Abstract:

To address the limitations of current road disaster early warning systems which overly relied on a single rainfall thresholds, failed to reflect the synergistic disaster-causing effects of "rainfall-traffic", and could not meet the requirements of real-time early warning due to low computational efficiency of traditional numerical simulations,a road safety risk assessment model under rainfall-traffic synergistic hazard-inducing effects was proposed. Firstly, based on the improved infiltration theory and the hydro-mechanical coupling mechanisms, a road moisture safety index based on water content, and a stability safety index based on shear stress was constructed. Secondly, a traffic disturbance index was innovatively introduced to analyze the synergistic disaster-causing impacts of heavy vehicle dynamic loads coupling with rainfall-induced subgrade softening, establishing a coupled safety risk assessment model incorporating both rainfall and traffic effects. To ensure the general applicability and reliability of the model, grading warning thresholds for different road safety risk states were determined according to relevant specifications and theories. The applicability of the model under multidimensional working conditions, including soil-property variation, extreme traffic scenarios, and intermittent rainfall, was analyzed, and systematic verification was conducted. The results show that, compared with the traditional finite element method, the proposed coupled safety risk assessment model not only improves the computational efficiency while accurately reproducing the stability evolution process of the detailed numerical simulation, but also can sensitively capture the risk accumulation effects under "light rain + heavy load" and intermittent rainfall.

Key words: rainfall-traffic, synergistic effect, road safety, risk assessment, moisture content, traffic disturbance