Energy Conservation and Mechanical Behavior of Granite and Marble Under Confining Pressure

This study investigates the mechanical behavior of three types of granite and marble under compression to understand the impact of energy transformation, microcracks, and confining pressure on their deformation and failure mechanisms. Rock samples, differentiated by grain size and texture, were subjected to laboratory tests using Eagle Scientific and UTEST triaxial machines. The results revealed that granite B, with the highest silicon content, exhibited higher peak stress compared to granite A and C, aligning with its finer grain size and reduced microcrack density. The increasing confining pressure from 0 to 10 MPa significantly enhanced peak stress, with granite B showing the highest strength (211 MPa), followed by marble (137 MPa). Stress-strain analysis highlighted abrupt failure post-peak, with finer-grained rocks, such as granite A and marble, displaying more complex stress-time relationships due to inherent microcracks. The study also examined energy dissipation, revealing that elastic strain energy accumulates rapidly until failure, while dissipative energy stabilizes during loading.