Experimental investigation on mechanical properties and strength criteria of frozen soft rock.
Excavation of underground engineering structures involving deeply buried water-rich soft rocks is generally carried out using the artificial freezing method. A series of undrained uniaxial and triaxial shear and creep tests were conducted on soft rocks under different confining pressures (0, 0.2, 0....
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Public Library of Science (PLoS)
2025-01-01
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Online Access: | https://doi.org/10.1371/journal.pone.0313493 |
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author | Zhenhua Wang Zecheng Wang Dongwei Li Zhiwen Jia Xiqi Liu |
author_facet | Zhenhua Wang Zecheng Wang Dongwei Li Zhiwen Jia Xiqi Liu |
author_sort | Zhenhua Wang |
collection | DOAJ |
description | Excavation of underground engineering structures involving deeply buried water-rich soft rocks is generally carried out using the artificial freezing method. A series of undrained uniaxial and triaxial shear and creep tests were conducted on soft rocks under different confining pressures (0, 0.2, 0.5, and 1.0 MPa) at different freezing temperatures (room temperature, -5°C, -10°C, and -15°C). Test results indicate that the frozen soft rocks show strain softening characteristics. The stress-strain curve changes from a straight line to a curve as deviatoric stress constantly increases, while it decreases abruptly after the deviatoric stress reaches the peak and is slightly affected by the freezing temperature. At the same temperature, shear strength increases at a rate of 5.6 MPa/°C with increasing confining pressure; as freezing temperature decreases, the shear strength increases at 0.34 MPa/°C, and cohesion increases at 0.6 MPa/°C. Under the same confining pressure, the failure strain of soft rock decreases with the decrease of temperature. The Mohr-Coulomb (M-C) criterion can accurately describe the failure process of frozen soft rocks in the pre-peak stage, with a correlation coefficient greater than 0.98. Within the test stress range, soft rocks display attenuated stable creep deformation. Acoustic emission (AE) tests were conducted to further verify that the soft rocks show shear failure under load, with a shear plane showing an angle of 45° with the horizontal. The research findings provide technical support and theoretical reference for studying rock mechanical properties as well as for designing and carrying out underground freezing of rocks in a low-temperature environment. |
format | Article |
id | doaj-art-234b73aabc78438e8893617578dfd025 |
institution | Kabale University |
issn | 1932-6203 |
language | English |
publishDate | 2025-01-01 |
publisher | Public Library of Science (PLoS) |
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spelling | doaj-art-234b73aabc78438e8893617578dfd0252025-01-17T05:31:22ZengPublic Library of Science (PLoS)PLoS ONE1932-62032025-01-01201e031349310.1371/journal.pone.0313493Experimental investigation on mechanical properties and strength criteria of frozen soft rock.Zhenhua WangZecheng WangDongwei LiZhiwen JiaXiqi LiuExcavation of underground engineering structures involving deeply buried water-rich soft rocks is generally carried out using the artificial freezing method. A series of undrained uniaxial and triaxial shear and creep tests were conducted on soft rocks under different confining pressures (0, 0.2, 0.5, and 1.0 MPa) at different freezing temperatures (room temperature, -5°C, -10°C, and -15°C). Test results indicate that the frozen soft rocks show strain softening characteristics. The stress-strain curve changes from a straight line to a curve as deviatoric stress constantly increases, while it decreases abruptly after the deviatoric stress reaches the peak and is slightly affected by the freezing temperature. At the same temperature, shear strength increases at a rate of 5.6 MPa/°C with increasing confining pressure; as freezing temperature decreases, the shear strength increases at 0.34 MPa/°C, and cohesion increases at 0.6 MPa/°C. Under the same confining pressure, the failure strain of soft rock decreases with the decrease of temperature. The Mohr-Coulomb (M-C) criterion can accurately describe the failure process of frozen soft rocks in the pre-peak stage, with a correlation coefficient greater than 0.98. Within the test stress range, soft rocks display attenuated stable creep deformation. Acoustic emission (AE) tests were conducted to further verify that the soft rocks show shear failure under load, with a shear plane showing an angle of 45° with the horizontal. The research findings provide technical support and theoretical reference for studying rock mechanical properties as well as for designing and carrying out underground freezing of rocks in a low-temperature environment.https://doi.org/10.1371/journal.pone.0313493 |
spellingShingle | Zhenhua Wang Zecheng Wang Dongwei Li Zhiwen Jia Xiqi Liu Experimental investigation on mechanical properties and strength criteria of frozen soft rock. PLoS ONE |
title | Experimental investigation on mechanical properties and strength criteria of frozen soft rock. |
title_full | Experimental investigation on mechanical properties and strength criteria of frozen soft rock. |
title_fullStr | Experimental investigation on mechanical properties and strength criteria of frozen soft rock. |
title_full_unstemmed | Experimental investigation on mechanical properties and strength criteria of frozen soft rock. |
title_short | Experimental investigation on mechanical properties and strength criteria of frozen soft rock. |
title_sort | experimental investigation on mechanical properties and strength criteria of frozen soft rock |
url | https://doi.org/10.1371/journal.pone.0313493 |
work_keys_str_mv | AT zhenhuawang experimentalinvestigationonmechanicalpropertiesandstrengthcriteriaoffrozensoftrock AT zechengwang experimentalinvestigationonmechanicalpropertiesandstrengthcriteriaoffrozensoftrock AT dongweili experimentalinvestigationonmechanicalpropertiesandstrengthcriteriaoffrozensoftrock AT zhiwenjia experimentalinvestigationonmechanicalpropertiesandstrengthcriteriaoffrozensoftrock AT xiqiliu experimentalinvestigationonmechanicalpropertiesandstrengthcriteriaoffrozensoftrock |