爆炸荷载作用下缆索承重桥梁塔梁构件的破坏特征  

Damage Characteristics of Steel Girder and RC Pylon of Cable-supported Bridge Suffered from Blast Loading

作　　者：朱璨[1] 马如进[1] 陈艾荣[1] 

机构地区：[1]同济大学土木工程学院,上海200092

出　　处：《公路交通科技》2016年第8期92-98,共7页Journal of Highway and Transportation Research and Development

基　　金：交通运输部西部交通建设科技项目(2011 318 494 160)

摘　　要：大型缆索支撑桥梁遭受爆炸荷载作用的风险在不断增加,相关抗爆研究仍不足。本文采用数值模拟方法,研究了大跨度缆索支撑桥梁中的钢箱梁、钢筋混凝土主塔在不同当量爆炸荷载作用下的冲击响应,着重分析了桥面爆炸影响下钢箱梁、钢筋混凝土主塔的局部破坏特性,考虑多种爆炸当量在桥面的多种典型位置模拟爆炸作用。首先运用非线性有限元软件,基于CONWEP算法,通过数值模拟,深入分析了钢箱梁、钢筋混凝土主塔的爆炸动力响应、破坏模式、破坏参数及其主要影响因素。结果表明:钢箱梁顶板受近距离爆炸冲击波作用出现开裂破口,横隔板对破口有明显的约束作用;由于爆炸点与桥塔距离较远和主塔壁较厚,钢筋混凝土桥塔的局部破坏较小,桥塔不会在恒、活荷载作用下压溃。为了模拟爆炸对于全桥的影响,提出了全桥数值简化方法。The potential risks of long-span cable-supported bridge subjected to blast loadare increasing, but the studies are inadequate. The impulse responses of steel box girder, reinforced-concrete pylon in this kind of bridge under several explosion equivalent loads are investigated by numerical simulation. The local failure characteristics of steel box girder and reinforced-concrete pylon when explosion occurs on the deck are emphasized. Considering several explosion equivalent loads and several typical positions on the deck, based on the CONWEP algorithm, the dynamic response process, failure mode, failure parameters and main influencing factors of the steel box girder and the reinforced concrete pylon subjected to blast load are simulated with nonlinear finite element software. The result shows that （ 1 ） there is deck-rupture appearing after steel box girder affected by the close range explosion wave, the deck local crack is significantly constrained by diaphragm; （2） because of the far distance between the explosion point and pylon as well as the thick pylon wall, the local under dead and live loads. To forward. damage of steel and concrete pylon is not obvious, pylon will not collapse simulate the effect of explosion to the whole bridge, a simplified method is put forward.

关 键 词：桥梁工程 缆索承重桥梁 数值模拟 爆炸荷载 钢箱梁 钢筋混凝土桥塔 局部破坏 

分 类 号：U443.38[建筑科学—桥梁与隧道工程]