Long Term Bridge Monitoring

Monitoring of Vienna’s Reichsbrücke (Bridge)

On a Sunday morning in August 1976, the Vienna Reichsbrücke was destroyed by a natural frequency oscillation. The bridge was constructed in 1937, making it only 39 years old at the time. A new bridge was built to transport the automobile traffic and the metro rail way. To avoid another incident at the new bridge, a monitoring system was installed to permanently monitor the condition of the bridge.

Four requirements that lead to the decision to use the e.bloxx modules:

• Decentralized structure of the measuring units because of the long distances and the very small signals (strain,
  temperature, acceleration).
• Synchronized (20 μs) measurement and acquisition of the signals to detect interrelationships of the signals.
• Rough environment conditions and high degree of reliability.
• Conditioners to measure 12 accelerations, 4 strain gauges, and 6 temperatures.

The single modules are connected via long distances to an e.gate. A Linux server collects the data and transfers the results via internet to the monitoring system. For the data acquisition the Aplica software Green Node is in operation.

Due to the fast LocalBus which connects the module to the e.gate and due to the synchronization with a maximum jitter of only 20 μs, first time bridge monitoring system can be realized by the use of fieldbus technology.