Penn State Hershey Medical Center Matthew Vandersall Children’s Hospital Structural Option AE Senior Thesis - 2011 Hershey, Pennsylvania Dr. Richard Behr – Thesis Advisor
Introduction Children’s Hospital – Hershey Medical Center Location: Hershey, PA Introduction Number of Stories: 5 Above Grade / 1 Below Grade Existing Structural System Size: ~263,000 SF Thesis Proposal Height: 83.5 ft to top of the roof Structural Depth Structural Engineer: Gannett Fleming Slab Design Shear Wall Design Construction: 3/17/2010 – 8/20/2012 Column Design Contracted Cost: $115,726,613 Construction Management Breadth (http//www.pennstatehershey.org) Delivery Method: Design-Bid-Build Conclusion
Existing Structural System Children’s Hospital – Hershey Medical Center Foundation • 600 micropiles • 3’ x 3’ to 10’ x15’ pile caps • Strut beams span between pile caps Introduction • f’c = 4000 psi for all concrete elements Existing Structural System Thesis Proposal Structural Depth Slab Design Shear Wall Design Column Design Construction Management Breadth Conclusion
Existing Structural System Children’s Hospital – Hershey Medical Center Foundation • 600 micropiles • 3’ x 3’ to 10’ x15’ pile caps • Strut beams span between pile caps Introduction • f’c = 4000 psi for all concrete elements Existing Structural System Gravity System Thesis Proposal • Composite Floor System: Structural Depth • 2 ” deep, 20 -gage composite metal deck with 4 ½” topping • ¾” Shear studs to wide flange beams Slab Design • All columns are W 14s • Shear Wall Design Beams are typically W16s - W21s Column Design Construction Management Breadth Conclusion
Existing Structural System Children’s Hospital – Hershey Medical Center Foundation • 600 micropiles • 3’ x 3’ to 10’ x15’ pile caps • Strut beams span between pile caps Introduction • f’c = 4000 psi for all concrete elements Existing Structural System Gravity System Thesis Proposal • Composite Floor System: Structural Depth • 2 ” deep, 20 -gage composite metal deck with 4 ½” topping • ¾” Shear studs to wide flange beams Slab Design • All columns are W 14s • Shear Wall Design Beams are typically W16s - W21s Column Design Lateral System • 4 Moment Frames in East-West direction Construction Management Breadth • 4 Braced Frames in North-South direction Conclusion
Thesis Proposal Children’s Hospital – Hershey Medical Center Structural Depth • Redesign structure using reinforced concrete • Minimize structural layout impact • Design for future expansion Introduction Existing Structural System Construction Management Breadth • Compare cost of existing versus proposed design Thesis Proposal • Generate project schedules Structural Depth Mechanical Breadth Slab Design • Analyze heat flow through the insulating glass curtain wall • Shear Wall Design Propose an efficient curtain wall system to minimize heat transfer Column Design MAE Coursework • AE 597A – ETABS model Construction Management Breadth • AE 542 – heat transfer analysis for curtain wall systems Conclusion (Payette Associates)
Structural Depth Children’s Hospital – Hershey Medical Center Solution • Gravity System: • Two-way reinforced flat slab system • Shear caps if necessary for punching shear Introduction • Lateral System: Existing Structural System • Reinforced concrete shear walls • Two additional patient floors Thesis Proposal • Structural height = 113.5 ft Structural Depth Proposed Column Layout Slab Design • Column line F and G eliminated • Shear Wall Design Typical span: 30’ x 34.5’ Column Design Proposed Layout Construction Management Breadth Conclusion
Structural Depth Children’s Hospital – Hershey Medical Center Two-Way Flat Slab Design • Typical span considered for preliminary design • Element stiffness determined • Introduction Performed moment distribution • Moments distributed to columns strips and middle strips Existing Structural System • Designed reinforcement Thesis Proposal Assumptions: Structural Depth • f’c = 5000 psi • Slab thickness of 9” Slab Design • Shear cap depth of 4.5” Shear Wall Design Final Design Column Design Construction Management Breadth Conclusion
Structural Depth Children’s Hospital – Hershey Medical Center Ram Concept Model Typical Floor • Used to check all floor sections Max ∆ = 1.6” • Live load patterns were considered Introduction • Punching Shear checks performed 𝑀 • Allowable deflection, Δ = 240 = 1.73” Existing Structural System Thesis Proposal • Penthouse live load of 250 psf • Slab thickness increased for penthouse level Structural Depth Slab Design Penthouse Level Max ∆ = 1.4” Shear Wall Design Column Design Construction Management Breadth Conclusion
Structural Depth Children’s Hospital – Hershey Medical Center Final Slab Design: • Typical Floor Introduction • 9” two -way flat slab for typical floor Existing Structural System • f’c = 5000 psi • 4.5” deep shear caps Thesis Proposal • Penthouse Floor • Structural Depth 11” thick slab • f’c = 6000 psi Slab Design • 9.5” deep shear caps • #7 and #8 rebar for column strip Shear Wall Design • #5 rebar for middle strip Column Design Construction Management Breadth Conclusion
Structural Depth Children’s Hospital – Hershey Medical Center Design of Shear Walls 3 • 4 in North-South direction • D 4 in East-West direction C Introduction Y 2 Deflection/Story Drift Limitations 4 Existing Structural System • Wind - H/400 1 B A Thesis Proposal • Seismic - 0.02*h sx Structural Depth Assumptions X • Slab Design f’c = 5000 psi • Slab acts as a rigid diaphragm Shear Wall Design • Cracked sections • Columns – 0.7I g Column Design • Shear Walls – f 22 = 0.5 Construction Management Breadth • Shear walls take no out-of-plane bending • P- Δ effects considered within model Conclusion
Structural Depth Children’s Hospital – Hershey Medical Center Wind Loading 3 • Recalculation of base shear due to increased story height • D ASCE 7-10 wind load cases applied C Introduction • Load Case 1 controlled in both directions 2 • 696.3 k Serviceability checked for H/400 4 Existing Structural System 1 B A Thesis Proposal 2109.76 k Structural Depth Wind Base Shears Slab Design Shear Wall Design Column Design Construction Management Breadth Conclusion ASCE 7-10 Figure 27.4-8 Serviceability Check
Structural Depth Children’s Hospital – Hershey Medical Center Seismic Loading 3 • Original response modification factor (R) = 3 • D Ordinary reinforced concrete shear walls (R) = 5, Cd = 4.5 C Introduction • Base shear calculated for additional weight of the structure 2 • 850 k Accidental torsional effects e = 0.05 4 Existing Structural System • Drift checked against 0.02h sx 1 B A Thesis Proposal 850 k Load Cases: Structural Depth ASCE 7-10 Section 12.5.3 (a) - “the requirement for considering the orthogonal combination is deemed Seismic Base Shears satisfied if members are designed for 100% of the forces for one direction plus 30% of the forces for the Slab Design perpendicular direction.” Shear Wall Design • 30%E x + 100%E y Column Design • 30%E x – 100%E y • 100%E y + 30%E x Construction Management Breadth • 100%E y – 30%E x Conclusion Drift Limits
Structural Depth Children’s Hospital – Hershey Medical Center 3 Shear Wall Design D C • Designed using ACI 318-08 Section 11.9 – “Provision for Walls” 2 4 • 1 Design with controlling shear for each wall A B Introduction • Wall 3 experienced greatest lateral force • Load combination: Existing Structural System • 1.2D + 1.6L + 1.0W Thesis Proposal Structural Depth Final Design Maximum Wall Shear Forces Slab Design Shear Wall Design Column Design Construction Management Breadth Conclusion
Structural Depth Children’s Hospital – Hershey Medical Center Column Design • Designed in RAM Structural System • All columns are square geometry Introduction • Three columns sizes • 24” x 24” Existing Structural System • 20” x 20” Thesis Proposal • 18” x 18” • Reinforcement pattern: Structural Depth • 14 bars, long. #6-#10 (four faces), transverse #3 • Slab Design 16 bars, long. #6-#10 (four faces), transverse #3 • 20 bars, long. #6-#10 (four faces), transverse #3 Shear Wall Design Column Design Construction Management Breadth Load Capacity Ratios Conclusion
Construction Management Breadth Children’s Hospital – Hershey Medical Center Cost Analysis • Costs determined from RS Means Introduction • Accounts for material, labor, and equipment costs Existing Structural System • Equivalent structure difference = $256,000 Thesis Proposal Structural Depth Slab Design Shear Wall Design Column Design Construction Management Breadth Conclusion
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