FATIGUE FAILURE OF A STEEL CRANE BEAM CONSOLE CONNECTED TO A CONCRETE WALL

摘要

Few months after their construction, fatigue failure occurred in steel crane beam cantilevering consoles which are connected to the concrete walls of an important waste treatment plant in Belgium. As the cranes are used extensively, resulting in a high number of loading cycles and important stress ranges, the main origin of the problem was identified as being the limited fatigue resistance of the concrete wall. This failure stresses the importance of checking fatigue resistance of all supporting parts of crane beams and steel consoles, as well as the connections to the building itself, being in the present case concrete walls of the plant building. This contribution focuses on actual fatigue failure, as well as on the various concepts for connecting the consoles of heavy duty steel crane beam to industrial buildings. The introduction of a concentrated force into a wall will become extremely complex if the load results from a crane beam,especially if dynamic loading and limited fatigue resistance is expected. Although static shear resistance of a properly reinforced concrete wall may be sufficiently high, its fatigue strength may be surprising Iow in the presence of loads variations. Hence influence of shear forces may need to be distributed across a wide area of the concrete wall. While the connection of crane beam consoles to a steel structure,consisting of columns and beams might seem easier, this paper proves that connecting such an equipment to a concrete wall is feasible, if proper attention is given to the fatigue problem.