Each tunnel involves different surveying activities, from siting to control measurements during operation. In this master thesis we decided to analyse the influence of different types of geodetic grid point signalling and the influence of different geodetic grid geometries on the quality of the smoothed coordinates. We used three different types of signaling, namely the usual large prism, which we took as a reference, a mini-prism and a reflective target used daily in the tunnel. The effect of the grid geometry was analysed for two different solutions. The first solution uses all measurements, i. e. five measured points back and forth from each stand of the polygon, while in the second solution, only half of the measured points are taken into account between each stand. The results of the balancing exercise, where points were selected on different lengths of road sections, were included in the analysis. The analysis results in 9 different offset variations, 6 for the mini-prism and 3 for the reflective target. We found that with a reflective target and a mini-prism, we obtain negligibly small deviations in the precision of the aligned coordinates. Therefore, a reflective target, which is more affordable and accessible, is suitable for measuring displacements on a daily basis in tunnels
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