【摘要】 地震作用下大跨斜拉桥梁端会发生很大位移,过大位移可能会导致主梁与引桥发生碰撞。针对地震作用下大跨斜拉桥伸缩缝处的碰撞现象,以一座大跨斜拉桥工程设计为例,采用非线性时程法研究了纵向地震作用下大跨斜拉桥主引桥碰撞效应对结构地震反应的影响规律。研究结果表明:碰撞效应不仅会产生很大的撞击力,而且可能使引桥地震力需求、引桥梁端位移、主引桥相对位移及引桥梁体搭接长度需求有较大增长,极易造成引桥的落梁或者破坏;但碰撞效应对主桥的地震需求影响较小。更多还原

【Abstract】 For a long span cable-stayed bridge,the seismic displacement at the end of the deck may severely exceed the allowance which due to the occurrence of the pound between the main span and the approach span usually which can causes the collision of falling-beams and structures under strong earthquakes.In this paper,based on the pounding phenomenon at expansion joints of long span cable-stayed bridge under strong earthquake and employing a long span cable-stayed bridge,with the time history ana-lysis method,the pounding effects of adjacent girders at expansion joints on seismic responses of long-span cable-stayed bridge are studied.The results indicate that the pounding can amplify the seismic demand of piers of the approach span and also can amplify the displacement of beam of the approach span,the relative displacement between main span and approach span and the hinge seat width of beam of approach span obviously and it causes easily the collision of falling-beams and structures under strong earthquakes.But the pounding has minor effects on seismic demand of the main span.更多还原