Crack closure effect during the impact coal seam with high-pressure air blasting and the influence of gas drainage efficiency

Frontiers in Earth Science

Earth Science

Huice Jiao¹  Yingwei Wang²  Weihua Song³ 

[1] College of Mining, Liaoning Technical University, Fuxin, Liaoning, China;State Key Laboratory of Coking Coal Exploitation and Comprehensive Utilization, China Pingmei Shenma Corporation Group, Pingdingshan, Henan, China;State Key Laboratory of Coking Coal Exploitation and Comprehensive Utilization, China Pingmei Shenma Corporation Group, Pingdingshan, Henan, China;College of Mining, Liaoning Technical University, Fuxin, Liaoning, China;

关键词: high-pressure air blasting;    impact coal seam;    gas drainage;    crack closure;    gas emission;   

DOI  :  10.3389/feart.2023.1131386

 received in 2022-12-25, accepted in 2023-02-21,  发布年份 2023

来源: Frontiers

【 摘 要 】

The crack closure in impact coal seams induced by high-pressure air blasting greatly affects gas drainage efficiency. The length of the crack closure was calculated and analyzed based on energy and elastic theories. The closure region was then determined to be 3.8 m from the blasting hole. The results of a high-pressure air blasting experiment in the underground of one coal mine in China showed that the effect of crack closure on gas drainage efficiency manifested as a decreased amplitude of gas emission in the crack closure region. At 1.0–4.0 m from the blasting hole, the amplitude of gas emission in the observation holes first increased and then decreased with increasing distance from the blasting hole. At 1.8–2.5 m from the blasting hole, the amplitude of the gas emission was maximal. At 4.0 m from the blasting hole, the crack was nearly closed, and the gas emission in the observation holes was minimal. The theoretical calculation had good consistency with the field test results; thus, it can provide an important reference for an appropriate arrangement of gas drainage boreholes.

【 授权许可】

Unknown   
Copyright © 2023 Song, Jiao and Wang.