Figure 11
From: Attenuation model of tunnel blast vibration velocity based on the influence of free surface

Spectrogram of particle vibration velocity waveform: (a) Full section model. (b) Upper step model. (c) Lower step model.
From: Attenuation model of tunnel blast vibration velocity based on the influence of free surface

Spectrogram of particle vibration velocity waveform: (a) Full section model. (b) Upper step model. (c) Lower step model.