Study on mechanical behavior and microscopic failure characteristics of deep rocks considering the influence of internal stress

To address the limitation of traditional discrete element modelling in considering internal stress, this study proposes a new numerical simulation process based on particle flow code in 2-D, which successfully achieves internal stress consolidation-sealing. Triaxial compression tests were conducted to analyze the impact of internal stress evolution on rock mechanical properties. Under a confining pressure of 10-20 MPa, internal stress causes the peak stress of the rock to be higher than when there is no internal stress, while the opposite is true at 30-40 MPa. The elastic modulus is consistently higher in rocks with internal stress. The trend of increasing the number of rock cracks with and without internal stress is similar, and the growth rate of tensile cracks is higher than that of shear cracks. Internal stress promotes crack propagation. The axial development of cracks is more pronounced. This study offers new insights into in-situ rock mechanics.