Effect of shock-flame interactions on initial damage characteristics in highway tunnel under hazmat tanker truck accident

Hazardous materials road transportation (HMRT) accidents are the main hazards of highway tunnels, and the damage evolution process subject to catastrophic consequences have gained significance due to increasing accidental events. This study presents the scene reconstruction referenced with actual case of methanol tanker truck explosion in highway tunnel and integrates it with effecting parameters such as location, causation, consequence, time series data, tunnel structure, hazmat properties, emergency. In this work, the damage characteristics caused by tanker truck explosion are discussed by comparing with different traffic situations inside the highway tunnel. The results indicate the strength of shock wave is enhanced as the traffic flow grows, especially in the ceiling and ground of tunnel, the peak overpressures are significantly higher than that in other areas. With the increasing of the traffic vehicles in tunnel, the process of the explosion overpressure changing in tunnel can be categorized in five stages. This study presents the predictive model relating with explosion specific impulse, which can be better presented in impulse changes in tunnel with the minimum degree of fitting is 0.9139. By comparison between different traffic situations in tunnel, it reveals the formation of precursor shock wave enhances the flame propagation, and the accelerated flame in turn strengthens the overpressure, indicating the underlying damage mechanism. This study contributes to better understanding multi-factor damage mechanism of HMRT accident in highway tunnel, and further optimizing HRMT accident detections and emergency plans.