THE NEW PARKLAND HOSPITAL A Case Study on the Design-Assist Process for the Structural Glass Façade Presented by: Chuck Armstrong – Corgan Associates, Inc. Jeff Haber – W&W Glass, LLC
¨
Architect: ¡
¨
CM at Risk: ¡
¨
HDR & Corgan Associates, Inc. (Joint Venture), Dallas, TX
BARA (Joint Venture), Dallas, TX
Structural Glass System: ¡
Pilkington, St. Helens, UK ú Manufacturer - Structural Glass Fabrication & Fittings
¡
W&W Glass, LLC, Nanuet, NY ú Engineering & Design
¡
Tripyramid Structures, Waterford, MA ú Manufacturer - Plate Beams, Tension Rods & Fittings
¡
Harmon, Inc., Lewisville, TX ú Installation
Video Tour of The New Parkland Hospital
¨
In the Beginning…
Cable Wall Pros
vs.
Tension Rod/Plate Beam Wall
-‐ Higher Transparency
-‐ Less Load on Boundary Structure
-‐ No Horizontal Metal
-‐ Good Transparency -‐ Less Expensive Boundary Structure -‐ VerAcal Rods Smaller Than Cables
Cable Wall Cons
-‐
Higher Loads on Boundary Structure
-‐
AddiAonal Steel Required….$$$
Tension Rod/Plate Beam Wall
vs. -‐
Steel Blades May Block View (Inside to Out)
-‐
ConnecAons to Columns Visible
-‐ Large ConnecAons at Head and Sill (If Exposed = $$$; If Concealed, Perimeter Detailing Can Be Challenging) -‐ IGU Glass DeflecAons Are Higher, Requiring Significant AddiAonal Restraint; Can Result in Higher Loads into Building and Larger Dia. Cables = $$$
¨
Cable Wall ¡
Reaction Loads ú 45 Kips Tension per Cable (Tension Load at Head and Sill) 1” Stainless Steel Cables
¡
Steel Sizing at Head ú W24 x162
¨
Tension Rod/Plate Beam Wall ¡
Reaction Loads ú 4 Kips – Dead Load 3/8” Stainless Steel Rods
ú 3.7 Kips per Plate Beam (7.4 Kips per Column @ 30’ O.C.) –
Wind Load
¾” x 10” Plate Beams ¡
Steel Sizing at Head ú W16x57 - Savings of 16,650 Pounds of Steel!
Architect + Structural Engineer + Faรงade Contractor Affordable Solution to Meet the Design Intent and Satisfy the Budget
¨
Desired Performance: ¡ ¡ ¡ ¡ ¡
¨
VLT: Rf: SHGC: SC: U-Value:
0.50 0.10 0.28 0.32 0.24/0.26 (Summer/Winter)
IGU Lami was requested for Acoustics & Safety
¨
¨
¨
Meeting the architect’s design intent while satisfying the Owner’s budget restraints. Looking for cost reductions in the boundary structure as a result of modifications to the glazing system. Finding an IGU/spacer that was capable of meeting the aesthetic requirement of a 5’ x 9’ panel with only four corner support.
¨
¨
Approx. $100,000 reduction in steel costs! Additional savings from decrease in concrete reinforcement in the floor and columns.
Cable Wall
6” Narrower Beam Plate Beam Wall 8.5” Shorter Beam
DESIGN CRITERIA 9 ft span 20 psf wind load Edge Defl. Limit
Req’d Glass Thickness
Glass Cost Increase
L/175
3/8” -‐ Air -‐ 3/8” -‐ SGP -‐ 3/8”
+ 50%
L/140
3/8” -‐ Air -‐ 3/8” -‐ SGP -‐ 5/16”
+ 43%
L/100 L/50
3/8” -‐ Air -‐ 5/16” -‐ SGP -‐ 5/16” 3/8” -‐ Air -‐ 1/2”
+ 35% -‐
Surface 1: Contracts Surface 2: Stretches
Typical IGU Construction
PIB Seal Degradation
PIB Seal Degradation
PIB Seal Failure
¨
¨
Typical insulating unit manufacturers allow L/175 edge deflection. Some of the highest quality manufacturers allow a maximum IGU edge deflection of L/140. Edge Defl. Limit
Req’d Glass Thickness @ 5’ Wide x 9’ Tall
L/175 L/140 L/100 L/50
3/8” -‐ Air -‐ 3/8” -‐ SGP -‐ 3/8” 3/8” -‐ Air -‐ 3/8” -‐ PVB -‐ 3/8” 3/8” -‐ Air -‐ 5/16” -‐ SGP -‐ 5/16” 3/8” -‐ Air -‐ 1/4” -‐ PVB -‐ 1/4”
Glass Cost Increase + 50% + 45% + 35% -‐
DeflecFon 0.62” 0.77” 1.08” 2.2”
IGU Lami Glass Make-up: 3/8” Optiwhite w/ HP 50/27 low-e on #2 – 5/8” Air – 1/4” Optiwhite – .060” PVB – 1/4” Optiwhite
¡
¨
Only Pilkington could provide an IGU that could deflect + 2” and - 2” at the edges and still remain completely sealed without failure. This equals L/50.
Centre Square Deflection Video 7’ x 14’ Panels Deflect Up to 4” In and 4” Out!!!
City Creek Center Deflection Video 5’2” x 7’5” Panels Deflect Up to 4 5/8” In / 4 5/8” Out!!!
¨
¨
The Pilkington Planar IGUs were put through accelerated weather and dew point testing to determine if there were any seal failures (condensation forms inside the unit showing a failure) after the extreme deflections the IGUs were put through. The IGUs were then retested and put through the full process again and PASSED.
IGU Construction
Failed Condensation Test: Unit PIB Seal Compromised
ASTM E-546 Standard Test Method for Frost/Dew Point of Sealed Insulating Glass Units
¨
Pilkington’s Large Deflection Spacer Design ¡ ¡
300% increase in amount of butyl for the primary seal. Unique corner conditions for discontinuous spacers to keep unit sealed under shear stress at the edges.
STANDARD SPACER
LARGE DEFLECTION SPACER
CONSTRUCTION Erection of the Structural Glass Wall
THE NEW PARKLAND HOSPITAL A Case Study on the Design-Assist Process for the Structural Glass Façade Presented by: Chuck Armstrong – Corgan Associates, Inc. Jeff Haber – W&W Glass, LLC