Blast holes are mostly used for mining, tunneling and civil engineering construction, demolition of old buildings, removal of underwater reefs, etc.
Blast hole
Use a drill or rock drill to drill a hole in the rock or soil and place explosives for blasting, or use it as an artificial seismic source.
Blast holes are mostly used for mining, tunneling and civil engineering construction, demolition of old buildings, removal of underwater reefs, etc. The diameter of the blast hole is determined according to the construction requirements and the diameter of the explosive roll. The diameter of blast holes used in underground shaft mining and tunnel excavation is mostly about 50 mm. The blast hole depth is less than 4 meters as a shallow hole, and greater than 4 meters is a deep hole. In addition to the early use of manpower hammers to drill steel drills, blast hole construction methods have since developed pneumatic, electric, hydraulic and internal combustion engine driven rock drills and rock drill rigs. There are three types of rock crushing methods: rotary cutting type, impact type and impact rotary type. Open-pit mines and large-scale civil engineering use self-propelled blasthole drills with a high degree of automation, with a drilling diameter of 80 to 440 mm and a drilling depth of 10 to 20 meters. They are drilled with roller cone bits and pneumatic DTH hammers. The artificial source hole is used for seismic exploration, that is, the use of the sound waves generated by artificial blasting underground and the different wave speeds reflected or refracted to the ground to help identify the stratigraphic structure and the position of the oil and gas reservoir.
