Biot’s equations RANS equations consolidation effect constitutive model critical hydraulic gradient cyclic mobility disturbance function disturbed state concept dual-stage Eulerian–Lagrangian technique excess pore pressure excess pore water pressure finite element analysis fluidization degree foundation trench fractional order hybrid Lagrangian–ALE method immersed tunnel in situ test irregular wave liquefaction liquefied submarine sediments local radial basis function collocation method marine structures mesh-free model multiphase theory n/a numerical modeling numerical modelling oscillatory liquefaction pile jacking