A blast pattern designed for a particular block is considered, and optional variants of explosion of charges from different delay groups are analyzed.
The data on measurement of seismic effect exerted on surrounding rock mass by blasting with nonelectric blast initiation systems are presented, a calculation method is proposed based on analysis of blast seismograms recorded at a distance of 150–200 m from an explosion. A seismogram is divided into amplitude-based ranges and velocity peaks are counted in each range. Then, the range with the highest number of the velocity peaks is selected (the highest recurrence frequency); this range corresponds to the number of charges with the highest explosion recurrence frequency.
Based on the obtained values, seismicity coefficient is determined. Later on, the amplitudes of the maximum velocities are picked, and the weight of charge producing such velocities is calculated. If the actual weights of charges exceed the calculated values, then the time between blasting of groups of charges in the next block is increased until the weight of charges producing maximum velocity amplitudes is equal to the calculated values.

Keywords

Explosion, accuracy, slowdown, methods.