Study on the damage characteristics of overburden of mining roof in deeply buried coal seam

Abstract

The study of water-conducting fracture zone development height is key to the scientific prevention and control of water damage in mines. Based on the geological conditions of the Wenjiapo coal mine in Binchang, China, this paper investigates the development of water-conducting fracture zone in overlying bedrock during mining under large buried depth and huge thick aquifer by combining on-site well-location microseismic monitoring and laboratory similar material simulation. To overcome the limitation of the " limited outlook " of water-conducting fracture zone investigation, the spatial development characteristics of roof fissures in coal seam mining were determined by on-site " the underground - ground" combined microseismic monitoring and follow-up monitoring, and the development of overlying rock fracture under the large depth of burial was concluded. The fractures were mainly distributed in the upper part of the protective coal pillar on both sides of the working face, but less in the upper part of the working face, and primarily distributed in the protective coal pillar on the side of the working face and the adjacent mining area. To verify the accuracy of the conclusion, the overlying bedrock movement and deformation characteristics and the development process of the hydraulic fracture zone during coal seam mining were analyzed by simulating similar materials in the laboratory, using the monitored area as a prototype. The results show that the development height of the mining fracture zone obtained from microseismic monitoring is basically consistent with the simulation results of similar materials. The research finding have significant implications for the study of fracture distribution characteristics and the evolution law of mining overburden, and provide a foundation for scientific prevention and control of water damage on the roof.

Results of research on the stability of mine workings, fixed by arched supports made of composite materials, in the conditions of the Pokrovske Mine Administration

“…Moreover, at great depths (H > 1000 m), the stress intensity can increase up to 200-250 MPa, and more will be inexpedient. The results obtained do not contradict numerous geomechanical studies [47][48][49][50][51]. This confirms that the models correspond to the real conditions for conducting mine workings in coal mines.…”

Elastic wave prospecting of water-conducting fractured zones in coal mining

“…Therefore, locating the key layer is the central idea behind zonation of the coal mine roof based on microseismic monitoring. Since microseismic monitoring data are statistical in nature, accurate location of the key layer requires comprehensive analysis based on the differential distribution of microseismic events and energy along both sides of the key layer, in conjunction with geological information (primarily borehole logs) 29 , 30 .…”

Water-Filling Characteristics and Water Source of Weakly Rich Water and Weakly Conducting Water Aquifers in the Changxing Formation after Mining Damage

“…The aquifers directly filling water into the coal-bearing strata of the Longtan Formation were the overlying Changxing Formation limestone and the underlying Maokou Formation limestone. The limestone of the Changxing Formation (P3c), in contact with the Longtan Formation strata, varied in thickness in the range of 17 The main aquifers within the mining area include the Triassic Yelang Formation Yulongshan section (T 1 y 2 ) limestone, the Permian Changxing Formation (P 3 c) limestone, and the Permian Maokou Formation (P 2 m) limestone. The limestone within the Yulongshan section of the Triassic Yelang formation (T 1 y 2 ) served as the main aquifer, exhibiting a thickness range of 176.62-248.3 m and an average of 211.92 m. The karst development of this aquifer varied significantly, making it a weak-strong aquifer with abundant water.…”