Influence of initial micro-crack damage on strength and micro-cracking behavior of an intrusive crystalline rock

Rocks inherently contain some micro-cracks. The existence of initial micro-cracks introduces weakness to the rock specimen and hence affects the strength and deformation behavior of rocks. This paper numerically investigates the influence of initial micro-crack damage on the strength and deformation...

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Main Authors: Peng, Jun, Wong, Louis Ngai Yuen, Liu, Guang, Teh, Cee Ing
Other Authors: School of Civil and Environmental Engineering
Format: Article
Language:English
Published: 2020
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Online Access:https://hdl.handle.net/10356/137844
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Institution: Nanyang Technological University
Language: English
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spelling sg-ntu-dr.10356-1378442020-04-16T03:34:03Z Influence of initial micro-crack damage on strength and micro-cracking behavior of an intrusive crystalline rock Peng, Jun Wong, Louis Ngai Yuen Liu, Guang Teh, Cee Ing School of Civil and Environmental Engineering Engineering::Environmental engineering Initial Micro-crack Damage Loading/unloading Rocks inherently contain some micro-cracks. The existence of initial micro-cracks introduces weakness to the rock specimen and hence affects the strength and deformation behavior of rocks. This paper numerically investigates the influence of initial micro-crack damage on the strength and deformation behavior and the associated micro-cracking process of a crystalline rock using a previously-calibrated grain-based model (GBM), which is implemented in two-dimensional Particle Flow Code (PFC2D). The initial micro-crack damage is generated by loading/unloading of the model numerically, and a damage parameter is defined to quantify the degree of initial micro-crack damage. After the initial micro-crack damage is generated, compressive loading tests under different confining pressures are conducted. The simulation results reveal that the initial micro-crack damage has a significant influence on the simulated stress–strain curve, rock strength, elastic modulus, and total number of generated micro-cracks. In general, as the initial micro-crack damage increases in the numerical model, the simulated rock strength and elastic modulus gradually decrease. However, the decrease in rock property (strength and elastic modulus) will become significant only after sufficiently high initial micro-crack damage in the model is reached. The elastic modulus to UCS ratio (E/UCS) is not significantly affected by the initial micro-crack damage. Overall, the initial micro-crack damage weakens the model. The simulation results are in good agreement with previous laboratory tests results. The PFC2D-GBM approach in this study can be used to capture the strength and deformation behavior of damaged rocks, which are induced from initially-generated micro-cracks, e.g., rock drilling and coring, cyclic loading, and thermal loading. MOE (Min. of Education, S’pore) 2020-04-16T03:34:03Z 2020-04-16T03:34:03Z 2019 Journal Article Peng, J., Wong, L. N. Y., Liu, G., & Teh, C. I. (2019). Influence of initial micro-crack damage on strength and micro-cracking behavior of an intrusive crystalline rock. Bulletin of Engineering Geology and the Environment, 78(4), 2957-2971. doi:10.1007/s10064-018-1317-3 1435-9529 https://hdl.handle.net/10356/137844 10.1007/s10064-018-1317-3 2-s2.0-85048044494 4 78 2957 2971 en Bulletin of Engineering Geology and the Environment © 2018 Springer-Verlag GmbH Germany, part of Springer Nature. All rights reserved.
institution Nanyang Technological University
building NTU Library
country Singapore
collection DR-NTU
language English
topic Engineering::Environmental engineering
Initial Micro-crack Damage
Loading/unloading
spellingShingle Engineering::Environmental engineering
Initial Micro-crack Damage
Loading/unloading
Peng, Jun
Wong, Louis Ngai Yuen
Liu, Guang
Teh, Cee Ing
Influence of initial micro-crack damage on strength and micro-cracking behavior of an intrusive crystalline rock
description Rocks inherently contain some micro-cracks. The existence of initial micro-cracks introduces weakness to the rock specimen and hence affects the strength and deformation behavior of rocks. This paper numerically investigates the influence of initial micro-crack damage on the strength and deformation behavior and the associated micro-cracking process of a crystalline rock using a previously-calibrated grain-based model (GBM), which is implemented in two-dimensional Particle Flow Code (PFC2D). The initial micro-crack damage is generated by loading/unloading of the model numerically, and a damage parameter is defined to quantify the degree of initial micro-crack damage. After the initial micro-crack damage is generated, compressive loading tests under different confining pressures are conducted. The simulation results reveal that the initial micro-crack damage has a significant influence on the simulated stress–strain curve, rock strength, elastic modulus, and total number of generated micro-cracks. In general, as the initial micro-crack damage increases in the numerical model, the simulated rock strength and elastic modulus gradually decrease. However, the decrease in rock property (strength and elastic modulus) will become significant only after sufficiently high initial micro-crack damage in the model is reached. The elastic modulus to UCS ratio (E/UCS) is not significantly affected by the initial micro-crack damage. Overall, the initial micro-crack damage weakens the model. The simulation results are in good agreement with previous laboratory tests results. The PFC2D-GBM approach in this study can be used to capture the strength and deformation behavior of damaged rocks, which are induced from initially-generated micro-cracks, e.g., rock drilling and coring, cyclic loading, and thermal loading.
author2 School of Civil and Environmental Engineering
author_facet School of Civil and Environmental Engineering
Peng, Jun
Wong, Louis Ngai Yuen
Liu, Guang
Teh, Cee Ing
format Article
author Peng, Jun
Wong, Louis Ngai Yuen
Liu, Guang
Teh, Cee Ing
author_sort Peng, Jun
title Influence of initial micro-crack damage on strength and micro-cracking behavior of an intrusive crystalline rock
title_short Influence of initial micro-crack damage on strength and micro-cracking behavior of an intrusive crystalline rock
title_full Influence of initial micro-crack damage on strength and micro-cracking behavior of an intrusive crystalline rock
title_fullStr Influence of initial micro-crack damage on strength and micro-cracking behavior of an intrusive crystalline rock
title_full_unstemmed Influence of initial micro-crack damage on strength and micro-cracking behavior of an intrusive crystalline rock
title_sort influence of initial micro-crack damage on strength and micro-cracking behavior of an intrusive crystalline rock
publishDate 2020
url https://hdl.handle.net/10356/137844
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