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Checker Building – Structural Analysis and Design

Zhiyong Chen1, Minghao Li2, Ying H. Chui1, Marjan Popovski3, Eric Karsh4, and Mahmoud Rezai4

1 Univ. of New Brunswick, 2 Univ. Canterbury,3 FPInnovations, and 4 Equilibrium Consulting Inc.

www.NEWBuildSCanada.ca

65.880

50.000

40.000

30.000

20.000

10.000

0.000

67.310

50.000

40.000

30.000

20.000

±0.000

10.000

67.31m

Yingxian Wood Pagoda

Wood as a structural material can date back to more than

7000 years.

Stadthaus

1. Background

…?f/ρ,

materials &technology

32.25m

Horyu-ji Temple

>30

m

2

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20-Storey Mass Timber Building – CHECKER

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Design data North Vancouver: “high earthquake, wind

and rain”

20 storeys: 19 standard storeys + 1 podium

Total height: about 60m with 3m per storey

Plan dimensions: 27m x 27m with 9m grid

Wood Materials: structural composite lumber

(SCL), cross laminated timber (CLT), and

glued laminated timber (Glulam)

Connection: Wood-Steel-composite (HSK)

system, Wood-Concrete-composite (HBV)

system, and dowel-type connection

20-storey timber building

2. Structural Challenges & Solutions No. 1 – high wind and seismic load develop a shearwall + core system of high stiffness, strength, and ductility

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Simplified

Lateral load resisting system Schematic diagram of the LLRS

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2. Structural Challenges & Solutions No. 1 – high lateral wind and seismic load establish a high performance connection system

5Dowel type connection with self-tapping screws for panel-to-panel

HSK system for use as hold-down and shear connections for panel-to-panel and to the concrete podium

2. Structural Challenges & Solutions No. 2 – large vertical deformation & complicated horizontal

connections balloon framing construction technique

6Gravity load resisting system

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2. Structural Challenges & Solutions No. 3 – long span floor & roof wood-concrete composite system

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Glulam-concrete composite floor

2. Structural Challenges & Solutions No. 4 – No design principles

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Size Structural Assemblies & Connections

Design Criteria

Code Provisions

Final Design

Mechanical Theory

Numerical Simulation

[No]

[Yes]

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Step 2 – Wind induced-response:(1) Static wind & (2) Dynamic wind

Size structural assemblies & connections based on 1.6W

3. Structural Design

[Yes]

[No]

[Yes]

[Yes]

[Yes]

[No]

[No]

[No]

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Step 1 – Linear seismic response:(1) Modal analysis & ESFP & (2) RSA

Step 3 – Non-linear static behaviour:Pushover analysis

Step 4 – Seismic response:Non-linear time history analysis

Final design

Design Results

Lateral load resisting system

Grade 50 Steel beam S5 × 10

Grade 2.1E “TimberStrand LSL” (19m × 2.44m × 89mm, 3 layers)

The typical storey

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Design Results

Dowel-type connection (19mm) of LSL with k=25.5kN/mm & Pmax=32.5kN

HSK system, Pmax=0.8kN, Kparallel=7.4kN/mm & Kperpendicular=2.5kN/mm for each hole

Lateral load resisting system

The typical storey

Design Results

DLF 24f-E Glulam beam(315×532mm)

DLF 16c-E Glulam column(365×418mm & 730×418mm)

Gravity load resisting system

The typical storey

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Design Results

Floor

HBV – Vario system, 125mm

concrete + 175 ×532 mm Glulam

beam @ 0.8mGravity load resisting system

The typical storey

Design Results

Roof

SLT9 (309mm) and SLT3 (99mm)

CrossLamTMwith single-span

Floor

Gravity load resisting system

The typical storey

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4. Numerical Simulating Solutions

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Strong assembly - weak connectionMacro-element model for connections

Deformation

Force

Deformation

Force

Macro-element connectors

(a) Vertical & shear connectors

(b) Hold-down connector

FEM of CHECKER

Macro-element model for connector

A

B

5.1 Gravity loading – differential shortening

5. Modeling Structural Performance

(a) In X (E-W) direction (b) In Y (N-S) direction

The differential shortening is not significant. 16

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5.2 Vibration of Composite Floor

Vibration has a great influence on diaphragm design

17f1

d1kN0.44

6.0

0.0640.44 20.118.9

(a) FEM of composite floor

(b) The 1st mode shape(c) Deformation shape under a

concentrated load of 1kN

f1d1kN

0.4418.9

Static Procedure: fn > 1.00 Hz

Dynamic Procedure: 0.25 ≤ fn ≤ 1.00 Hz

Experimental procedure: fn < 0.25 Hz

fn = 0.53 Hz, therefore dynamic procedure is required.

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1

1

2

ni

ii n

nn

in i

i n

xF

xf

xx M

x

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5.3 Wind-Induced Response

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5.3 Wind-Induced Response FEA was performed to calculate the lateral deformation of the

tall wood building under wind load.

iP

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5.3 Wind-Induced Response

0 10 20 30 400

5

10

15

20

Num

ber

of S

tore

y

Lateral Drift, mm

Static Dynamic

0.0 0.5 1.0 1.5 2.0 2.50

5

10

15

20

Num

ber

of S

tore

y

Inter-Storey Drift, mm

Static Dynamic

(a) Storey drifts (b) Inter-storey drifts

Under static wind load: the roof drift is 31.2 mm (≈hn/1800) and the inter-storey drift of each storey is less than hi/500 (=6mm).

Under pseudo-static wind load: the roof drift is 33.7 mm (≈hn/1700) and the inter-storey drift of each storey is less than hi/500 (=6mm).

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5.3 Wind-Induced Response

The across- and along-wind accelerations, aW and aD (m/s2), were estimated by

Substituting the values of the parameters into equations, aW

and aD are 0.9% and 1.1% of g, which are both less than the acceleration limits of 1.5%g for residential occupancy.

2 rW nW p

B W

aa f g wd

g

2 24 SD nD p

eH D g

K Fa f g

C C

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5.4 Seismic Response(1) Fundamental Natural Period, Ta

the period of the FEM of the building was 1.97 s. It is almost twice that estimated by NBCC equation.

(2) Seismic Force Modification Factor, Rd

CLT Handbook: Ro=1.5 and Rd=2.0 for CLT panel system

The tall wood report: a higher Rd value (3.5) could be used

Pushover analysis: Rd= 2.03

Therefore RoRd = 3.0 (1.5 × 2.0) was used.

(3) Design lateral earthquake force, V, (Equivalent Static Force Procedure)

the specified design base shear is about 4893kN.

3 40.05 1.04a nT h s

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a V E d oV S T M I W R R

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0 5 10 15 20 25 300

5

10

15

20

Num

ber

of S

tore

y

Inter-Storey Drift, mm

xi

xiR

dR

o/I

E

5.4 Seismic Response

Response Spectrum Analysis

(a) Storey drifts (b) Inter-storey drifts

The roof drift is 431 mm, and the inter-storey drift is less than 2.5%hs (=75mm).

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0 100 200 300 400 5000

5

10

15

20

Num

ber

of S

tore

y

Lateral Drift, mm

Xi

XiR

dR

o/I

E

5.4 Seismic Response

Pushover AnalysisThe stiffness, yield strength and deformation, maximum strength and deformation,

and failure / collapse deformation, of the building under lateral load.

iP

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0 200 400 600 800 10000

2000

4000

6000

8000

10000

K = 23.7 kN/mmP

y = 7430 kN

Pmax

= 8140 kN

= 2.55R

d = 2.03

FEA result EEEP

Bas

e S

hear

, kN

Lateral Drift at Top, mm

4893kN

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5.4 Seismic Response

Pushover Analysis

(a) Yield of vertical

joints of shear wall

(b) Yield of vertical

joints of core

(c) Yield of connections

between core panels

(d) Yield of shear

connectors

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5.4 Seismic Response

Non-linear Time History Analysis Seismic response of the high-rise wood building is crucial in the ultimate

limit state.

Ten (10) “Far-Field” earthquake records were scaled at the corresponding fundamental period of the building model to match the spectral acceleration, Sa, of the Vancouver design spectrum.

0.01 0.1 1 101E-3

0.01

0.1

1

10

Spe

ctra

l Acc

eler

atio

n, S

a(g)

Period, T(s)

Target Spectrum Results Geom. Mean

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5.4 Seismic Response

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0 3 6 9 12 15-0.50

-0.25

0.00

0.25

0.50

Acc

eler

atio

n, g

Time, s

Input acceleration

5.4 Seismic Response

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5.4 Seismic Response

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0 3 6 9 12 15-6000

-3000

0

3000

6000

Bas

e sh

ear,

kN

Time, s

Base shear

5.4 Seismic Response

Non-linear Time History Analysis

0 2 4 6 8 104000

5000

6000

7000

8000

9000

Bas

e S

hear

, kN

No. of Earthquake Records

Non-linear P

max

Py of EEEP

Design Value

0 2 4 6 8 100.0

0.5

1.0

1.5

2.0

2.5

3.0

Inte

r-S

tore

y D

rift

Rat

io, %

No. of Earthquake Records

Non-linear Design Criterion

(a) Base shear (b) Inter-storey drift ratio

- All the base shears are less than the yield load of EEEP and the maximumcapacity derived by Pushover Analysis

- All inter-storey drift ratios are less than the design requirement of 2.5%.30

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6. Conclusions

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Gravity loading analysis– the compressive deformation is small

Pushover analysis– the static load-carrying capacity and ductility are sufficient

Wind-induced response analysis– the deformation, through & across-wind accelerations are less than the limits

Non-linear time history seismic analysis– the inter-storey drift ratios are less than limit

20-storey timber buildings with the advanced products and connections are possible.

20-storey timber building

The End.Thanks for your attentions!

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