The sound waves propagating in the rock body by ultrasonic surrounding rock fissure detector was measured in Daqiang Mine, the physical and mechanical properties and stress state of the rock body were studied. The results showed that the thickness of the loosening circle accelerated and increased from 0 to 20 d in mining, with a constant speed from 20 to 50 d, at a second acceleration from 55 to 70 d. Loose circle increased gradually with time and distance, and finally out of the range of 300 cn. Therefore, Daqiang Mine belongs to the VI type of surrounding rock, and the support should adopt the composite support based on anchor net spray.
许德轩1,方 鑫2. 大强煤矿松动圈现场测试及分析[J]. 煤炭与化工, 2021, 44(6): 4-8.
Xu Dexuan1, Fang Xin2. Field test and analysis of loose rings in Daqiang Mine. CCI, 2021, 44(6): 4-8.