Analysis of Seepage Effects on Seabed Slope Stability Under Earthquake Loading

To find out the combined effect of seismic action, seepage, and sandy and argillaceous interlayers on the seabed slope stability, the safety factors of seabed slopes, which include sandy and argillaceous interlayers, under different hydraulic gradients and seismic loads, were calculated using the geotechnical simulation software Geo-Studio 2012. Results demonstrate that both seismic action and seepage exert significant impacts on seabed slope stability: seismic loads play a dominant role in governing slope stability, while seepage acts as a key triggering factor for slope failure. With the gradual increase in seismic load magnitude, the influence of seepage hydraulic gradient on slope safety factor decreases progressively. For homogeneous segregated slopes, which consist of silty clay, a higher seepage hydraulic gradient reduces the magnitude of critical seismic load that induces slope instability. Under identical seismic load and hydraulic gradient conditions, seabed slopes with sandy interlayers exhibit higher stability compared to homogeneous soil slopes, whereas slopes with argillaceous interlayers show reduced stability.