In view of the unclear attenuation law of shock wave in curved tunnel is unclear, the influence of radius and turning angle on shock wave propagation in curved tunnel was analyzed. It was found that its influence on the wave dissipation efficiency is limited, and the wave attenuation efficiency of curved tunnel is similar to that of direct turning tunnel with the same angle, which is basically less than 7.2%. In order to improve the wave attenuation efficiency of shock wave in curved tunnel, a new protective idea of constructing arc-shaped diffusion tunnels based on arc-shaped tunnels by setting up diffusion chambers was proposed. The influence laws of diffusion ratio and diffusion forms (inner diffusion, two-side diffusion and outer diffusion) on the wave attenuation efficiency of curved diffusion tunnels were also discussed. The calculation shows that curved diffusion tunnel can greatly improve the wave attenuation efficiency of shock wave, and the wave attenuation efficiency can reach 55.9%. Among them, the outer diffusion curved tunnel has the highest wave attenuation efficiency, followed by the inner diffusion type and the two-sided diffusion type. Moreover, the wave attenuation efficiency increases continuously with the increase of the diffusion ratio. As the peak pressure of the shock wave increases, the wave attenuation efficiency of the curved diffusion tunnel also improves, reaching up to 64.4%. When the peak pressure continues to increase, the wave attenuation efficiency of the curved diffusion tunnel slightly decreases but remains basically unchanged. The wave attenuation efficiency of the curved diffusion tunnel decreases with the increase of the positive pressure duration of the shock wave. When the positive pressure duration is 100 ms, the wave attenuation efficiency drops to 25.4%. However, as the positive pressure duration further increases, the wave attenuation efficiency of the curved diffusion tunnel remains almost unchanged.

Prestressed reinforced concrete (RC) T-beam bridges are commonly employed in highway bridges construction. After explosive attacks, the deck damage mostly exists in the form of breaches and affects its traffic capacity. While significant attention has been devoted to evaluating post-blast residual capacity of RC beam bridge piers and girders in existing blast damage assessment studies, there remains a critical gap in methodologies enabling intuitive and rapid damage assessment method for bridge serviceability. Therefore, the rapid assessment of bridge deck damage is investigated in this study by combining numerical simulation with multivariate nonlinear regression analysis, in which the breach size of the prestressed RC T-beam bridge deck subjected to explosive loading is taken as the damage index. Through comparative analysis of the transverse size of the deck breach under blast loading, it was revealed that concrete strength exhibits relatively minor influence, whereas parameters including explosion location, deck thickness, diaphragm spacing, TNT equivalent, and scaled distance demonstrate more pronounced effects. Owing to the pronounced reinforcing and constraining effects of webs and diaphragms on the bridge deck, comparative analyses under identical conditions demonstrate that transverse size of the breach caused by explosion above deck areas between webs and diaphragms is significantly smaller than that by explosion directly above the web, while on-bridge explosion exhibit lower damage compared to under-bridge explosion. Based upon the aforementioned parameters with significant influence, utilizing transverse size of the breach as the damage index, a rapid blast damage assessment formula is proposed for predicting the post-blast traffic capacity of bridges.