Failure mechanism of submarine slopes based on the wave flume test

Although submarine landslides rarely occur in shallow or coastal areas, they are intensely violent and dangerous, causing serious damage to submarine structures and cables and drilling platforms. In this study, simulation experiments in the wave flume reveal that the submarine sand slope will oscillate, disperse, and form sand grains under the action of waves. In addition, the erosion depth of the wave on the seabed gradually deepens over time. Water depth decreases gradually. When the water depth reaches a certain depth, the erosion reaches a critical state. In combination with previous studies, the failure conditions and failure mechanisms of submarine slopes under wave action are analyzed, and a mechanism is proposed for the submarine slope failure induced by liquefied flow slip failure, shear failure, and shallow erosion failure. The risk of shear failure on the seabed is considered greater than that of liquefaction under wave action. Under shear failure, the seabed slope experiences a nearly complete liquefaction damage. By contrast, for shallow erosion damage, the structure of the seabed soil loosens, and the related strength becomes lower than that of the surrounding soil.