Cargando…

Mechanical and Microcrack Evolution Characteristics of Roof Rock of Coal Seam with Different Angle of Defects Based on Particle Flow Code

The creation of the natural ceiling rock of the coal seam is rife with fractures, holes, and other flaws. The angle of the defects has a significant influence on the mechanical characteristics and crack evolution of coal seam roof rock. Multi-scale numerical simulation software PFC2D gets adapted to...

Descripción completa

Detalles Bibliográficos
Autores principales: Deng, Qinghai, Liu, Jiaqi, Wang, Junchao, Lyu, Xianzhou
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2023
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9959630/
https://www.ncbi.nlm.nih.gov/pubmed/36837031
http://dx.doi.org/10.3390/ma16041401
_version_ 1784895324847865856
author Deng, Qinghai
Liu, Jiaqi
Wang, Junchao
Lyu, Xianzhou
author_facet Deng, Qinghai
Liu, Jiaqi
Wang, Junchao
Lyu, Xianzhou
author_sort Deng, Qinghai
collection PubMed
description The creation of the natural ceiling rock of the coal seam is rife with fractures, holes, and other flaws. The angle of the defects has a significant influence on the mechanical characteristics and crack evolution of coal seam roof rock. Multi-scale numerical simulation software PFC2D gets adapted to realize the crack propagation and coalescence process in the roof rock of a coal seam with different angles of defects under uniaxial compression. The effect of flaw angles on the micro and macro mechanical characteristics of rock is also discovered. The results show that: (1) the defect angle has influence on the stress-strain, elastic modulus, peak strength, peak strain, acoustic emission (AE) and strain energy of roof rock of coal seam. When the defect angles are different, the starting position of the roof rock in a coal seam fracture is different. The quantity of microcracks firstly reduces with an increase in defect angles before gradually increasing. At the same fault angle, the cracks are mostly tensile ones and only a few shear ones. (2) When the defect angle is less than 90°, tensile and shear fractures are mostly localized at the defect’s two tips and propagate along the loading direction. When the defect angle is 90°, the tensile and shear cracks are not concentrated at the tip of the defect. (3) As the defect angles increase, the elastic strain energy rises initially and then falls, and the dissipated energy and total input energy both increase continuously. The elastic strain energy is greatest at the highest strength. The study provides a certain reference for the use of various analysis methods in practical engineering to evaluate the safety and stability of rock samples with pre-existing defects.
format Online
Article
Text
id pubmed-9959630
institution National Center for Biotechnology Information
language English
publishDate 2023
publisher MDPI
record_format MEDLINE/PubMed
spelling pubmed-99596302023-02-26 Mechanical and Microcrack Evolution Characteristics of Roof Rock of Coal Seam with Different Angle of Defects Based on Particle Flow Code Deng, Qinghai Liu, Jiaqi Wang, Junchao Lyu, Xianzhou Materials (Basel) Article The creation of the natural ceiling rock of the coal seam is rife with fractures, holes, and other flaws. The angle of the defects has a significant influence on the mechanical characteristics and crack evolution of coal seam roof rock. Multi-scale numerical simulation software PFC2D gets adapted to realize the crack propagation and coalescence process in the roof rock of a coal seam with different angles of defects under uniaxial compression. The effect of flaw angles on the micro and macro mechanical characteristics of rock is also discovered. The results show that: (1) the defect angle has influence on the stress-strain, elastic modulus, peak strength, peak strain, acoustic emission (AE) and strain energy of roof rock of coal seam. When the defect angles are different, the starting position of the roof rock in a coal seam fracture is different. The quantity of microcracks firstly reduces with an increase in defect angles before gradually increasing. At the same fault angle, the cracks are mostly tensile ones and only a few shear ones. (2) When the defect angle is less than 90°, tensile and shear fractures are mostly localized at the defect’s two tips and propagate along the loading direction. When the defect angle is 90°, the tensile and shear cracks are not concentrated at the tip of the defect. (3) As the defect angles increase, the elastic strain energy rises initially and then falls, and the dissipated energy and total input energy both increase continuously. The elastic strain energy is greatest at the highest strength. The study provides a certain reference for the use of various analysis methods in practical engineering to evaluate the safety and stability of rock samples with pre-existing defects. MDPI 2023-02-07 /pmc/articles/PMC9959630/ /pubmed/36837031 http://dx.doi.org/10.3390/ma16041401 Text en © 2023 by the authors. https://creativecommons.org/licenses/by/4.0/Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).
spellingShingle Article
Deng, Qinghai
Liu, Jiaqi
Wang, Junchao
Lyu, Xianzhou
Mechanical and Microcrack Evolution Characteristics of Roof Rock of Coal Seam with Different Angle of Defects Based on Particle Flow Code
title Mechanical and Microcrack Evolution Characteristics of Roof Rock of Coal Seam with Different Angle of Defects Based on Particle Flow Code
title_full Mechanical and Microcrack Evolution Characteristics of Roof Rock of Coal Seam with Different Angle of Defects Based on Particle Flow Code
title_fullStr Mechanical and Microcrack Evolution Characteristics of Roof Rock of Coal Seam with Different Angle of Defects Based on Particle Flow Code
title_full_unstemmed Mechanical and Microcrack Evolution Characteristics of Roof Rock of Coal Seam with Different Angle of Defects Based on Particle Flow Code
title_short Mechanical and Microcrack Evolution Characteristics of Roof Rock of Coal Seam with Different Angle of Defects Based on Particle Flow Code
title_sort mechanical and microcrack evolution characteristics of roof rock of coal seam with different angle of defects based on particle flow code
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9959630/
https://www.ncbi.nlm.nih.gov/pubmed/36837031
http://dx.doi.org/10.3390/ma16041401
work_keys_str_mv AT dengqinghai mechanicalandmicrocrackevolutioncharacteristicsofroofrockofcoalseamwithdifferentangleofdefectsbasedonparticleflowcode
AT liujiaqi mechanicalandmicrocrackevolutioncharacteristicsofroofrockofcoalseamwithdifferentangleofdefectsbasedonparticleflowcode
AT wangjunchao mechanicalandmicrocrackevolutioncharacteristicsofroofrockofcoalseamwithdifferentangleofdefectsbasedonparticleflowcode
AT lyuxianzhou mechanicalandmicrocrackevolutioncharacteristicsofroofrockofcoalseamwithdifferentangleofdefectsbasedonparticleflowcode