Numerical simulation and experimental study on crack radius caused by roof deep hole blasting in Gaojiapu Coal Mine
Rock burst disaster is one of the problems restricting the safe and efficient mining in Gaojiapu Coal Mine,as an effective method for controlling rockburst disasters,deep hole blasting of the roof has been applied to the prevention and control of rockburst in Gaojiabao Coal Mine.The crack radius of deep hole blasting is one of the important parameters in blasting design.In order to study the crack radius caused by deep hole blasting in the Gaojiapu Coal Mine roof,numerical simulation and field test was used to study based on the geological conditions of No.205 working face in No.2 panel of Gaojiapu Coal Mine.Firstly,the rock pillar blasting was numerically simulated based on the strain softening model of the Hoek-Brown failure criterion.The numerical results indicated that under this condi-tion,the radius of the crushing zone in the direction of the drilling hole diameter of the roof deep hole blasting was 0.58 m,and the radi-us of the fracture zone was 3.00 m.Then,on-site experiments were conducted to determine the cracking radius of the roof deep hole blasting in the retreat channel of the No.205 working face of Gaojiapu Coal Mine,and the gas composition of the testing hole before and after the blasting was measured by using beam tube analysis technology.The results showed that the No.3 detection hole with a distance from the blasting hole 2.95 m presented a reduction of oxygen and carbon dioxide components,while the nitrogen component increased.Moreover,carbon monoxide gas was detected.It indicated that blasting-crack leads through the No.3 detection hole,and the roof blas-ting-crack radius of Gaojiapu Coal Mine can reach 2.95 m,which was basically consistent with the numerical simulation.The research results can provide some guidance for the design of roof deep hole blasting scheme under similar conditions.
roof deep hole blastingblasting-crack radiusnumerical simulationbeam tube analysis technology
万方数据
维普
