Award of Excellence: Parking Structures Category
Winsor Suites Parking Garage Restoration
Submitted by Carl Walker, Inc.
Windsor Associates, LP
Carl Walker, Inc.
Structural Maintenance Systems
The 192-car Windsor Suites valet parking garage, constructed circa 1963, is on the second through fourth floors of the 23-story hotel in historic Philadelphia, PA. The structural frame consists of cast-in-place flat concrete slabs, varying in thickness from 7 to 9 in. (178 to 229 mm). The slabs are supplemented with beams at the edge of the slab and at various interior locations. The column arrangement requires reinforcing steel to be placed at asymmetrical strips parallel to lines that connect column centerlines. The lateral load resistance is provided by the shear walls of the elevator core and stair towers. The foundation system includes caissons that bear on rock strata.
In 2008, a portion of Level 2 was close to collapse. Immediate measures were taken for public safety. Once the conditions were stabilized, an intense investigation was expeditiously made to determine the extent of the problem and make recommendations for repair. The evaluation revealed significant deterioration of concrete slabs, failure of previous top and bottom slab repairs, delaminations around columns, and severe corrosion of reinforcing steel. Immediate actions included closing 40% of Level 2 and 15% of Level 3 parking areas, closing part of the Mezzanine office, and installation of shoring in the garage entrance.
The repair program was developed addressing the requirements of the building structure, maintaining public access, and keeping the garage operational. The phased restoration included temporary shoring and bracing elements; repair, replacement, or both of the garage slabs; and slab waterproofing.
Dealing with the potential of losing the facility, a major economic recession, and the highly visible location in a major city, the owners of the Windsor Hotel assembled a team that would work together to solve this complex problem.