• The presence of a cross passage significantly alters propagation paths and spatial distribution of blasting-induced vibration velocity, with PPV at the cross-passage corner amplified by approximately 1.92 times due to wave reflection and geometric focusing.
• Blasting-induced vibration waves attenuate non-uniformly across the tunnel cross-section, with PPV on the blast-face side being 1.54–6.56 times higher than that on the opposite side.
• An improved PPV attenuation model accounting for the propagation path effect significantly improves fitting accuracy and resolves anomalous parameter estimates in traditional equations.
• Optimal monitoring point placement and targeted vibration control measures for tunnel blasting are discussed based on the observed spatial distribution of blasting-induced vibration.