P a r k P o t o m a c O f f i c e B u i l d i n g E Kyle Wagner l - PowerPoint PPT Presentation

P a r k P o t o m a c O f f i c e B u i l d i n g “ E ” Kyle Wagner l Structural Option AE Senior Thesis l Spring 2010 Faculty Consultant l Prof. Kevin Parfitt

Presentation Overview • Project Information • Existing Structural System g y • Problem Statement and Solution • Structural Depth Study • Cost and Schedule Analysis • Additional Topics • Conclusions • Acknowledgements • Questions and Comments

Presentation Overview Project Information • Project Information • Existing Structural System • Located off I ‐ 270 in Potomac, MD • Problem Statement and Solution • Part of Park Potomac Place • Townhomes, Office Space, Retail, Dining • Structural Depth Study • Prominent location within Community • Cost and Schedule Analysis • Focal point from Cadbury Ave. • Additional Topics p • Face of community from I ‐ 270 • Conclusions • Acknowledgements View from Cadbury Ave www.parkpotomacplace.com • Questions and Comments

Presentation Overview Project Information • Project Information • Two levels mostly underground parking • Existing Structural System • 100 000+ SF each • 100,000+ SF each • Problem Statement and Solution • Seven levels of mostly office space • Structural Depth Study • Approx. 25,000 SF each • Cost and Schedule Analysis • Additional Topics p • Conclusions • Acknowledgements North Entrance to Parking Levels • Questions and Comments Building Footprint

Presentation Overview Existing Structural System • Project Information • Existing Structural System • Underground Parking all Cast ‐ in ‐ place concrete • 7” Thick slab post ‐ tensioned in N ‐ S direction 7” Thi k l b t t i d i N S di ti • Problem Statement and Solution • 72” x 20” D Beams post ‐ tensioned in E ‐ W direction • Structural Depth Study • Concrete Moment Frames • Cost and Schedule Analysis in both directions • Additional Topics p • Long Spans accomplished L S li h d • Conclusions • Flexibility for Tenant • Acknowledgements • 12’ Cantilever at N, S ends • Questions and Comments Existing Structural System

Presentation Overview Problem Statement • Project Information • Existing Structural System • Concrete structure results in large building self weight • Problem Statement and Solution • Larger gravity members result • Large mat foundations at soil level • Structural Depth Study • Central Foundation 52’ x 64’ x 60” Deep • Cost and Schedule Analysis • Longer schedule duration from concrete construction • Additional Topics p • Conclusions • End Result: Negative Cost and Schedule Implications Existing Foundation Plan • Acknowledgements • Questions and Comments

Presentation Overview Problem Solution • Project Information • Existing Structural System • Reduce building self weight by utilizing a steel structure • Problem Statement and Solution • Composite Beams and lightweight concrete used • To maintain integrity of existing design: • Structural Depth Study • Maintain current column layout • Cost and Schedule Analysis • Maintain current ceiling heights in Tenant Spaces • Additional Topics p • Maintain current MEP Spaces • Maintain current MEP Spaces • Conclusions • Braced Frames used to resist lateral forces • Steel construction likely to reduce construction schedule • Acknowledgements • Parking levels will remain unchanged • Questions and Comments

Presentation Overview Project Goals • Project Information • Existing Structural System • Reduce building self weight • Problem Statement and Solution • Maintain integrity of tenant spaces • Reduce overall cost • Structural Depth Study • Reduce schedule duration • Cost and Schedule Analysis • Additional Topics p • Conclusions • Acknowledgements • Questions and Comments

Presentation Overview Design Loads • Project Information Floor Live Loads Area Design Load (psf) ASCE 7 ‐ 05 Load (psf) • Existing Structural System Assembly Areas 100 100 • Design Loads Corridors 100 100 • Problem Statement and Solution Corridors Above First Floor 80 80 • ASCE 7 ‐ 05 Lobbies 100 100 Marquees & Canopies 75 75 • Structural Depth Study • Superimposed Dead Loads Mechanical Rooms 150 125 Offices 80 + 20 psf Partitions 50 + 20 psf Partitions • 5 psf Floor Parking Garages 50 40 • Cost and Schedule Analysis Plaza, Top Floor Parking Fire Truck Load or 250 psf 250 Retail ‐ First Floor 100 100 • 10 psf Roof Stairs and Exitways 100 100 • Additional Topics p Storage (Light) Storage (Light) 125 125 125 125 • Flat Roof Snow Load • Conclusions Live Load Values • 21 psf • Acknowledgements • Questions and Comments

Presentation Overview G r a v i t y S y s t e m D e s i g n • Project Information • Existing Structural System • 5 ½” Thick Slab on 2”, 18 Gage Metal Decking • Provides adequate 2 hour fire rating between floors P id d t 2 h fi ti b t fl • Problem Statement and Solution • Beams spacing does not exceed 10’ • Structural Depth Study • Unshored • Cost and Schedule Analysis • Minimize number • Additional Topics p of beams required of beams required • Conclusions • Columns spliced every other floor • Acknowledgements Typical Floor Layout RAM Model • Questions and Comments

Presentation Overview Cantilevered Ends • Moment connection at • Project Information interior to balance • Existing Structural System • 12’ Cantilever on North and South Ends moment at column • Unobstructed glass around building • Unobstructed glass around building • Problem Statement and Solution corners • Structural Depth Study • Moment from cantilever: 575 ft ‐ k • Cost and Schedule Analysis • Moment from interior: 376 ft ‐ k • Four beams used to transfer • Moment to column: 199 ft ‐ k • Additional Topics p load back to columns • Design for moment and axial due to • Conclusions • Beam required: gravity load • Acknowledgements • Final Design shown at right • W18x55 • Questions and Comments

Presentation Overview Floor Depth Comparison • Project Information • Existing Structural System • Existing post ‐ tensioned system • Maintain ceiling heights and MEP Spaces • 20” depth at beams • 20 depth at beams • Problem Statement and Solution • Structural Depth Study • Steel Design • Increase overall building height • Cost and Schedule Analysis • Deepest Beam: W27x84 • No code restrictions • Additional Topics p • Increase by 12” per floor • Conclusions • Overall height increase by 7’ • Acknowledgements • Recalculate lateral loads • Questions and Comments • Floor Depth Approx. 32”

Presentation Overview Lateral Loads • Project Information • Existing Structural System • Wind: Method 2 of ASCE 7 ‐ 05 Chapter 6 • Problem Statement and Solution • Assume wind negligible beneath plaza level • Structural Depth Study • Seismic: ELFP of ASCE 7 ‐ 05 Chapter 11 • Seismic Design Category B • Cost and Schedule Analysis • Seismic Base Level taken at plaza level • Additional Topics p • Wind controlled for strength and serviceability Wi d t ll d f t th d i bilit • Conclusions • Acknowledgements • Questions and Comments

Presentation Overview ETABS Model • Project Information • Existing Structural System • 7 Load combinations, 4 wind cases, accidental • Problem Statement and Solution torsion (5% ecc.) due to seismic all manually included • Structural Depth Study • Floors modeled as rigid diaphragms • Loads distributed based on relative stiffnesses of frames • Cost and Schedule Analysis • Only lateral system modeled • Additional Topics p • Gravity loads applied using additional area mass to diaphragm G i l d li d i ddi i l di h • Conclusions ETABS Model • Acknowledgements • Questions and Comments

Presentation Overview Braced Frame Design • Project Information • Existing Structural System • Symmetry in Geometry and Stiffness • Problem Statement and Solution • Loads distributed evenly to each frame • Structural Depth Study • Cost and Schedule Analysis • SAP used to calculate forces in braces • Additional Topics p for critical load combination for critical load combination • Critical load combination used to design columns • Conclusions • Final Brace Frame Design shown at right • Acknowledgements • E ‐ W Frames larger than N ‐ S Frames N-S Braced Frame E-W Braced Frame • Questions and Comments

Presentation Overview Lateral Analysis • Project Information • Existing Structural System • Primary controlling load case was 0.9D+1.6W • Problem Statement and Solution • Controlling wind case was Wind Case 1 • Structural Depth Study • Center of mass and rigidity both at geometric center • Overall building torsion was negliglible • Cost and Schedule Analysis • Wind drift within L/400 • Additional Topics p • Seismic drift found to be well within limitations • Seismic drift found to be well within limitations • Conclusions • Acknowledgements • Questions and Comments

Presentation Overview Foundation Design • Project Information • Existing Structural System • Problem Statement and Solution • Structural Depth Study • Cost and Schedule Analysis • Additional Topics p • Conclusions • Existing foundations • Steel Structure Foundations • Acknowledgements • 17’ x 17’ x 34” Deep (U.N.O.) • Questions and Comments