为研究侧向荷载模式和目标位移计算对不同类型竖向刚度不规则结构推覆分析结果的影响,建立竖向刚度不规则结构推覆分析方法。选择一栋12层的钢筋混凝土框架结构作为标准模型,通过对其刚度进行调整,建立4种常见的竖向刚度不规则形式的结构计算模型。采用5种固定侧向荷载模式和4种目标位移计算方法,分别对4种不同形式的竖向刚度不规则结构进行推覆分析,并与弹塑性时程分析结果进行比较分析。研究结果表明,在预测目标位移和层间位移上,侧向荷载模式和目标位移计算方法的选择对计算结果有较大影响,对不同的竖向刚度不规则结构应根据其不规则形式。给出竖向刚度不规则形式所对应的侧向荷载模式和目标位移计算方法合理选择表,其中侧向荷载模式三角分布ITR和能力谱方法(Cap S)在计算竖向刚度不规则结构层位移和层间位移计算具有较好的通用性和实用性。研究成果可为竖向刚度不规则高层建筑结构抗震性能评估提供参考。
Pushover analysis of the vertically stiffness-irregular high-rise structures was established to investigate the influence of lateral-load mode and target-displacement calculation method on the calculated results of pushover analysis.A 12-storey RC frame was selected as the standard model, based on which the calculation models of four patterns of vertically stiffness-irregular structures were obtained by adjusting the stiffness. Pushover analysis was conducted by using five fixed lateral-load modes and four target-displacement calculation methods, and the calculated results were compared with elastic-plastic time history analysis. The results show that the selection of lateral-load mode and target-displacement calculation method significantly influences the predicting target-displacement and storey drift, and should be chosen according to irregular-pattern. The lateral-load mode with regard to vertically stiffness-irregular pattern and reasonable option list with regard to target-displacement calculation method can be obtained, and triangular distribution of lateral-load mode(ITR) and Capacity spectrum method(Cap S) have better popularity and practicability in calculating storey drift. The results can be the reference for seismic estimation of vertically stiffness-irregular high-rise structures.