Geomatic engineering activities and tunnel deformations in tunnel construction

Tunnels are underground passageways that are used to ensure safe, comfortable and economical transportation in areas where topography prevents transportation on earth. In our country and in the world tunnel boring works are still developing areas of engineering application that require large-scale planning and organization. It is necessary to direct the tunnel construction structures in accordance with the project, to monitor the movements that occur in the work area and, if any, in the surrounding structures, to determine the amount of deformation depending on the time of these movements and to determine in advance whether these deformations will cause any damage. As well as performing deformation measurements, which is one of the most important actions taken for human and environmental safety, correct and accurate interpretation of the obtained data is highly essential too. This can only be achieved by ensuring so many different engineering disciplines work together closely. One of these engineering disciplines is Geomatic Engineering. In tunnel construction works, geomatic engineers carry out the geodetic studies required for the production of location/ map information, which is the basis of tunnel excavation applications, the necessary geodetic studies to guide the project according to the project data, and the deformation measurement and analysis activities required for the safe progress of the project. In this study, the construction of Tunnel-15, which is under construction within the scope of the Ankara - Sivas Railway project, where NATM tunneling methods are applied and the project length is 4.593.20 meters, was selected as the application area, the requirements of the tunneling studies were determined, the literature was researched, the management of the geodetic studies in the tunnel works were examined, and in the light of this information, the measurement data obtained in the tunnel was used. Information was given about the duties and responsibilities of the Geomatic Engineers in tunnel construction activities, the excavation directions of the Tunnel-15 were made using the acquired data, the determination of vertical and horizontal deformations and the changes of deformations over time were obtained. By making a comparison with the actual readings gained in the field, it has been observed that surface deformations can be detected before reaching very large values that might pose danger, and also some suggestions provided in this study are thought to be useful for Geomatic Engineers in tunnel construction that is still developing in our country. Keywords: Deformation measurements, Geodetic and Geotechnical Method, Tunnel, Tunneling techniques, Tunnel measurements