Project of the Year: High-Rise Category
Structural Modifications to Comete Guam
Tumon Bay, Guam
Submitted by Structural Technologies, Inc.
The Comete Guam building was constructed during 1996 and 1997 and was originally proposed for retail and department store development. In mid-1998 the owners amended the proposed use to that of an indoor aquarium, virtual-reality indoor theme park, and restaurant. To accommodate Underwater World, a 750,000 gallon (3.4 million liter) indoor aquarium with 400 linear feet (120 m) of walk-through tunnel, featuring marine life indigenous to Micronesia, was constructed. Gameworks required several virtual-reality games such as an IMAX ride-theater to be supported on existing suspended floors.
Sam Choy’s Restaurant required significant structural revisions to accommodate new stair access and mechanical openings. Large openings were required, of dimensions 20 feet by 24 feet (6 m by 7 m), in the existing bonded post-tensioned (PT) floor system. Given the corrosive environment of the proposed aquarium tank, carbon fiber was selected as a superior material for strengthening the adjacent slabs and beams. The controlled demolition of the floor openings was undertaken by first detecting the PT tendons using non-destructive testing techniques. Then using diamond-blade-floor and track-mounted saws, panels were cut and lowered.
The application of carbon-fiber reinforcement was the first for Guam and Micronesia, and a series of large-scale tests were conducted to verify the technology. Three 12-foot (3 m) long beam specimens were tested in flexure to failure to demonstrate the ability of these advanced materials to strengthen existing concrete structures.
Several hundred floor penetrations were required to accommodate mechanical services for marine life and human occupants. All PT tendons were located using electro-magnetic testing equipment to allow the mechanical contractor to avoid severing PT tendons.