Numerical Simulation on Mechanical Characteristics of Deep-hole Blast in Soft and Loose Coal-beds

 

CAI Feng1,2,3,4, LIU Ze-gong1,2, HUANG Wen-yao 1,2

1.School of Resource and Safety of Anhui University of Science and Technology, Huainan 232001, China
2. Key Laboratory of Integrated Coal Exploitation and Gas Extraction of Anhui Province, Huainan 232001, China
3. Key Lab of Mining Coal Safely and Efficiently Mining Constructed by Anhui Province and Ministry of Education, Huainan 232001, China
4. Department of Mining Engineering, West Virginia University, Morgantown, 26505, USA

 

 ABSTRACT

Deep-hole blasting is an ideal technique to increase permeability of coal-beds and is applied in more and more high-gas coal mines in recent years, but there are few theoretic studies on blasting in coal-beds. Based on the parameters of special explosive for deep-hole blast and arrangement of blast borehole and control boreholes, the mechanism of deep-hole blast in coal-bed is simulated and studied using numerical simulation method. The numerical model for simulating cylindrical explosive blast is built, and the damage range in coal-bed and blasting stress wave's impact on coal-bed is studied. The researching results show that the maximum damage radius is 40cm, and effective gas drainage radius increases to almost 10m, and gas drainage increasing results in coal-bed within 4m around blast borehole are significant. The displacement field of control boreholes are simulated and studied, and the simulated results is consistent with gas drainage data after blast. The researching results provide theoretic support for increasing permeability of soft and loose coal-beds by deep-hole blast technique.

Keywords: Deep-hole blast; mechanical characteristics, soft and loose coal-bed; numerical simulation

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