Bump At the End of the Bridge

Interface bumps between bridge abutments and embankments increase risk and add over $100 million to maintenance expenses every year. New research reveals effective ways to deal with the bump problem. The bump at the end of the bridge is a common but complex problem that involves a dizzying range of design factors, including soil settlement in embankments, approach fill material, abutment foundation type, abutment type, structure type, joints, approach slab, paving and construction methods. The bump problem affects about 25% of U.S. bridges, or approximately 150,000 structures. The amount of money spent every year on the repair of this problem nationwide is estimated to be at least $100 million. In addition, bump problems can tarnish a transportation agency’s public image. Our bridge bump research, sponsored by the National Cooperative Highway Research Program and the American Association of State Highway and Transportation Officials in cooperation with the Federal Highway Administration and the Transportation Research Board of th National Research Council, examined the current literature on the problem and included a questionnaire completed by 72 highway engineers from 48 states.