Abstract This paper presents a novel semi-implicit two-phase double-point Material Point Method (MPM) for modelling large deformation in geotechnical engineering problems. To overcome the computational limitations of explicit methods, we develop a semi-implicit approach that eliminates time step dependency in soil–water coupled problems. Unlike existing single-point methods that use one set of material points to represent soil–water mixtures, our approach employs two distinct sets of material points to model soil …