Abstract: The downstream section of the longitudinal Roller Compacted Concrete (RCC) cofferdam in the secondstage construction in Xiangjiaba Hydropower Station needs to be removed by blasting. In this paper, the design and selection of the cofferdam 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 highprecision detonating tube detonator on a large scale blasting network design. Under this design, the vibration resulted from the largest single blasting meets the requirement.  Other safety assurance measures are also adopted to ensure the safety.

Key words: Demolition Blasting, Concrete Cofferdam, Blasting Network, Safety Assurance