多次内爆炸荷载下剪力墙累积毁伤破坏试验

Experimental Study on Cumulative Damage of Shear Wall Under Multiple Internal Explosions

随着导弹武器制导精度和侵彻能力的提高,多次内部爆炸毁伤逐渐成为打击建筑物的重要形式。剪力墙作为建筑物中重要的结构构件,内爆炸下的毁伤机制和破坏模式有待深入研究。为较好地再现剪力墙的约束条件和荷载环境,利用一个1/3缩尺钢筋混凝土剪力墙结构,对剪力墙开展不同TNT当量的多次内爆炸试验。通过分析构件的裂缝分布、损伤情况和跨中位移等,探讨内爆炸威力、加载次数等对剪力墙构件的破坏模式、毁伤等级的影响。试验结果表明:内爆炸荷载较弱时,多次作用将使剪力墙的破坏模式由弯曲破坏向弯剪破坏、且以弯为主转变;当内爆炸荷载较强时,剪力墙的破坏模式由弯剪破坏且以剪为主向完全剪切破坏转变;多次内爆炸作用后,当剪力墙存在初始轻度毁伤时,其抵抗变形能力强于不存在初始损伤的剪力墙,当剪力墙存在初始中度及其以上毁伤时,其抵抗变形能力弱于不存在初始损伤的构件;开展剪力墙构件的累积毁伤评估时,应考虑多次毁伤间的相互关联性。

With the improvement of guidance precision and penetration capability of missile weapons,multiple internal explosions have gradually become an important form of attacking buildings.Shear wall is an important structural component in buildings,and its damage mechanism and failure mode need to be further studied under internal explosions.In order to reproduce the constraint conditions and load scenarios of shear wall,a 1/3 scaled reinforced concrete structure was used to conduct multiple internal explosion tests with different TNT charge masses.By analyzing the crack pattern,damage level and mid-span displacement of structure component,the influence of internal explosion strength and loading times on the failure mode and damage level of the shear wall is studied.The results indicated that when the internal explosive load is small,the failure mode of shear wall would change from bending to bending-shear.However,when the internal explosive load is large,the failure mode of shear wall would change from bending-shear to complete shear.Under the multiple explosive loading scenarios,the deformation resistance of shear wall with initial mild damage is larger than that of the shear wall without initial damage.On the other hand,the deformation resistance of shear wall with the initial moderate or higher-level damage is lower than that of the shear wall without initial damage.Therefore,the correlation between multiple damages should be considered in order to evaluate the cumulative damage of shear wall component.