Gong-kuang zidonghua (Jan 2022)
Blasting pressure relief technology for preventing rock burst in deep heading roadway
Abstract
In order to solve the problems of low pressure relief intensity, untimely pressure relief and high labor intensity in the prevention and control of rock burst by using large diameter borehole pressure relief in deep heading roadway, taking the 401103 withdrawal roadway of Mengcun Coal Mine in Binchang mining area of Shaanxi Province as the engineering background, the main control factors of rock burst are analyzed. It is considered that the strong rock burst tendency, large buried depth and fault structure of coal and rock layers are the main reasons of rock burst. Coal and rock layers have strong rock burst tendency, which makes the coal rock system capable of generating rock burst. The large buried depth of the working face leads to a high level of concentrated static load, which reduces the threshold for rock burst. The high concentrated static load in the main bearing area superimposes the concentrated dynamic load released by fault energy accumulation, which can easily induce shock start and lead to the appearance of rock burst. The use of blasting pressure relief to prevent rock burst is manifested in structural reconstruction, stress release and energy consumption. The implementation of blasting cracking in the peak area of the supporting pressure of the surrounding rock of the heading roadway can form a pressure relief protection zone in the surrounding rock of the roadway, thereby reducing the tendency of coal rock burst, weakening high concentrated stress, increasing rock burst energy consumption and reducing the risk of rock burst. For the 401103 withdrawal roadway, the blasting pressure relief scheme of roof, heading face and side are proposed. And the effect of pressure relief and anti-rock burst is tested by seismic wave CT detection and micro-seismic monitoring. The results show that after adopting the blasting pressure relief scheme, the area of the high stress area is reduced by 50%, and the stress concentration is significantly reduced. The average energy of microseismic events is significantly reduced, the energy is all less than 104 J. And there is no sharp change in the energy of microseismic events and the pressure relief effect is good.
Keywords
