The characteristics of abnormal gas emission in tunneling through the small fault groups of Yizhong coal mine

Abstract

In light of the complex tectonic structure, and large quantities of buried faults in Yizhong coal mine, the paper, on the basis of analyzing the characteristics of abnormal gas emission caused by production factors such as tunneling and blasting technologies, blasting strength, and tunneling rate, investigates the characteristics of abnormal gas emission in the context of diversified combinations of faults in tunneling through the fault groups in Yizhong coal mine. The study demonstrates the maximum absolute gas emission rate under the procedure of blasting in Yizhong coal mine is approximately 5 times higher than under other procedures, and generally returns to its normal level in 30–40 min; the tunneling rate and blasting strength are in direct proportion to absolute gas emission rate, and the mined coal surpassing 18 tons an hour for a time can cause the risk of gas concentration in return air exceeding limits; in tunneling through the small fault groups, the group largely embodies the influences of individual faults on gas emission, and it is easy to form a space sealed with gas between two sealing faults, where the gas emission intensity and its influence sphere are far greater than separate small faults.

Keywords:

• Fault groups
• tunneling technology
• absolute gas emission rate
• characteristics of abnormal gas emission