This bachelor’s thesis addresses the challenge of monitoring tunnel excavations, using tunnel T8 of the Second track Divača–Koper railway project as an example, where traditional surveying methods are often time-consuming, costly, and may require work in difficult-to-access or hazardous areas. The aim of the thesis is to investigate the use of close-range photogrammetry for tunnel excavation monitoring and to evaluate its accuracy, applicability, and potential integration into existing monitoring systems.
The methodology comprises a review of the theoretical foundations of photogrammetry, an analysis of a practical case study, and a comparison between photogrammetric and conventional surveying methods in terms of accuracy, speed, cost, and safety. The results were evaluated using two approaches: profile comparison in Amberg TMS and direct comparison of total station points with the photogrammetric 3D model. The profile comparison in Amberg TMS showed a standard deviation of 0.031 m, a mean deviation of 0.004 m, and a maximum deviation of 0.190 m. In the direct comparison, the standard deviation was 0.020 m, the mean deviation was 0.002 m, and the maximum deviation was 0.070 m, confirming that direct comparison with the model surface provides a methodologically more appropriate assessment of geometric accuracy.
The limitations of the study concern the analysis of a single case and the influence of data acquisition conditions, such as lighting, visibility, and image quality, on the achieved accuracy. The findings suggest that close-range photogrammetry can serve as an effective complement to conventional tunnel excavation monitoring methods and, in specific applications, even as an alternative. The results confirm its potential for monitoring geometric changes and documenting excavation progress
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