基于倒塌分析的连续梁桥地震损伤评估方法

为了掌握钢筋混凝土连续梁桥在地震作用下从完好到倒塌的破坏历程,首先,基于振动台试验研究对两跨连续梁桥模型进行倒塌仿真分析;其次,建立结构层次的单一倒塌准则;最后,根据影响结构倒塌的关键构件提出两跨连续梁桥地震损伤的整体评价指标D和破坏等级划分标准。结果表明:提出的能量比指标可以有效识别出地震损伤时刻甚至倒塌时刻,当能量比小于能量比限值时即可判定进入倒塌阶段;纵向地震动作用下中墩墩柱和固定支座是关键受力构件;基于关键构件提出的两跨连续梁桥地震损伤整体评价指标D可对不同损伤程度的两跨连续梁模型桥进行评估,该评价体系也可为同类桥型的地震损伤评估和抗震加固提供参考。

Collapse Analysis-Based Seismic Damage Evaluation of Continuous Girder Bridge

To explore seismic damage history from sound to collapse of reinforced concrete continuous bridge based on shaking table test, the collapse analysis of two-span continuous girder bridge model is carried out, and then a single collapse criterion is established at a structural level. Based on the key components of collapse, the overall evaluation index of seismic damage of the two-span continuous beam bridge D is proposed, and the criteria for the classification and damage grades are presented. Numerical analysis results show that the energy ratio index proposed in this paper can effectively identify the time of earthquake damage and even the time of collapse. If the energy ratio is not more than the limit, the bridge will collapse. The middle pier and fixed bearing are the key components. It is proved that index D proposed on the key components can assess the damage of the two-span continuous girder bridge model with different degrees. This evaluation system can also provide a reference for seismic damage assessment and seismic retrofitting of the same kind of bridges.