The Alpharetta City Hall Parking Deck is a 5 story precast concrete public parking deck serving the City Hall and several other facilities.
With an overall addition size of 121,959 square feet in five structured levels the architectural design was carefully chosen to match the City Hall, located on the same grounds. In addition, the parking deck was designed to be expandable on one side for the future.
The project is a precast concrete structure composed almost entirely of concrete, including foundations. It was chosen to be precast concrete as a function primarily of economy compared to a similar sized cast-in-place concrete parking deck. The project was on a schedule to be complete for the governing assembly to meet when their session started.
The lateral load resisting system for the project is composed precast concrete shear walls in both directions (3 short walls in one direction and one long wall in the other direction). The shear walls are founded on pile caps and grade beams supported below by auger-cast in place concrete piles. The structure utilized concrete pile caps founded on high-capacity auger-cast concrete piles. Basement and retaining a walls were cast-in-place concrete with a concrete slab on grade at the lowest level.
The floor system consists of precast concrete double tees connected for lateral stability by weld plates and topped with a field-topped concrete slab and welded wire fabric. Joints were hand tooled. Double tees are supported by spandrel girders at the outer edge and by the metro wall in the garage center. Girders are in turn supported by concrete columns and shear walls. Complex
The parking deck has a very complex façade of colored concrete, inlayed brick, and a system of reveals and decorative inlays to compliment the complex façade design of the Alpharetta City Hall it serves. Expandability: The parking deck is designed to be expanded on one side for future increased capacity.
The Alpharetta City Hall Parking Deck, using a precast concrete structure, provides a very presentable appearance to the center of city government.