Results 21 to 30 of about 139,472 (275)

Analysis and Application on Controlling Thick Hard Roof Caving with Deep‐Hole Position Presplitting Blasting [PDF]

open access: yesAdvances 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   +2 more sources

Development status and Prospect of directional hydraulic fracturing technology for coal mine roof [PDF]

open access: yesE3S Web of Conferences, 2020
Aiming at the harm and control methods of thick and hard roof in coal mine, the paper firstly analyzes the advanced control methods of thick and hard roof, such as directional shaped charge blasting roof control technology, hydraulic fracturing roof ...
Liangwei LI
doaj   +1 more source

Investigation on the Movement and Fracture Characteristics of an Extra-Thick Hard Roof during Longwall Panel Extraction in the Yima Mining Area, China

open access: yesGeofluids, 2021
As an extra-thick hard roof is a significant contributing factor to frequently induced sudden roof collapse accidents and coal bursts, this study investigates the relationship between extra-thick hard roof movement and mining-induced stress using ...
Hongwei Wang   +5 more
doaj   +1 more source

Mechanism and control of deformation in gob-side entry with thick and hard roof strata

open access: yesJournal of the Southern African Institute of Mining and Metallurgy, 2023
Deformation of gob-side entries has always been a critical concern for ensuring stability in longwall coal mines. This paper addresses the significant deformation and support challenges that arise in thick and hard roof longwall faces (THRLF) due to dynamic pressure.
Guo, J.S., Ma, L.Q., Ngo, I.
openaire   +2 more sources

Geologic considerations in underground coal mining system design [PDF]

open access: yes, 1981
Geologic characteristics of coal resources which may impact new extraction technologies are identified and described to aid system designers and planners in their task of designing advanced coal extraction systems for the central Appalachian region ...
Camilli, F. A.   +3 more
core   +2 more sources

Mechanical Analysis of the First Fracture Characteristics of Hard Roof of Extra-thick Coal Seam

open access: yesMeikuang 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   +1 more source

Study on Fracture Behavior of Directly Covered Thick Hard Roof Based on Bearing Capacity of Supports

open access: yesApplied Sciences, 2023
Mine pressure at the working face is severe due to it being directly covered by a thick hard roof. To further investigate the technology of controlling the mine pressure of a thick hard roof, the upper working face of 13,121 in Gubei mine of Huainan ...
Jiawen Li   +4 more
doaj   +1 more source

Research on reasonable cutting roof parameters of gob side entry retaining by roof cutting in thick and hard roof

open access: yesMeitan xuebao, 2023
In the engineering practice of gob side entry retaining by roof cutting, the height and angle of roof cutting are the direct influencing factors, and the reasonable roof cutting parameters allowed by the hard roof with a wide range of roof thickness change have their particularity.
Xuhui XU   +5 more
openaire   +1 more source

Study on Fracture and Stress Evolution Characteristics of Ultra-Thick Hard Sandstone Roof in the Fully Mechanized Mining Face with Large Mining Height: A Case Study of Xiaojihan Coal Mine in Western China

open access: yesAdvances in Civil Engineering, 2018
Ultra-thick hard sandstone roofs present high thickness, poor delamination, and wide caving range. The strata pressure of the working face during actual mining increases, having a significant influence on the safe mining of the working face.
Feng Ju   +4 more
doaj   +1 more source

The engineering geology of the Nottingham area, UK [PDF]

open access: yes, 2009
Nottingham was built near a crossing point on the River Trent in the East Midlands of England. Initially, the City developed on a low sandstone hill close to the north bank of the river, which provided a secure, well-drained location above the marshes ...
Bell, F.G.   +3 more
core   +1 more source

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