Kinematic safety assessment framework of particulate contaminated road based on discrete element method

Road particulate contaminants could affect the safety of outdoor running activities. To enhance the understanding and management of such risks, this study proposed a novel framework for evaluating the impact of particulate contaminants on road surface safety by utilizing the discrete element method (DEM). The road surface-shoe DEM sliding models with different particle characteristics (size and concentration) were established to analyze sliding characteristics of the shoes. The results were validated by the use of the actual pendulum friction tester. Notably, this method required only laser texture scanner derived texture data and particle coverage fraction as inputs, with the coefficient of friction (COF) as the output, significantly reducing testing costs and time. The results indicate that the road surface COF initially decreased and subsequently increased with the increase in particle dosages, whereas the larger particle sizes decrease the minimum friction level of the road surface. Specifically, for 1.18 mm particles with a coverage fraction less than 50 %, the road surface COF loss exceeded 60 %. This approach contributes to the development of warning and cleaning strategies for road particulate contaminants.