Effect of internal fractures on mechanical properties and failure of sandstone under multi-physical fields
Tianyi Shi,
Jianxin Fu,
Weidong Song,
Jie Wang,
Kazimi M. Y
Affiliations
Tianyi Shi
School of Civil and Resources Engineering, University of Science and Technology Beijing, Beijing 100083, China; State Key Laboratory of High-Efficient Mining and Safety of Metal Mines of Ministry of Education, University of Science and Technology Beijing, Beijing 100083, China
Jianxin Fu
School of Civil and Resources Engineering, University of Science and Technology Beijing, Beijing 100083, China; State Key Laboratory of High-Efficient Mining and Safety of Metal Mines of Ministry of Education, University of Science and Technology Beijing, Beijing 100083, China; Corresponding author. School of Civil and Resources Engineering, University of Science and Technology Beijing, Beijing 100083, China.
Weidong Song
School of Civil and Resources Engineering, University of Science and Technology Beijing, Beijing 100083, China; State Key Laboratory of High-Efficient Mining and Safety of Metal Mines of Ministry of Education, University of Science and Technology Beijing, Beijing 100083, China
Jie Wang
School of Civil and Resources Engineering, University of Science and Technology Beijing, Beijing 100083, China; State Key Laboratory of High-Efficient Mining and Safety of Metal Mines of Ministry of Education, University of Science and Technology Beijing, Beijing 100083, China
Kazimi M. Y
School of Civil and Resources Engineering, University of Science and Technology Beijing, Beijing 100083, China; State Key Laboratory of High-Efficient Mining and Safety of Metal Mines of Ministry of Education, University of Science and Technology Beijing, Beijing 100083, China
Under deep mining conditions, rocks are subjected to complex multi-physical fields and can contain numerous pores and fractures. To explore the influence and correlation of these factors on the physical and mechanical properties of fractured rock samples, this study conducted triaxial compression tests on sandstone specimens under various physical conditions using a rock full stress multi-field coupling triaxial tester. Additionally, a random fracture model for multi-field coupling numerical simulation was established. This allowed the study to obtain the mechanical parameters, failure mode, and internal fracture development of rocks under multi-physical field conditions. By analyzing the complete stress-strain curve, mechanical characteristic points, and permeability, a combination of laboratory tests and numerical simulations was used to examine how temperature, seepage, and stress fields affect the development of pores and fractures in rocks. It was found that the temperature field, under conventional geothermal conditions, generates tensile force through thermal expansion and the presence of fluid, thereby promoting fracture development within the rocks. This mechanism is similar to that of seepage. The confining pressure caused by deep geo stress uniformly inhibits the expansion of pores and fissures within the rocks.
