Fundamental design approaches for
improvement of the fire safety in car parks
UGent: structural aspects
Prof. dr. ir. Luc Taerwe
Ir. arch. Emmanuel Annerel
Magnel Laboratory for Concrete Research – Department of Structural Engineering

Objectives of the project with
respect to structural aspects
• to develop advanced mechanical models for the structural
behaviour of car park structures taking into account
non-linear behaviour due to indirect actions in the
accidental situations of fire and explosion
• to develop a particular analysis of the punching shear
problem in case of fire and explosions
Magnel Laboratory for Concrete Research 2

WP1: Determination of design parameters, scenarios
and objectives
Determination of design parameters for
- large scale structural tests
- numerical simulations of structural behaviour under fire and explosions
This implies decisions on:
- geometrical conditions, such as size, ceiling configurations, etc.;
- performance conditions, such as fire scenarios and explosion scenarios.
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Column-slab connections
Slab types
Mushroom slabs (paddestoelvloeren)
Flat slabs (vlakke plaatvloeren)
Precast thin slabs with lattice girders
(breedplaatvloeren of predallen)
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Parking structures in the city of Ghent
Kouter
Sint-Pietersplein
Vrijdagsmarkt
Zuid
Sint-Michiels
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General classification of loads according to
variation in time
Permanent loads (G)
P[G] = 1 δG ≅ 0
Live loads (Q)
0 < P[Q] < 1 δQ↑
Accidental loads (A) e.g. fire and explosions
P[A] ≅ 0 A↑
Magnel Laboratory for Concrete Research

WP4: Structural models
The objectives of this work package are to develop
- an appropriate methodology for the analysis and design of underground car park
structures in case of fire in combination with explosions.
- the analysis of structural members of car park structures for fire in combination with
explosions, with emphasis on slab / column behaviour and on punching resistance;
- protection measures from a structural point of view.
Note:
The choice is made not to include the extrapolation of the results obtained for
elements, towards robustness analysis of a whole building structure. Moreover, the
initially foreseen WP on masonry walls is also not considered in the present
two year project.
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Task 4.1: Parametric analysis of structural
members
Het brandeffect: thermo-mechanisch model DIANA
Temperatuur:
- Thermische geleidbaarheid
- Volumetrische specifieke warmtecapaciteit
- Coefficiënt voor convectie en straling
Mechanische acties:
-Sterktedegradering staal/beton
Vervormingen, bezwijkvorm
-Effect van explosie?
Implementeren als kortstondig
optredende kracht
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Task 4.2: Connections
Focus on
- study of moment resisting connections between structural elements
- analysis of the punching resistance in case of fire
and fire in combination with explosions.
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Punching
A : referentienazichtsdoorsnede
B : referentienazichtsgebied Acont
C : referentienazichtsomtrek u1
D : belast gebied
rcont : straal van een andere
nazichtsomtrek
uout,ef : omtrek vanaf waar geen
ponswapening meer nodig is
Magnel Laboratory for Concrete Research

Controle aan de omtrek van de kolom
β VEd u0 volgens type kolom
vEd = ≤ 0,5 ν fcd
u0 d
Bepaling uout,ef
uout ,ef = β vEd /( vRd,c d)
afstand uiteinde ponswapening tot uout
Magnel Laboratory for Concrete Research

Example
Gretzenbach 2004 (CH)
Fire of one parked car: 6 am
Collapse of roof slab: 7.30 am
(7 fire workers killed)
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Collapse is combination of mistakes during design
and excution
- thicknes of soil layer larger in reality than assumed in design
- top reinforcement at lower level than planned
- top of columns partly in slab
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Kolom-plaatverbindingen
Problemen bij brand
Thermische uitzetting
Afschuifbreuken kolommen !!
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Kolom-plaatverbindingen
Problemen bij brand
Uitwendige vervormingsverhindering
verschuiving van momentenlijn
→ toename steunpuntsmomenten
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Test program
1. Three full scale column – slab connections (Magnel Lab and
Warringtonfire)
2. Blast tests on selected connection configurations (KMS)
Objectives:
- Influence of reinforcement configurations on failure modes
- Elaboration of mechanical model for punching resistance
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WP5: Reliable design calculation methods
WP8: Dissemination
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