带自控连梁的双肢剪力墙振动台试验研究

本文通过带自控连梁的双肢剪力墙与普通剪力墙的振动台模型试验对比,进一步研究了自控连梁在动力作用下的抗震性能。对观测到的裂缝发展、破坏形式、自振频率和阻尼比的变化以及动力反应等进行了对比分析。结果表明:在弹性阶段,两模型的自振频率和阻尼比基本保持不变;当裂缝出现后进入弹塑性阶段时,带自控连梁剪力墙的阻尼比一直比普通剪力墙的高,并随着振动次数的增多,阻尼比增长更快一些;试验结束后,普通剪力墙的连梁和墙肢破坏严重,而带自控连梁的剪力墙基本完好。强烈振动时自控连梁开裂成两根小梁,通过其端部塑性铰的转动和上下小梁之间素混凝土凹槽中水平裂缝的错动摩擦消耗振动能量,延性好,有效地保护了墙肢。因此带自控连梁的双肢剪力墙具有良好的抗震性能。

Experimental study of coupled shear wall models with self-control connecting beam on shaking table

To study the seismic behavior of coupled shear wall with self-control connecting beams, the shaking table test of models of a conventional coupled shear wall and the new special coupled shear wall was carried out. Based on the results of the experiment, the cracking process and the failure pattern, the variation of vibrating frequency and damping ratio, and dynamic response were analyzed and compared between the two types of shear walls. The results showed that the natural frequencies and damping ratios of the both models were almost unchanged in elastic stage; as cracks appeared and the member entered upon plastoelastic stage, the damping ratio of the coupled shear wall with self-control connecting beam was being higher than that of the conventional shear wall, and the more were the number of vibration, the quicker the increasing of the damping ratio would be. After the test, the coupling beam and limbs of the conventional shear wall were seriously damaged, while the coupled shear wall with self-control connecting beam were still in almost fair condition. The coupled shear wall with self-control connecting beams could dissipate the vibration energy efficiently through the move of the plastic hinges at the ends of the two cracked small beams and the friction between them when subjected to high intensity vibrating, and therefore, its seismic behavior performed much better than those of conventional shear wall.