Full-lifecycle catastrophic evolution mechanisms of red-bed translational landslides

Red-bed landslides are a widespread geohazard Among these, translational landslides exhibit the most complex geological processes and mechanical mechanisms, warranting detailed investigation. This study investigates their full-lifecycle mechanisms through a typical case analysis and multi-scale experiments. Results reveal the key mechanisms controlling landslide dynamics: Water-rock interaction weakens slip-zone cohesion by approximately 40% (from 2.04 MPa to 1.24 MPa in 30 days), while consolidation enables strength healing, recovering the internal friction angle by 4.5° (from 22.23° to 26.76° in 168 h). Physical modeling indicates the critical water head for initiation ranges from 13.1 to 38.6 cm, controlled by slip-surface angle (3°-9°) and interface moisture (20%-40%). A four-stage evolution model and a corresponding three-criterion identification system are established. Furthermore, an initiation criterion incorporating time-dependent strength degradation is derived. The integrated quantitative framework merges geological processes and mechanical principles, providing a theoretical basis for predicting and mitigating translational landslide hazards.