钢筋混凝土框架结构基于规范需求谱Pushover分析方法的保证率

Probability analysis of reinforced concrete frame structure Pushover analysis method based on specification demand spectrum

运用SAP2000软件从5个方面探讨了三维框架结构顶点位移对地震烈度、场地条件、侧向力加载模式、结构重量和材料性能等不确定性因素的敏感性程度。然后建立了一个7层的三维框架模型,详细地分析了各类场地条件下的确定性Pushover分析顶点位移和Pushover实际需求谱分析顶点位移。根据统计分析原理对顶点位移的概率分布进行了研究,从而得到确定性Pushover分析方法的保证率和适用性。结果表明:顶点位移对需求曲线的敏感性远强于能力曲线;若地震作用下结构的变形进入弹塑性状态,则确定性Pushover分析结果保证率较高,在这样的情况下,Pushover分析方法是一种可靠的抗震性能评估方法;若结构变形在地震作用下始终处于弹性状态,则Pushover分析方法不适用。

The sensitivities of the top displacements of three-dimensional reinforced concrete frame structure to the uncertainty factors were discussed through using SAP2000 software from five aspects,such as the seismic intensity,site characteristics,lateral load loading mode,structural weight and material properties. Then,a 7-storey three-dimensional frame model was established to analyze the top displacements with the certainty Pushover analysis method and the Pushover actual demand spectrum analysis method under various site conditions. According to the principle of statistical analysis,the probability distribution of the top displacement was studied,and the guarantee rate and applicability of the certainty Pushover analysis method were obtained. The results show that the sensitivity of top displacement to demand curve is much stronger than to the capacity curve; if the deformation of structure enters the elastic plastic state under seismic action,certainty Pushover analysis results have higher guarantee rate,and in such a situation,the Pushover analysis method is a reliable method of seismic performance evaluation; if the structure deformation is always elastic state under the action of earthquake,Pushover analysis method is not applicable.