We are pleased to share with you our recently published journal articles on modelling the use of protective barriers catastrophic debris flow events. These two papers focus on using the coupled Eulerian Lagrangian large deformation method, as part of Mr Shiyin Sha’s PhD research.
Abstract: The impact load of boulders transported by debris flow is crucial in designing protective structures constructed along the potential flow paths. In this study, the Coupled Eulerian-Lagrangian (CEL) method is applied to establish a three-dimensional model for analysing debris flow, boulders, and barrier interactions in various scenarios, with an Australian rivulet serving as a case study. The proposed CEL method was verified by simulating the runout and impact behaviour based on experimental granular and debris flow tests. Subsequently, a comprehensive series of numerical simulations explores the impacts of transported boulders on a rigid tooth barrier, encompassing various boulder shapes and sizes. The results indicate a direct correlation between boulder size and impact force, while the influence of boulder shape on peak impact force is minimal. Nevertheless, boulder shape affects the arrival time, as noted with increased boulder size. Although boulder dimensions remain the primary factor affecting impact force, variations in the geometry are observed to influence the overall dynamics of debris flow-boulder interactions. This study proposes a procedure for assessing barrier impact forces through simulations combining debris flow and boulder transport with the CEL method. The research presents the effectiveness of the CEL method in estimating the impact force of media transported by debris flows in intricate 3D terrains. The findings contribute significantly to the existing measures for assessing the risk of debris flows.
A full copy of the article can be found at https://www.sciencedirect.com/science/article/pii/S0307904X23005401.
Abstract: Flexible ring nets exhibit complex nonlinear mechanical behaviour when subjected to static and dynamic impact loads. This research presents the development of an efficient numerical model for assessing the performance of flexible netting barriers used in debris flow and rockfall risk mitigation. The model is calibrated through benchmark analyses and based on the equivalent stiffness method. The results demonstrate that the proposed numerical approach offers a significant computational cost reduction of 80% compared to complex numerical models while maintaining high accuracy. The coupled Eulerian–Lagrangian finite element method (CEL) is employed to simulate fluid–debris–structure interaction, showing damage characteristics consistent with flexible ring net barriers. The model is suitable for accurately determining the impact forces acting on the barrier and presents the debris behaviour and movement at various flow velocities. Notably, the results confirm that the presented model is capable of evaluating the interaction between the flexible barrier and debris flow with boulders and is an efficient approach to estimating the performance of flexible protection subjected to impacts.
A full copy of the article can be found at https://link.springer.com/article/10.1007/s40999-023-00914-5.