Experimental Study on Quasi-Static Pressure of Slot Hydraulic Blasting

Air is commonly used as the noncoupling borehole medium in directional slot blasting where the quasi-static pressure is small, the energy utilization rate of the explosive is low, and the breaking efficiency of the coal-rock mass is not high. This study investigates the effect of quasi-static pressu...

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Bibliographic Details
Main Authors: Chengwei Liu, Binwei Xia, Yiyu Lu, Yugang Gao
Format: Article
Language:English
Published: Wiley 2018-01-01
Series:Shock and Vibration
Online Access:http://dx.doi.org/10.1155/2018/6584634
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Summary:Air is commonly used as the noncoupling borehole medium in directional slot blasting where the quasi-static pressure is small, the energy utilization rate of the explosive is low, and the breaking efficiency of the coal-rock mass is not high. This study investigates the effect of quasi-static pressure on crack propagation in closed-field blasting. Crack length propagation in the quasi-static pressure stage accounts for more than 60% of the total crack length. Water is therefore proposed as the noncoupling medium of the slotting borehole to increase the quasi-static pressure. A series of experiments was performed to investigate and compare quasi-static pressures generated using noncoupled water-medium blasting and noncoupled air-medium blasting. The experimental results show that the quasi-static pressure is 37–46 times larger in water-medium blasting than in the air-medium case. The experimental measurements show good agreement with theoretical analysis. The results show that the energy utilization rate of the explosives in the hydraulic slotting blasting is high with a notable energy storage effect, and that the fracturing range can be significantly increased. Additionally, fracture by directional blasting using this approach can be more controllable.
ISSN:1070-9622
1875-9203