Investigations on the buckling behaviour due to different launching bearings

In general, today two types of launching bearings are used in the construction of large steel and steel concrete composite bridges, sliding rockers and systems with hydraulic bearings. During incremental launching, the center of the webs of the superstructure is not perfectly in line with the center of the launching bearings due to unavoidable tolerances. The advantages and disadvantages of the respective systems are under discussion. At the Technical University Munich, large-scale buckling tests were carried out on longitudinally stiffened plates under biaxial stresses with different types of launching bearings and eccentric load introduction. In this paper the test results as well as differences of the respective systems are presented. Based on experimental results, a numerical model is validated. The test results as well as the results from the validated numerical model demonstrate the influence on the buckling behaviour from different types of launching bearings.