N.G. JACOBSON & ASSOCIATES, INC.

NGJ was the Prime Engineering Design Consultant to 1501 – 4^th Avenue Limited Partnership (Bentall) for the restoration of an 8-Story, Reinforced Pre-Cast Concrete Parking Structure, constructed in 1963.  The Parking Structure had significant corrosion-related distress in the structural 'Cofar' steel deck and Pre-Cast Concrete Spandrel connections resulting from chloride contamination.  NGJ performed an "Investigation and Recommendations for Restoration and Waterproofing Report" in 1998 that included Budget Estimates and Life Cycle Cost Evaluation as part of a review of the remaining service life available with this structure.  Phase I Repairs and Waterproofing Work were completed in the Fall of 1999.

Also in 1998, NGJ performed a Level One Seismic Review of the Parking Structure and the adjacent Columbia Building immediately to the North.  The Columbia Building had been laterally tied to the Parking Structure in the 1980’s as part of its seismic upgrade.

To extend the service life of the steel 'Cofar' deck, galvanized steel reinforcing plates were installed to the underside of the deck to provide additional flexural strength where metal deck corrosion was prevalent at high stress areas.  Other repairs and upgrades consisted of re-striping of the parking stall layout to comply with current ADA parking stall requirements, cleaning and waterproofing of the top level concrete deck, routing and sealing of existing cracks in the concrete deck, and a complete replacement of all stairwell, exit, and emergency lighting.