【摘要】 地震具有丛集的特征,主震发生之后通常伴随余震,主震震级越高,余震对结构的破坏越大。桥梁结构作为生命线工程中的重要一环,应在整个地震序列发生时确保通行。选用集集地震序列时程数据,对桥梁进行地震响应分析,发现结构在主震作用下,主梁发生落座,余震作用下有落梁的可能。结合国内外现有的连梁装置设计方法对结构布设抗震措施,并与初始结构的地震响应作对比,结果显示,连梁装置可有效抑制桥梁上、下部结构相对位移,提高结构抗推能力与整体性。因边墩负荷增大,主震激励下边墩发生了塑性破坏,余震序列作用下结构仍保安全。分析结构地震序列作用下的抗震性能,以保证结构在地震时的通行能力,这是非常必要的。更多还原

【Abstract】 Earthquake has the character of cluster.The aftershocks happen after the mainshock and the mainshock with great magnitude has larger destructive aftershocks.As an important part of lifeline engineering,bridges are required to be secure during earthquake.Using the Chi-Chi earthquake sequence,the time-history analysis has been carried out for bridge;the girder will fall down from supports under mainshock,and may fall off the piers under aftershocks.Based on the related design standards at home and abroad,we designed the cable-unseating prevention devices for the bridge.The change of the structural seismic responses and the effect of collapse-resistance were compared.Unseating prevention devices can provide the ultimate security to the structure under earthquake,ensure the integrity and increase the anti-pushing rigidity of the structure.As the load of side-pier is increased,the plastic deformation occurs under mainshock,but the bridge is secure under aftershocks.It’s necessary to analyze the seismic performance of bridges under earthquake sequences.更多还原