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Mechanical properties and progressive failure characteristics of sandstone containing elliptical and square openings subjected to biaxial stress
Two kinds of common tunnel shapes, i.e. elliptical opening and square opening were selected for biaxial compression tests, and the influences of two kinds of opening shapes on the mechanical properties, failure characteristics and failure modes of sandstone were compared and analyzed. The complex va...
Autores principales: | , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Public Library of Science
2021
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7932157/ https://www.ncbi.nlm.nih.gov/pubmed/33661935 http://dx.doi.org/10.1371/journal.pone.0246815 |
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author | Zhao, Honggang Sun, Haitao Zhang, Dongming Liu, Chao |
author_facet | Zhao, Honggang Sun, Haitao Zhang, Dongming Liu, Chao |
author_sort | Zhao, Honggang |
collection | PubMed |
description | Two kinds of common tunnel shapes, i.e. elliptical opening and square opening were selected for biaxial compression tests, and the influences of two kinds of opening shapes on the mechanical properties, failure characteristics and failure modes of sandstone were compared and analyzed. The complex variable theory and mapping functions were used to obtain the analytical stress solution around elliptical and square openings. The results show that the stability of the specimen containing an elliptical opening was better than that of the specimen containing a square opening under the same lateral stress. Compared with the elliptical opening, the local damage was formed earlier in the square opening which might be caused by a higher stress concentration around the square opening. The stress distributions around openings were influenced by the opening shape and lateral stress coefficient. The top and bottom of square opening were more prone to tensile fracture, and the distribution range of tensile was larger than that of elliptical opening. When the opening failed, the intensity of square opening failure was weaker than that of elliptical opening. On the basis of the average frequency value and the rise angle value, the failure mode of specimen containing elliptical or square opening was distinguished. It was found that the mixed tension and shear failure dominated the failure of specimens with different opening shapes, and the number of shear cracks in the specimen containing a square opening was greater than that in the specimen containing an elliptical opening. The above method of judging failure mode by acoustic emission signals was well verified by the CT images of damaged specimens. |
format | Online Article Text |
id | pubmed-7932157 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2021 |
publisher | Public Library of Science |
record_format | MEDLINE/PubMed |
spelling | pubmed-79321572021-03-15 Mechanical properties and progressive failure characteristics of sandstone containing elliptical and square openings subjected to biaxial stress Zhao, Honggang Sun, Haitao Zhang, Dongming Liu, Chao PLoS One Research Article Two kinds of common tunnel shapes, i.e. elliptical opening and square opening were selected for biaxial compression tests, and the influences of two kinds of opening shapes on the mechanical properties, failure characteristics and failure modes of sandstone were compared and analyzed. The complex variable theory and mapping functions were used to obtain the analytical stress solution around elliptical and square openings. The results show that the stability of the specimen containing an elliptical opening was better than that of the specimen containing a square opening under the same lateral stress. Compared with the elliptical opening, the local damage was formed earlier in the square opening which might be caused by a higher stress concentration around the square opening. The stress distributions around openings were influenced by the opening shape and lateral stress coefficient. The top and bottom of square opening were more prone to tensile fracture, and the distribution range of tensile was larger than that of elliptical opening. When the opening failed, the intensity of square opening failure was weaker than that of elliptical opening. On the basis of the average frequency value and the rise angle value, the failure mode of specimen containing elliptical or square opening was distinguished. It was found that the mixed tension and shear failure dominated the failure of specimens with different opening shapes, and the number of shear cracks in the specimen containing a square opening was greater than that in the specimen containing an elliptical opening. The above method of judging failure mode by acoustic emission signals was well verified by the CT images of damaged specimens. Public Library of Science 2021-03-04 /pmc/articles/PMC7932157/ /pubmed/33661935 http://dx.doi.org/10.1371/journal.pone.0246815 Text en © 2021 Zhao et al http://creativecommons.org/licenses/by/4.0/ This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/) , which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. |
spellingShingle | Research Article Zhao, Honggang Sun, Haitao Zhang, Dongming Liu, Chao Mechanical properties and progressive failure characteristics of sandstone containing elliptical and square openings subjected to biaxial stress |
title | Mechanical properties and progressive failure characteristics of sandstone containing elliptical and square openings subjected to biaxial stress |
title_full | Mechanical properties and progressive failure characteristics of sandstone containing elliptical and square openings subjected to biaxial stress |
title_fullStr | Mechanical properties and progressive failure characteristics of sandstone containing elliptical and square openings subjected to biaxial stress |
title_full_unstemmed | Mechanical properties and progressive failure characteristics of sandstone containing elliptical and square openings subjected to biaxial stress |
title_short | Mechanical properties and progressive failure characteristics of sandstone containing elliptical and square openings subjected to biaxial stress |
title_sort | mechanical properties and progressive failure characteristics of sandstone containing elliptical and square openings subjected to biaxial stress |
topic | Research Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7932157/ https://www.ncbi.nlm.nih.gov/pubmed/33661935 http://dx.doi.org/10.1371/journal.pone.0246815 |
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