METHOD OF PREVENTING GAS-DYNAMIC PHENOMENA IN DRIVING OF DEVELOPMENT WORKINGS Russian patent published in 1999 - IPC

FIELD: mining industry. SUBSTANCE: method includes analysis of oscillogram of natural oscillations of rock mass in face part of coal seam caused by burst to determine their amplitude spectrum. Two values of resonance frequencies are distinguished. The first value is equal to minimum value at which first resonance occurred. The second value equals the frequency corresponding to maximum amplitude. Rock mass is acted upon by pulses whose sequence frequency is equal or multiple to minimum value of resonance frequency. Each signal pulse is characterized by the fact that frequency of its spectrum maximum is equal to resonance frequency corresponding to maximum value of amplitude. Pulse sources are used in the form of nonexplosive ones of pneumatic or pneumohydraulic type. Source is placed in hole drilled in working floor and filled with water. Value of spectrum maximum of single pulse is determined by changing depth of source immersion. EFFECT: higher efficiency and safety of vibration pulse treatment of coal seam. 4 cl, 5 dwg