Experimental Techniques for Steel Silo Transition Junctions

Abstract

Large elevated steel silos in general consist of a cylindrical vessel, a conical discharge hopper, and a skirt. The cone-cylinder-skirt junction is subject to a large circumferential compressive force due to the radial component of the meridional tension in the hopper, so either a ring is provided or the shell walls are locally thickened to strengthen the junction. This chapter provides a description of the development of an experimental facility for testing model junctions. The issues covered include the fabrication of quality model junctions using thin-steel sheets, the loading method, and the precise three-dimensional measurement of geometric imperfections and deformed shapes, using a laser-displacement meter. To build a model cone-cylinder-skirt junction, the cylinder, the conical hopper, and the skirt are first made by cutting and rolling a plate into the desired shape and welding the meridional seam. Then the conical hopper and the cylinder are welded together with a circumferential weld to form a cone-cylinder intersection. Finally, the skirt is welded to the cone-cylinder intersection with a second circumferential weld to form a junction consisting of the three components of cylinder, hopper, and skirt. If a ring is present, a third circumferential weld is required to connect the ring to the junction.