Geodetic supervision of specific extension of Euroherc building in Zagreb

In order to increase the workspace, the owner of the Euroherc building in Zagreb, had decided to extend building from the existing eight floors to the thirteen floors and to reconstruct entire building. It was specificied in the project, that new floors will be build on the four pillar blocks with three pillars in a block, they should be almost "invisible" and the building must be in function for all time during construction works. Geodetic works of supervision and control of constructing works, as well as establishing up a geodetic control for purpose of building extension and reconstruction, have been done by employees of the Chair of Engineering Geodesy, Faculty of Geodesy, University of Zagreb. The geodetic control has been established as a local control with the origin of the coordinate system below Earth surface (underground garage). In addition, the new geodetic control had to be incorporated in the local geodetic control which was used for the project design. The origin of this coordinate system were in the underground garage too. Due to a bad construction site condition, the biggest problem was to "take out" the local control from the garage and to stabilize local control points. From these points were precisly staked out pillar axises from the ground floor to the last floor of the building. Besides geodetic control establisment and supervision of all geodetic works, actual situation was carried out, deformation monitoring and geodetic report for building registration has been made. The most interesting geodetic works will be described in this paper.