BLASTING STRUCTURE THAT HAVE BLASTING PATTERN THAT MINIMIZE TUNNEL BLASTING PERFORATION

摘要

PURPOSE: A blasting structure with blast patterns to minimize tunnel blasting perforation is provided to prevent blasting vibration by forming a free surface which is continued along an excavating line of an excavation part and reduce impact, vibration, and noise with minimized a number of blasting charge, thereby blasting more safe and environmentally-friendly. CONSTITUTION: A blasting structure with blast patterns to minimize tunnel blasting perforation includes a free surface, a blast hole, and a blast pattern. High pressure water is sprayed into spaces among crushed bedrocks in a predetermined space along an excavating line of a tunnel by a water jet nozzle(130) to form the free surface depending on the excavating line. The blast hole is perforated in an excavation section(10) at constant intervals and blasting charge is mounted. Multiple perforations are formed inside the excavation section except an excavating line hole in predetermined blasting patterns.