Experimental Research on Stress Relief of High-Stress Coal Based on Noncoupling Blasting
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To discuss the mechanism and effects of noncoupling stress-relief blasting under high stress, theoretical analyses, laboratory experiments, and spot verifications were performed in this study. In addition, by studying the coal blasting mechanism, a theoretical formula to calculate the radius of the fracture area was determined. According to the noncoupling blasting characteristics, a stress relieving test for confined specimens was designed, and the results showed a significant stress reduction in the specimens after blasting. The stress and acoustic emissions showed that a noncoupling charge can relieve stress extremely well in a confined specimen. Combined with practical worksite conditions, for noncoupling stress-relief blasting, a deep hole was drilled into a deep-mine roadway with a high stress concentration, and we observed the electromagnetic radiation and coal stress to verify the effects. The result indicated that the technique had a positive effect on relieving the high stress concentration in roadways.
KeywordsRock bursts Stress-relief blasting Noncoupling blasting Stress concentration Blasting experiment
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This work was supported by “the Fundamental Research Funds for the Central Universities” (Grant No. 2017BSCXB47), “the Postgraduate Research & Practice Innovation Program of Jiangsu Province” (Grant No. KYCX17_1558) and “the Project of PADD funded by the Priority Academic Programme Development of Jiangsu Higher Education Instruction” (Grant No. SZBF2011-6-B35).
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