Gong-kuang zidonghua (Dec 2024)
Cross fan-shaped roof-cutting blasting technology for preventing rockbursts in gob-side mining roadways
Abstract
This study investigated the frequent occurrence of rockbursts in the advanced support areas of gob-side mining roadways. Taking a mine with severe rockburst occurrences as an example, based on an in-depth analysis of the occurrence patterns of 41 rockburst events, an engineering mechanics model of the interaction between the overlying roof of bocal goaf and the lateral goaf was developed. The triggering mechanism was revealed and cross fan-shaped roof-cutting blasting technology for preventing rockburst was proposed. The results showed that lateral support pressure in the gob-side roadways, support pressure in the lateral goaf area, advanced support pressure in the working face, and roadway intersections all have a significant impact on the occurrence of rockbursts. The probability of rockbursts increased with the number of interacting factors, with the combined effect of the overlying thick and hard roof in both the local and the lateral primary goaf as the primary controlling factor. The interaction between these areas formed a right-angle fan-shaped hanging roof structure. The large hanging roof provided static load, which triggered rockbursts, and dynamic load when ultimate collapse occurred, thus acting as the load source for the occurrence of rockbursts. The area influenced by advanced support pressure in the gob-side roadway was identified as the highest-risk zone for rockbursts. Implementing cross fan-shaped roof-cutting blasting technology in this zone effectively shortened the length of the right-angle fan-shaped hanging roof connecting the lateral goaf and the local goaf, thereby reducing the intensity of the dynamic load source. This study provides a novel approach and methodology for preventing and controlling the frequent occurrence of rockbursts during gob-side roadway mining.
Keywords
