为了正确评估不同受力状态下未约束和纤维增强复合材料(FRP)约束钢筋混凝土(RC)矩形空心桥墩的损伤性能,基于力-位移响应,提出了考虑残余位移和累积耗能的综合损伤模型。根据既有RC柱的损伤等级划分标准,应用该模型和已有损伤模型对未约束和FRP约束RC矩形空心桥墩的损伤性能进行判别,并与水平单向拟静力荷载作用下模型墩柱受力性能的试验结果进行对比。结果表明:提出的综合损伤模型可准确判别试验桥墩的微损伤和中等损伤程度,仅考虑塑性位移的损伤指标可准确判别其严重损伤程度;进一步应用FRP约束模型墩柱的损伤判别结果,结合模型墩柱的试验现象,提出了FRP约束RC空心桥墩的损伤等级划分标准。
In order to accurately evaluate damage performances of FRP confined and unconfined RC bridge piers with rectangular hollow cross section under different loading stages,on the basis of force-displacement response,a new composite damage model with residual displacement and cumulative energy was proposed.According to existing damage classification standards of RC column,the new damage model and the existing damage models were applied to estimate damage performances for unconfined and FRP confined RC bridge piers with rectangular hollow cross section,which was compared with the experimental results of stress performence on model pier under unidirectional horizontal quasi-static load.The results show that the proposed damage model can exactly identify micro damage and medium damage for tested bridge piers,and the damage index denoted by plastic displacement can correctly discern critical damage level.Based on the damage identification results and the experimental results of FRP confined model pier,a new damage classification standard is proposed for FRP confined RC bridge piers with rectangular hollow cross section.