Abstract

Shake table tests were conducted on three 1:3 reduced scale two-story RC frames having weaker beam-column joints. The models were subjected to multi-levels input acceleration time histories to understand the seismic behaviour of test models. The models incurred severe damages in beam-column joint panels, forming shear hinging in joint panels, and were found in the incipient collapse state under input excitation below the design level excitation. Elastic hypothetical structures were considered having fundamental frequency that of test structures, which were subjected to actually recorded input excitation, in order to assess the seismic demands (base shear force and lateral roof displacement) using simplified analytical static procedure. The analytically predicted demands were correlated with the measured inelastic response, in order to calculate seismic response parameters (force reduction factor R and displacement modification factors C_d). On average, R = 2.0 and Cd = 1.86 were obtained for the considered structures. The derived seismic response parameters can be employed in the analytical static force-based procedure for the seismic vulnerability assessment of RC frame structures having weaker beam-column joints. Example study is presented for the vulnerability assessment of considered structure using the proposed analytical static force procedure and the derived seismic response parameters.

摘要

振动台测试是在三个 1:3 缩小比例的两层钢筋混凝土框架上进行的，这些框架具有较弱的梁柱接头。对模型进行多级输入加速度时程，以了解测试模型的地震行为。模型在梁柱节点面板中发生严重损坏，在节点面板中形成剪切铰链，并且在低于设计水平激励的输入激励下发现处于初期坍塌状态。弹性假想结构被认为具有测试结构的基频，测试结构受到实际记录的输入激励，以便使用简化的分析静态程序评估地震需求（基础剪力和横向屋顶位移）。分析预测的需求与测量的非弹性响应相关，R和位移修正系数C _d )。对于所考虑的结构，平均而言，R = 2.0 和 Cd = 1.86。推导出的地震响应参数可用于基于分析静力的程序，用于对具有较弱梁柱节点的 RC 框架结构进行地震脆弱性评估。使用所提出的分析静力程序和导出的地震响应参数，对所考虑结构的易损性评估进行了示例研究。