NEWBuildS Tall Wood Building
Design Project – Seismic & Gravity
Load Analysis and Design
Zhiyong Chen
University of New Brunswick
www.NEWBuildSCanada.ca
1. Introduction
1.1 Customer Demands & Challenges
on Structures
 Taller Buildings
 Structural systems: Ductile
 Connection systems: High strength & Ductile
 Larger Open Space
 Floor systems: Long span & Vibration
We are trying to address these issues !!!
1.2 Flow Diagram
Site & Loads
(Dead, Live, Wind,
Snow and Seismic)
Structural System
Material,
Structural Assembles
& Connections
Checking on Structural
& Fire Issues using FEA
1~3
Iteration
s
[No]
[Yes]
Suitable Structural Assembles
& Connections
Structural Sketch
& Report
2. Structural Design
2.1 Concept Design
 Structural System
 Post-beam system
Possible storey number
 Shear wall system
 Shear wall + core system
+
 Shear Wall Construction
 Platform framing: Easy to be built storey by storey
 Balloon framing: Reduce the storey joints
2.1 Concept Design
 Stiffness, Strength & Ductility
Shear Wall
Steel Beam (1)
Core
Vertical Joints
(2)
(Dowel Type)
(3) Hold-Down
Shear Connector
(3)
2.2 Lateral Load Resisting System
Hold-Down
The typical storey
Shear Connector
LLRS
HSK System
(Wood-Steel-Composite)
2.3 Gravity Load Resisting System
The typical storey
Beams are divided by
column / wall
GLRS
2.3 Gravity Load Resisting System
Floor
The typical storey
GLRS
2.3 Gravity Load Resisting System
Roof
The typical storey
GLRS
2.4 Design Assemblies and Connections
Roof
Material
CLT panel
Type
SLT9
HBV-Vario Floor
Company
STRUCTURALAM
Glulam-concrete
Floor
TICOMTEC
(125mm Concrete + 175x532mm GL
composite deck
beam @ 800mm)
GL Beam
Glulam
D.L.F. 24f-E (215x532mm)
Steel Beam
Steel
G50 (S5x10)
D.L.F. 24f-E (730x418=2-365x418,
GL Column
Glulam
365x418mm)
Core & Wall
LSL
2.1E LSL (3-19x2.44x0.089m )
TIMBERSTRAND
Hold-Down Steel and Glue
HSK system
TICOMTEC
Shear
Steel and Glue
HSK system
TICOMTEC
Connector
Vertical
Steel
Dowel type connector
Joint
2.5 Sketch List
 GENERAL
G-01: PROJECT DECRIPTION AND SKETCH LIST
 STRUCTURAL
S-01: STRUCTURAL SYSTEM DESCRIPTION
S-02: TYPICAL FRAMING PLAN
S-03: TYPICAL BUILDING SECTIONS
S-04: TYPICAL DETAILS
S-05: TYPICAL DETAILS
S-06: CONSTRUCTION SEQUENCE DIAGRAMS
3. Structural Analysis
3.1 Massive-Timber-Panel Moment Frame
Steel Beam (1)
Vertical Joints (2)
Hold-Down (3)
Shear Connector (3)
MTPMF
3.1.1 Influence of Hold-Down
3.1.1 Influence of Hold-Down
60000
40000
Load, N
20000
0
-20000
-40000
-60000
-150
Without ductility
With ductility
-100
-50
0
50
100
150
Deformation, mm
Deformation
Hysteresis loops
The ductility of the hold-down affects the system ductility.
3.1.2 Influence of Steel Beam
3.1.2 Influence of Steel Beam
600000
500000
Load, N
400000
300000
200000
100000
Small beam section
No steel beam
0
0
20
40
60
80
Deformation, mm
Deformation
Load-deformation curve
Steel beam increases the system stiffness and ductility.
100
3.1.3 Influence of Vertical Connections
3.1.3 Influence of Vertical Joint
600
400
Load, kN
200
0
-200
-400
-600
-120
=9
-80
-40
0
40
80
Drift at the top, mm
Deformation
Load-deformation curve
Vertical joint affects the performance of the system.
120
(1) Stiffness of Vertical Joint
3.5
3.0
K/KK
con
=0
2.5
2.0
1.5
dcon=0.25m
1.0
dcon=1.00m
0.5
-10
-8
-6
-4
-2
10
10 10 10 10
dcon=2.00m
0
10
2
4
10
Kcon,equ/(G//t), m
10
6
10
8
10
10
10
-1
(1) The ratio system stiffness increases with increasing the
stiffness of the vertical joint.
(2) For a denser fastening case, the system derives a higher
stiffness in the rigid case.
(2) Strength of Vertical Joint
600
500
Load, kN
400
Fcon=INF
Fcon=40kN
300
Fcon=30kN
Fcon=25kN
200
Fcon=20kN
Fcon=15kN
100
Fcon=5kN
Fcon=0kN
0
0
20
40
60
80
100
120
Drift at the top, mm
(1) The curves of the two extreme cases form the boundaries
of the other intermediate strength cases.
(2) The first turning point of the curves from the infinite-connectionsstrength to zero-connection-strength cases increases with increasing the
connection strength.
(3) Ductility of Vertical Joint - Static
600
500
Load, kN
400
=1
=2
=3
=4
=5
=6
=7
=8
=9
=10
=INF
300
200
100
0
0
20
40
60
80
100
120
Drift at the top, mm
The first yield point increases with increasing ductility ratio of
the connection.
600
600
400
400
200
200
Load, kN
Load, kN
(4) Ductility of Vertical Joint - Cyclic
0
-200
-200
-400
-400
-600
-120
=1
-80
-40
0
40
80
-600
-120
120
Drift at the top, mm
600
400
400
200
200
0
-200
-80
-40
0
40
80
120
Drift at the top, mm
0
-200
-400
-600
-120
=5
600
Load, kN
Load, kN
0
-400
=9
-80
-40
0
40
Drift at the top, mm
80
120
-600
-120
=INF
-80
-40
0
40
80
120
Drift at the top, mm
The system ductility and energy dissipation ability are
improved by the ductile connections.
3.2 FEA Model of Tall Wood Building
 Geometrical Model and Elements
 LSL core, shear wall & diaphragm
Shell element – S4R
 Steel & glulam beams, columns
Beam element – B31
 Material Models
 Timber – Elastic
 Steel – Ideal Elastic-Plastic
Stress
Stress
Strain
Strain
3.2 FEA Model of Tall Wood Building
 Connection Models
 Vertical joint & shear connector
– Ideal Elastic-Plastic with ductility
Force
Deformation
 Hold-down connection
– Ideal Elastic-Plastic with ductility
under tension & without movement
Force
under compression
Deformation
3.2 FEA Model of Tall Wood Building
 Connection Models
 Steel beam & GL column
– Rigid connections
 GL beam to beam, column, wall & diaphragm
– Hinge connections
 Contact Models
 Steel beam to Wall
– Tie
 Panel to panel
– Frictionless
(in tangential direction)
– Hard contact
(in tangential direction)
Stress
Strain
3.2 FEA Model of Tall Wood Building
 Numerical Simulation Problem
• 3-Dimentional
• Non-linear
 Problem Size
•
Number of elements is
•
Number of nodes is
154,592
•
Total number of variables
585,762
90,834
(Degrees of freedom plus any Lagrange
multiplier variables)
It is a huge & complex computational
task with convergent problems
3.3 Frequency Analysis
 Sub-Space Method
In Y (N-S) direction
In Z (rotation) direction
In X (E-W) direction
3.3 Frequency Analysis
 Influence of joint stiffness
Rigid
Semi-Rigid
NBCC
T1
T2
T3
1.04 (Torsional)
0.88 (N-S)
0.64 (E-W)
1.66 (N-S)
1.46 (Torsional)
0.94 (E-W)
Shear wall: 1.04; Moment Frame: 1.90
Semi-rigid FEA should be used, else the periods of the
building would be under-estimated.
The fundamental period of this building with semi-rigid joints
in the East-West direction is close to that estimated by NBCC.
3.3 Frequency Analysis
1.66S (L=37.3+30.6=67.3m)
(1) Wind would control the
structural design in the NorthSouth direction, while seismic
would control it in the EastWest direction.
0.94S (L=60.5m)
1.46S
(2) Some external walls at axis
1 & 7 should be considered to
address the torsional issue
and the stiffness in N-S
direction.
3.4 Gravity Loading Analysis
3.4 Gravity Loading Analysis
In X (E-W) direction
In Y (N-S) direction
The differential shortening is not significant.
3.5 Pushover Analysis
 Risk method
In X (E-W) direction
In Y (N-S) direction
3.6 Seismic Analysis
Spectral Acceleration, Sa(g)
 Seismic response of the high-rise wood building is crucial in
the ultimate limit state.
 Investigation method: Nonlinear time history analysis
 22 “Far-Field” earthquake records will be scaled at the
corresponding fundamental period of the building model to
match the spectral acceleration, Sa, of the Vancouver design
10
spectrum.
1
0.1
0.01
Target Spectrum
Results Geom. Mean
1E-3
0.01
0.1
1
Period, T(S)
10
3.6 Seismic Analysis
0.25
0.00
-0.25
-0.50
0
3
6
9
t (s)
12
15
S1
S2
S3
S4
S5
S6
0.25
0.00
-0.25
-0.50
0
3
6
9
t (s)
12
15
1.0
Drift ratio (%)
0.50
Input earthquake record
Acceration (g)
Acceration (g)
0.50
S1
S2
S3
S4
S5
S6
0.5
0.0
-0.5
-1.0
0
3
6
9
t (s)
12
15
Thank you!
Yingxian Wood Pagoda
Tall Wood Building (66m)