为减小不等墩高的非规则连续梁桥的低墩地震损伤集中,研究橡胶支座布置对它的影响趋势,以5座非规则连续梁桥为研究对象,通过橡胶支座布置,使得不同墩高的桥墩刚度接近或相同,然后通过建立有限元模型,分析了桥梁的弹塑性地震反应,并进行了理论分析比较。研究结果表明:低墩采用柔性橡胶支座时,在低墩屈服之前,可以有效改善非规则连续梁桥的地震反应,减小低墩的地震损伤;在低墩屈服以后,改善效果明显降低,低墩仍然存在地震损伤集中;对于一座具体的非规则连续梁桥,首先需要根据设计地震输入,选择高、低墩的合理损伤状态组合,然后合理布置不同刚度的橡胶支座。
In order to decrease the earthquake damage concentration onto low piers of irregular continuous bridges with piers of different lengths, impact of laminated rubber bearings (LRB) on their seismic response was studied. Taking 5 irregular continuous bridges as examples, the stiffnesses of piers with different lengths were adjusted to be close to or the same with each other by distributing LRB. With the finite element method, their elastic-plastic seismic responses were analyzed and comparative analysis was conducted with theoretical methods. The results show that when the low pier adopts relatively flexible LRB, the earthquake damage concentration can be effectively decreased before the low pier yields, however, the earthquake damage concentration still exists after the low pier yields. Therefore, as for an irregular continuous bridge, the reasonable earthquake damage state of the low piers and tall piers should be firstly confirmed based on the corresponding designed earthquake input, and then the reasonable LRB distribution can be selected.