Experimental Investigation of Shear Strength of Carbonate Saline Soil under Freeze-Thaw Cycles
Climate change is accelerating its adverse impact on ecosystems and infrastructure systems in cold regions. For extensive carbonate saline soil areas, their response to the freeze-thaw cycle remains uncertain. By considering the continuous intensification of freeze-thaw cycle frequency, the mechanic...
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| Format: | Article |
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MDPI AG
2022-12-01
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| Series: | Atmosphere |
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| Online Access: | https://www.mdpi.com/2073-4433/13/12/2063 |
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| author | Kaichi Qiu Lin Ding Wenbing Yu Kezheng Chen Shuai Huang Kai Gao |
| author_facet | Kaichi Qiu Lin Ding Wenbing Yu Kezheng Chen Shuai Huang Kai Gao |
| author_sort | Kaichi Qiu |
| collection | DOAJ |
| description | Climate change is accelerating its adverse impact on ecosystems and infrastructure systems in cold regions. For extensive carbonate saline soil areas, their response to the freeze-thaw cycle remains uncertain. By considering the continuous intensification of freeze-thaw cycle frequency, the mechanical characteristics of carbonate saline soils are analyzed for different salt content (0.6% to 2.1%) based on the mechanical test in this paper. The purpose is to reveal the change law of shear strength and its parameters of carbonate saline soils under the scenario of continuous freezing and thawing cycles. The micro-characteristics of the carbonate saline soil before and after freeze-thaw cycling were analyzed by scanning electron microscopy, indicating changes in the structural soil properties caused by the combination of freeze-thawing and salinity. The scanning electron microscope images reveal the cumulative effect of frost heaving and salt expansion, i.e., increasing the number of pores between particles, reducing the effective contact between particles, and weakening the interaction force, resulting in cracks development. A series of mechanical tests demonstrate the stress-strain behavior of carbonate saline soils for different numbers of freeze-thaw cycles under different confining pressures. A transformation from strain-softening to strain-hardening is observed with an increase in the salt content from 0.6% to 2.1%. Furthermore, the shear strength of the carbonate saline soil decreases as the salt content and number of freeze-thaw cycles increase. The shear strength degradation mechanism is attributed to the cohesion and the internal friction angle. These shear strength parameters are critical in geotechnical analyses, such as evaluating of load capacity of foundations and slope stability in similar saline soils. |
| first_indexed | 2024-03-09T17:21:40Z |
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| institution | Directory Open Access Journal |
| issn | 2073-4433 |
| language | English |
| last_indexed | 2024-03-09T17:21:40Z |
| publishDate | 2022-12-01 |
| publisher | MDPI AG |
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| series | Atmosphere |
| spelling | doaj.art-f84449f9c3cf41beb93adfc1c6d9ed712023-11-24T13:12:14ZengMDPI AGAtmosphere2073-44332022-12-011312206310.3390/atmos13122063Experimental Investigation of Shear Strength of Carbonate Saline Soil under Freeze-Thaw CyclesKaichi Qiu0Lin Ding1Wenbing Yu2Kezheng Chen3Shuai Huang4Kai Gao5State Key Laboratory of Mountain Bridge and Tunnel Engineering, Chongqing Jiaotong University, Chongqing 400074, ChinaCollege of Architecture and Engineering, Heilongjiang University, Harbin 150080, ChinaState Key Laboratory of Mountain Bridge and Tunnel Engineering, Chongqing Jiaotong University, Chongqing 400074, ChinaCollege of Engineering and Technology, Northeast Forestry University, Harbin 150040, ChinaSchool of Civil Engineering, Northeast Forestry University, Harbin 150040, ChinaState Key Laboratory of Frozen Soil Engineering, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, ChinaClimate change is accelerating its adverse impact on ecosystems and infrastructure systems in cold regions. For extensive carbonate saline soil areas, their response to the freeze-thaw cycle remains uncertain. By considering the continuous intensification of freeze-thaw cycle frequency, the mechanical characteristics of carbonate saline soils are analyzed for different salt content (0.6% to 2.1%) based on the mechanical test in this paper. The purpose is to reveal the change law of shear strength and its parameters of carbonate saline soils under the scenario of continuous freezing and thawing cycles. The micro-characteristics of the carbonate saline soil before and after freeze-thaw cycling were analyzed by scanning electron microscopy, indicating changes in the structural soil properties caused by the combination of freeze-thawing and salinity. The scanning electron microscope images reveal the cumulative effect of frost heaving and salt expansion, i.e., increasing the number of pores between particles, reducing the effective contact between particles, and weakening the interaction force, resulting in cracks development. A series of mechanical tests demonstrate the stress-strain behavior of carbonate saline soils for different numbers of freeze-thaw cycles under different confining pressures. A transformation from strain-softening to strain-hardening is observed with an increase in the salt content from 0.6% to 2.1%. Furthermore, the shear strength of the carbonate saline soil decreases as the salt content and number of freeze-thaw cycles increase. The shear strength degradation mechanism is attributed to the cohesion and the internal friction angle. These shear strength parameters are critical in geotechnical analyses, such as evaluating of load capacity of foundations and slope stability in similar saline soils.https://www.mdpi.com/2073-4433/13/12/2063climate changefreeze-thaw cyclecarbonate saline soilshear strengthmicrostructure |
| spellingShingle | Kaichi Qiu Lin Ding Wenbing Yu Kezheng Chen Shuai Huang Kai Gao Experimental Investigation of Shear Strength of Carbonate Saline Soil under Freeze-Thaw Cycles Atmosphere climate change freeze-thaw cycle carbonate saline soil shear strength microstructure |
| title | Experimental Investigation of Shear Strength of Carbonate Saline Soil under Freeze-Thaw Cycles |
| title_full | Experimental Investigation of Shear Strength of Carbonate Saline Soil under Freeze-Thaw Cycles |
| title_fullStr | Experimental Investigation of Shear Strength of Carbonate Saline Soil under Freeze-Thaw Cycles |
| title_full_unstemmed | Experimental Investigation of Shear Strength of Carbonate Saline Soil under Freeze-Thaw Cycles |
| title_short | Experimental Investigation of Shear Strength of Carbonate Saline Soil under Freeze-Thaw Cycles |
| title_sort | experimental investigation of shear strength of carbonate saline soil under freeze thaw cycles |
| topic | climate change freeze-thaw cycle carbonate saline soil shear strength microstructure |
| url | https://www.mdpi.com/2073-4433/13/12/2063 |
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