Abstract In this study, the effect of an air shock wave discharged into a tunnel when an explosion occurs in front of a protective door was experimentally examined and the actual air shock waveforms in the tunnels with and without a protective door were analyzed and compared. It was found that both the waveform structure and the characteristic parameters of the air shock wave, such as the peak and the action time, were significantly changed after a protective door was installed. Moreover, by combing with dimensional analysis results, some detailed engineering algorithms of the residual shock wave effect, namely, the engineering algorithm of the overpressure peak of the residual shock wave in the tunnel, the equivalent explosive coefficient in the case without protective door, and the shock wave reduction coefficient with and without a protective door, were derived.