Study on Directional Coupling Controled Blasting Technique in Roadway Excavation

The paper studied cracking mechanism of directional coupling controled blastingby fracture mechanism and blasting theory,Introduced directional coupling chargestructure. Analyzed the load relationship between coupling direction and non-coupleddirection, mechanism of directional coupling split controled blastingtheoretically.Mechanism of directional coupling controled blasting is also analyzed bylaboratory test and numerical simulation, Through the research, found that: asymmetryof stress wave and strain wave transmission is obviously during the blastingprocess;maximum radial compressive strain and maximum tangential tensile strainboth appeared in coupling direction of blasthole. Directional coupling chargestructure changes symmetry characteristics of traditional charging structure, controledthe direction of transmission of energy, makes the energy transfered towards couplingdirection preferentially, afford super stress-strain field which maintain progress offracture, form initial crack finally,supplied prerequisites for quasi-static crack growthat last.It was proved by field test that it is reasonable and scientific to use directionalcoupling split controled blasting technique in swelling and fracture surrounding rockroadway excavation.