Experimental Study on Radial Decoupling Charge Blasting with Air and Water
Deqiang Yang 1,   Huaming An 2  
,   Zhen Lei 3
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Civil and Resource Engineering School, University of Science and Technology Beijing, Beijing, 100083, China
Kunming University of Science and Technology, Kunming, 650093, China
Guizhou Institute of Technology, Guiyang, 550003, China
Huaming An   

Kunming University of Science and Technology, Kunming, 650093, China
Mining Science 2020;27:265–281
In order to investigate the effects of different medium on the initial impact pressure and fragmentation of the hole wall under radial decoupling charge, this paper analyzes and compares the initial impact pressure of hole wall and the size of blasting lumpiness theoretically when air and water are used as coupling medium. Combined with blasting model test, strain datas are collected by high-speed multi-channel dynamic stress testing system, and the lumpiness of model test is sieved and measured. The blasting lumpiness is analyzed by G-G-S distribution function. The results show that compared with the air radial decoupling charge, the water radial decoupling charge has higher blasting peak pressure and more uniform lumpiness. According to the relation between peak strain pressure and decoupling coefficient, the optimal decoupling coefficients of air and water are 1.71 and 1.67 respectively. The results show that the best blasting effect can be achieved by using small hole diameter of water-decoupling charge compared with air-decoupling charge. When the decoupling coefficient is 1.50, the three evaluation indexes of and of blasting lumpiness in water-decoupling medium and boulder yield are minimum, and only two evaluation indexes of lumpiness and are minimum in air-decoupling medium. Applying the test results to the smooth blasting of cutting has certain guiding significance for improving the blasting effect.
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