Are our bridges safe? Monitoring solutions provide the answers

The Deutsche Bahn draws up recalculations at different levels for their railway bridges. New evaluations on complex bridge constructions must be carried out with the assistance of measurement technology.

This new evaluation can be implemented with short-duration measurements – so-called system measurements. They are however extremely complex and only provide a time-limited glimpse of the real loads.

Permanent monitoring solutions offer an alternative to short­ duration measurements. They show the behavior of the bridge over a longer period of time and provide information about the resulting load collective which includes not only the traffic loads, but also wind forces, temperature changes and other influences. This allows changes to the bridge to be detected in time and so avoid accidents.

The DB Netz AG is using HBM measurement technology within the framework of a pilot project aimed at developing durable permanent monitoring solutions for railway bridges. One example is the monitoring of the Ziegelgraben Bridge in Stralsund, Germany.

HBM transducers have been acquiring measured quantities here, such as strain and pressure, for many months. Resultant threshold values are also recorded to determine the behavior of the 'bridge-machine' combination

HBM's QuantumX CX22W measurement data recorder transmits all relevant data of a bridge elevation process to the persons responsible for the bridge.The QuantumX CX22W acquires the measurement data of widely distributed measurement modules fully autonomously during the longterm measurements in this stationary field application.

The measurement data is stored locally on a robust, exchangeable CF card and can also be called up online via Ethernet or Wireless LAN.The measurement data acquired during monitoring makes it clear how construction components interact under real loads.

This allows important information to be obtained for the maintenance and further use of existing bridges, and for the development of innovative construction methods.