Rock Bridge Fracture and Differential Deformation During Progressive Failure of Rock Slopes with Intermittent Joints Using a Stabilized Peridynamics Model

Progressive failure of rock slopes with intermittent joints involves crack propagation through intact rock bridges and the development of differential deformation. This study uses a stabilized non-ordinary state-based peridynamics model to investigate these processes. The model combines bond-level deformation gradient stabilization with a tensile strength criterion and a triple shear energy criterion. Its applicability is first assessed using a three-section landslide model containing an intact locking section. The predicted fracture path through the locking section agrees qualitatively with previous experimental and numerical results. Three slope configurations are then analyzed: parallel joints, nonparallel joints, and an irregular arrangement of three joints. Joint configuration influences crack initiation, propagation paths, rock bridge failure, and the deformation response. The parallel joints configuration is characterized by distributed crack initiation and progressive fracture through the intervening rock bridges, whereas the nonparallel joints configuration exhibits more localized initiation and a more branched crack network. In the irregular joint configuration, secondary cracks extending to the slope surface divide the deforming rock into regions with distinct displacements. These differences reflect the combined influence of joint geometry and spatial arrangement in each configuration rather than the isolated effect of a single geometric parameter. Analysis of the crack patterns, displacement fields, and stress fields indicates that progressive rock bridge failure controls the formation of the principal rupture path, while secondary cracks govern the development of differential deformation. These results clarify how fracture through rock bridges and secondary crack growth contribute to progressive slope failure.