Analysis of Vibration Influences of Small Spacing Tunnel Blasting on Existing Tunnel

The effect of blasting vibration on neighboring tunnel was analyzed based on the actual project.The damage test and safety evaluation for the existing tunnel liner structure was conducted before tunnel construction.Blasting vibration monitoring of the old tunnel was also carried out to ensure the safety of tunnel structure.With the method of statistical and regressive analysis of monitoring data,the influence law of distance to blast source and charge amount per delay to the blasting vibration were determined.Four grades of the effect on existing structure were classified as no effect,slightly effect,big effect and hazardous effect.Some control measures and suggestions were presented to ensure the blasting safety for the small spacing tunnel,including reasonable excavation method,determination of explosive charge and cutting mode.