Research on Reducing Mining-Induced Disasters by Filling in Steeply Inclined Thick Coal Seams

Abstract

Surface filling during the mining of steeply inclined thick coal seams is an efficient method for restraining disasters caused by the cascading movement of overburden rocks. This study aims to control rock damage during the mining of thick coal seams steeply inclined at typically more than 45° in fully mechanized coal caving work surfaces with high section heights. Based on the green mining concept, we analyzed the movement of roof strata after filling using multiple methods, including field investigation, theoretical analysis, numerical calculation, and field monitoring. Results show that, in dynamic mine disasters caused mainly by complex coal conditions and strong disturbances in fully mechanized coal caving in large sections, the strength of the filling material is dependent on the features of the surrounding rock and burial depth. Also, the mining-induced peak stress shows a linear increase after filling, with the goafs in stress-free conditions, and failure zones occur in the roof and floor strata after mining. The stability of the rock pillars and overburden strata are better, and there are no large-scale tensile fissures in the ground surface. We adopted an intelligent underground radar detection technique that can reflect the rock-failure characteristics through the propagation characteristics of the electromagnetic spectrum. The detection results show that the coal goafs were filled properly as they were matched with the caving roof, which will collapse along with the release of the top coal, with the filling body able to move downward along with the discharge of top coal. The use of surface filling can restrain the dynamic disaster induced by a fully mechanized coal caving surface with a large section when mining steeply inclined thick coal seams, thereby ensuring safety and promoting the use of green mining practices.

Monitoring and correction of the stress in an anchor bolt based on Pulse Pre‐Pumped Brillouin Optical Time Domain Analysis

“…Bolts are vital to the advancement of underground excavation in engineering work, such as subway tunnels and coal mines, as they connect broken rock mass, enhance the stability of underground coal mine roadways and surrounding rock, and reduce the occurrence of rock burst . In countries such as China where huge amount of coal is mined, problems of roof falling (roof collapse), land subsidence, and collapse result in a series of secondary disasters, directly threatening production, and life safety . Monitoring and evaluation of the anchoring performance is an important basis to judge the effectiveness of bolts, and hence, to ascertain the safety of the underground coal mine roadways.…”

Influence of Mechanical Properties of Filling Paste on Overlying Strata Movement and Surface Settlement

“…In the process of filling mining, the change of filling strength has different effects on the surface and overburden [26]. e characteristics of rock movement and surface subsidence under different filling strengths should be studied.…”

Tightness Analysis of Underground Natural Gas and Oil Storage Caverns With Limit Pillar Widths in Bedded Rock Salt

“…The water solution mining method is used for the excavation of both the UGS and SPR salt caverns. According to available standards [48], [49], the design life of the underground energy storage salt caverns is at least 30 years, which is used in the calculations. During the operating time, synchronized injection-withdraw patterns are recommended because instability influence may occur in pillars if asynchronous injection-withdraw patterns are adopted [29].…”