Michael A. Troxell Structural Option Senior Thesis 2006 The College of Business Administration Northern Arizona University Flagstaff, Arizona Presentation Outline Building Background Schedule Comparison Cost Analysis Structural Design Proposal Existing Structural System Conclusion Acknowledgements & Questions Design Professionals Owner: Northern Arizona University Architect: Carter Burgess Inc. Structural Engineer: Caruso Turley Scott Inc. M/E/P Engineer: ARUP General Contractor: Ryan Companies Civil Engineer:Carter Burgess Inc. Building Background 110,000 Sq. ft., 5 Story University Building Completed January 2006 Estimated Overall Project Cost: $24 Million LEED Certified Sustainability Measurement Signature Building for NAU Building Description Building Features 14 Classrooms 56 Faculty Offices 200 Seat Auditorium 5 Computer Labs Caf with outdoor plaza Student lounges Career Exploration Office Presentation Outline Building Background Schedule Comparison Cost Analysis Structural Design Proposal Existing Structural System Conclusion Acknowledgements & Questions Structural System Overview Superstructure:Precast Concrete Floor Framing:Hollow-Core Plank Foundation:Deep Caissons Shallow Grade Beams Lateral System:Moment Frames Braced Frames Shear Walls Floor Framing 10 Hollow-Core Plank span 36 ft. 3 Cast-in-place concrete topping Inverted T-Beams 34 x 27 most common span up to 38 ft psi Concrete Plank and Beams 3 Topping 10 Hollow-Core Plank Inverted T-Beam Vertical Framing Caissons with 2-0 Minimum Penetration into Bedrock Sizes: from 2-6 to 7-0 Diameter All Columns are 24 Square Typical Floor Plan 4 wide, 10 deep Plank 24 Square Column Inverted T-Beam N Lateral System Combination of: 1.Concrete Moment Frames 2.Concrete Shear walls 3.Concrete Frames w/ Steel Braces Lateral System Layout Blue = Moment Frame Red = Shear Wall Green = Braced Frame N Presentation Outline Building Background Schedule Comparison Cost Analysis Structural Design Proposal Existing Structural System Conclusion Acknowledgements & Questions Problem Statement Complicated Lateral System Combination of Braced frames, Moment frames, and Shear Walls Seismic Loads control design Lower Weight = Lower Loads A lot of Moment Connections Efficiency of System Is there a system which is Cheaper? Faster to Construct? Weight of Existing System is high High Loads & Longer Spans Solution Method Design Gravity System using Steel Members Develop new Seismic Loads using ASCE 7-02 Design Lateral System using Braced Frames Compare Construction Time of redesign to Existing System Compare Cost of redesign to Existing System Presentation Outline Building Background Schedule Comparison Cost Analysis Structural Design Proposal Existing Structural System Conclusion Acknowledgements & Questions Structural Design Design Criteria: Design Loads: Dead Loads Slab on Deck68 psf Steel Framing 8 psf Other14 psf Total 90 psf Live Loads All Floors 100 psf IBC 2003 LRFD 3 rd Edition ASCE 7-02 Gravity System Typical Floor Plan 1- Composite Steel Deck + 4 Concrete Slab Beams 9-0 O.C., Spans 11 to 38 Beam Sizes: W8X10 to W16X31 Girders E-W direction, span 36 Girder Sizes: W16X31 to W21X62 N RAM Model Lateral System Steel Braced Frames No Moment Connections Required Building weighs less so lower Seismic Loads Limit Story Drift to L/600 Plan with frames East-West Direction 3 Frames North-South Direction 4 Frames Torsion effects minimal due to layout N East-West Frame All Braces W 10 X 77 Lower Columns W 12 X 96 Upper Columns W 12 X 87 W 21 X 62 W 18 X 60 W 18 X 40 North-South Frame All Braces W 10 X 77 Lower Columns W 12 X 96 Upper Columns W 12 X 87 W 21 X 48 W 216X 26 Presentation Outline Building Background Schedule Comparison Cost Analysis Structural Design Proposal Existing Structural System Conclusion Acknowledgements & Questions Cost Analysis Presentation Outline Building Background Schedule Comparison Cost Analysis Structural Design Proposal Existing Structural System Conclusion Acknowledgements & Questions Schedule Comparison Presentation Outline Building Background Schedule Analysis Cost Analysis Structural Design Proposal Existing Structural System Conclusion Acknowledgements & Questions Conclusions Based on Analysis, the Proposed Steel framing effectively carries Gravity Loads Proposed Steel Lateral System limits story drift to less than L/600. The Cost Analysis showed the Proposed system to cost about 8% less than the Existing System. A Comparison of construction times, showed the Proposed system would take 2 weeks longer to construct. The Proposed Steel System is comparable to the Existing Precast System. Acknowledgements AE Faculty and Staff My thesis Advisor, Professor Parfitt Dave Melfi & Chris Glinski Mary Reik - NAU Craig Porter Caruso Turley Scott, Inc. My Family and Friends THANK YOU! QUESTIONS?