进行了两个3层、4×2跨的钢筋混凝土空间框架模型的连续倒塌试验,模型1的初始失效柱是底层长边中柱,模型2的初始失效柱是底层角柱。模型不考虑抗震要求,以机械千斤顶替换初始失效柱,通过机械千斤顶的分级卸载模拟柱的初始失效。观测并分析了两个试验模型的抗力-位移曲线、结构受力机制及结构抗连续倒塌能力。分析表明,对于模型1,结构抗连续倒塌机制包含梁机制和悬链线机制;对于模型2,结构抗连续倒塌机制仅为梁机制。
Progressive collapse experiments were carried out for two, (4 x 2)-bay and 3-storey reinforced concrete (RC) spatial frame models, which were designed without seismic demand. The middle of long side column and the comer column of the bottom floor, respectively in model 1 and model 2, were replaced by mechanical jacks to simulate the initial damage. Resistance-displacement curve, load transferring mechanism and progressive collapse resistance of the two models were analyzed. It is concluded that progressive collapse resistance consists of beam mechanism and catenary mechanism in model 1. Only beam mechanism plays a part in resisting progressive collapse in model 2.