olmati and giuliani
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PROGRESSIVE COLLAPSE SUSCEPTIBILITY OF A LONG SPAN SUSPENSION BRIDGE
Progressive Collapse and Structural Robustness: An International PerspectiveClay J. Naito, Ph.D., P.E., Associate Professor and Associate ChairKonstantinos Gkoumas, Ph.D., P.E., Associate Researcher
Pierluigi Olmati 1
P.E., Ph.D. StudentEmail: [email protected]
Luisa Giuliani 2
Ph.D., Assistant ProfessorEmail: [email protected]
1 Sapienza University of Rome2 Technical University of Denmark (DTU)
Olmati P, Giuliani LSapienza University of Rome & DTU
2 Presentation outline
Introduction on the progressive collapse
The Messina Strait Bridge
Damage based approach and numerical simulations
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4 Conclusions
Olmati P, Giuliani LSapienza University of Rome & DTU
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Progressive Collapse case history
Ronan Point – May 16, 1968Progressive Collapse triggered by precast concrete bearing wall failure (gas deflagration).
Ali Khobar – June 25, 1996Progressive Collapse was stopped (ANFO detonation, 9 ton TNTeq).
Oklahoma City – May 19, 1995Progressive Collapse triggered by concrete column failure(ANFO detonation, 1.8 ton TNTeq).
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Introduction
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Progressive Collapse case history
Deutsche Bank – September 11, 2001Progressive Collapse was stopped(Debris impact).
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Introduction
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Ronan Point – May 16, 1968
General view of Ronan Point prior to demolition/photo 1987/photographer
M Glendinning
Features:- apartments building;- built between 1966 and 1968;- 64 m tall with 22 story;- walls, floors, and staircases were made of precast
concrete;- each floor was supported directly by the walls in
the lower stories, (bearing walls system).
References: NISTIR 7396: Best practices for reducing the potential for progressive collapse in buildings. Washington DC: National Institute of Standards and Technology (NIST), 2007.
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Introduction
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Cause Damage Pr. Collapse
Features:- apartments building, built between ‘66 and ’68;- 64 m tall with 22 story;- walls, floors, and staircases were made of precast
concrete;- each floor was supported directly by the walls in
the lower stories, (bearing walls system).The event:- May 16, 1968 a gas explosion blew out an outer
panel of the 18th floor; - the loss of the bearing wall causes the progressive
collapse of the upper floors;- the impact of the upper floors’ debris caused the
progressive collapse of the lower floors.
Olmati P, Giuliani LSapienza University of Rome & DTU
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Introduction
Ronan Point – May 16, 1968
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Ali Khobar – June 25, 1996
References: NISTIR 7396: Best practices for reducing the potential for progressive collapse in buildings. Washington DC: National Institute of Standards and Technology (NIST), 2007.
Features:- apartments building;- precast concrete wall and floor components
were the structural bearing system;- ductile detailing and effective ties between the
precast components.
Olmati P, Giuliani LSapienza University of Rome & DTU
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Introduction
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Features:- apartments building;- precast concrete wall and floor components
were the structural bearing system;- ductile detailing and effective ties between the
precast components.
Cause Damage Pr. Collapse
The event:- June 25, 1996 9 ton of
TNTeq detonated in front of the building;
- the exterior wall was entirely destroyed;
- collapse did not progress beyond areas of first damage.
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Introduction
Ali Khobar – June 25, 1996
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Progressive Collapse
Definitions:1- "Progressive collapse is defined as the spread of an initial local failure from element to element resulting, eventually, in the collapse of an entire structure or a disproportionate large part of it." (ASCE 7-05 2005)2- "A progressive collapse is a situation where local failure of a primary structural component leads to the collapse of adjoining members which, in turn, leads to additional collapse. Hence, the total collapse is disproportionate to the original cause." (GSA 2003)3- "Progressive collapse. A chain reaction failure of building members to an extent disproportionate to the original localized damage." (UFC 4-010-01 2003)
References: (ASCE 7-05 2005): "Minimum design loads for buildings and other structures." American Society of Civil Engineers (ASCE).(GSA 2003): "Progressive collapse analysis and design guidelines for new federal office buildings and major modernization projects." General Services Administration (GSA).(UFC 4-010-01 2003): "DoD minimum antiterrorism standards for buildings." Department of Defense (DoD).
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Introduction
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Cause Damage Pr. Collapse
Disproportionate Collapse ???
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Introduction
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Cause Damage Pr. Collapse
Disproportionate Collapse ???
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Introduction
14 Presentation outline
Introduction on the progressive collapse
The Messina Strait Bridge
Damage based approach and numerical simulations
Conclusions
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Olmati P, Giuliani LSapienza University of Rome & DTU
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Messina Bridge
Proposed Messina Strait BridgeLength of main span: 10827 feetHeight of tower: 1255 feet
Golden Gate BridgeLength of main span: 4200 feetHeight of tower: 746 feet
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DECK
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Messina Bridge
19 Presentation outline
Introduction on the progressive collapse
The Messina Strait Bridge
Damage based approach and numerical simulations
Conclusions
Olmati P, Giuliani LSapienza University of Rome & DTU
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Olmati P, Giuliani LSapienza University of Rome & DTU
Damage based approach, numerical simulations
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εy ε 1 ε 2 ε 3
σy
χy χ 1 χ 2 χ 3
My
(a) (b)M1 σ1
M2 σ2
Flexural My
[MN m] M1
[MN m] M2
[MN m] χy [1/m] χ1 [1/m] χ2 [1/m] χ3 [1/m]
Railways girders
60 63 6.3 0.0015 0.0085 0.01 0.015
Highway girders
130 136.5 13.65 0.001 0.0045 0.005 0.01
Transverse 80 84 8.4 0.00155 0.0095 0.011 0.0155 Axial σy [MPa] σ1 [MPa] σ2 [MPa] εy [-] ε1 [-] ε2 [-] ε3 [-]
Hangers 1620 1782 162 0.0077 0.01925 0.024 0.03
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Damage based approach, numerical simulations
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East side
330 m
DS1DS2
DS3DS4
DS5DS6
1650 m960 m
210 m
80 m
not to scale
Airbus A380-800
West side
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Damage based approach, numerical simulations
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Olmati P, Giuliani LSapienza University of Rome & DTU
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Damage based approach, numerical simulations
East side
330 m
DS1DS2
DS3DS4
DS5DS6
1650 m960 m
210 m
80 m
not to scale
Airbus A380-800
West side
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1650 m960 m
not to scale
East hanger West hanger
Mid-pointWest extremity point
East extremity point
Damage zone
East side
West side
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Damage based approach, numerical simulations
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Moments on the high way deck – DS 1
Mid-point
West extremity point
Yield moment
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Damage based approach, numerical simulations
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Moments on the high way deck – DS 3
Mid-point
West extremity point
Yield moment
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Damage based approach, numerical simulations
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Moments on the high way deck – DS 4
Mid-point
West extremity point Yield moment
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Damage based approach, numerical simulations
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Moments on the high way deck – DS 5
Mid-point
West extremity point Yield moment
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Damage based approach, numerical simulations
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Moments on the high way deck – DS 6
Mid-point
West extremity point
Yield moment
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Damage based approach, numerical simulations
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Average axial force on the East and West hangers
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Damage based approach, numerical simulations
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Relative displacement at the Mid-point
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Damage based approach, numerical simulations
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Olmati P, Giuliani LSapienza University of Rome & DTU
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Damage based approach, numerical simulations
33 Presentation outline
Introduction on the progressive collapse
The Messina Strait Bridge
Damage based approach and numerical simulations
Conclusions
Olmati P, Giuliani LSapienza University of Rome & DTU
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On the numerical simulations:
1- The progression of the damage from the hangers to the bridge deck occurs for at least 8 destroyed hangers.
2 - The complete failure of the deck occurs for at least 10-12 destroyed hangers.
3 - The progression of the damage to an adjoin hanger occurs for 12 destroyed hangers.
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Conclusions
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On the performance evaluation of this long span suspension bridge:
1- When the damage could be considered disproportionate?
- When the deck fails?- When the damage progresses to an adjoin
hanger?(And when the initial damage could be considered to be local?)
2- Research on the progressive collapse should lead on a quantitative evaluation of the progressive collapse susceptibility.
Olmati P, Giuliani LSapienza University of Rome & DTU
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Conclusions
Progressive Collapse and Structural Robustness: An International PerspectiveClay J. Naito, Ph.D., P.E., Associate Professor and Associate ChairKonstantinos Gkoumas, Ph.D., P.E., Associate Researcher
Olmati P, Giuliani LSapienza University of Rome & DTU