DEVELOPMENT OF CROSS SECTION MANAGEMENT SYSTEM IN TUNNEL USING TERRESTRIAL LASER SCANNING TECHNIQUE

摘要

Laser scanning technology with high positional accuracy and high density will be widely applied in vast range of fields including geomatics. Especially, the development of laser scanning technology enabling long range information extraction is increasing its full use in civil engineering. This study taps into the strengths of a terrestrial laser scanning technique to develop a tunnel cross-section management system that can be practically employed for determining the cross-section of tunnels more promptly and accurately. First, high-density three-dimensional data was obtained in a prompt and accurate manner using a terrestrial laser scanner. Data processing was then conducted to promptly determine arbitrary cross-sections at 0.1-, 0.5-, and 1-meter intervals.A laser scanning technique was also used to quickly and accurately calculate the overbreak and underbreak of each cross-section and from the entire tunnel length. As the developed system utilizes vast amounts of data, it was possible to promptly determine the shape of arbitrary cross-sections and to calculate the overbreak and underbreak more accurately with higher area precision.A economic analysis of various techniques for determining the tunnel cross-section revealed that this measurement system is also outstanding from an economical perspective. It is expected, therefore, that the system will not only enable more efficient and cost-effective tunnel drilling management and monitoring but also will provide a basis for future construction and management of tunnel cross-sections.