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Professor Andy BuchananUniversity of Canterbury
New Technologies in Timber Buildings
Canterbury Earthquakes Royal Commission
ENG.BUC.0001.1
Earthquake fundamentals
Design philosophy
Minor earthquake No damage
Moderate Repairable earthquake damage
Big earthquake No deaths. Damage is ok
We have to find a better solution
ENG.BUC.0001.2
Rebuild for damage resistance
1. Overdesign (expensive)
2. Base isolation
3. Energy dissipation
4. Rocking frames and walls
How do we do this with timber?
ENG.BUC.0001.3
Old Government Buildings, Wellington, 1870
Why not wood?
We have done it before
ENG.BUC.0001.4
New Technologies in Timber
Damage to houses and timber buildings
New wood materials
Plywood, LVL, CLT, piles
New fasteners
Epoxy, post-tensioning, screws, rivets
New structural systems
Base isolation, rocking systems
Examples
ENG.BUC.0001.5
Liquefaction damage
ENG.BUC.0001.6
Differential settlement
Differential settlement, veneer damage, timber structure OK
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Vertical accelerations
Roof shaken off
Timber housestructurally safe
ENG.BUC.0001.8
Internal linings
Gib plasterboard
Provided bracing for most houses
ENG.BUC.0001.9
Veneer failure
ENG.BUC.0001.10
Veneer ties
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Wall bracing failures
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Old timber building collapse
Before
After
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Before
Soft storey collapse
After
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Solid wood houses
Good performance despite differential slab movement
ENG.BUC.0001.15
Concrete slab floors
Lateral spreading
Differential sinking
No reinforcing
ENG.BUC.0001.16
Engineered timber buildings
Most performed very well
Lateral spreading of portal bases
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Shear cracks in column
Engineered timber buildings
ENG.BUC.0001.18
EXPAN building, UC campus
Engineered timber buildings
No structural damage. Immediate occupancy.
ENG.BUC.0001.19
New Technologies in Timber
Damage to houses and timber buildings
New wood materials
LVL, CLT, foundation piles
New fasteners
Epoxy, post-tensioning, screws, rivets
New structural systems
Base isolation, rocking systems
Examples
ENG.BUC.0001.20
LVL - Laminated veneer lumber
Veneers 3mm thick
ENG.BUC.0001.21
CLT - Cross laminated timber
ENG.BUC.0001.22
New Technologies in Timber
Damage to houses and timber buildings
New wood materials
LVL, CLT, piles
New fasteners
Epoxy, post-tensioning, screws, rivets
New structural systems
Base isolation, rocking systems
Examples
ENG.BUC.0001.23
Epoxied steel rods
Robert fairweather
ENG.BUC.0001.24
Post-tensioned timber frames
Post-tensioning solves the problem of moment connections for heavy timber
ENG.BUC.0001.25
Post-tensioned timber walls
U
U
U
ENG.BUC.0001.26
New Technologies in Timber
Damage to houses and timber buildings
New wood materials
LVL, CLT, piles
New fastening techniques
Epoxy, post-tensioning, screws, rivets
New structural systems
Base isolation, rocking systems
Examples
ENG.BUC.0001.27
Base isolation
L’Aquila, Italy. 2009
ENG.BUC.0001.28
Base isolation
L’Aquila, Italy. 2009
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Re-levelable buildings
Light building
Adjustment
Strong foundation
Concrete foundation
ENG.BUC.0001.30
Light building
Adjustment
Strong foundation
Concrete foundation
Re-levelable buildings
ENG.BUC.0001.31
Light building
Adjustment
Strong foundation
Concrete foundation
Re-levelable buildings
ENG.BUC.0001.32
Light building
Adjustment
Strong foundation
Concrete foundation
Re-levelable buildings
ENG.BUC.0001.33
CLT buildings
7 storey CLT building, London
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7 storey CLT shake test
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Light timber frame
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Light timber frame test
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Post-tensioned beams
Long spans (draped tendons)
Fewer columns
ENG.BUC.0001.38
Post-tensioned timber building
ENG.BUC.0001.39
Post-tensioning
Post-tensioned timber building
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Post-tensioned timber
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Post-tensioned timber walls
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Post-tensioned timber frames
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9 storeys – London(CLT panels)
International
6 storeys – Switzerland(Light timber frame)
7 storeys – Berlin(Glulam)
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International
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Photos of St Elmo, Vic St.
Re-building Christchurch
Sheppard and Rout Architects, Kirk Roberts Engineers
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Rick Proko Architects, Ruamoko Engineers
Re-building Christchurch
ENG.BUC.0001.47
Conclusions
New wood materials
LVL, CLT
New fasteners
Epoxy, post-tensioning
New structural systems
Base isolation, rocking systems
Timber solutions are available
ENG.BUC.0001.48