Results 21 to 30 of about 4,362 (258)
Geofluids, 2022 To solve the problem of instability and failure of a roadway in the Dianping coal mine working face under the condition of traditional gob-side entry retaining, a mechanical model was established for analysis. The reasons for the damage are as follows: (1) the mining height is high, and the hard thick old roof exhibits large space for rotation and ...
Daoyong Zhu, Huyue Zhang, Yi Su
openaire +3 more sources
Characteristics of mine pressure and roof disaster prevention and control technology on hard and thick roof of working face [PDF]
Meitan kexue jishuMine pressure appears extremely strong during mining in hard and thick roof working faces. The prevention and control of this type of roof disaster has always been a problem that has plagued the safe and efficient production of working faces in my ...
Gang XU +8 more
doaj +2 more sources
Thick-hard strata movement law and multi-dynamic load mechanism in longwall face with ultra-large cutting height [PDF]
Meitan xuebaoLarge mining height technology is characterized by high yield, high efficiency, and high recovery rate. It has become the preferred technology for mining thick coal seams in Yushen mining area.
Jiachen WANG +6 more
doaj +2 more sources
Applied SciencesThe safety and efficiency of underground coal mining are threatened by thick hard roofs characterized by large overhang areas, problematic spontaneous caving, and high dynamic load upon their breakage.
Wei Zhang +5 more
doaj +2 more sources
Analysis and Application on Controlling Thick Hard Roof Caving with Deep‐Hole Position Presplitting Blasting [PDF]
Advances in Civil Engineering, 2018 For the thick hard roof (THR) in Datong mining area, mining operations often led to large‐scale hanging‐roof and frequent and strong strata behavior, threatening mining safety seriously. Based on the instability mechanism, the fracture model for THR was established, including rock blocks articulation and combined cantilever beam, and the limit initial ...
Baobao Chen, Changyou Liu
openaire +3 more sources
An Innovative Approach for Gob-Side Entry Retaining With Thick and Hard Roof: A Case Study
Tehnički vjesnik, 2018 An innovative roadway layout in a Chinese colliery based on gob-side entry retaining (GER) with thick and hard roof (THR) was introduced. Suspended roof is left with a large area in GER with THR, which leads to large area roof weighting (LARW). LARW for GER with THR and mechanism of shallow-hole blasting to force roof caving in GER were expounded.
Zhang, Zizheng +6 more
openaire +5 more sources
Mechanical Analysis of the First Fracture Characteristics of Hard Roof of Extra-thick Coal Seam
Meikuang Anquan, 2020 In order to investigate the failure mechanisms of the hard roof in the fully mechanized caving face in the extra-thick coal seam, the mechanical analysis model of the first breaking of the hard top roof in the fully mechanized caving mining of the extra-
LIANG Shaping, LU Yinlong, GUO Peng, WU Bingzhen
doaj +2 more sources
Geofluids, 2021 Based on the occurrence conditions of a thick and hard main roof and wedge-structure immediate roof in the Zhuxianzhuang Coal Mine, the fracture characteristics and instability migration law of a thick and hard roof (THR) were examined via physical ...
Tong Zhao +5 more
doaj +2 more sources
Effect of Thick–Hard Main Roof Fracturing on the Spatiotemporal Evolution of Overburden Fractures
Applied SciencesGas gushing and the co-mining of coal and gas outbursts are common disasters in coal mines. The weakening of thick–hard main roof fracturing can effectively alleviate the gas overrun in the initial mining stage. Four numerical simulation schemes were designed to determine the optimal fracturing treatment scheme for the gas overrun problem in the ...
Jinfeng Ju, Chengen Qi, Zhu Li
openaire +3 more sources
Applied SciencesThis study aims to address the pronounced stress concentration in roadway-surrounding rock under conditions of multiple thick and hard roof strata at Xiao jihan coal mine, China.
Hui Liu +5 more
doaj +2 more sources