PRIMARY PRESPLIT CONTROLLED BLASTING AND EQUIPMENT FOR DOUBLE-PARALLEL STEP BENCH OF OPEN-CUT MINE

The controlled blasting nearly to fixed boundary,i.e.effective presplit blasting,effective control of explosive charge at maximum step and total explosive charge and effective thickness control of blasting shock layer nearly close to fixed boundary,is discussed.It is considered that primary presplit blasting formed process of double-parallel bench slope and equipment are keys to parallel step bench,which is normally used at home and abroad.Primary formed process and drilling blasting parameter optimization of the double bench parallel-step slope are presented in accordance to the special slope presplit drilling hole equipment (US CM695D) with primary 36m deep pierce.PLITCONTROL