터널확공시 이방향 병용천공 발파공법의 개발

Development of New Drill and Blast Method with Two Different Drilling Directions for Pilot Tunnel Enlargement

This paper presents an evaluation of new drill and blast method with two different drilling directions for pilot tunnel enlargement using numerical experiment and field test. To evaluate the effieiency of new tunnel enlargement method, field tests were performed and compared with conventional drill and blast method. Also, three dimensional transient dynamic analysis was made to investigate the effect of the ground vibration when blasting was performed at same position using the equivalent single hole charge.