基于易损性的冻融损伤圆形桥墩抗震能力评价

ASSESSMENT OF SEISMIC CAPACITY OF CIRCULAR PIERS DAMAGED BY FREEZE-THAW BASED ON VULNERABILITY

为研究寒冷气候条件下的冻融循环作用对桥墩抗震性能劣化的影响,文中基于地震易损性分析理论,引入抗震能力裕度比这一概念,提出了冻融损伤桥墩抗震能力评价方法,并据此研究了冻融损伤对圆形桥墩抗震能力的影响程度。结果表明抗震能力裕度比可直观反映冻融损伤对桥墩抗震能力的影响程度;随着冻融损伤程度增加,圆形桥墩的抗震能力裕度不断降低;冻融损伤对桥墩抗完全破坏能力的储备程度影响最为显著。研究可为实际中考虑冻融损伤桥墩设计提供理论依据。

This paper studies the impact of freeze-thaw cycles under cold climate conditions on the seismic performance degradation of bridge piers.Based on the theory of seismic vulnerability analysis and introducing the concept of seismic capacity margin ratio,this paper proposes an evaluation method of seismic capacity of bridge piers damaged by freeze-thaw to study the influence of freeze-thaw damage on seismic capacity of circular piers.The results show that the margin ratio of seismic capacity directly reflects the impact of freeze-thaw damage on the seismic capacity of piers.With the increase of freeze-thaw damage,the margin of seismic capacity of circular piers decreases.Freeze-thaw damage has the most significant impact on the reserve degree of pier's ability to resist complete damage.The study may provide the theoretical basis for considering freeze-thaw damage in bridge pier design in practice.