A Combined Analysis Procedure for Submarine Landslide Evolution-Paper

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The paper presents an integrated finite-element procedure for simulating submarine landslides from sediment deposition through failure and post-failure movement. Developed in ABAQUS, it links three analyses by transferring results between them.<br /><br />First, a coupled hydro-mechanical model simulates sediment deposition and consolidation, including the development of excess pore pressure. Second, a dynamic analysis applies earthquake ground motion to the resulting slope conditions, modelling cyclic soil behaviour, strength degradation, and shear-band development. If failure becomes self-driven and deformations grow too large for a conventional mesh, a coupled Eulerian–Lagrangian analysis simulates the subsequent movement of the soil and surrounding water.<br /><br />A two-dimensional example of a curved slope with a weak layer illustrates the process. Slow deposition produces a largely consolidated slope. During seismic loading, shear strains concentrate in the weak layer, which progressively loses strength until a self-sustaining failure develops. In the post-failure stage, the shear band extends, the slope forms a global failure mechanism, and the sliding mass moves downslope before slowing on the gentler seabed.<br /><br />The framework combines different analysis techniques while maintaining consistent soil-strength definitions across stages. It can support submarine-slope hazard assessment and analysis of potential impacts on offshore structures and tsunami generation. The authors note that the example’s limited model length prevented simulation of the slide to its final resting state. The post-failure model also does not account for water entrainment within the moving soil, which may underestimate run-out distances, especially for slides that evolve into turbidity currents. Validation against historical events and extensions to include offshore infrastructure are identified as future work.

Keywords

submarine landslides

finite-element analysis

ABAQUS

sediment deposition

hydro-mechanical model

pore pressure

earthquake loading

shear band development

Eulerian-Lagrangian analysis

tsunami generation