Abstract
Various engineering tasks, such as geological mapping and taking photographs, are required for geological investigations in tunnels. Generally these tasks are performed during brief interruptions of construction activities under less than ideal conditions. For instance, the quality of photographic images may be adversely affected by inconsistent lighting conditions and the quality of geological mapping depends greatly on the skills of the geologist. 3D laser-scanning techniques provide consistent quality images that are unaffected by ambient lighting conditions. Comparison of digitally processed images with manually prepared maps of the shaft wall in the Mizunami Group (Miocene age) were preformed. The 3D laser-scanning technique shows promise in making geological investigations in tunnels more accurate and efficient.
