Innovation and future of mining rock mechanics

The 121 mining method of longwall mining first proposed in England has been widely used around the world. This method requires excavation of two mining roadways and reservation of one coal pillar to mine one working face. Due to considerable excavation of roadway, the mining roadway is generally des...

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Main Authors: Manchao He, Qi Wang, Qunying Wu
Format: Article
Language:English
Published: Elsevier 2021-02-01
Series:Journal of Rock Mechanics and Geotechnical Engineering
Subjects:
Online Access:http://www.sciencedirect.com/science/article/pii/S1674775521000020
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author Manchao He
Qi Wang
Qunying Wu
author_facet Manchao He
Qi Wang
Qunying Wu
author_sort Manchao He
collection DOAJ
description The 121 mining method of longwall mining first proposed in England has been widely used around the world. This method requires excavation of two mining roadways and reservation of one coal pillar to mine one working face. Due to considerable excavation of roadway, the mining roadway is generally destroyed during coal mining. The stress concentration in the coal pillar can cause large deformation of surrounding rocks, rockbursts and other disasters, and subsequently a large volume of coal pillar resources will be wasted. To improve the coal recovery rate and reduce excavation of the mining roadway, the 111 mining method of longwall mining was proposed in the former Soviet Union based on the 121 mining method. The 111 mining method requires excavation of one mining roadway and setting one filling body to replace the coal pillar while maintaining another mining roadway to mine one working face. However, because the stress transfer structure of roadway and working face roof has not changed, the problem of stress concentration in the surrounding rocks of roadway has not been well solved. To solve the above problems, the conventional concept utilizing high-strength support to resist the mining pressure for the 121 and 111 mining methods should be updated. The idea is to utilize mining pressure and expansion characteristics of the collapsed rock mass in the goaf to automatically form roadways, avoiding roadway excavation and waste of coal pillar. Based on the basic principles of mining rock mechanics, the “equilibrium mining” theory and the “short cantilever beam” mechanical model are proposed. Key technologies, such as roof directional presplitting technology, negative Poisson's ratio (NPR) high-prestress constant-resistance support technology, and gangue blocking support technology, are developed following the “equilibrium mining” theory. Accordingly, the 110 and N00 mining methods of an automatically formed roadway (AFR) by roof cutting and pressure releasing without pillars are proposed. The mining methods have been applied to a large number of coal mines with different overburdens, coal seam thicknesses, roof types and gases in China, realizing the integrated mode of coal mining and roadway retaining. On this basis, in view of the complex geological conditions and intelligent mining demand of coal mines, an intelligent and unmanned development direction of the “equilibrium mining” method is prospected.
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spelling doaj.art-0aa0ab74a83748959b99f77ba82ec68e2022-12-21T21:31:18ZengElsevierJournal of Rock Mechanics and Geotechnical Engineering1674-77552021-02-01131121Innovation and future of mining rock mechanicsManchao He0Qi Wang1Qunying Wu2Key Laboratory for Geo-mechanics and Deep Underground Engineering, China University of Mining and Technology, Beijing, 100083, China; Research Institute for Deep Underground Science and Engineering of Beijing, China University of Mining and Technology, Beijing, 100083, China; Corresponding author.Key Laboratory for Geo-mechanics and Deep Underground Engineering, China University of Mining and Technology, Beijing, 100083, China; Research Institute for Deep Underground Science and Engineering of Beijing, China University of Mining and Technology, Beijing, 100083, China; Corresponding author.Shanbei Coal Industry Co., Ltd., Shaanxi Shanmei Group, Yulin, 719000, ChinaThe 121 mining method of longwall mining first proposed in England has been widely used around the world. This method requires excavation of two mining roadways and reservation of one coal pillar to mine one working face. Due to considerable excavation of roadway, the mining roadway is generally destroyed during coal mining. The stress concentration in the coal pillar can cause large deformation of surrounding rocks, rockbursts and other disasters, and subsequently a large volume of coal pillar resources will be wasted. To improve the coal recovery rate and reduce excavation of the mining roadway, the 111 mining method of longwall mining was proposed in the former Soviet Union based on the 121 mining method. The 111 mining method requires excavation of one mining roadway and setting one filling body to replace the coal pillar while maintaining another mining roadway to mine one working face. However, because the stress transfer structure of roadway and working face roof has not changed, the problem of stress concentration in the surrounding rocks of roadway has not been well solved. To solve the above problems, the conventional concept utilizing high-strength support to resist the mining pressure for the 121 and 111 mining methods should be updated. The idea is to utilize mining pressure and expansion characteristics of the collapsed rock mass in the goaf to automatically form roadways, avoiding roadway excavation and waste of coal pillar. Based on the basic principles of mining rock mechanics, the “equilibrium mining” theory and the “short cantilever beam” mechanical model are proposed. Key technologies, such as roof directional presplitting technology, negative Poisson's ratio (NPR) high-prestress constant-resistance support technology, and gangue blocking support technology, are developed following the “equilibrium mining” theory. Accordingly, the 110 and N00 mining methods of an automatically formed roadway (AFR) by roof cutting and pressure releasing without pillars are proposed. The mining methods have been applied to a large number of coal mines with different overburdens, coal seam thicknesses, roof types and gases in China, realizing the integrated mode of coal mining and roadway retaining. On this basis, in view of the complex geological conditions and intelligent mining demand of coal mines, an intelligent and unmanned development direction of the “equilibrium mining” method is prospected.http://www.sciencedirect.com/science/article/pii/S1674775521000020Mining rock mechanicsEquilibrium mining theoryShort cantilever beam modelAutomatically formed roadway without pillarsIntelligent mining
spellingShingle Manchao He
Qi Wang
Qunying Wu
Innovation and future of mining rock mechanics
Journal of Rock Mechanics and Geotechnical Engineering
Mining rock mechanics
Equilibrium mining theory
Short cantilever beam model
Automatically formed roadway without pillars
Intelligent mining
title Innovation and future of mining rock mechanics
title_full Innovation and future of mining rock mechanics
title_fullStr Innovation and future of mining rock mechanics
title_full_unstemmed Innovation and future of mining rock mechanics
title_short Innovation and future of mining rock mechanics
title_sort innovation and future of mining rock mechanics
topic Mining rock mechanics
Equilibrium mining theory
Short cantilever beam model
Automatically formed roadway without pillars
Intelligent mining
url http://www.sciencedirect.com/science/article/pii/S1674775521000020
work_keys_str_mv AT manchaohe innovationandfutureofminingrockmechanics
AT qiwang innovationandfutureofminingrockmechanics
AT qunyingwu innovationandfutureofminingrockmechanics