Quantifying the Protective Efficacy of Baffles Through Numerical Simulation with the MPM-DEM Method

Soil–rock mixtures pose significant challenges in mountainous regions due to their complex flow behavior and destructive potential during landslides and debris flows. Despite growing interest in using baffle arrays as protective measures, current research has focused on idealized soil or rock materials, leaving a notable gap in understanding their efficacy against heterogeneous soil–rock mixtures under varied slope and baffle configurations. This study employs the Material Point Method to simulate the continuum behavior of the soil matrix, while the Discrete Element Method (DEM) models the discrete dynamics of rock boulders. By incorporating Spheropolygon DEM, the model accurately captures complex soil–rock structure interactions. Parametric simulations are conducted to evaluate the effects of baffle location and slope angle on flow kinematics, impact forces, and energy dissipation. Results show that baffles placed closer to the structure significantly reduce downstream impact forces and kinetic energy by enhancing energy dissipation. Steeper slope angles result in increased impact forces on the structure due to greater conversion of potential energy to kinetic energy. The findings provide quantitative insights into optimizing baffle placement for improving infrastructure resilience against soil–rock mixture flows.