Capital Improvement & Infrastructure

Innovative Cost-Effective Standard Decks for Movable Bridges In Reserve

New Jersey has the third-most movable bridges of the 50 states, with an average age of approximately 40 years and more than 50% of these bridges are structurally deficient mainly due to their bridge decks. Moreover, many of these bridges, whether state or locally owned, are subjected to significant amounts of average daily truck traffic (ADTT). Because of their condition and their location on significant commerce routes in the state, many of these bridge decks are expected to be replaced in the coming years as part of the NJDOT capital program. Being directly subjected to repeated abrasive loading from passing vehicles; the elements of weather; and road salts as part of winter maintenance, bridge decks are the most vulnerable component. To reduce the demands on the primary moving elements, most movable bridge decks are designed to be lightweight, mostly by employing open or partially filled grid decks. Concrete decks are particularly susceptible to corrosion damage, requiring frequent re-decking. On the other hand, open grid decks are prone to fatigue cracking, the exposed superstructure and movable elements are susceptible to corrosion damage, and contribute adversely to the environment by draining directly into the river below. Steel orthotropic bridge decks are ideal for movable bridges, however, the closed rib decks tend to be costly owing to intensive fabrication demands. Open rib variation of these decks can provide an efficient solution for movable bridges. Moreover, with proper design, these decks can provide a service life of 75 years or more with minimal maintenance. In addition, the ability for steel orthotropic decks to be designed and constructed in modular sections has the potential of reducing time and cost of construction. An experimental and computational research project is proposed for developing a standardized open rib orthotropic deck that can provide a long lasting, cost-effective solution for replacing decks of movable bridges in New Jersey. In addition, the research proposes to explore alternative deck designs and materials, including solution for bridges having low ADTT (such as aluminum and composite bridge decks).

Idea Submitted by Sougata Roy

List your Agency /Division / Bureau, County, City Univ. or Other Associate Research Professor, CEE/CAIT, Rutgers University

Idea Champion - Who at NJDOT, NJ Transit or NJ Motor Vehicle? (if known) Eddy Germain, NJDOT

Why is this a priority and what are the benefits for the State/County/City?

New, lightweight, modular bridge decks for movable bridges will reduce cost of fabrication, reduce duration of construction, reduce long term maintenance and increase service life, thereby providing effective life cycle cost. Moreover, this timely research will provide significant cost savings in NJDOT's capital program over the coming years by being ready before the movable bridge decks are up for replacement. The research results will help with standardizing decks for other short and medium span bridges owned by NJDOT and other state agencies. The knowledge generated will benefit the state economy by promoting in-state manufacturing of standard bridge decks.


Archive: 2018 Ideas
Archive: 2018 Ideas
Idea No. 105