  Numerical modeling of slope failures seeks to predict two key phenomena: the
initiation of failure and the post-failure runout. Currently, most modeling
methods for slope failure analysis excel at one of these two but are deficient
in the other. For example, the Finite Element Method (FEM) models the
initiation of instability well but quickly loses accuracy when modeling large
deformations because of mesh distortion, restricting its ability to predict
runout. Conversely, the Material Point Method (MPM) utilizes material points
which move freely across a background grid, allowing for indefinite
deformations without computational issues. However, MPM is restricted in its
ability to model slope failure initiation due to limitations of the available
boundary conditions and reduced accuracy of its stress distributions. The
sequential hybridization of these two methods, initiating a model in FEM and
then transferring to MPM, presents an opportunity to accurately capture both
initiation and runout by a single model. The exact time for this transfer is
not self-apparent, but it must be conducted after the initiation mechanism and
before excessive mesh distortion. By simulating two granular column failures
and two slope failures, we demonstrate the effectiveness of this hybrid FEM-MPM
method and identify the appropriate time to transfer.
