高架桥混凝土多室箱梁水压爆破破碎机理数值模拟

Numerical simulation of water-pressure blasting mechanism in breaking viaduct box girder

高架桥钢筋混凝土箱梁属于薄壁空腔结构,钢筋含量高,难以进行钻孔爆破破碎。以武汉沌阳高架桥爆破拆除工程为背景,提出了采用水压爆破破碎多室钢筋混凝土箱梁的方案,并采用动力有限元数值模拟方法模拟了全封闭多室箱梁结构的水压爆破破坏过程,研究了炸药在水中爆炸后诱发的冲击波和爆生气体对下箱梁结构的双重作用过程;在对数值模拟与实际爆破效果分析基础上,探讨了箱梁水压爆破方案的药包布置方式、爆破参数和起爆顺序等。

As a thin-walled structure with a very high content of reinforcement,a viaduct box girder is hard to break using the drilling-style blasting.In this paper,based on the demolition project of Zhuan Yang Viaduct in Wuhan,a blasting plan using the water-pressure blasting technique was proposed to demolish multi-chamber reinforced concrete box girders.The breaking process of the multi-chamber box girder was simulated using the dynamic finite element method,the role played by the shockwave and the explosive gas in the breaking process were analyzed and,on the basis of the analysis and the actual blasting results,the charge arrangement,the blasting parameters and the blasting sequence of the water pressure blasting plan were discussed.