Numerical modeling of the rockslide break-runout-impact on the flexible barrier using DEM-FDM coupled method

Rockslides can cause severe damage to infrastructure, while flexible barriers offer an effective prevention measure. The protection and control effect of flexible barriers can be estimated from the process of rockslide break-runout-impact on the flexible barrier, which can be simulated using the DEM-FDM coupled method in the finite difference code FLAC3D. However, accurate modeling of this process has been hindered by the inability to adequately describe the mechanical behavior of flexible barriers in FLAC3D. To address this issue, this study presents an equivalent continuum model to describe the mechanical behavior of a flexible barrier under rockslide impact. This equivalent model reduces computational complexity while maintaining accuracy. The proposed theoretical model incorporates tensile and bending components along with yield criteria governing stress state changes. Furthermore, the model was implemented in FLAC3D through secondary development. Three experiments were numerically simulated to verify the effectiveness of the proposed model. Utilizing the proposed flexible barrier model and the DEM-FDM coupled method, the process of rockslide break-runout-impact on flexible barriers was numerically investigated. The proposed method was applied to predict the rockslide break-runout-impact process on a flexible barrier in Sichuan Province, China. The numerical results offer scientific guidance for the selection of appropriate flexible barriers.