Monitoring data for railway bridge KW51 in Leuven, Belgium, before, during, and after retrofitting

This data set is obtained from a monitoring campaign of 15 months on a steel bowstring railway bridge in Leuven, Belgium. In this period, the connections of the diagonals to the bridge deck and the arches were strengthened after the observation of damage. The monitoring consists of measurements of acceleration on the bridge deck and the arches, strain on the bridge deck and the diagonals connecting the bridge deck with the arches, strain on the rails, displacement at the bearings, and temperature and relative humidity. Data is provided for two train passages and six periods of ambient vibration per day. In addition, the evolution of the identified modal characteristics over time is added. The data set is well-suited for the validation of vibration-based structural health monitoring methods, as it includes data for different states of the structure, i.e. before, during, and after the retrofitting.