Project: 250 West Street, Columbus, Ohio Kevin A. Sponsler Project: 250 West Street, Columbus, Ohio
Presentation Outline Building Overview Typical Floor System Analysis Lateral System Analysis Cost and Schedule (Current vs. Redesign) Office Space Lighting System Design
Project Team Developer: Nationwide Reality Investors Architect: Acock Associates Architects Structural: Jezerinac Geers & Associates Civil: Evans, Mechwart, Hambleton & Tilton MEP: Prater Engineering Associates Landscape: Myers-Schmalenberger/MSI General Contractor: Messer Construction
Building Use 7-Story Building With Basement Approximately 200’ x 100’ 143,000 Square Feet Multi-Use Building Parking Storage Retail Space Office Space
Site Location
Architectural Aspects Brick Columns With Limestone Accents Large Glass Panels Metal Panels 7th Story Balcony/Terrace
Structural System ASD Designed Floor System Lateral System Foundation Composite Beams/Deck Lateral System Braced Frames Foundation Concrete Spread Footings
Mechanical Systems Variable Air Volume System 4 Air Handling Units / Cooling Tower VAV Boxes on Each Floor Restrooms Fed by Constant Air with Exhaust CO Sensors, Exhaust System in Parking Area
Lighting Systems Lobby Garage Exterior Low Voltage Recessed Cans Wall Sconces Garage Metal Halide Exterior Metal Halide Cylinders on Columns Remaining Lighting Not In Initial Contract
Electrical Systems Shared With Adjacent Building 277/480 Volt, 3 Phase System Each Floor Supplied with 277/480 V, 3 Phase Powers Lighting/Other Equipment Stepped Down at Each Floor to 120/208 Volt Powers Receptacles
Current Floor System
Floor System Options Composite Beams/Deck Framed N-S Direction Composite Beams/Deck Framed E-W Direction (Current System) Non-Composite System Framed E-W Direction
Preliminary System Comparisons Preliminary Design in RAM Results Composite N-S Composite E-W Non- Composite Cost ($) 89,200 79,000 96,000 Erection (days) 9.5 8.5 6 Steel Depth (in.) 24 27 30 Weight (tons) 47.6 44.8 74.0
Building Corner Framing
Corner Connection Options Field Welded Flanges Moment End Plate Flange Plates Beam Cantilevered Over Column
Corner Framing Comparison Costs ($) Field Welded Flanges Moment End Plates Top & Bottom Flange Plates Beam Cantilevered Over Column Materials 698 708 730 842 Shop 720 765 1080 870 Field 296 49 76 Total 1714 1522 1886 1761
Final Floor Design
Floor System Comparison Current Design New Design Steel (tons) 59.2 50.2 Members 117 111 Shear Studs 1291 3710
Floor System Conclusion New System vs. Current System (1 Floor) 9.0 Less Tons of Steel 2,419 More Shear Studs Costs $8,800 Less Depth of System Reduced 3”
Current Lateral System 4 Braced Frames Located in Central Core of Building 2 North-South Direction 2 East-West Direction Combination of: Diagonal Braces Inverted V-Type Braces
Earthquake Loads (R=3 vs. R=5) Ordinary Concentrically Braced Frame R=5 Brace Strength = .8ФcPn Inverted V-Type Bracing Strength = 1.5 x Required Slenderness Restrictions Connection Restrictions System Not Specifically Designed for Seismic R=3 No Other Restrictions
Story Forces
Difference in Brace Sizes Frame on Line D From 4.4-5.1 Braces Below Level R=3 R=5 2 HSS 8x8x5/16 3 HSS 8x8x1/4 4 5 6 7 HSS 6x6x1/4 Roof HSS 6x6x3/16
Lateral Load Conclusion Members Extra Restrictions on Design Using R=5 Some Member Sizes Reduced Using R=5 2 Tons Less Steel Costs $ 2,700 less with R=5 Little Effect on Other Systems
Current Design Cost & Schedule Material $743,000 Field Labor $222,000 Total Cost $965,000 Erection Gang 24 Days Detailing Gang 35 Days Shear Studs 10 Days
New Design Cost & Schedule R=3 R=5 Material $698,000 $695,000 Field Labor $216,000 Total Cost $914,000 $912,000 Erection Gang 23 Days Detailing Gang 32 Days Shear Studs 20 Days
Cost Conclusion Redesign Saves Over $50,000 Seismic Design Criteria Has Little Effect on Structural Costs (This Building)
Lighting Criteria First Floor Open Plan Office Tasks Reading Copied Tasks – Ditto Copies Handwritten Tasks With #2 Pencil Keyboard Reading Target Illumination 75 fc
Fixture Selection Recessed Parabolic 2’ x 4’ Fixture 4” Louver Manufacturer: Lumax Industries Inc. 4PG33224-CO4L18 Lamps: Sylvania FO32/835XPS/ECO Ballast: Sylvania QTP 3x32T8/277 ISN-A
Office Layout / Reflectance
Lighting Design
Lighting Design
Conclusion Floor System Lateral System Maintained Strength Reduced Cost - $8,800/floor Reduced Depth Lateral System Reduced Material Costs Overall – Reduced Cost by $50,000
Questions