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| Triaxial compression behavior of sandstone under temperature influence: loading characteristics, shear deformation, and development of prediction software |
| ZHONG Hao1, CAI Xianqing1, SUN Hao1, KONG Qingxuan2, ZHANG Yongping3
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1. Sichuan Provincial Transportation Survey and Design Research Institute Co., Ltd., Chengdu 610031, Sichuan, China;
2. Chengdu Branch of Sichuan Chengmian Cangba Expressway Company Limited, Chengdu 610213, Sichuan, China;
3. Sichuan Railway Construction Co., Ltd., Chengdu 610031, Sichuan, China |
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Abstract This study conducted triaxial compression tests on sandstone under temperatures of 20-150 ℃ and confining pressures of 5-35 MPa and systematically revealed the coupled effects of temperature and confining pressure on the loading characteristics, shear deformation, and failure modes of sandstone. The results showed that in the low-temperature range(20-60 ℃), sandstone predominantly exhibits brittle failure, with the shear deformation band angle significantly decreasing as confining pressure increases(64.7°→58.3°). In the high-temperature range(≥120 ℃), plastic yielding characteristics were intensified, and at 150 ℃, the increase in confining pressure(5-35 MPa)resulted in a 15.3° reduction in the shear angle. The failure mode transitions from tensile failure under low confining pressure to shear failure under high confining pressure, with elevated temperatures increasing the roughness of failure surfaces. Compared to the Mogi-Coulomb, Drucker-Prager, and Tresca criteria, the modified Lade criterion was found to demonstrate optimal fitting performance(R2≥0.97)by incorporating deviatoric stress invariants and the Lode angle parameter. Based on this criterion, a prediction model for shear deformation band angles was developed. The developed multi-temperature discrete prediction software, integrated with PyCharm and Gradio, achieved high-precision predictions within 0.8 seconds(absolute error: 2.5°, R2=0.92). The output parameters were designed to be embedded into finite element platforms, providing theoretical and practical tools for stability assessments of high-stress tunnels and deep rock mass engineering.
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Published: 18 June 2025
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