Bracing located at either the top flange or bottom flange of a stringer to prevent lateral deformation is called?

• A. Leveling Course
• B. Lighting Standard
• C. Load Rating
• D. Lateral Bracing

Answer: (D)

Lateral bracing provides the essential restraint that keeps a slender stringer from moving sideways. By tying the top and bottom flanges together, this bracing resists lateral displacement and helps prevent lateral deformation or buckling under bending and transverse loads. In bridge practice, components like diaphragms, cross-frames, or stiffeners act as lateral bracing to maintain the stringer’s alignment and stiffness, especially against lateral-torsional buckling.

Other terms mentioned refer to unrelated functions: a leveling course is about surface preparation, a lighting standard deals with illumination, and a load rating indicates how much load the bridge can carry. None of these describe the restraint that stops lateral movement of the stringer’s flanges.