Town of Manchester, VT Route 7A Precast Arch Bridge
This project presented a number of design challenges combined in the design of one 8 x 28 foot arch bridge. The design requirements included mating to an existing marble arch, contouring to follow a change in stream direction to the desired outlet and accommodation for an existing sanitary sewer outlet.
The design solution and detailing were complicated by the culvert geometry, opening and railing. The bridge geometry needed to marry the proposed layout to the limitations of the precast forming system and the structural design had to consider several local combinations to find the controlling case. Delta Precast provided the structural design and detailed shop drawings for the bridge.
In addition to the curved orientation, an opening in the arch units was designed to accommodate an existing sanitary sewer near the outlet end. Structural design had to consider the opening, traffic live load and lateral load from a traffic parapet railing with lamp post. This project demonstrates our capability to design custom precast solutions that require exact dimensions for complex sites with multiple constraints. Project installation proceeded without a hitch. Praise manufacturing enabled the precast units to match the cast in place foundations exactly.