Recent research sheds light on the complex relationship between surface subsidence and strong mine earthquakes, particularly within the challenging geological conditions of deep coal mines. The study, conducted at the Yingpanhao Coal Mine located in Inner Mongolia, China, reveals how extensive coal mining under high-positioned and thick-hard strata leads to significant seismic activity, posing risks to both mining operations and the local communities.
Mining practices have intensified over recent years, with the depth of operations increasing and leading to more frequent and severe mine earthquakes. These events, triggered by the fracturing of overlying rock layers, directly contribute to surface subsidence, creating potential hazards for both the mining infrastructure and surrounding areas. The researchers utilized both field observations and theoretical analyses to investigate this phenomenon comprehensively.
The Yingpanhao Coal Mine serves as the backdrop for the study, characterized by its thick geological strata, which complicate the interactions between mining activities and seismic events. The research examined how multiple working faces within the mine influenced the spatiotemporal distribution of mine earthquakes and surface movement. Key observations were made between the operations of working faces 2201 and 2202, conducted from 2017 to 2021, to understand this dynamic relationship.
Utilizing advanced microseismic monitoring technologies, the study discovered significant correlations between surface subsidence rates and the occurrence of strong mine earthquakes. The results suggest three distinct stages of surface movement: slow subsidence, rapid subsidence, and stable subsidence, aligning these shifts with periods of intense mining activity.
Specifically, during the activity of the 2202 working face, marked increases in surface subsidence were observed, with maximum rates reaching as high as 9.87 mm per day. This peak subsidence corresponded with the strongest earthquake events, reinforcing the notion of linkage between these geological occurrences. The findings suggest the structural integrity of the thick-hard strata is compromised during mining, leading to significant deformation and failure risks.
The study highlights concerns surrounding not just mining safety but public safety as well. Mine earthquakes can cause considerable surface shaking, fostering anxiety among residents within mining zones and framing these events as public safety issues rather than solely mining operational challenges.
To bolster the mining industry's response to these challenges, the research advocates for improved monitoring and predictive techniques to mitigate the effects of subsidence and seismic events. By correlatively studying the fractures of high-positioned thick strata and seismic activity, they aim to develop preventative measures to safeguard the integrity of mining operations and the welfare of surrounding communities.
Considering the empirical evidence gathered, the authors conclude with recommendations for future research avenues exploring the interconnectedness of geological structures and mining practices. Understanding these dynamics presents opportunities to improve safety measures and inform the development of more resilient mining methodologies, ensuring both environmental stability and community safety.