Coal and Gas Outburst Affected by Law of Small Fault Instability during Working Face Advance

Abstract

To analyze the effect of small faults in the working face on coal and gas outbursts, the coal and gas outburst accident in the 21431 working face was studied with the 3DEC numerical simulation method, and the main research contents were the change laws of both stresses at the small fault and the overburden strata movement rate in the small fault zone of which the drop height and the strike were designed into different groups. The results show that the risk of small fault slip increases with the advancing working face. In addition, there is a positive correlation between the risk and the small fault throw. The movement rate of overburden strata in the small fault zone increases along with the rising of the small fault throw, which increases the energy transferred to the coal seam from the surrounding rock under the effect of the small fault. Hence, the effect of small faults on the working face on coal and gas outbursts was positively correlated with the small fault throw. Under the influence of a small fault strike, the closer it is to the small fault along the dip distance at the same working face, the greater the risk will be of a coal and gas outburst. And the bigger the small fault strike is, the greater is the stress concentration degree in front of the working face and the more the elastic energy is stored and the greater is the possibility of an outburst. The paper analyzes the influence of small faults on coal and gas outbursts in the working face, which has reference significance for the prediction and prevention of coal and gas outburst disaster in the working face.

Research on the Force Characteristics and Structural Optimization of Mine Antioutburst Door under the Influence of Coal and Gas Outburst Impact Airflow

“…It can also be seen from some accident cases that after the disaster, the antioutburst doors of many mine vents were thrown out as a whole, and the material of the antioutburst doors was not damaged. Instead, it is directly separated from the weaker connection between the door leaf and the door wall, causing the overall structure to fail (5) The location and number of on-site antioutburst doors did not consider the requirements of disaster prevention design. When antioutburst doors are arranged near locations where impact disasters are likely to occur, wrong designs such as shortdistance placement and insufficient strength often occur on site, making the antioutburst doors vulnerable to disaster shock waves…”

“…The antioutburst door is one of the basic safety facilities in coal and gas outburst mines and an important guarantee for the safe production in mines [1][2][3]. When a serious coal and gas outburst disaster occurs underground, the antioutburst door near the disaster site should have disaster protection capabilities to reduce the scope of disasters, prevent harmful substances such as gas, carbon monoxide, coal dust, or impact gases from entering other areas outside the antioutburst door, and reduce the possibility of secondary disas-ters [4][5][6][7]. However, due to the lack of professional disaster prevention structural design theory and technical support, the disaster resistance of many mine antisurge doors is still poor.…”

Study on Gas Migration Law of Mining Coal Seam under the Influence of Normal Fault

“…Faults destroy the continuity of coal seams, which is an important factor causing frequent accidents in coal mines. In particular, the occurrence of coal and gas outburst accidents is closely related to fault structures [4][5][6][7]. According to relevant statistical data, most of the prominent accidents in Pingdingshan mining area, Jiaozuo mining area, and Huainan mining area in China are related to fault-based structures [6][7][8][9][10][11].…”

“…In particular, the occurrence of coal and gas outburst accidents is closely related to fault structures [4][5][6][7]. According to relevant statistical data, most of the prominent accidents in Pingdingshan mining area, Jiaozuo mining area, and Huainan mining area in China are related to fault-based structures [6][7][8][9][10][11]. 134 coal and gas outburst accidents occurred in the eastern mining area of Pingdingshan; most of them occurred in the vicinity of fault structural belt, especially the small fault which has obvious influence on gas outburst accidents, and tectonic coal widely developed in the outburst area [6]; Daping coal mine gas accident occurred near the reverse fault, and outburst accident caused 1894 tons of coal into the working face, resulting in 148 deaths [7].…”

Experimental Study on Mechanical Properties of Briquette Coal Samples with Different Moisture Content

“…Coal and gas outburst and rock burst are relatively serious disasters in coal mines, which causes significant property losses and casualties [1][2][3][4][5]. Water injection is an important industrial measure to prevent these disasters and has been widely used in coal mines [6,7].…”