拉链柱支撑钢框架结构振动台试验研究

为研究拉链柱支撑钢框架结构的抗震性能并对设计方法进行验证，完成了一个3层单跨1∶4缩尺比例的拉链柱支撑钢框架结构模型在24个地震作用工况下的模拟地震作用振动台试验。通过试验，得到了结构的动力特性、层间位移响应、加速度响应以及各结构构件的受力状态等。结果表明，8度多遇及设防烈度地震作用工况下，结构基本未进入塑性，试验模型振动时以第1阶模态振动为主。超9度罕遇地震作用工况下，底层支撑失稳明显，顶层支撑未见失稳。底层受拉支撑的最大轴拉力接近屈服轴力，受压支撑的屈曲后承载力约为支撑稳定承载力的30%，表明由支撑失稳产生的竖向不平衡力按受拉支撑的最小屈服承载力和受压支撑的最大屈曲承载力的30%计算是可行的。拉链柱主要通过受拉传递因支撑失稳产生的竖向不平衡力。因变形协调关系，被支撑梁可以承受一定的竖向不平衡力，在拉链柱未屈服的前提下，一般下层被支撑梁承受的竖向不平衡力要高于上层的。总体上，各构件的受力状态及传力路径与设计初衷基本一致，结构体系在模拟地震作用振动台试验中表现出了良好的抗震性能。

Shaking table test of zipper frames

In order to investigate the seismic performance and verify the design method of zipper frames, a 3-story 1∶4 scaled single-span zipper frame model was designed and tested using the shaking table under 24 different earthquake events. The dynamic properties, acceleration response, displacement response and force state of structural members were studied. The results show that, under frequent and occasional earthquake events of intensity 8, the test model does not develop plastic deformation and the dynamic performance is predominated by the first mode. Under rare earthquake events of over intensity 9, the first story brace buckles obviously and the top story brace doesn’t buckle. The maximum brace axial tension force is close to the yielding force and the brace post-buckling force is about 30% of the stability bearing capacity, indicating that the unbalanced vertical force due to brace buckling can be calculated using the yielding force of the tension brace and 30% of the stability bearing capacity of the compression brace. The unbalanced vertical force is mainly transferred by the zipper struts. Due to deformation compatibility, the braced beams also can transfer part of the unbalanced vertical force. If the zipper strut has not yielded, the unbalanced vertical force transferred by the braced beam at the lower story is larger than that at the upper story. In general, the force state and force-transferring path of the structural members are basically in accordance with the design objective and the zipper frame shows good seismic performance in the shaking table test.