Evaluation of seismic response of soft-storey infilled frames
Evaluation of seismic response of soft-storey infilled frames
复制标题
软层填充框架地震反应评价
DOI：
10.12989/cac.2005.2.6.423
复制
发表时间：
2005
影响因子：
4.1
通讯作者：
K. Muthumani
中科院分区：
文献类型：
--
作者：
M. Santhi;G. Knight;K. Muthumani
本研究设计了两个单跨三层空间框架，一个在第二层和第三层填充砖砌体，代表软层框架，另一个没有填充，并根据非抗震构造和相似律建造了1：3的模型。使用振动台，以印度地震规范IS 1893-2002中反应谱形式规定的地震运动强度对模型进行激励。比较了软层框架与裸层框架的基频、振型、基底剪力和刚度等地震反应。据观察，开放的底层的存在下，在软层填充框架的固有频率降低了30%。在软层框架的剪切需求被发现是超过2.5倍以上，在裸框架。从振型分析可知，裸框架为弯曲振型，而软层框架为剪切振型。框架进行了测试失败和损坏的软层框架进行了改造与混凝土护套，并受到相同的地震运动的原始框架。使用SAP 2000软件包进行推覆分析，以验证测试结果。获得了所有框架的性能点，因此，框架被认为是足够的重力荷载和中等地震。结果表明，静力非线性pushover分析能够较好地模拟砌体填充钢筋混凝土框架的整体非线性地震反应。
In this study two single-bay, three-storey space frames, one with brick masonry infill in the second and third floors representing a soft-storey frame and the other without infill were designed and their 1:3 scale models were constructed according to non-seismic detailing and the similitude law. The models were excited with an intensity of earthquake motion as specified in the form of response spectrum in Indian seismic code IS 1893-2002 using a shake table. The seismic responses of the soft-storey frame such as fundamental frequency, mode shape, base shear and stiffness were compared with that of the bare frame. It was observed that the presence of open ground floor in the soft-storey infilled frame reduced the natural frequency by 30%. The shear demand in the soft-storey frame was found to be more than two and a half times greater than that in the bare frame. From the mode shape it was found that, the bare frame vibrated in the flexure mode whereas the soft-storey frame vibrated in the shear mode. The frames were tested to failure and the damaged soft-storey frame was retrofitted with concrete jacketing and, subjected to same earthquake motions as the original frames. Pushover analysis was carried out using the software package SAP 2000 to validate the test results. The performance point was obtained for all the frames under study, therefore the frames were found to be adequate for gravity loads and moderate earthquakes. It was concluded that the global nonlinear seismic response of reinforced concrete frames with masonry infill can be adequately simulated using static nonlinear pushover analysis.