Abstract:To reduce the great vibration caused by the conventional blasting in the Jinduicheng stopes above the Dongchuan River tunnel, which is quite close to the stopes, digital electronic detonators were adopted and proper hole-to-hole and row-to-row blasting delays needed to be determined. Vibration was measured both inside the tunnel and on the working platform. A test was done comparing the different delays of digital electronic detonators and high precision blasting caps. Through studying the vibration wave profiles and other vibration data, the optimal short delay was determined to minimize the vibration. A blasting method that best controls the blasting vibration is thus found, to ensure the operation safety of the Dongchuan River Tunnel. As the result indicates, when the hole to hole delay is set at 30ms and row-to-row delay at 75ms, the blasting vibration frequency can be improved, reducing the vibration intensity by 22.7% as compared with the effect by conventional blasting. The test result serves as a good reference for further attenuating the blasting vibration in advanced stages of the Jinduicheng open-pit mine.
