TRAM-R2: A Quantitative Model for Railway Tunnel Risk Analysis

The paper introduces TRAM-R2 (Tunnel Risk Analysis Model – Road&Railway), a novel quantitative risk analysis model for rail and road tunnels, compliant with European and Italian safety regulations. TRAM-R2 generates F-N curves, relating the frequency of accidental scenarios to potential fatalities, aligning with safety directives. It considers four initial events: collision, derailment, fire, and dangerous goods release, resulting in 30 scenarios analyzed using Event Tree Analysis (ETA). The model estimates fatalities considering train and tunnel characteristics and assesses user evacuation feasibility via egress modeling. It employs results of 1D, zone, and 3D computational fluid dynamics (CFD) simulations to evaluate scenario dynamics and consequences. TRAM-R2 allows simulating scenarios for different tunnels, considering layout, infrastructure, equipment, and management impacts on egress and scenario propagation. It accounts for interdependent measures and their reliability during emergencies. The paper demonstrates TRAM-R2's application through case studies, highlighting its potential for quantitative risk assessment in railway tunnels, facilitating comparison with regulatory criteria. Overall, TRAM-R2 provides a comprehensive tool for assessing and mitigating risks in rail tunnel operations, aiding compliance with safety standards and regulations.