Research on Fire Smoke Characteristics and Key Factor Evaluation in High‐Altitude Traffic Tunnels

ABSTRACT Given the seriousness of fire safety issues in high‐altitude traffic tunnels, it is essential to investigate the spatial temperature characteristics under the coupling of multiple factors and their correlation with fire safety elements. This study systematically conducted full‐scale simulation analyses of highway tunnels to reveal the distribution of transverse and longitudinal spatial temperature as well as the longitudinal smoke diffusion patterns. Based on the simulation data, an integrated approach utilizing orthogonal test analysis, deviation analysis, and sensitivity analysis was employed to explore the impacts of various factors, including altitude, the transverse position of the fire source, fire scale, and wind speed, on tunnel fire safety. The results indicate that the influence of altitude on the longitudinal temperature along the arch and the position of spatial cross‐section characteristic points varies. Longitudinal ventilation speed is a relatively key factor affecting tunnel fire safety, particularly in terms of arch temperature and smoke backflow length, where its impact is significant. Additionally, fire scale has a notable impact on evacuation safety, with its overall influence ranking just below that of wind speed. In contrast, altitude and fire source position have relatively minor effects on tunnel fire safety. Inadequate longitudinal ventilation hinders the escape of personnel during tunnel fires, indicating that the design and operation of ventilation systems should be prioritized in fire prevention and control strategies. The findings of this study have significant practical implications for optimizing fire prevention and response capabilities in high‐altitude tunnels.