Monitoring of the Gerber hinges in the maintenance project Grenzbrucke Basel

Monitoring helps to detect damage of structures at an early stage and provides more safety for the users of the infrastructure [1-3]. It is reasonable to consider only neuralgic points to reduce the amount of the measured data and provide clarity. Monitoring can help to receive information about the condition of the structure, the load situation, and environmental influences (e.g. temperature deformations). In the maintenance project, Grenzbrucke Basel, the Gerber hinges are retrofitted by diagonal prestressed rods. Fiber-optic strain and temperature sensors are applied on the rods to get more information about the stress state. Based on this stress state a warning system is installed. If the stress state exceeds a limit, a message is sent to the responsible engineer. This paper presents the concept of the warning system, the fiber-optic measurements, and its calibration using trucks with defined loads.