附加与不附加粘滞阻尼墙的RC框架对比振动台试验研究

Comparative experimental study of concrete frames with and without supplemental viscous damping walls

本文阐述了附加与不附加粘滞阻尼墙的两个相同的RC框架模型模拟地震振动台对比试验的情况.这两个钢筋混凝土框架模型为三层一跨两开间,几何相似关系大致为1:2.首先进行力学性能试验,认识粘滞阻尼墙的耗能能力,得到其力学性能计算公式;然后将阻尼墙附加到一个RC框架模型当中,先后对附加与不附加阻尼墙的两个相同的RC框架模型进行振动台试验.试验结果表明,附加阻尼墙以后,框架模型的第1自振频率由1.66Hz提高到1.94Hz,第1振型阻尼比由2.4%提高到20.9%;在较小和中等加速度峰值的不同地震波作用下,结构的楼层位移反应、加速度反应和层间剪力都有不同程度的减小;输入结构的地震能量有大约60%～70%被阻尼墙吸收、耗散.在同样强烈的地震作用下,附加阻尼墙的耗能框架模型破坏较轻,不附加阻尼墙的普通框架模型破坏严重.

This paper presents a comparative experimental study on seismic behavior of two identical concrete model frames with and without supplemental viscous damping walls. The two models are 1/2-scale three-story, one-bay by two-bay frames. The experiment on the viscous damping walls was done first, and the mechanical performance of these dampers was acquired. Then these dampers were installed to one of the two identical concrete frames, and shaking table tests of the two frames were carried out with different seismic input respectively. The test restdts showed that the first natural frequency of the concrete frame is increased from 1.66 Hz to 1.94 Hz, the damping ratio of the first frequency is increased from 2.4% to 20.9% after installing three viscous damping walls. Under minor and moderate earthquake, the interstory drifts, floor accelerations and the story shears of the frame with dampers are reduced remarkably in comparison to the undamped one. Meanwhile, the viscous damping walls dissipate 60%-70% of the input seismic energy in the damped frame. When earthquake is more intense, the undamped frame become cracked and crushed at the ends of beams and columns, and the natural frequencies are much reduced; but the frame with dampers keeps in better condition under the same intense earthquake.