Some numerical approaches for landslide river blocking: introduction, simulation, and discussion

This paper aims to present several approaches for fluid-solid coupling applied in landslide river blocking simulations based on the Abaqus software. These approaches include the coupled Eulerian Lagrangian (CEL) model and the finite element method-smoothed particle hydrodynamics (FEM-SPH) model, which use discrete finite element meshed blocks to simulate landslides, and use continuum models of Eulerian material and SPH material for river simulations, respectively. Another approach is to use the Eulerian model with Eulerian material to simulate landslides and river at the same time. A physical model of an elastic plate subjected to time-dependent water pressure was applied to validate the selected methods in the fluid-solid coupling. The process was recorded and corresponding numerical simulations were performed. The results show that the simulated plate and water behavior is consistent with the physical model in all simulations. Afterwards, the methods were applied to a real-scale rock avalanche river blocking simulation and the processes of sliding mass movement, impulse wave behavior, and the formation of landslide dams were described and analyzed. Applied Eulerian materials and discrete finite element meshed blocks were used to simulate the sliding mass and similar sliding movement characteristics were obtained. However, discrete blocks have shown better potential for simulating more complex situations and processes leading to better mass movement and deposition results. In addition, discrete finite element meshed blocks and other similar discontinuum models can better reflect the structural characteristics of the source rock in the simulation. As for the impulse wave, the use of Eulerian model for simulating the sliding mass will lead to an abnormally high wave height. Whether to consider a water effect and how to consider it affect the shape of the landslide dams and the simulation results show the importance of fluid-solid coupling in the landslide river blocking simulation. Similar and accurate results can be obtained using the Eulerian method and the SPH method for water simulation. However, it is worth noting that the existence of the Eulerian boundary makes the Eulerian method a better option for simulating more complex flow conditions compared to the SPH method. The meshless characteristics of the SPH method make it more computational efficient provided the fluid volume is constant and the final scale of the model is uncertain.

Automated summary

This paper presents several approaches for fluid-solid coupling simulations in landslide river blocking scenarios using Abaqus software. Discrete finite element meshed blocks were found to be more suitable for simulating complex situations and flow processes compared to other methods, as validated by physical models and real-scale simulations.