楼盖的，而阻尼比相对于现浇楼盖的有较大提高，前3阶的振动模态中只有第1阶与现浇楼盖的相同；板缝连接件可有效传递全装配楼盖横板向振动，大幅提高其振动频率、减小楼盖振动响应；连接件数量和位置对全装配楼盖竖向振动响应有较大影响，跨中连接件的影响最显著；随着荷载频率和行人的增加，全装配楼盖的峰值加速度逐渐增大，荷载越靠近楼盖中心则峰值加速度越大，单人激励下全装配楼盖与现浇楼盖的峰值加速度差值大于多人激励下的；全装配楼盖的振动频率满足舒适度要求，但峰值加速度响应不满足舒适度性能指标，设计中可根据要求选择连接件规格和数量，以达到自振频率和峰值加速度双控条件下的舒适度评价标准；基于正交各向异性双向板振动理论提出用于预测全装配楼盖自振频率和峰值加速度的计算方法，所得理论值与试验值吻合良好。

Experimental study on vibration behavior of simple supported untopped precast RC floor under bounce and jumping loads

An experimental program consisting of two discretely connected precast reinforced concrete diaphragm (DCPRCD) specimens and one cast-in-situ slab (CISS) specimen were conducted to investigate their dynamic characteristics and human-induced excitation response. The vertical vibrating characteristics of the test specimens under the four sides simply supported condition were tested, and the vibration performance under bounce and jumping loads were analyzed by applying a variety of human-induced excitations on the specimens. The results show that the natural frequency of DCPRCD is slightly lower than that of CISS, but the damping ratio improves notably compared to CISS. Among the first three modes of DCPRCD, only mode 1 is the same as CISS. The slab joint connectors can effectively transmit the horizontal vibration of DCPRCD, greatly increase the frequency of DCPRCD, and reduce the vibration response. The number and position of connectors have a great impact on the vertical vibration response of DCPRCD and the mid-span connectors have the most significant impact. The peak acceleration of DCPRCD increases with the increase of load frequency and the number of people. The closer the load is to the center of the floor, the greater the peak acceleration. The difference between the peak acceleration of DCPRCD and CISS under single-person excitation is greater than that under multiple-person excitation. The vibration frequency of the DCPRCD meets the serviceability requirements, but the peak acceleration does not. The specification and quantity of connectors should be designed to meet both requirements in practical application. The numerical calculation models for predicting the natural frequency and peak acceleration of DCPRCD were proposed based on the vibration theory of orthogonal two-way anisotropic plates and a good correlation between the test values and calculated values was observed.