abattage par longs trous

CONT: L'abattage par longs trous et, en particulier, avec des charges concentrées [...] permet l'utilisation de gros diamètres de foration et de toute la technique des exploitations à ciel ouvert.
OBS: Selon le Dictionnaire des industries, il y aurait deux méthodes d'abattage par longs trous, l'abattage par longs trous horizontaux et l'abattage par longs trous verticaux.

CONT: Long-hole blasting. This method of blasting, employing diamond drills or extension steel drills with tungsten carbide bits, is being applied increasingly to ore winning operations where conditions are suitable. The essential requirements from the practical and economic point of view are: (1) a large ore body or wide regular vein; (2) a strong country rock; (3) a good parting between the ore and the rock to avoid undue contamination of the ore. Holes to take up to 2-inch diameter cartridges may be drilled. Since the drilling of long holes is relatively expensive, high-strength, high-density gelatinous explosives are usually employed so that the maximum burden can be placed on each hole. For this reason also, the largest diameter of explosive cartridge that can be loaded into the holes should be used to obtain the greatest possible loading density.