Experimental Study on the Rheological Shear Mechanical Behavior of Bolted Joints

Landslides, which are predominantly caused by the rheological behavior of preexisting joints, occur frequently around the world and are among the most catastrophic disasters. However, most researchers have rarely considered the rheological characteristics of bolted rock joints. In this study, based on rock-like materials, rheological direct shear tests of joints with and without anchor bolts were carried out, and direct shear tests were conducted for comparison. The results showed that under direct shear conditions, with the presence of bolts, less spalling and failure of the rock mass occurs, and the shear strength of the joints was significantly enhanced. Under rheological direct shear conditions, joints with bolts have more total rheological shear displacement, but the effect of the bolt on the shear displacement of the steady creep stage was not obvious, and the shear stiffness of the rock mass was reduced by the coupling effect between the bolt and joint. Using the Mohr–Coulomb criterion for further analysis, we found that during the rheological process, the reinforcement of bolts mainly focuses on cohesion, while under direct shear conditions, the reinforcement of bolts is mainly reflected in the internal friction angle. This study is expected to provide theoretical guidance for landslide control and protection and to further reduce the occurrence frequency of geohazards. This research is expected to provide theoretical guidance for the prediction and prevention of geological disasters.