Thermal Influence on Damage Behavior and Constitutive Response of Granite under Variable Cyclic Loading

• Published in: Geotechnical and geological engineering Vol. 43; no. 7; p. 355
• Main Authors: Bao, Xiankai, Huang, Shunjia, Lv, Yongjun, Wang, Lizhi, Huang, Yue, Li, Xinya, Ou, Jiaao, Yin, Meng
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 01.10.2025; Springer Nature B.V
• Subjects: Acoustic emission; Acoustics; Blasting; Civil Engineering; Constitutive equations; Constitutive relationships; Crack propagation; Cyclic loading; Cyclic loads; Damage; Damage assessment; Earth and Environmental Science; Earth Sciences; Fractal geometry; Geotechnical Engineering & Applied Earth Sciences; Granite; High temperature; Hydrogeology; Mechanical properties; Modulus of elasticity; Original Paper; Physical tests; Poisson's ratio; Rock; Rocks; Stone; Strain gauges; Stress-strain curves; Stress-strain relations; Temperature; Temperature effects; Terrestrial Pollution; Tunnel construction; Unloading; Vibrations; Waste Management/Waste Technology; China; Constitutive equation; Acoustic emission; Fractal dimension; Granite
• ISSN: 0960-3182; 1573-1529
• DOI: 10.1007/s10706-025-03328-3

During tunnel construction, blasting vibrations or mechanical disturbances subject the surrounding rock to cyclic loading and unloading, leading to rock damage, crack propagation, and eventual instability. To investigate the damage characteristics and mechanical behavior of surrounding rock under cyclic loading and unloading, uniaxial cyclic loading and unloading tests were conducted on granite samples at 30, 40, 55, 75, and 100 °C, with acoustic emission (AE) monitoring employed. By analyzing the AE characteristics of granite, this study examines the changes in mechanical properties, fractal features, and constitutive equations under cyclic loading and unloading. Research indicates that as the temperature of granite increases, the peak strength, elastic modulus, and Poisson’s ratio of granite at 75 °C reach their minimum values, which are 102.83 MPa, 16.81 GPa, and 0.12, respectively. The acoustic emission cumulative ring count curve for granite at each temperature goes through a stable development phase and a rapid development phase. The ring count for granite at 75 °C undergoes an “explosive” increase during the rapid development phase, ultimately reaching 3.1 × 10⁷ counts, with the most severe damage and the highest degradation level. As the temperature rises, the fractal dimension under cyclic loading and unloading shows a general trend of fluctuating increase followed by a sharp decline. The fractal dimension reaches its peak at 75 °C, with the fractal dimensions in the top-down and side-view directions being 0.8216 and 0.7248, respectively. The damage process of granite at 75 °C is the most complex. The constitutive relationship derived from AE parameters closely aligns with the full stress–strain curve obtained from physical tests, validating the accuracy of the model. These findings provide theoretical insights into the mechanical behavior and damage failure of high-temperature granite under cyclic loading and unloading.