This study aims at integrating three SPH numerical models into a 3D SPH code. The first model simulates bed-loadtransport phenomena. The second model represents the transport of solid bodies in free surface flows. The third modelis based on a boundary treatment with discrete surface wall elements (“DB-SPH” method, just for simplicity ofnotation).

So far, the model couplings mainly involve the following features: a sequential coupling of the OpenFOAMmesh generator (SnappyHexMesh) with the SPH code to define the initial distribution and conditions of the surface wallelements and the fluid semi-particles (DB-SPH); the extension of the DB-SPH boundary treatment to any 3D frontiershape and translational kinematics; a simplified procedure to initialize the integral Shepard coefficient for any 3D initialconditions. Preliminary validations are obtained by comparison with available measures and SPH model intercomparisonsare also reported.

Further, the model couplings have allowed the simulation of a 3D demonstrative dambreach (earth-filled dam break driven by a breach channel) on complex topography, with simultaneous transport of fivetree trunks and granular material. The model couplings have also permitted a preliminary implementation of themolecular viscosity term (in the momentum equation) at boundaries (DB-SPH treatment). This would allowrepresenting the bottom drag at low Reynolds numbers, which are often detected in the bed-load transport layer.