Abstract: The basting loading capabilities of the main girder of a long-span cable-stayed bridge after different levels of explosives explosion on the inner lane and the outer lane have obtained by using fluid-structure interaction analysis． The analysis models of concrete girder and part of girder were established，and the damage of main girder after different levels of explosives explosion was analyzed． The results show that damage scope is mainly affected by the quality of the explosion and the type of main girder; and it has small relevance with the location of explosion． Full-bridge model is established to perform dynamic analysis，and the results show that axial stress of main girder have little change during vibration; the cables close to the explosion have the high risk of break．

Key words: blast loads, cable-stayed bridge, local damage, dynamic response

摘要： 以大跨径斜拉桥为例，运用流固耦合分析得到了不同等级炸药在内车道以及外车道爆炸后主梁承受的爆炸荷 载力。建立混凝土箱梁、钢箱梁局部分析模型，分析不同等级爆炸发生后主梁的损伤。结果表明:主梁损伤范围主 要受主梁类型以及爆炸质量影响，与爆炸发生水平位置的关联度很小。进一步建立全桥分析模型，根据爆炸荷载时 域模型，开展了动力响应分析。结果表明:振动作用下主梁轴向应力变化很小，靠近爆炸点附近的拉索有较高的断 索风险。

关键词: 爆炸荷载, 斜拉桥, 局部损伤, 动力响应