Award of Merit: Parking Structures Category
Rehabilitation of the Jordan Commons Parking Structures
Submitted by Sika Corporation
Miller Family Real Estate
D & D Reconstruction
The Jordan Commons Parking Structures are part of a complex of multi-use commercial buildings and entertainment facilities constructed in 1999 south of Salt Lake City. Each parking structure consists of a slab-on-ground below two supported levels, with spaces for approximately 1200 cars. The structural system consists of 64 ft (19.5 m) post-tensioned beams (18 ft [5.5 m] apart on center) and post-tensioned slabs.
After only 3 years in service, severe cracking appeared in the slabs where they were connected to the walls below and repairs were performed. In 2009, column cracking was observed and concerns were raised concerning the stability of the structure.
It was determined that a 2 in. (50 mm) length difference in the 395 ft (120 m) long slab from an 80°F (27°C) temperature swing resulted in seasonal stress cycles that were putting strain on the columns. The existing columns were found to be poorly designed and were under-reinforced. In addition, spalling was occurring on the deck slab as a result of minimal cover over the reinforcing steel.
Remediation measures included the addition of expansion joints, the removal of shear walls at the new expansion joint locations, the addition of new shear walls to the newly isolated portions, the extension of retrofitted column sections to the footings, and the installation of epoxy-applied glass fibers to the perimeter columns. The installation of the new expansion joints required cutting and restressing of the post-tensioned strands in the deck slabs. This was done by cutting every third strand and tying those strands in before cutting other strands.
After all repairs were made to the top levels of both structures, a traffic-bearing polyurethane waterproofing system was applied.