Mechanical behaviors and damage characteristics of excavated jointed rocks within 3D printed structures

The presence of structural planes in rock masses reduces their mechanical properties and greatly affects their failure mode, resulting in physical and mechanical anisotropy. This study investigated the mechanical behaviors and damage characteristics of excavated jointed rocks in three-dimensional (3D) printed structures. A digital fracture network model based on the fractal principle was also developed to simulate a complex and rough network of fractures. Using 3D printing technology, rock specimens within a single rough structure surface, different dip angles, and rough fracture network models were established, considering different excavation sizes. Uniaxial compression was performed experimentally to investigate the mechanical response of rock masses. The failure processes of the jointed specimens were analyzed based on the digital image correlation (DIC) technique. The uniaxial compressive strength and elastic modulus were compared considering different excavation sizes. The results show that the geometric characteristics of the joints significantly influence the strength and failure mode of the rock mass. The strength of the layered rock mass shows a significant linear correlation with increasing excavation sizes. This research could provide a reference for studying the mechanical behavior of jointed rock masses using 3D printing technology.