Experimental study on granite acoustic emission and micro-fracture behavior with combined compression and shear loading: phenomenon and mechanism

Abstract One element that is essential to consider in underground mining engineering applications is the possibility of pillar failure, which can result in deadly geological disasters, including earthquakes and surface subsidence. Pillars are commonly present under an inclined state and are signific...

Descripción completa

Guardado en:
Detalles Bibliográficos
Autores principales: Yue Cao, Jinhai Xu, Liang Chen, Peng Wu, Faiz Shaikh
Formato: article
Lenguaje:EN
Publicado: Nature Portfolio 2020
Materias:
R
Q
Acceso en línea:https://doaj.org/article/36404a58b82648c6bc4e7277a179fe26
Etiquetas: Agregar Etiqueta
Sin Etiquetas, Sea el primero en etiquetar este registro!
id oai:doaj.org-article:36404a58b82648c6bc4e7277a179fe26
record_format dspace
spelling oai:doaj.org-article:36404a58b82648c6bc4e7277a179fe262021-12-02T12:42:27ZExperimental study on granite acoustic emission and micro-fracture behavior with combined compression and shear loading: phenomenon and mechanism10.1038/s41598-020-78137-02045-2322https://doaj.org/article/36404a58b82648c6bc4e7277a179fe262020-12-01T00:00:00Zhttps://doi.org/10.1038/s41598-020-78137-0https://doaj.org/toc/2045-2322Abstract One element that is essential to consider in underground mining engineering applications is the possibility of pillar failure, which can result in deadly geological disasters, including earthquakes and surface subsidence. Pillars are commonly present under an inclined state and are significantly dependent upon combined compression and shear loading. However, many scholars regard the pure uniaxial compression strength (UCS) of rock as the main evaluation index of pillar strength, which is inconsistent with the field practice. Hence, the present study developed a novel combined compression and shear test (C-CAST) system, which was applied in the investigative acoustic emission (AE) experiments to characterize the failure mechanism and micro-fracture behavior of granite specimens at different inclination angles. The experimental results presented the exponential decrease of UCS of inclined specimens with increase in the shear stress component. Changes in the inclination angle with a range of 0°–10° produced a splitting-shear failure fracture mode from the initial splitting failure. In comparison, an increase in the inclination angle from 10° to 20° produced a single shear failure fracture mode from the initial combined splitting-shear failure. The specimens exhibited nonlinearly reduced microcrack initiation (CI) and damage (CD) thresholds following an increase in the inclination angle, suggesting the dependence of the microcrack initiation and propagation on the shear stress component. The ratio of CI and CD thresholds to inclined UCS varies within a certain range, indicating that the ratio may be an inherent property of granite specimens and is not affected by external load conditions. Additionally, the rock fracture behavior was largely dependent upon the mechanism of shear stress component, as validated by the microcrack initiation and growth. Finally, a modified empirical formula for pillar strength is proposed to investigate the actual strength of inclined pillar. Results of a case study show that the modified formula can be better used to evaluate the stability of inclined pillars.Yue CaoJinhai XuLiang ChenPeng WuFaiz ShaikhNature PortfolioarticleMedicineRScienceQENScientific Reports, Vol 10, Iss 1, Pp 1-17 (2020)
institution DOAJ
collection DOAJ
language EN
topic Medicine
R
Science
Q
spellingShingle Medicine
R
Science
Q
Yue Cao
Jinhai Xu
Liang Chen
Peng Wu
Faiz Shaikh
Experimental study on granite acoustic emission and micro-fracture behavior with combined compression and shear loading: phenomenon and mechanism
description Abstract One element that is essential to consider in underground mining engineering applications is the possibility of pillar failure, which can result in deadly geological disasters, including earthquakes and surface subsidence. Pillars are commonly present under an inclined state and are significantly dependent upon combined compression and shear loading. However, many scholars regard the pure uniaxial compression strength (UCS) of rock as the main evaluation index of pillar strength, which is inconsistent with the field practice. Hence, the present study developed a novel combined compression and shear test (C-CAST) system, which was applied in the investigative acoustic emission (AE) experiments to characterize the failure mechanism and micro-fracture behavior of granite specimens at different inclination angles. The experimental results presented the exponential decrease of UCS of inclined specimens with increase in the shear stress component. Changes in the inclination angle with a range of 0°–10° produced a splitting-shear failure fracture mode from the initial splitting failure. In comparison, an increase in the inclination angle from 10° to 20° produced a single shear failure fracture mode from the initial combined splitting-shear failure. The specimens exhibited nonlinearly reduced microcrack initiation (CI) and damage (CD) thresholds following an increase in the inclination angle, suggesting the dependence of the microcrack initiation and propagation on the shear stress component. The ratio of CI and CD thresholds to inclined UCS varies within a certain range, indicating that the ratio may be an inherent property of granite specimens and is not affected by external load conditions. Additionally, the rock fracture behavior was largely dependent upon the mechanism of shear stress component, as validated by the microcrack initiation and growth. Finally, a modified empirical formula for pillar strength is proposed to investigate the actual strength of inclined pillar. Results of a case study show that the modified formula can be better used to evaluate the stability of inclined pillars.
format article
author Yue Cao
Jinhai Xu
Liang Chen
Peng Wu
Faiz Shaikh
author_facet Yue Cao
Jinhai Xu
Liang Chen
Peng Wu
Faiz Shaikh
author_sort Yue Cao
title Experimental study on granite acoustic emission and micro-fracture behavior with combined compression and shear loading: phenomenon and mechanism
title_short Experimental study on granite acoustic emission and micro-fracture behavior with combined compression and shear loading: phenomenon and mechanism
title_full Experimental study on granite acoustic emission and micro-fracture behavior with combined compression and shear loading: phenomenon and mechanism
title_fullStr Experimental study on granite acoustic emission and micro-fracture behavior with combined compression and shear loading: phenomenon and mechanism
title_full_unstemmed Experimental study on granite acoustic emission and micro-fracture behavior with combined compression and shear loading: phenomenon and mechanism
title_sort experimental study on granite acoustic emission and micro-fracture behavior with combined compression and shear loading: phenomenon and mechanism
publisher Nature Portfolio
publishDate 2020
url https://doaj.org/article/36404a58b82648c6bc4e7277a179fe26
work_keys_str_mv AT yuecao experimentalstudyongraniteacousticemissionandmicrofracturebehaviorwithcombinedcompressionandshearloadingphenomenonandmechanism
AT jinhaixu experimentalstudyongraniteacousticemissionandmicrofracturebehaviorwithcombinedcompressionandshearloadingphenomenonandmechanism
AT liangchen experimentalstudyongraniteacousticemissionandmicrofracturebehaviorwithcombinedcompressionandshearloadingphenomenonandmechanism
AT pengwu experimentalstudyongraniteacousticemissionandmicrofracturebehaviorwithcombinedcompressionandshearloadingphenomenonandmechanism
AT faizshaikh experimentalstudyongraniteacousticemissionandmicrofracturebehaviorwithcombinedcompressionandshearloadingphenomenonandmechanism
_version_ 1718393677399719936