Effect of fractures on mechanical behavior of sand powder 3D printing rock analogue under triaxial compression

In practical engineering applications, rock mass are often found to be subjected to a triaxial stress state. Concurrently, defects like joints and fractures have a notable impact on the mechanical behavior of rock mass. Such defects are identified as crucial contributors to the failure and instability of the surrounding rock, subsequently impacting the engineering stability. The study aimed to investigate the impact of fracture geometry and confining pressure on the deformation, failure characteristics, and strength of specimens using sand powder 3D printing technology and conventional triaxial compression tests. The results indicate that the number of fractures present considerably influences the peak strength, axial peak strain and elastic modulus of the specimens. Confining pressure is an important factor affecting the failure pattern of the specimen, under which the specimen is more prone to shear failure, but the initiation, expansion and penetration processes of secondary cracks in different fracture specimens are different. This study confirmed the feasibility of using sand powder 3D printing specimens as soft rock analogs for triaxial compression research. The insights from this research are deemed essential for a deeper understanding of the mechanical behavior of fractured surrounding rocks when under triaxial stress state.