The main trends in the development of blasting techniques in mining

Abstract

and a high degree of mechanization. The annual mineral output of a single enterprise reaches 30-40 million tons of ore or coal, and the total amount of processed rock, including stripped overburden, reaches tens of millions of cubic meters.The principal method of detaching hard rock and preparing it for further processing is blasting: this involves the problems of breaking down the rock and simultaneously crushing it to fragments with sizes and positions which will maximize throughput and minimize wear in the loading, transportation, and crushing equipment.The quantity of explosives used by a single mining enterprise amounts to 15-20 thousand tons per annum, and the quantity used in simultaneous blasting is 1300 tons. These scales require safe explosives and necessitate mechanizationoftheiruse. However, the development of mechanization in blasting has lagged behind the growth in output and behind the mechanization of other mining processes; charging has been mechanized (most completely in underground extraction faces), but very laborious manual processes remain in loading and deloading, storage, and delivery of explosives. Only in some individual mining enterprises [Leninogorsk, Sevemyi GOK (Krivbass)] has a start been made on combined mechanization of blasting, including reception, transportation, storage, delivery, and charging.

Safety Distance of Shotcrete Subjected to Blasting Vibration in Large‐Span High‐Speed Railway Tunnels

“…It is hard to determine which empirical formula is the best one, because the fitting errors of different empirical formulas cannot be avoided. e Sadovsky equation covers two site-specific parameters considering the effects of blasting and geology, and they can be determined by regression analysis [17]. erefore, the Sadovsky equation is most widely used to study the attenuation of blast vibration in China [18], that is, Shock and Vibration 3…”

“…erefore, the vibration monitoring inside the rock and at the tunnel crown is vital for the security of shotcrete. In general, the common approach to investigate wave propagation characteristics is by field monitoring data regressed by empirical equations such as Sadovskii equation [17], which is widely used in blasting operations in China [18]. e Sadovsky equation can describe the attenuation of maximum blast vibration velocity (or PPV) which depends on blasting charge (Q), geotechnical parameters (K and α), and the distance between blasting work face and monitoring point (R).…”