End‐Bolted Cover Plates

Welding a cover plate to a rolled beam and high‐strength bolting the loose ends with a friction‐type connection increased the fatigue strength from Category E for end‐welded cover plates to Category B. The required number of end bolts is that needed to develop the cover plate's portion of the bending moment. A parametric analysis indicated that the design of two‐span continuous bridges with end‐bolted cover plates subjected to HS‐20 truck loading was not governed by fatigue. The weight savings from shortening the cover plate from its Category E length to the length between the theoretical cut‐off points were greater than the added cost of end‐bolting. This method of construction has the potential of fatigue proofing cover plates on rolled beams while lowering their cost of fabrication. It utilizes existing technology and can be implemented at once. Tests of 22 beams showed that end‐bolting the loose ends of welded cover plates increased the fatigue life by three categories, from EB. End‐bolted cover plates on bridge girders can usually be stopped at the theoretical cut‐off point. Such girders are fatigue proof and cheaper to fabricate than conventionally end‐welded cover plates.