Recycling Bridge Abutments Saves Owners Money and Time
This installment of "A Bridge Moment" describes a recent bridge rehabilitation project that involved the “recycling” of the existing concrete abutments or what bridge engineers refer to as a superstructure replacement. The original 75-foot span bridge was built in 1983 and consisted of glue-laminated timber beams and an 8” timber deck with concrete abutments supported on 12” diameter steel monotube piles. The abutments were in good shape but the timber deck and beams were deteriorated and required major repairs or replacement. The bridge owners (Bridgeway Villas HOA in Pelican Bay, Naples, FL) did not want to maintain the existing timber components or replace using timber due to the high maintenance costs they endured over the prior 35 years. Bridging Solutions determined that a concrete beam and deck superstructure would overload the piles supporting the existing abutments. A steel beam and concrete deck superstructure was also heavier than timber but the calculated pile loads were within the allowable design pile load that was provided in the record plans. To match the appearance of the existing bridge the owners decided to paint the W36X183 steel rolled beams a dark brown color similar to the color of the original timber beams. The steel beams needed to be bent on their strong axis by the fabricator to provide the required camber for the 4”calculated dead load deflection and the existing 18” vertical curve ordinate. The owners requested custom designed and fabricated steel railings to provide an open view of the water below. The project was completed in less than 50 days and the contractor was Thomas Marine Construction out of Fort Myers, FL. Bridging Solutions estimates that recycling the original abutments saved the bridge owners at least $500,000 and 2 months of construction time compared to a full bridge replacement.
