NEWBuildS Tall Wood Building Design Project – Seismic & Gravity Load Analysis and Design
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Transcript of NEWBuildS Tall Wood Building Design Project – Seismic & Gravity Load Analysis and Design
NEWBuildS Tall Wood Building Design Project – Seismic & Gravity
Load Analysis and Design
Zhiyong ChenUniversity 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 !!!
[Yes]
1.2 Flow Diagram
Checking on Structural & Fire Issues using FEA
Suitable Structural Assembles & Connections
Structural SystemMaterial,
Structural Assembles& Connections
Site & Loads(Dead, Live, Wind, Snow and Seismic)
Structural Sketch& Report
[No]
1~3 Iteration
s
2. Structural Design
2.1 Concept Design
Structural System Post-beam system 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
Possible storey number
+
-
2.1 Concept Design
Stiffness, Strength & Ductility
CoreShear Wall
Steel Beam
Vertical Joints(Dowel Type)
Shear Connector
Hold-Down
(1)
(2)
(3)
(3)
2.2 Lateral Load Resisting System
Shear Connector
LLRS
The typical storey
HSK System(Wood-Steel-Composite)
Hold-Down
2.3 Gravity Load Resisting System
GLRS
The typical storey
Beams are divided by column / wall
2.3 Gravity Load Resisting System
GLRS
The typical storeyFloor
2.3 Gravity Load Resisting System
GLRS
The typical storeyRoof
2.4 Design Assemblies and Connections
Material Type CompanyRoof CLT panel SLT9 STRUCTURALAM
FloorGlulam-concrete composite deck
HBV-Vario Floor
(125mm Concrete + 175x532mm GL beam @ 800mm)
TICOMTEC
GL Beam Glulam D.L.F. 24f-E (215x532mm)Steel Beam Steel G50 (S5x10)
GL Column GlulamD.L.F. 24f-E (730x418=2-365x418,
365x418mm)Core & Wall LSL 2.1E LSL (3-19x2.44x0.089m ) TIMBERSTRANDHold-Down Steel and Glue HSK system TICOMTEC
Shear Connector
Steel and Glue HSK system TICOMTEC
Vertical Joint
Steel Dowel type connector
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
Vertical Joints
Shear Connector
Hold-Down
(1)
(2)
(3)
(3)
MTPMF
3.1.1 Influence of Hold-Down
3.1.1 Influence of Hold-Down
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
Deformation Load-deformation curve
Steel beam increases the system stiffness and ductility.
3.1.3 Influence of Vertical Connections
3.1.3 Influence of Vertical Joint
Vertical joint affects the performance of the system. Deformation Load-deformation curve
(1) Stiffness of Vertical Joint
(2) For a denser fastening case, the system derives a higher stiffness in the rigid case.
(1) The ratio system stiffness increases with increasing the stiffness of the vertical joint.
(2) Strength of Vertical Joint
(2) The first turning point of the curves from the infinite-connections-strength to zero-connection-strength cases increases with increasing the
connection strength.
(1) The curves of the two extreme cases form the boundaries of the other intermediate strength cases.
(3) Ductility of Vertical Joint - Static
The first yield point increases with increasing ductility ratio of the connection.
(4) Ductility of Vertical Joint - Cyclic
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
Strain
Stress
Strain
Stress
3.2 FEA Model of Tall Wood Building
Connection Models Vertical joint & shear connector – Ideal Elastic-Plastic with ductility
Hold-down connection – Ideal Elastic-Plastic with ductility under tension & without movement under compression
Deformation
Force
Deformation
Force
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) Strain
Stress
3.2 FEA Model of Tall Wood Building
Numerical Simulation Problem• 3-Dimentional• Non-linear
Problem Size• Number of elements is 90,834
• Number of nodes is 154,592
• Total number of variables 585,762
(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
T1 T2 T3
Rigid 1.04 (Torsional) 0.88 (N-S) 0.64 (E-W)Semi-Rigid 1.66 (N-S) 1.46 (Torsional) 0.94 (E-W)NBCC Shear wall: 1.04; Moment Frame: 1.90
The fundamental period of this building with semi-rigid joints in the East-West direction is close to that estimated by NBCC.
Semi-rigid FEA should be used, else the periods of the building would be under-estimated.
3.3 Frequency Analysis
0.94S
1.66S
1.46S
(1) Wind would control the structural design in the North-South direction, while seismic would control it in the East-West direction.
(2) Some external walls at axis 1 & 7 should be considered to address the torsional issue and the stiffness in N-S direction.
(L=37.3+30.6=67.3m)
(L=60.5m)
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.
Risk method
3.5 Pushover Analysis
In X (E-W) direction In Y (N-S) direction
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 spectrum.
3.6 Seismic Analysis
3.6 Seismic Analysis
Thank you!
Yingxian Wood Pagoda (67.31m)
Tall Wood Building (66m)