On June 3, the Pittsburgh Chapter of the Association for Bridge Construction & Design (ABCD) announced their award winners for bridges constructed in 2019. The Lovedale Road bridge replacement in Allegheny County was recognized as the Outstanding New Single Span bridge.
Prior to replacement, the bridge was a severely deteriorated concrete-encased steel beam bridge over Wylie Run that was posted for 28 tons. The project team was committed to a short road closure to minimize impacts on the local community. When a box culvert was dismissed based on the district's past experience with Wylie Run, the design team looked to accelerated bridge construction (ABC) techniques despite site conditions that did not make this project an ideal candidate for ABC.
The ABC bridge structure was designed with precast components. The substructure consisted of precast, horizontally post-tensioned concrete walls in which each segment is composed of an integral stem and footing. The superstructure comprised three prefabricated modules, each consisting of a concrete deck panel precast on a pair of steel beams. Ultra-high performance concrete (UHPC) and accelerated concrete was specified for closure pours and cast-in-place elements. Additionally, soldier pile walls with precast concrete lagging that could be constructed with a single lane closed were prescribed for two of the wingwalls.
The design was considered constructible in approximately seven weeks, and the contract permitted a 30-day road closure within the schools' summer recess. The winning bid was about 20 percent under the design estimate. The replacement structure, as specified, was constructed within the required time frame and within budget.