Engineer: CBRE|Heery & Carl Walker Parking
Construction Management: Gilbane Building Compan
General Contractor: Knutson Construction
Concrete Contractor: Knutson Construction
Rebar Producer: Nucor
Reinforcing Bar Fabricator: Ambassador Steel
Rebar Placer: Knutson Construction
Reinforcing Tons: 6,200
Total Concrete Yards: 41,250
Total Project Cost: $460 Million
STRUCTURAL FRAMING SYSTEM
The floor-to-floor alignment and the need for a thin system lead to an 11” two-way reinforced concrete slab with 16” drop panels. This maximized space above the ceilings for the extensive healthcare mechanical and electrical systems. The unique layout of the building created a customized grid and forced the structural system to accommodate long spans up to 36’. Reinforced concrete elevator and stair shafts were used as the children’s hospital’s lateral support. The underground parking ramp is situated between the existing hospital and a busy road. This required a surrounding secant wall with tie-backs for permanent earth retention. Many of the footings and columns in the ramp were designed to support a future bed tower above.
UNIQUE DESIGN FEATURES
The owner’s primary objectives for the children’s hospital included matching the main hospital’s existing floor levels due to critical departmental adjacencies requiring patient and staff movements. The top level of the parking structure was designed as a landscaped park at grade. Foam blocks were sculpted to create mounds and minimize structural load. Minimization of noise and vibration throughout construction was mandated due to the existing hospital’s proximity with functioning operating rooms, research laboratories… No pile driving was allowed which led to reinforced concrete caissons and secant walls for foundation support.
REASONS FOR CHOOSING REINFORCED CONCRETE
Reinforced Concrete was chosen due to its ability to accommodate a flexible design, its resilience and lifespan, and financial savings. Other key factors were the availability of concrete and lack of structural steel fabricators. Most general contractors in the area self-perform their own concrete work.