ABSTRACT
A technology is developed that can project ground information such as images of the tunnel face and rock hardness/softness data directly on a shotcreted tunnel face. The system is simply operated using push buttons installed on the driver’s platform of the drill jumbo (the hydraulic rock drilling machine). There is no need for the installation of projectors, surveying work, or interaction with a PC, which are problematic in the severe tunnel environment, because the technology has been designed for safety and ease of use by field workers and other staff in charge at the tunnel face. It is confirmed that appropriate quantities of explosives can be determined according to rock mass strength, greatly reducing the need for extra shotcreting near the face due to over-blasting. Further, damage to construction equipment due to flying rocks is prevented. All of these improvements contribute to improved construction efficiency and on-site safety.
