Abstract
This paper presents a tunnel deformation measurement technique by using digital images taken from a moving car. Because the three-dimensional coordinate of each target installed on tunnel wall can be calculated through photogrametric analysis, it is possible to obtain the positions of the pairs of targets whose distances represent the crown settlement and convergence. This paper summarized the results of experiments performed to verify measurement precision. As a result, the coordinate values of targets with a high degree of precison can be obtained from the geometric constraint conditions of the geodetic network without having to set any fiducial points. Based on this study, this paper argues the practicability of the proposed technique in the tunnel maintenance phase.
