Blasting Vibration Damping Characteristics of Digital Electronic Detonators in Flood Drainage Channel

Field tests of blast vibrations were conducted based on the concept of interference between blast-induced seismic waves for the purpose of reducing blasting vibration intensity and controlling blasting vibration hazards. Three different blast schemes were realized by using electronic detonators, and nonel detonators were used for the fourth blast scheme as comparison. Monitoring points were arranged at the locations of 15 m, 30 m, 45 m and 60 m away from the working face. By studying variation law of the blasting vibration velocity, the optimal delay intervals between holes and rows were selected as those of the third scheme based on the characteristics of accurate timing of electronic detonators. In the third scheme, the cut holes were initiated every two holes from top to bottom with an inter-hole delay of 8 ms. The slashing holes were arranged symmetrically along the center of the working face, and initiated hole by hole with an inter-hole delay of 16 ms and inter-row delay of 100 ms. In addition, the roof holes and bottom holes were initiated with a delay interval of 100ms. This scheme was used to obtain a vibration reduction effect by wave destruction interference. The test results show that the blast parameters are the key to reduce the blast vibration intensity. With the same distance to the blast source, the peak particle velocity when electronic detonators are used is much smaller than that when nonel detonators are used. At the same time, the dominant frequency of electronic detonators is higher than that of the nonel detonators. This engineering technology has achieved significant vibration reduction effect in the blasting construction of the flood discharge tunnel of Luoning pumped-storage power station in Henan Province.