Arena Stage - The tallest free-standing timber-backed façade in the world


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This presentation from the 2013 AIA Convention looks at how the architects and engineers designed the tallest free-standing timber-backed façade in the world. The use of wood allowed for time and labor savings for the Arena Stage project while satisfying code officials’ concerns. The presentation also reviews how extensive modeling and prefabrication played an essential role in the construction of this groundbreaking project.

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Arena Stage - The tallest free-standing timber-backed façade in the world

  1. 1. EE151Case Study: Arena Stage
  2. 2. This presentation is protected by U.S.and international copyright laws.Reproduction, distribution, display anduse of the presentation without writtenpermission of the speaker is prohibited.
  3. 3. This program is registered with AIA CES for continuingprofessional education. As such, it does not includecontent that may be deemed or construed to constituteapproval, sponsorship or endorsement by the AIA of anymethod, product, service, enterprise or organization. Thestatements expressed by speakers, panelists, and otherparticipants reflect their own views and do not necessarilyreflect the views or positions of The AIA or of AIAcomponents, or those of their respective officers,directors, members, employees, or other organizations,groups or individuals associated with them. Questionsrelated to specific products, publications, and servicesmay be addressed at the conclusion of this presentation.
  4. 4. Learning Objectives1. Describe how the architects and engineers designed the tallestfree-standing timber-backed façade in the world.2. Explain how the use of wood allowed for time and laborsavings for the Arena Stage project.3. Observe how the Arena Stage design team satisfied codeofficials’ concerns to realize this groundbreaking project.4. Examine how extensive modeling and prefabrication played anessential role in the construction of Arena Stage.
  5. 5. Case Study:Arena StageWashington, D.C.Cheryl Ciecko, AIA, CSI , ALA, LEADAP, GGP SeniorTechnical Director,WoodWorks
  6. 6. Arena StageLocation: Washington, D.C.Completed: 2010Size: 200,000 s.f.Budget: $100 millionArchitect: BingThom ArchitectsEngineer: Fast + EppGeneral contractor:Clark ConstructionTimber façade design-builder:StructureCraft Builders
  7. 7. Background• Founded in 1950• By late ’90s, facility was no longer meetingneeds spatially or technically• Needed twice as much space• Dated aesthetics• Performances interrupted by outside noiseAfter its founding in 1950, Arena Stage built a reputation for cutting-edge performancesin the Washington, DC area.A new artistic director who came in 1997 found herself with a complex that no longermet the theater company’s needs, spatially or technically: they needed twice as muchspace, the aesthetics were dated, and performances were interrupted by noise.
  8. 8. DesignVision• Artistic director wanted to celebrate all thatwas “deep, dark and dangerous” in theAmerican spirit• Historic structure in a city that highly valueshistory• Lobby large enough for 1,400 patrons from allthree theaters at the same timeIn her direction to the architects, the artistic director said she wanted to celebrate all that was “deep, dark anddangerous” in the American spiritAt the same time, it is a historic structure in a city that highly values history, so BingThom had to determinehow to meet the director’s needs without compromising the character of the existing theaters.
  9. 9. BingThom and his team decided to cover andwrap the two existing theaters, and the newtheater, with a heavy timber-supported roofand glazing system.The design enclosed thenew and old spaces while creating a new,larger lobby and offices.
  10. 10. Developing a glass wall was important tocreate transparency and ensure the oldtheaters were visible.The insulated glass wallalso provided much-needed acousticseparation from the nearby airportThey added a new third theater, and coveredit all with a 500-foot-long cantilevered roof,creating 200,000 square feet of enclosedspace.Overall Concept200,000 s.f. of new spacecreated:• Insulated glass wallcovers and wraps thetwo existing theaters• New third theater• 500-foot-longcantilever roofenclosing everything
  11. 11. The premier feature of the new Arena Stage,the Insulated glass wall encloses the theatersand lobby, and is the tallest free-standingtimber-backed façade in the world.It is 650 feet long and features large woodcolumn cross-sections shaped according tothe internal stresses, increasing transparency
  12. 12. The glass wall was created with 18 PSL columnsaround the perimeter of the façade. Each columnmeasures 45 to 63 feet tall and supports the steel rooftrusses, which cantilever beyond the envelope tocreate the overhang that runs around the structure.•The wood columns are spaced 36 feet apart and areelliptically shaped for structural efficiency, as well as tominimize their visual impact and to create a feeling oftransparency into and throughout the space.•They’re designed to brace the tall glass façadeagainst wind loads and to carry the roof loads (up to400,000 pounds) from the steel roof trusses, some aslong as 170 feet.•The PSL columns are unreinforced solid engineeredwood using no internal steel support.Glass Wall18 parallel strand lumber(PSL) columns around theperimeter• 45 to 63 feet tall, 36 feetapart• Elliptical shape• No internal steelsupport
  13. 13. The glass panels are supported by 324 muntins and 216support arms, all made from custom-shaped PSL. Fifty-fourspring-loaded stainless steel cables stretch between theroof and floor to carry the glazing.Conventionally, the designers would have a buildingstructure holding up the roof, and then have a separatestructure to hold the curtain wall. Here, wood did doubleduty:The columns hold up the windows and the roof.When comparing the cost of an integrated wood systemagainst a conventional steel column and separate aluminumcurtain wall system, the wood system came out as beingless expensive.Glass Wall• Panels supported by324 muntins and 216support arms• 54 spring-loadedstainless steel cablesstretch between theroof and floor to carrythe glazing
  14. 14. PSL consists of long veneer strandslaid in parallelformation, bondedtogether withadhesiveto formthe finishedstructuralsection. PSL is commonlyused for long-spanbeams, heavilyloaded columns,and applicationswherehigh bendingstrength is needed.PSL was chosen both for its structural capacity andits aesthetic—consistency, nice texture/patternStructureCraft cut slabs from PSL, laminated theminto larger billets, and bolted them together tocreate a rough rectangular cross-section.Bolting, rather than gluing, helped control checkingThe columns were then shaped into elliptical cross-sections with tapered ends.Finally, they were sanded and coated with twolayers of clear coat.StructureCraft then de-slivered to the bottom 10feet, and added a third layer of clear coat. The thirdcoat was added to that section because they knewthe beauty of the PSL would draw people to touchit.The beams were installed with the narrow directionin the same plane as the glazing to minimize themvisuallyMuntins and support arms brace the columnsagainst bucklingAdditional details:• Columns are tapered near the floor tomake them seem lighter and less obtrusive• Columns are sized identically for visualconsistency• Columns are installed at a four-degree tiltto minimize glare from the glassPSL Beams• PSL slabs cut and shapedinto elliptical cross-sectionswith tapered ends• Installed with the narrowdirection in the same planeas the glazing to minimizethem visually• Muntins and support armsbrace the columns againstbuckling
  15. 15. Connections were key to this design.With timberconstruction, the connections are usually the mostexpensive component, so when you develop a connectionthat can be repeated over and over again, you savemoney. Since they repeated the same connection 18times, they could spend time making it quite beautiful.The custom-designed ductile-iron castings for the columnbases bring enormous forces down to a single pin.The castings were mounted on all of the columns beforethey were shipped:It was a complex connection.With 400,000 poundscoming through the columns, they needed a positivebearing connection, which required accurate shapingbetween the bottom of the PSL column and the top of thecasting.Connections• Custom-designed ductile-iron castings for columnbases• Delicate-looking butstructurally efficient• Castings mounted oncolumns before shipping
  16. 16. Here’s an additional interior view of the glasswall
  17. 17. The director wanted the thirdtheater to be smaller than theother two and designed in a waythat allowed the actors to takemore risks.The resulting, unique space iswomb-shaped, with a spiralingentrance form, lending itself tothe name “The Cradle”The Cradle also played animportant role because it servesas a structural anchor to supportthe roof.The Cradle• Third theater• Smaller, womb-shaped• Structural anchor ofroof
  18. 18. This rendering provides a better idea of thetheater’s unique shape.But while it’s unique aesthetically,unfortunately, the shape created strangesound reflections
  19. 19. To solve the acoustic challenge, BingThomdeveloped a wall system that would appear visuallysubstantive, but could absorb and disperse sound.The result was a wood slat system, made frompoplar, designed in a basketweave. The material andshape provided character as well as the necessaryacoustic dispersion.Despite its intricate appearance, the slat system wassimple enough to be installed by the drywallcontractor.The CradlePoplar slatsystem inbasketweavepattern
  20. 20. Here’s a wider view of the poplar slat system
  21. 21. Performance Assurance• Column cross-section governed by deflection underwind-loading• Scale model underwent wind-tunnel test• Full-height mock-up five panels wide, lab-tested tohurricane conditionsColumn cross-section was governed by deflection under wind loading.While some supported smaller tributary areas, all columnswere sized identically for visual consistency.To verify the design, the team built a scale model and conducted a wind tunnel test in London, Ontario. StructureCraft also built afull-height mock-up five panels wide, and the general contractor tested the assembly in a Pennsylvania lab under hurricaneconditions.Although cost of the mock-up and testing was considerable, the process helped the team fine-tune connection details anderection procedures.The investment more than paid for itself in terms of avoiding problems during installation.
  22. 22. 3-D Modeling• Customized production process linked to aparametric 3-D solids computer model; tied togethershop prefabrication, quality control, and on-siteerectionThe pre-fabricated elements were made off-site while the base structure was beingconstructed, which simplified and shortenedinstallation time.And StructureCraft used itsown crews for installation.
  23. 23. Overcoming Fire Concerns• In-depth fire report• Smoke study• Computer modeling• Char analysisLocal code authorities were skeptical about allowing wood; they had concerns about fire safety. So the design team presented anin-depth fire report, along with a smoke study done by a code consultant working for the team. Through computer modeling, theyshowed that effects of a fire on the structure would be minimal, and there would be plenty of time for safe building evacuation.They also did a char analysis, and showed District of Columbia code officials how char actually protects the interior of the wood.While charring would leave a column of reduced size, calculations showed that because the column was sized mainly for deflection,it already had additional strength capacity.It was a long but productive process educating D.C. code officials. As a result, the process will be much easier for the next project.
  24. 24. Wood at this scale isn’t common in Washington, D.C., which is dominated by historicmasonry and stone, or modern concrete and glass. As mentioned, code officials requiredconvincing from a fire perspective.But wood was the right material for several reasons. First was budget. The warm aestheticachieved via the PSL columns came without the need for expensive finishes, and is a naturalcomplement to the views outside the wall. It also served triple duty—holding up the roof,holding up the glass, and serving as a finish material.Arena Stage demonstrated what’s possible with wood, how timber can be used for structuresin ways that may not have been considered before. The beauty is that wood works well withother materials—for Arena Stage, they integrated wood with the steel roof trusses andcables, with the aluminum connection plates, with the ductile iron castings and the glasscurtain wall, and with other connections.Benefits ofWood to Arena StageBudget• Beautiful withoutpricey finishes• Triple duty—holdsup the roof, holdsup the glass, finalfinish material
  25. 25. Wood lowers a building’s carbon footprint in twoways.• It continues to store carbon absorbed during thetree’s growing cycle, keeping it out of theatmosphere for the lifetime of the building—longerif the wood is reclaimed and used elsewhere.• When used in place of fossil fuel-intensivematerials such as steel and concrete, it also resultsin ‘avoided’ greenhouse gas emissions.As a result, the total potential carbon benefit forArena stage is 675 metric tons of CO2.This is in addition to wood’s other sustainablebenefits: renewability, responsible sourcing, andbiophilia, to name a few.Benefits ofWood to Arena StageCarbon Reduction• Stores carbon• Replaces fossil-fuel-intensive materials
  26. 26. Wood was definitely the right material to usefor this project.Arena Stage is an indicator ofnot only what’s possible, but what we plan forthe future—which is to keep innovating withwood.
  27. 27. Contact InformationCheryl Cieko AIA, CSI , ALA, LEAD AP, GGPMidwest Regional Director, WoodWorks708. 354.3480 |