Classification standard for open-air blasting methods

Classification TYPE Ⅰ Micro-vibration excavation method TYPE Ⅱ Precision vibration-controlled blasting TYPE Ⅲ·Ⅳ Vibration-controlled blasting TYPE Ⅴ General blasting TYPE Ⅵ Large-scale blasting
Small scale Medium scale
Method overview

A method by which vibration can be reduced to a level within the TYPE II method around the security object, and where secondary crushing is executed using a large-scale breaker.

A method by which secondary crushing by a large-scale breaker is executed after generation of cracks in bedrock using a small amount of explosives.

A method by which regulation standards can be complied with via execution of a blasting design in accordance with "test blasting" results when the security object exists within the influential sphere of blasting.

A method applied to an area separated from a security object to the extent that the maximum charge per hole can meet the regulation standards for blasting.

A method that considers only blasting efficiencies in mountainous remote areas, etc. in which no security objects exist within the influential sphere of blasting.

Main explosives or blast supplies in use Explosives less than the minimum unit for micro-vibration crusher, micro-vibration crushing, etc. Emulsion-based explosives Emulsion-based explosives Emulsion-based explosives Main explosive : ammonium nitrate fuel oil explosive
Priming explosive : emulsion
Charge amount per hang fire (kg) Explosive standard less than 0.125 0.125∼0.5 0.5∼ 1.6 1.6 ∼ 5.0 5.0∼15.0 More than 15.0
Bored hole diameter Less than 51mm Less than 51mm Less than 51mm More than 76mm More than 76mm More than 76mm
Boring equipment Selection and use of air compressor-type crawler drill or hydraulic crawler drill
Standard pattern Micro-vibration excavation method Precision vibration-controlled blasting Vibration-controlled blasting General blasting Large-scale blasting
Small scale Medium scale
Boring depth(m)※ 1.5 2.0 2.7 3.4 5.7 8.7
Minimum resistance wire(m)* 0.7 0.7 1.0 1.6 2.0 2.8
Boring interval(m)* 0.7 0.8 1.2 1.9 2.5 3.2
Standard charge per hang fire(kg) - 0.25 1.0 3.0 7.5 20.0
Crushing extent Only cracks generated (less than average rock) Shredding + Crack Shredding + Crack Shredding + Boulder Shredding + Boulder
Measurement management Mandatory Mandatory Mandatory Optional Optional
Blasting protection hole Mandatory Mandatory Mandatory Not required Not required
Secondary shredding Large breaker application Large breaker application - - -