English：

Regarding the control of blasting operations in tunnels with small clearance distances, this study uses the dovetail section at the exit of a railway tunnel in Southwest China as a case study. Based on the kinetic energy formula, the relationship between the distance from the vibration source and energy attenuation was derived. Combining this with the DP criterion formula and considering the radii of the fractured zone and the plastic zone generated by blasting, this study proposes a relationship between the explosive charges, the mechanical properties of the surrounding rock, and the vibration velocities. Blasting excavation exerts significant influence on existing tunnel structures, and the side adjacent to the existing tunnel exhibits a vibration velocity concentration effect, resulting in stress concentration at the crown and toe of the existing tunnel on the side nearest the blasting excavation. The model derived to describe the relationship between blasting vibration velocity and charge quantity incorporates various physical parameters of the surrounding rock, making it more universally applicable. Practical engineering applications demonstrate that this theoretical formula is highly applicable in realworld projects.