Reduction of blast vibration by means of sequentially optimized delay blasting

摘要

The major concern of this research is the reduction of blast vibration at a certain point of importance. A new blasting design concept called "Sequentially Optimized Delay Blasting", supposing the use of electronic detonators, to further reduce the peak particle velocity (PPV) at the point of interest, is proposed. This concept allows a proper delay time design for unlimited numbers of blastholes. Three different variations of this concept are discussed in this paper. The first one aims to reduce PPVs at a certain point of interest; the second one aims to reduce the kinetic energy of the vibration by minimising the cross-correlation coefficient; and the third one aims to vanish the dominant frequency component. Software calculating a proper delay time series was developed which can design, for example, 20-hole delay blast in a couple of minutes. Simulation results of vibration time histories and PPVs using this software indicated considerably favorable results.