Danube Bridge Sinzing


Problem statement

A consulting monitoring project was carried out at the Danube Bridge in Sinzing, Germany in December 2007 in order to collect data to explain unusually fast abrasion of the bridge’s sliding bearings. The bridge features twin steel girder decks supported by pot bearings on eight piers and the abutments.

Bridge inspections had revealed that the PTFE material of a number of the bridge bearings was significantly worn after only five years of service. Recommendations for appropriate remedial works were requested of the mageba project team.

Unusually large movements of the bridge under traffic loading were surmised to be the cause of the accelerated wear. The extent of the movements had to be understood, in order to implement sensible remedial works.
A modern high-grade polyethylene sliding material, ROBO-SLIDE, offers an alternative to PTFE in sliding bearings, with enhanced characteristics including far higher durability than PTFE. It was therefore decided to monitor the bridge’s movements and determine if new bearings featuring ROBO-SLIDE would offer a satisfactory solution.

Monitoring approach

A short-term analysis to evaluate the exact movements of the bridge deck over its bearings was required, and since manual measurements cannot offer the precision required, an automated system was necessitated. The short-term nature of the project made a “Portable” system ideal for this purpose. Mageba offered the assessment of the data during a two-week recording period.

Outcome and benefit for the customer

A clear correlation between longitudinal displacement and temperature was evident, with extrapolation of the recorded data indicating accumulated longitudinal sliding distance of approximately 2.5km in one year. It could be concluded that excessive movement was the primary cause of the wear problem, and that use of ROBO-SLIDE instead of PTFE would significantly prolong the life of the bearings.

A detailed understanding of the behaviour of the bridge was obtained from this temporary and relatively affordable monitoring system, enabling the bridge owner to have confidence that the proposed solution to the problem of premature bearing failure will have long-term success.

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Key data