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brb-system
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Innovative anti-seismic tool
Cost-savings
Faster construction
Outstanding performance
www.starseismic.eu
Buckling Restrained Braced Frame
• Star Seismic
• Buckling Restrained Braced Frames (BRBF) History
• BRB element
• Verification tests
• BRBF system
• Application
• Cost advantages
• Projects
www.starseismic.eu
Part 1: BRBF Introduction
• Star Seismic
• Buckling Restrained Braced Frames (BRBF) History
• BRB element
• Verification tests
• BRBF system
• Application
• Cost advantages
• Projects
www.starseismic.eu
Part 1: BRBF Introduction
• Star Seismic
• Buckling Restrained Braced Frames (BRBF) History
• BRB element
• Verification tests
• BRBF system
• Application
• Cost advantages
• Projects
www.starseismic.eu
Part 1: BRBF Introduction
Development in Japan and USA
Introduction in the USA 1st paper: Convention of Structural Engineers Association of California (SEAOC),
2000
1st building: University of California, 2000
Several design presentations: Convention of Structural Engineers Association of California (SEAOC)
North American Steel Construction Conference (NASCC)
American Institute of Steel Construction (AISC)
American Society of Civil Engineers (ASCE)
Steel TIPS
Governing provisions 2005 ASCE-7
2005 AISC Seismic provisions
FEMA 450
2006 IBC
www.starseismic.eu
History of BRBF
• Star Seismic
• Buckling Restrained Braced Frames (BRBF) History
• BRB element
• Verification tests
• BRBF system
• Application
• Cost advantages
• Projects
www.starseismic.eu
Part 1: BRBF Introduction
www.starseismic.eu
Ductility
Material
• Mild steel
Member
• BRB
Structure
• BRBF
Ductility:
The ability to sustain large inelastic deformations
without significant loss in strength
Permits structures to survive severe earthquakes
www.starseismic.eu
Pcr
Limited Hysteretic Energy Dissipation
Strength and stiffness Hysteretic Degradation
Unbalanced behavior
Tension
Compression
Conventional bracing
www.starseismic.eu
PT = 100kN
PC = 40kN
PC = 60kN
PC = 90kN
PC = 100kN
Small amplitude buckling
P C P C
P CP C
P C P C
P C P C
P T P T
How Does a Buckling-Restrained Brace Work?
www.starseismic.eu
Continuous support
(Mechanics Definition)
Balanced Hysteresis
(Performance Definition)
Tension
Compression
How Does a Buckling-Restrained Brace Work?
• Star Seismic
• Buckling Restrained Braced Frames (BRBF) History
• BRB element
• Verification tests
• BRBF system
• Application
• Cost advantages
• Projects
www.starseismic.eu
Part 1: BRBF Introduction
www.starseismic.eu
PERFORMANCE
Full scale tests
University of California, San Diego
University of Utah, Salt Lake City
Lehigh university, Pennsylvania
Verification tests
• Star Seismic
• Buckling Restrained Braced Frames (BRBF) History
• BRB element
• Verification tests
• BRBF system
• Application
• Cost advantages
• Projects
www.starseismic.eu
Part 1: BRBF Introduction
Tension Brace: Yields Compression Brace: Yields
Elastic Columns and Beams
Response of BRBF in seismic event
Compression Brace: Yields Tension Brace: Yields
Response of BRBF in seismic event
Elastic Columns and Beams
• Star Seismic
• Buckling Restrained Braced Frames (BRBF) History
• BRB element
• Verification tests
• BRBF system
• Application
• Cost advantages
• Projects
www.starseismic.eu
Part 1: BRBF Introduction
Single Diagonal Inverted V V Bracing
X- Bracing
Two Story X- Bracing
Application – BRB Configuration
www.starseismic.eu
PROHITECH
Earthquake PROtection of HIstorical Buildings
by Reversible Mixed TECHnologies
develop sustainable methodologies in the seismic protection of existing constructions
save human lives
reduce economic and cultural losses
innovative materials and special devices, allowing ease of removal if necessary
Application – Seismic retrofit
www.starseismic.eu
PROHITECH
Earthquake PROtection of HIstorical Buildings
by Reversible Mixed TECHnologies
PROHITECH WP5: Innovative materials and techniques
”BRBF systems do not usually require structural members andfoundation strengthening as do conventional braced frame systemsusing traditional braces, thereby achieving more cost savings.”
”the installation of BRBs allows for a decrease in the cross-sectional area of the steel-frame beams and columns, thus theweight of steel framing members used in the entire building caneasily be reduced.”
Application – Seismic retrofit
• Star Seismic
• Buckling Restrained Braced Frames (BRBF) History
• BRB element
• Verification tests
• BRBF system
• Application
• Cost advantages
• Projects
www.starseismic.eu
Part 1: BRBF Introduction
Energy dissipation
High behavior factor
Low seismic design forces
Lower structural costs
Savings on beams, columns and foundation
Less material and labor
Savings on connactions
Faster construction, savings on crane
Larger area to be used
Cheaper post-earthqake repair
www.starseismic.eu
Cost savings with BRBs
www.starseismic.eu
Special Concentrically
Braced Frame
Independent cost analysis
q=6 q=8Buckling Restrained
Braced Frame
www.starseismic.eu
• 3 story:
• over 50 000EUR savings, 9 EUR/m2
• 3% of entire structural cost
• 6 story:
• over 230 000EUR savings, 19EUR/m2
• 6% of entire structural cost
Independent cost analysis
• Star Seismic
• Buckling Restrained Braced Frames (BRBF) History
• BRB element
• Verification tests
• BRBF system
• Application
• Cost advantages
• Projects
www.starseismic.eu
Part 1: BRBF Introduction