Insight into the Evolutionary Mechanism of the Rear Fissure of Landslides That Conform to the Three-Section Mechanism

Abstract

In landslides that conform to the three-section mechanism, the rear fissure is the essential component of the potential sliding surface. Hence, the evolutionary mechanism behind that is important for reducing the risk of such landslides. In this research, the evolutionary features and processes were analyzed through a case of landslides that conform to the three-section mechanism; then, base friction testing was carried out to explore the evolutionary mechanism of the rear fissure. On the reliability–validation basis of the consistency of outside deformation features between the testing model and real slopes, deeper analysis of the inner deformation field linked to different rear fissure depths indicates that the weak front interlayer controls the inevitability of the rear tension fissure onset. During rear tension fissure propagation from zero to the critical depth (Hcr), the driving effect of tension fissure propagation undergoes a process of accelerating followed by decelerating roughly bounded by Hcr/2. Moreover, the rear tension fissure closure trend may start at a tension fissure depth of approximately Hcr/2 instead of starting at nearly Hcr. Because of this, the rear tension fissure closure trend that previously suggested by researchers may not always be a perfect indicator of landslides that conform to the three-section mechanism. It may result in the misprediction of such landslides. The findings of this research contribute to a better understanding of the evolutionary mechanisms underlying rear fissures, which, in turn, can help to promote disaster mitigation for landslides that conform to the three-section mechanism. This research can enhance sustainable development by improving safety for people and their property.