The influence of electronic detonators on the quality of the tunnel excavation

Abstract

In drill and blast tunneling method (D&B), non-electric detonators are the most commonly used initiation system. The constant development of excavation technology provides advanced tools for achieving better results of excavation. The research presented in this paper was focused on the attempt to evaluate the influence of electronic detonators, which nowadays are unconventional in tunnelling engineering, on the quality of the excavated tunnel contour. Based on the data form Bjørnegård tunnel in Sandvika, where electronic detonators were tested in five blasting rounds, detailed analysis of drilling was performed. The analysis was made based on the data from laser scanning of the tunnel. 103 profile scans were used for the analysis: 68 from non-electric detonators and 35 from electronic detonators rounds. The results analyzed in terms of contour quality showed that comparing to the results from rounds blasted with non-electric detonators, there was not significant improvement of the contour quality in rounds with electronic detonators.

Keywords

• drill&blast method
• contour quality
• scanning
• electronic detonators