Geodetic measurements in tunnel Šentvid

This article describes the geodetic monitoring of the impact that the tunnel excavations have on the rock mass at the tunnel face in the Sentvid tunnel. In the preliminary phase, an exploratory gallery was built almost along the main tunnel axis to collect geological, tectonic zone and other relevant data. The exploratory gallery is now being used for geodetic and other monitoring of the impact of tunnel excavations on the surrounding rock mass. Before the beginning, methods of point and station point stabilization, and a measurement method were chosen. Thus, the chosen methods are the method of 3D inner intersection with adjustment of redundant observation for station point determination, and the polar method for calculating 3D coordinates of detail points. The method of determination of station point was chosen because of the far reaching influence that the tunnel excavations have on rock mass behaviour at the tunnel face.