NEWBuildSTWB_Seismic-Gravity_Zhiyong

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)