Abstract:

Submarine landslides pose a severe threat to the safety of seabed infrastructure and coastal cities. Compared with subaerial landslides, submarine counterparts in deep water commonly occur on gentle slopes with gradients less than 5º and involve much larger sliding mass volumes. The progressive failure of these large-scale landslides is difficult to reproduce using traditional methods such as limit equilibrium and strength reduction methods. By incorporating the strain-softening behavior of cohesive soils into theoretical analyses and numerical simulations, the progressive failure of gentle slopes driven by shear band propagation can be effectively captured. Consequently, this framework has attracted growing attention in recent years. This paper systematically reviews recent advances in shear band propagation methods and summarizes the principles and applicability of key theoretical frameworks, including linear elastic fracture mechanics, energy-balance methods, and process-zone approaches. The review also discusses analytical and numerical solutions for complex conditions, including dynamic effects, two-dimensional curved slopes, three-dimensional slopes, deep-seated slip surfaces, and presents quantitative criteria for slope instability. The potential of shear band propagation methods for practical applications to submarine landslides is highlighted with reference to typical triggering factors such as rapid sedimentation, toe erosion, gas migration, and earthquakes.

Key words: safety factor, submarine landslide, shear band propagation, rapid sedimentation, strain softening