踮脚和跳跃荷载下全装配式RC楼盖振动特性试验研究

EXPERIMENTAL STUDY ON THE VIBRATION CHARACTERISTICS OF UNTOPPED PRECAST RC FLOORS UNDER BOUNCEAND JUMPING LOADS

  • 摘要: 为研究分布式连接全装配RC楼盖(DCPCD)在人致激励下的动力特性和振动响应,进行了6个足尺DCPCD试件和1个现浇对比试件的锤击法试验和在踮脚、单人跳跃荷载下的人致激励试验,研究了板缝和连接件布置对DCPCD振动特性的影响。结果表明:DCPCD与现浇楼盖的低阶振型基本相同,但自振频率略低;DCPCD与现浇楼盖有相同的振动传递机制;相同激励下DCPCD的振动响应略大于现浇楼盖,现浇楼盖的加速度峰值出现在跨中的边缘,DCPCD的加速度峰值出现在近跨中板缝的边缘;DCPCD的自振频率随连接件的增加而提高,随板缝的增加降低,连接件对频率的影响大于板缝的影响;提出了两对边简支条件下DCPCD横板向竖向自振频率与加速度计算方法,并以试验验证了所提方法的准确性。

     

    Abstract: To study the dynamic characteristics and vibration responses of discretely connected precast RC diaphragms (DCPCD) under human-induced excitation, six full-scale DCPCD specimens and one cast-in-place specimen were tested by hammer modal test and human-induced excitation test under bounce and jumping loads. The effects of plate seam and connector layout on DCPCD vibration characteristics were examined. The results show that the low-order vibration mode of DCPCD and cast-in-situ floor was basically the same, but the natural frequency of DCPCD was slightly lower. The DCPCD had the same vibration transmission mechanism as the cast-in-situ floor. The vibration response of DCPCD was slightly larger than that of the cast-in-situ floor under the same excitation. The peak acceleration value of the cast-in-situ floor appeared at the edge of the mid-span, and the peak acceleration of DCPCD appeared at the edge of the slab joint near the mid-span. The natural frequency of DCPCD increased with the increase of the slab joint connectors and with the decrease of the slab joint connections, where the effect of the connector on the frequency was greater than that of the slab joint connection. Methods for calculating the vertical natural frequency and acceleration of the DCPCD in the orthogonal slab laying directions with two pairs of sides simply supported were proposed. The accuracy of the proposed methods was verified by the experimental results.

     

/

返回文章
返回