基于推倒分析的桥梁地震损伤评估模型与方法

Seismic Damage Assessment Model and Method Based on Pushover Analysis for Bridges

推倒分析方法作为一种结构非线性地震响应的近似计算方法 ,以其概念简明、操作简便、能用图形方式直观地表达结构的抗震能力与需求等特点 ,正逐渐受到重视和推广 .A .Ghobarah提出利用两次推倒分析结果来计算多层建筑结构的损伤指数 .针对普通规则的桥梁结构 ,提出了推倒损伤模型的改进计算方法 ,该方法避免了非线性动力分析的繁琐 ,用简便的手段描述结构非线性特性 ,评价结构遭受不同地震烈度时的损伤程度 .通过一座双柱式桥墩的计算分析表明 ,采用这种方法可以简单、合理、可靠地得出结构的损伤值 .

Push over analysis is becoming an accepted method for the seismic evaluations of structures.The popularity of this approximate,nonlinear static analysis method is due to its conceptual simplicity and ability to graphically describe a structure's capacity and demand.A.Ghobarah proposed an approach to evaluate the damage index for multi storey buildings by using results of twice pushover analysis.In this paper,an improved method of the pushover damage model for standard bridge is proposed.This method can,without complex nonlinear dynamic analysis,describe nonlinear properties of structures by a simplified approach and can estimate the damage degree when the structures subjected to earthquakes with different intensities.The analysis of a double column pier has proved that this damage assessment model can give a simple,reasonable and consistent damage indicator for structures.