Zugverankerung von gelenkig aufgelagerten Kranbahnträgern - Unerwartet hohe Ermüdungsbeanspruchung und verbesserte Detaillösung

Uplift fixing bolts in simply supported crane girders - unexpectedly high fatigue stresses and improved detailing solution.

Crane girders with hinged supports on top of the columns are often fixed to the column head by placing vertical bolts between the girder's lower flange and the column's head plate, in order to prevent uplift of the girder. The passing of the crane load over the girder causes a deflection of the latter, which in turn leads to rotations of the girder end cross-sections. The relative movements and rotations between the girder's lower flange and the column's head plate can lead to exceptionally large bending stresses in the fixing bolts, as is illustrated by means of a numerical (FEM) example in this paper. A simple engineering model, which is however capable of capturing all the relevant parameters for the different types of fixing detailing, is developed for the determination of these additional bending stresses and was verified by comparisons with the FEM models. Finally, proposals for an improved detailing solution are presented.