Selection, Design, and Construction of Two Fender System Replacements: Case Study and Recommendations

Abstract

Many bridges constructed over navigable waterways in the United States during the highway construction boom of the 20th century still have their original fender systems. These were often constructed of timber and integrated with the bridge pier foundations, making them difficult to repair and replace. Furthermore, as the original systems reach the end of their service lives and require replacement, the American Association of State Highway and Transportation Officials (AASHTO) vessel collision specifications adopted since the original construction may require a significantly more robust fender system, preventing a replace-in-kind approach. The Virginia Department of Transportation has begun to develop and implement a fender replacement program. The design strategies for this fender replacement program are complicated by low overhead clearance under bridge decks, the need to maintain channel width, the presence of large fast-moving vessels, and the presence of underwater cables and obstructions at each site. Providing a replacement fender system that requires minimal maintenance and has a long service life is a top priority.