AspenArtMuseumDesignandConstruc4onoftheWoodRoofStructure
GregKingsley,PE,Peng,PhDPresidentandCEOKL&AInc.,StructuralEngineersandBuilders
Disclaimer: This presentation was developed by a third party and is not funded by WoodWorks or the Softwood Lumber Board.
“The Wood Products Council” is a Registered Provider with The American Ins<tute of Architects Con<nuing Educa<on Systems (AIA/CES), Provider #G516.
Credit(s)earnedoncompleDonofthiscoursewillbereportedtoAIACESforAIAmembers.CerDficatesofCompleDonforbothAIAmembersandnon-AIAmembersareavailableuponrequest.
ThiscourseisregisteredwithAIACESforconDnuingprofessionaleducaDon.Assuch,itdoesnotincludecontentthatmaybedeemedorconstruedtobeanapprovalorendorsementbytheAIAofanymaterialofconstrucDonoranymethodormannerofhandling,using,distribuDng,ordealinginanymaterialorproduct.
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QuesDonsrelatedtospecificmaterials,methods,andserviceswillbeaddressedattheconclusionofthispresentaDon.
Course Descrip<on
TheAspenArtMuseum,designedbyarchitectShigeruBan,includesalong-spanthree-dimensionalwoodspace-frameroof.
Ban’schargewastocreateawoodspaceframewithspansofmorethan50feetandcanDleversof14feet,inastructuraldepthof3feet.ThespaceframewastohavetwoplanesofintersecDngdiagonalwebsofcurvedmembersthatundulatedupanddowntotouchtheplanesofthetopandboUomchordswithnovisibleconnectors.
ThiscasestudypresentaDonwilldescribethedesignandconstrucDonofthewoodstructure,includingpathsexploredbutnotchosenforthefinaldesign.
Learning Objec<ves
1. ArDculatetheparDculardemandsassociatedwithcreaDnga3-dimensionalspaceframeenDrelyinwood.
2. RecognizetheadvantagesanddisadvantagesofseveralwoodconnecDonstrategiesinspace-framestructures.
3. BeawareofmanufacturingcapabiliDesandlimitaDonsthatinfluencedthedesignoftheAspenArtMuseumroofstructure.
4. UnderstandtheimportanceofearlyengagementofmanufacturingandengineeringpartnersinthedesignprocessforinnovaDvewoodstructures.
Aspen Art Museum
Aspen Art Museum
THE PLAYERS
OUTLINE
• THE BUILDING CONCEPT
• THE ARCHITECT’S CONCEPT FOR THE ROOF
• 4 STRUCTURAL CONCEPTS FOR THE ROOF
• FABRICATION TESTS: MOCK UPS
• STRENGTH TESTS: MATERIAL TESTING
• FINAL FABRICATION
• ERECTION
• FINISHED BUILDING
THE BUILDING CONCEPT
Aspen, Colorado, USA
Snow load = ~ 90 psf
Early rendering – view up the main stair
Early rendering – 3rd floor terrace with wood space frame
Early rendering – 3rd floor terrace with wood space frame
BASEMENT GROUND LEVEL
FLOOR PLANS
2ND FLOOR 3RD FLOOR
FLOOR PLANS
3RD FLOOR REFLECTED CEILING PLAN
100 ft x 100 ft on a 4 ft grid Max span = ~ 50ft
BUILDING SECTION Maximum 3 ft structural depth
THE ARCHITECT’S CONCEPT
STRUCTURAL CONCEPTS THREE ATTEMPTS AND FAILURES … AND THE FINAL ROAD TO SUCCESS
1ST CONCEPT: REINFORCED LAP SPLICES WITH DEHONIT COMPOSITE MATERIAL
2ND CONCEPT: KNIFE PLATES WITH TIGHT DRIVEN PINS
3RD CONCEPT: MICRO LAMINATIONS CROSSING AT JOINTS WITH NO HALF LAPS
CNC CuSng
Hermann in Paris
Hermann in Paris
FINAL CONCEPT: KERTO CHORDS BIRCH PLYWOOD WEBS HALF-LAPPED JOINTS FULL-THREAD SCREW CONNECTIONS
KERTO BOTTOM CHORD – LAYER 1
KERTO BOTTOM CHORD – LAYER 2
BIRCH PLYWOOD WEB – LAYER 1
BIRCH PLYWOOD WEB – LAYER 2
KERTO TOP CHORD – LAYER 1
KERTO TOP CHORD – LAYER 2
Kerto S LVL Chords
WEB LAYOUT
WHY PLYWOOD?
BIRCH PLYWOOD LAYUP
31 1.5 mm laminations
BIRCH PLYWOOD WEB SPLICING PATTERN
Why Birch?
Connection concept
4-SCREW JOINT
8-SCREW JOINT
12-SCREW JOINT
15-SCREW JOINT
15-SCREW JOINT
TRUSS FABRICATION MODEL OVERVIEW
STRUCTURAL MODEL
DEFORMATIONS
NORMAL FORCES – TOP CHORD
NORMAL FORCES - WEBS
NORMAL FORCES – BOTTOM CHORD
THE MOCK-UP
TESTING
BIRCH PLYWOOD LAYUP
BIRCH PLYWOOD TEST SPECIMENS
BIRCH PLYWOOD TEST SPECIMENS
SHOP FABRICATION
KERTO CHORDS
BIRCH PLYWOOD LAMINATIONS
THE “LIBRARY”
LAYOUT OF BIRCH PLYWOOD IN PREPARATION FOR GLUING
CLAMPING
BIRCH PLYWOOD WEB AFTER GLUING with PURBOND HB E452 single-component polyurethane adhesive
Test Coupons
BIRCH PLYWOOD WEB PRODUCTION
BIRCH PLYWOOD WEBS READY TO SHIP (NOTE THICKENED WEBS AT COLUMN LOCATION)
SITE CONSTRUCTION
TOP OF THE THIRD FLOOR STRUCTURE, READY FOR WOOD SPACE FRAME INSTALLATION
SCAFFOLDING
BOTTOM CHORD
Bottom Chords
WEB SPLICES
COLUMN CONNECTION
8-SCREW CONNECTION (Top) 4-SCREW CONNECTION (Bottom)
15-SCREW CONNECTION
Quality Control
Screw connections
4
8
8
12
4
20,000 SCREWS -7°C (20° F)
Pulling the shores …
COMPLETED PROJECT
WHAT WE LEARNED
WHAT WE LEARNED Objective 1
Design challenge centers on the nodes and connections.
“Structures are connections held together by members.” - Hardy Cross
Wood is orthotropic. With engineered wood products, you can orient the wood fibers to your advantage.
WHAT WE LEARNED Objective 1
Curved space frame members are beautiful, and yet at odds with their structural function.
WHAT WE LEARNED Objective 1
Knife plates and bolts are expensive and do not always take the best advantage of the wood properties
WHAT WE LEARNED Objective 2
Notches and half-lap joints dramatically reduce the strength of wood
WHAT WE LEARNED Objective 2
Screws create strong, redundant wood connections
WHAT WE LEARNED Objective 2
Preparation of precision virtual models for CNC fabrication is essential.
WHAT WE LEARNED Objective 3
Design cannot be divorced from fabrication and construction process.
WHAT WE LEARNED Objective 4
Ques<ons? ThisconcludesTheAmericanInsDtuteofArchitectsConDnuingEducaDonSystemsCourse
GregKingsleyKL&AInc.,StructuralEngineersandBuilders
