The invention provides a smooth blasting method based on phi 32 mm cartridges. The method includes the steps that
punching,
powder charging and the
initiation process are conducted on a working face, and a smooth blasting layer is composed of a
peripheral smooth blasting hole array located on the outer side and more close to the boundary of the top, and an outer ring
spallation hole array located in the
peripheral smooth blasting hole array. The density coefficient m of
peripheral smooth blasting holes ranges from 1.25 to 1.43. Charged
powder in the peripheral smooth blasting holes in the peripheral smooth blasting hole array comprises bottom charged
powder located at the bottoms and multiple bags of middle charged powder located at different depths in the holes. The powder charging amount of the middle charged powder is smaller than that of the bottom charged powder. The intervals between the bottom charged powder and the middle charged powder and between the bags of the middle charged powder are the same, and the
initiation time of the peripheral smooth blasting hole array is later than that of the outer ring
spallation hole array. Smooth blasting powder
string processing procedures and
processing materials are reduced; smooth blasting powder
string processing cost, and cost of materials such as bamboo chips and
adhesive tape are saved, and over-excavation is effectively controlled, so that a large amount of concrete backfill caused by over-excavation is reduced, and construction cost is reduced.