Investigation on Dynamical Mechanics, Energy Dissipation, and Microstructural Characteristics of Cemented Tailings Backfill under SHPB Tests
As mining depth increases, the backfill mining method is more and more widely used in underground mines. The dynamic load generated by the blasting can affect the stability of the cemented tailings backfill (CTB). The CTB samples were prepared to conduct a test of the split Hopkinson pressure bar (S...
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doaj-92476b24180e40df9bd1996ade5a303a2021-06-01T00:32:02ZengMDPI AGMinerals2075-163X2021-05-011154254210.3390/min11050542Investigation on Dynamical Mechanics, Energy Dissipation, and Microstructural Characteristics of Cemented Tailings Backfill under SHPB TestsDi Zheng0Weidong Song1Shuai Cao2Jiajian Li3Lijuan Sun4School of Civil and Resources Engineering, University of Science and Technology Beijing, Beijing 100083, ChinaSchool of Civil and Resources Engineering, University of Science and Technology Beijing, Beijing 100083, ChinaSchool of Civil and Resources Engineering, University of Science and Technology Beijing, Beijing 100083, ChinaSchool of Civil and Resources Engineering, University of Science and Technology Beijing, Beijing 100083, ChinaState Key Laboratory for Nonlinear Mechanics (LNM) Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190, ChinaAs mining depth increases, the backfill mining method is more and more widely used in underground mines. The dynamic load generated by the blasting can affect the stability of the cemented tailings backfill (CTB). The CTB samples were prepared to conduct a test of the split Hopkinson pressure bar (SHPB) to investigate the dynamic disturbance of CTB. The present paper discusses dynamical mechanics, energy dissipation, and microstructure analysis of CTB. Micro-computer tomography (micro-CT) scanning of CTB samples after the SHPB test was performed to analyze the evolution of internal cracks. The experimental results showed that when the average strain rate (ASR) increased from 30 to 98 s<sup>−1</sup>, the dynamic uniaxial compression strength (DUCS) of the CTB showed a trend of first increasing and decreasing with the increase in ASR. The dynamic stress–strain pre-peak curve of CTB directly enters the linear elastic stage. As ASR increases, the absorbed energy of the CTB shows a trend of first increasing and then decreasing. Moreover, according to the micro-CT scanning results, the crack area of CTB accounts for about 16% of the sample near the incident bar and about 1% near the transmitted bar. The crack area ratio is exponentially related to the specimen height. These findings can provide reasonable dynamical CTB strength data selection for underground pillar mining.https://www.mdpi.com/2075-163X/11/5/542cemented tailings backfill (CTB)split Hopkinson pressure bar (SHPB)dynamical characteristicsenergy dissipationmicro-computer tomography |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
Di Zheng Weidong Song Shuai Cao Jiajian Li Lijuan Sun |
spellingShingle |
Di Zheng Weidong Song Shuai Cao Jiajian Li Lijuan Sun Investigation on Dynamical Mechanics, Energy Dissipation, and Microstructural Characteristics of Cemented Tailings Backfill under SHPB Tests Minerals cemented tailings backfill (CTB) split Hopkinson pressure bar (SHPB) dynamical characteristics energy dissipation micro-computer tomography |
author_facet |
Di Zheng Weidong Song Shuai Cao Jiajian Li Lijuan Sun |
author_sort |
Di Zheng |
title |
Investigation on Dynamical Mechanics, Energy Dissipation, and Microstructural Characteristics of Cemented Tailings Backfill under SHPB Tests |
title_short |
Investigation on Dynamical Mechanics, Energy Dissipation, and Microstructural Characteristics of Cemented Tailings Backfill under SHPB Tests |
title_full |
Investigation on Dynamical Mechanics, Energy Dissipation, and Microstructural Characteristics of Cemented Tailings Backfill under SHPB Tests |
title_fullStr |
Investigation on Dynamical Mechanics, Energy Dissipation, and Microstructural Characteristics of Cemented Tailings Backfill under SHPB Tests |
title_full_unstemmed |
Investigation on Dynamical Mechanics, Energy Dissipation, and Microstructural Characteristics of Cemented Tailings Backfill under SHPB Tests |
title_sort |
investigation on dynamical mechanics, energy dissipation, and microstructural characteristics of cemented tailings backfill under shpb tests |
publisher |
MDPI AG |
series |
Minerals |
issn |
2075-163X |
publishDate |
2021-05-01 |
description |
As mining depth increases, the backfill mining method is more and more widely used in underground mines. The dynamic load generated by the blasting can affect the stability of the cemented tailings backfill (CTB). The CTB samples were prepared to conduct a test of the split Hopkinson pressure bar (SHPB) to investigate the dynamic disturbance of CTB. The present paper discusses dynamical mechanics, energy dissipation, and microstructure analysis of CTB. Micro-computer tomography (micro-CT) scanning of CTB samples after the SHPB test was performed to analyze the evolution of internal cracks. The experimental results showed that when the average strain rate (ASR) increased from 30 to 98 s<sup>−1</sup>, the dynamic uniaxial compression strength (DUCS) of the CTB showed a trend of first increasing and decreasing with the increase in ASR. The dynamic stress–strain pre-peak curve of CTB directly enters the linear elastic stage. As ASR increases, the absorbed energy of the CTB shows a trend of first increasing and then decreasing. Moreover, according to the micro-CT scanning results, the crack area of CTB accounts for about 16% of the sample near the incident bar and about 1% near the transmitted bar. The crack area ratio is exponentially related to the specimen height. These findings can provide reasonable dynamical CTB strength data selection for underground pillar mining. |
topic |
cemented tailings backfill (CTB) split Hopkinson pressure bar (SHPB) dynamical characteristics energy dissipation micro-computer tomography |
url |
https://www.mdpi.com/2075-163X/11/5/542 |
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