ABSTRACT
Members designed to carry primarily axial forces are found in steel railway bridges as main truss members, span bracing members, steel tower columns and bracing, and spandrel columns in arches. Axial tension main members in steel railway superstructures are often fracture critical and nonredundant. Shear lag occurs at connections when the tension load is not transmitted by all of the member elements in the connection. Therefore, at tension member connections with elements in different planes, an effective area is determined to reflect that the tensile force is not uniformly distributed across the net area at the connection. Tension members in steel railway bridges may comprise eyebars, cables, structural shapes, and built-up sections. Eyebars are not often used in modern bridge superstructure fabrication, and suspension or cable-stayed bridges are unusual for freight railway structures due to flexibility concerns. Perforated cover plates are often used for built-up compression members in modern railway steel superstructures.
