向家坝水电站二纵下游混凝土围堰拆除爆破设计优化

向家坝水电站二期纵向混凝土围堰下游段为碾压混凝土同堰，根据工程要求需进行爆破拆除。对围堰拆除爆破方案设计、比选，以振动控制和堰内堆渣量为主要评价指标，采用以坡面倾斜孔为主的钻爆方案。采用高精度导爆管雷管进行大规模的爆破网路设计，使最大单段药量产生的振动满足爆破安全的要求，同时采取必要的安全防护设计确保水电站主要设施的安全。

Downstream Longitudinal Concrete Cofferdam Demolition Blasting of in the Second-stage Project of Xiangjiaba Hydropower Station

The downstream section of the longitudinal Roller Compacted Concrete （RCC） cofferdam in the second-stage con struction in Xiangjiaba Hydropower Station needs to be removed by blasting. In this paper, the design and selection of the cof ferdam demolition blasting methods, vibration control criteria and the quantity inside the cofferdam are presented. The selected drilling and blasting plan was the method with predominant inclined boreholes. This method optimizes the design of blasting scheme and parameters, and utilizes the highprecision detonating tube detonator on a large scale blasting network design. Un- der this design, the vibration resulted from the largest single blasting meets the requirement. Other safety assurance measures are also adooted to ensure the safety.