ABSTRACT
Recently, the Japanese construction industry has been promoting labor savings through mechanization and automation, as well as improvements in methodology. This promotion has led to a gradual increase in overall productivity in the construction industry and a reduction in working hours. Under such background, the authors developed a system called “BLAST MASTER” in 2019, a system that reduces drilling-induced overbreak by controlling the angle of contours(outermost blast holes). The concept of this development was to collect and utilize objective information as much as possible and to aim for a construction process that does not rely on experience or sense of a skilled worker. The developed “BLAST MASTER” has produced numerous results at our construction sites. In other words, the authors were able to respond to social needs such as resolving the shortage of skilled workers and improving the safety, productivity, and quality of construction works. However, because the main goal was to reduce overbreak, the authors focused only on automatic control of the drilling angle contours (blast holes located along the outermost circumference) and have not developed the technologies related to automatic design of blasting patterns and their drilling sequence. In automatic design of blasting patterns, the number of required blast holes as well as their distance and angles would be determined based on the characteristics of the ground to be excavated, and in automatic design of drilling sequence, the possible shortest path and time to complete drilling would be simulated to a given blasting pattern. Consequently, the authors have developed a technology that simultaneously performs the automatic design of blasting patterns and the automatic design of the drilling sequence for the blast holes based on the “BLAST MASTER”, which is expected to improve furthermore the safety, productivity, and quality of tunnel excavations. This paper reports an overview of the technology developed, the results of trial excavations, and the conclusions obtained.
