High-low-blasting Technology Based on Multi-parameters Cooperative in Gas Dynamic Disaster Prevention

For the status of high gas contents, high stress and low-permeability of Ji15 seam of No.12 Coal Mine in Pingmei Group, the gas cooperative control model combined local pressure-relief with regional pressure-relief was established based on the theory of multi-parameters cooperative. The laws of detonation wave propagation and ground-stress change distribution were simulated by means of the finite element analysis software. The technology of high-low-blasting, composed of high blasting(deep crossing hole controlled hydraulic blasting) and low blasting (special roadway deep hole controlled blasting) was developed. The research showed that maximum tension fracture failure was produced around control hole when the distance between control hole and blasting hole is 0.6 m., and it resulted in directional and controlled blasting. The theory made advantage superimpose for blasting force and hydraulic force, which raised the effect of pressure relief and permeability enhancements compared with general blasting. High blasting influence radius and low blasting influence radius superimposed with each other, which prevents gas dynamic disaster.