The Tensile–Shear Behavior of Loess and the Mechanism of the Tensile Strength Measured by the Unconfined Penetration Test
Publication: International Journal of Geomechanics
Volume 24, Issue 10
Abstract
The tensile strength is an important parameter in engineering. Many engineering-related problems in buildings as well as the damage caused to them during natural disasters occur owing to a lack of tensile strength. The unconfined penetration (UP) test is an indirect method to measure the tensile strength of soil. Analyses of the mechanism of the UP test and simulations based on the discrete-element method have shown that the UP test is a complex process involving tensile and shear strengths. In this study, the authors use the modified Mohr–Coulomb model to establish a joint criterion for the failure of the tensile strength and the shear strength of loess, and derive expressions for the correlations between the relevant mechanical parameters. A combination of the results of the aforementioned model and laboratory tests showed the following: (1) the process of failure of loess samples during the UP test consisted of four stages: (I) the shaping of the wedge-shaped split body, (II) tension-induced fracture, (III) the yield stage, and (IV) damage to the sample; (2) the tensile strength of the loess decreased exponentially with its saturation; (3) the ratio of the unconfined compressive and cohesive strengths to the tensile strength of the remolded loess was 1.37 times that of the undisturbed loess, while the ratio of the unconfined compressive strength of remolded loess to its cohesion was similar to that of undisturbed loess; (4) the wedge-splitting angle ranged from 13° to 23°, and had a negative correlation with the internal angle of friction, a positive correlation with the water content, and decreased exponentially with the tensile strength.
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Data Availability Statement
Some or all data, models, or codes that support the findings of this study are available from the corresponding author upon reasonable request.
Acknowledgments
This work was supported by the Gansu Province Science and Technology Major Special Projects (Grant No. 22ZD6FA004), the National Natural Science Foundation of China (Grant No. 51968041), the Postdoctoral Project of Gansu Province and The Independent Research Project of State Key Laboratory of Frozen Soil Engineering, and the Science and Technology Plan of Gansu Province (Grant No. 22JR5RA059).
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Published In
International Journal of Geomechanics
Volume 24 • Issue 10 • October 2024
Copyright
© 2024 American Society of Civil Engineers.
History
Received: Nov 28, 2023
Accepted: Mar 28, 2024
Published online: Jul 23, 2024
Published in print: Oct 1, 2024
Discussion open until: Dec 23, 2024
ASCE Technical Topics:
- Bodies of water (by type)
- Coasts, oceans, ports, and waterways engineering
- Compressive strength
- Engineering fundamentals
- Engineering mechanics
- Field tests
- Geotechnical engineering
- Geotechnical investigation
- Hydraulic engineering
- Hydraulic structures
- Loess
- Material mechanics
- Material properties
- Materials engineering
- Mathematics
- Parameters (statistics)
- Penetration tests
- River engineering
- Sediment
- Shear strength
- Statistics
- Strength of materials
- Structural behavior
- Structural engineering
- Structural strength
- Structures (by type)
- Tensile strength
- Tests (by type)
- Water and water resources
- Water management
- Waterways
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