【摘要】 限制楼层刚度比是结构抗震设计中的关键控制指标之一。通过3个首层层高不同的钢筋混凝土框架结构模型振动台试验和动力弹塑性时程分析,研究楼层刚度突变对钢筋混凝土框架结构软弱层的形成和结构破坏倒塌模式的影响,结果表明:限制上、下楼层侧向刚度比对于防止结构发生软弱层的破坏、倒塌是十分必要的;控制楼层侧向刚度不小于相邻上一层的70%或不小于其上相邻3个楼层侧向刚度平均值的80%,采用楼层剪力与层间位移比的方法来计算楼层侧向刚度比,并以此方法判定结构的软弱楼层比较合理;对于刚度比不满足限制条件的楼层,地震剪力取1.15的放大系数,但其数值偏小,宜适当提高。更多还原

【Abstract】 Limiting the lateral stiffness ratio is one of the important issues in seismic design. Through three shaking table tests and a dynamic elastoplastic time-history analysis of reinforced concrete frame structures with different storey heights of the first floor,the effects of sudden change of stiffness on structure collapse and soft storey formation are studied. It is found that it is necessary to limit the lateral stiffness ratio of neighboring storey in preventing destroyed or collapsed in soft storey. Storey lateral stiffness should not be less than 70% of the story above or not less than 80% of the average stiffness of the three stories above. It is reasonable to use the ratio of storey shear and storey displacement as the storey lateral stiffness index to determine soft storey. For the storey with stiffness ratio out of the limit range,the commonly employed factor for soft storey,1.15,should be increased in seismic design.更多还原