Bewertung historischer Brückenlager

Assessment of historic bridge bearings - Experimental investigations on rolling friction.

This paper presents tests to determine the rolling resistance of historic bridge bearings with four rollers. The experimental investigations were conducted as part of a project which was funded by the German Research Foundation (Deutsche Forschungsgemeinschaft). Overall, eight rolling bearings with four rollers have been tested in terms of their rolling friction. In this paper the experimental work as well as the results of the investigation is described.
For all bearings a satisfactory rolling behaviour was observed. Without rust and dirt on the rolling surfaces the rolling friction is at the same level which is given in the German standards for new build rolling bearings. This value was observed at vertical loads up to 1.5 times the design load as well as at higher vertical loads up to 2.7 times the design load of the bearings. Furthermore, the findings have shown that there is a clear correlation between the measured rolling friction and the roughness of the bearing plates due to manufacturing and aging. From this a method could be derived to estimate the existing rolling friction by means of the roughness of the bearing plates.