Restoration of Arch Bridge by Additional Horizontal Prestressing

The general focus of the paper is to show a method of strengthening arch bridge that has longitudinal cracks. The process is done by new reinforced concrete spandrel walls stabilized by transverse prestressed monostrands. Specifically, the paper is aimed at the reconstruction of the brick arch railway bridge, which was in disrepair. At the beginning of the design work it had to be decided whether it would be effective to carry out reconstruction of the existing bridge, or to accede to build a new bridge on the existing place. For the decision-making process there was a comprehensive diagnostic survey made - the survey of experimental measurement of modulus and strain measurement masonry walls in the crown during the operational load using tough half-frames (ribes). After evaluating the measurement, it has been recommended to do reconstruction. After the work was done, new measurements were done during the operational load when the measured values should confirm the effectiveness and appropriateness of reconstruction. After the evaluation the strain of the top cross-section reduced to 40% of the values before amplification. The text will also be given a numerical model and its' calibration using the measured values of the deformation of the top section.