Firedesign Ws

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Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels, 27-28 November 2012 1

EN 1991-1-2

Basic design methods

Worked examples

Prof. VASSART Olivier

Chairman of the CEN/TC250 EC1/ Fire E.G.ArcelorMittal R&D

email: [email protected]


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Basic design methods of EN1991-1-2

Fire part of Eurocode 1


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Fire parts of Eurocodes 2 to 6 and 9

Following common layout to provide design rules for fire

resistance of various types of structures:- General

Scope, application field, definitions, symbols and units

- Basic principles

Performances requirements, design values of material propertiesand assessment approaches

- Material properties Mechanical and thermal properties at elevated temperatures

- Assessment methods for fire resistance

- Constructional details- Annexes

Additional information: common case - more detailed design rules

3


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Fire resistance - European classes

According to European standard, 3 criteria to define the fireresistance:

R load bearing function

E integrity separating function

I thermal insulating separation function

Above criteria may be required individually or in combination:separating only: integrity (criterion E) and, when requested, insulation(criterion I)

load bearing only: mechanical resistance (criterion R)separating and load bearing: criteria R, E and, when requested I

Fire resistance is defined in terms of time as follows: Relevant time of fire exposure during which the corresponding fire

resistance function of a structure is maintained despite fire actions

4


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R load bearing function

Capacity of a structure to maintain its required mechanical resistance incase of fire

Mechanical loading

5


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E integrity separating function

Capacity of a structure to maintain its required integrity separatingfunction to hot gases in case of fire

With or without additionalmechanical loading

200, 300,400C, (no limitation)

hot gas

heat

6


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With or withoutadditionalmechanical

loading

Average temperature rise140 K (under standard fire)Maximum temperature rise

180 K (under standard fire)

hot gas

heat

I thermal insulation separating function

Capacity of a structure to maintain its required thermal insulationseparating function in case of fire

7


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8

4: Thermal

response

time

R

5:Mechanical

response6: Possible

collapse

Resistance to Fire - Chain of Events

time

2: Thermal action 3: Mechanical actions

Loads

Steelcolumns

1: Ignit ion

8


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9

Structural Fire Safety Engineeringvs. Classification

Prescriptive Performance based

9


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P

Normalised fire

Time

Displacement

P

Objective of the classif ication

Describe the Thermal and mechanical

behaviour of structures subjected to fire

Means

10

S l i S f i i


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11


Prescriptive Performance based

11

i S d i


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12

Actions on Structures Exposed to FireEN 1991-1-2 - Prescriptive Rules

Prescriptive Rules

(Thermal Actions givenby Nominal Fire)

Performance-Based Code

(Physically based Thermal Actions)

Design Procedures


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Nominal Temperature-Time Curve

*) Advanced Fire Models

- Two-Zone Model

- Combined Two-Zones and One-Zone fire

- One-Zone Model

- CFD

- Parametric Fire

Localised Fire Fully Engulfed Compartment

(x, y, z, t) (t) uniformin the compartment

Standard temperature-, External fire - &

Hydrocarbon fire curve

- HESKESTADT

- HASEMI

No data needed

Rate of heat release

Fire surfaceBoundary properties

Opening area

Ceiling height

+

Exact geometry

*) Nominal temperature-time curve

*) Simplified Fire Models

P i ti Fi R l ti D fi i


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14

Prescriptive Fire Regulations DefiningISO Curve Requirements

* does not consider the PRE-FLASHOVER PHASE* Does not depend on FIRE LOAD and

VENTILATION CONDITIONS0

200

400

600

800

1000

1200

0 30 60

[C]

90 120 180

ISO-834 Curve (EN1364 -1)

Time [min]

ISO ISOISO

ISO ISO

ISO

ISO

ISO

The ISO curve

* Has to be considered in the WHOLE compartment, even if

the compartment is huge

* Never goes DOWN

1110

945

10061049

842

T = 20 + 345 log (8 t + 1)

St f N t l Fi d th


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15

Temperature

Cooling .

ISO834 standard fire curve

Ignit ion - Smouldering

Pre- Flashover

Heating

Post- Flashover1000-1200C

Natural fi re curve

Time

Flashover

Stages of a Natural Fire and theStandard Fire Curve

i d i


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16

Prescriptive Rules

(Thermal Actions givenby Nominal Fire)

Performance-Based Code

(Physically based Thermal Actions)

Actions on Structures Exposed to FireEN 1991-1-2 - Performance Based Code

Design Procedures


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Some National Fire Regulationsinclude now alternative requirements

based on Natural Fire

Implemented in:

EN 1991-1-2

0

200

400

600

800

1000

1200

0 30 60 90

[C]

120 180

Time [min]

Natural Fire Safety Concept

17


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18

NFSC Valorisation Project


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Natural Fire Model


- Two-Zone Model


- One-Zone Model

- CFD

- Parametric Fire





- HESKESTADT

- HASEMI

No data needed



Opening area

Ceiling height

+

Exact geometry



19

Li t f d d Ph i l P t


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20

List of needed Physical Parametersfor Natural Fire Model

Boundary properties

Ceiling height

Opening AreaFire surface


Geometry

Fire

Characteristics of the Fire


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21

Characteristics of the FireCompartment

Fire resistant enclosures

defining the fire compartment

according to the national

regulations

Material properties of

enclosures: c, ,

Definition of Openings

Characteristic of the Fire


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22

OccupancyFire Growth

RateRHRf

[kW/m]

Fire Load qf,k80%fractile

[MJ/m]

Dwelling Medium 250 948

Hospital (room) Medium 250 280

Hotel (room) Medium 250 377

Library Fast 500 1824

Office Medium 250 511

School Medium 250 347

Shopping Centre Fast 250 730Theatre (movie/cinema) Fast 500 365

Transport (public space) Slow 250 122

Characteristic of the Firefor Different Buildings


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23

Fire Load Density

1,90

2,00

2,13

Danger of

Fire Activation

Compartment

floor area Af [m]

1,50

1,1025

250

2500

5000

10000

q10,78

1,00

1,22

1,44

1,66

Danger ofFire Activationq2

Examples

ofOccupanciesArt gal lery, museum,

swimming pool

Residence, hotel, office

Manufactory for machinery& engines

Chemical laboratory,Painting workshop

Manufactory of fireworks

or paints

Automatic

Water

ExtinguishingSystem

Independent

Water

Supplies

Automatic fi re

Detection

& Alarmby

Heat

by

Smoke

Automatic

Alarm

Transmission

to

Fire Brigade

Function of Active Fire Safety Measuresni

0 1 2

Automatic Fire Suppression Automatic Fi re Detect ion

n1 n2 n3 n4 n5

0,61 0,87 or 0,73 0,871,0 0,87 0,7

Work

Fire

Brigade

Off Site

Fire

Brigade

Safe

Access

Routes

Fire

Fighting

Devices

Smoke

Exhaust

System

n10

Manual Fire Suppressi on

n6

n7

n8

n9

0,61 or 0,780,9 or 1

1,5

1,0

1,5

1,0

1,5

kfniqqdf qmq ,21, .... =

Rate of Heat Release Curve


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24

Rate of Heat Release CurveStationary State and Decay Phase

RHR [MW]

Time [min]0

tdecay

Decay phase

0

1

2

3

4

5

6

7

8

9

10

0 5 10 15 20 25 30

t [min]

x RHRA f f

x RHR fA f

COMPARTMENT FIRE

Ventilation Controlled FireRHR[M

W]

Steady state

70% (q f,d A fi)

Decay Phase

01

2

3

4

5

6

7

8

9

10

0 5 10 15 20

t [min]

RHR[M

W]

75''

Fast (FGR)

Medium (FGR)

Fire Growth Rate = FGR

Slow (FGR)

Ultra-

Fast

(FGR)

150'' 600''300''

Growing phase


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Natural Simplified Fire Model


- Two-Zone Model


- One-Zone Model

- CFD

- Parametric Fire



Standard temperature-, External fi re - &


- HESKESTADT

- HASEMI

No data needed


Fire surface

Boundary properties

Opening area

Ceiling height

+

Exact geometry



25


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FULLY ENGULFED

COMPARTMENT

(t) uniform in the compartment

LOCALISED FIRE

(x, y, z, t)

Simplified Fire Models Localised Fire

26


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Real Localised Fire Test

27


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Annex C of EN 1991-1-2:

Flame is not impacting the ceiling of a compartment (L f < H)

Fires in open air

The flame length L f of a

localised fire is given by :

Flame axis

L

z D

f

H

(z) = 20 + 0,25 (0,8 Qc)2/3 (z-z0)-5/3 900C

L f= -1,02 D + 0,0148 Q2/5

Localised Fire: HESKESTAD Method

28


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Annex C of EN 1991-1-2:

Flame is impacting the ceiling (Lf > H)

Y = Height of the

free zone

concrete slab

g

x

= Air Temperatureat Beam Level Calculated by CaPaFi

Localised Fire: HASEMI Method

beam

29

Simplified Fire Models


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FULLY ENGULFED

COMPARTMENT

(t) uniform in the compartment

LOCALISED FIRE

(x, y, z, t)

Simplified Fire ModelsFully Engulfed Compartment

30

Real Fire Test Simulating


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Real Fire Test Simulatingan Office Building

Fully engulfed fire

31



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Demonstration test : set-up

Fire load with realoffice furniture

Openings w ith normal

glazed windows




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Early stage of fire

Fully developed f ire




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0100200300400500600700

0 10 20 30 40 50 60 70 80 90 100Time (min)

Vert

ical

displacem

ent(mm)

020040060080010001200

Temperature(C)

Maximum verticaldisplacement

Steel

temperature


34

Fully Engulfed Compartment


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Annex A of EN 1991-1-2

0

100

200

300

400

500

600

700

800

900

10001100

0 10 20 30 40 50 60 70 80 90 100 110 120

time [min]

O = 0.04 m

O = 0.06 m

O = 0.10 m

O = 0.14 m

O = 0.20 m

Iso-Curve

Fully Engulfed CompartmentAnnex A: Parametric Fire

Temperature [C]

For a given b, qfd, At & Af

35

N t l Ad d Fi M d l


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Natural Advanced Fire Model


- Two-Zone Model


- One-Zone Model

- CFD

- Parametric Fire





- HESKESTADT

- HASEMI

No data needed



Opening area

Ceiling height

+

Exact geometry



36

Ad d fi M d l


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Advanced fire Models

LOCALISED FIRE

LOCALISED FIRE FULLY ENGULFED

COMPARTMENT

The Fire stays localisedThe Fire switch to a

fully engulfed fire

37

Ad d fi M d l


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38

Advanced fire Models

I iti


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39

Ignition

L li d Fi


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40

T

Localised Fire

G i f L li d Fi


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41

T

Growing of Localised Fire

Th f t d l


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42

T

Qmp

H

ZS

ZP

0

Lower layer

Upper layer

mOUT,U

mIN,L

mIN,L

QC

QR

mU , TU, VU,

EU, U

mL , TL, VL,

EL, L

p

ZLocalised Fire Ozone Software Model

Theory of two zones models

Theor of t o ones models


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43

T

2 1 zone: if one of the following cri teria is reachedThot gases> 500

oCCombustible material in the smoke and Tsmoke> 300

oCLocalised fire> 25 % of the compartments surfaceSmoke height > 80 % of the total height of the compartment




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44

Generalised Fire Ozone Software Model

H

ZP

0

mOUT

mOUT,L

mIN,L

QC

QRm, T, V,

E, (Z)

p = f(Z)

Fire: RHR,

combustion products

QC+R,O

Z


Large Compartment Test


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Large Compartment TestFire Load

45



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a ge Co pa e esExternal Flaming During the Test

46



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g pAfter the Test

47

Two Zone Calculation


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Software OZone V2.2

48

Software OZone V2.2


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49

Definition of the Compartment

Software OZone V2.2


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50

Definition of the boundaries

Software OZone V2.2


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51

Definition of the fire


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OZone results :


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Input and Computed RHR

53

OZone results :


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Hot

Cold

Gas Temperatures

54

OZone results :S k L Thi k


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Smoke Layer Thickness

55


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56


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57


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58

Compartment Fire test


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Compartment Fire test

59

Calibration of Software OZone:G T


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60

Gas Temp

0

200

400

600

800

1000

1200

1400

0 200 400 600 800 1000 1200 1400

TEST [C]

OZone[C]

MAXIMUM AIR T EMPERATURE

OZone

MAXIMUM AIR T EMPERATUREIN THE COMPARTMENT

Calibration of Software OZone:St l T


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61

0

200

400

600

800

1000

1200

1400

0 200 400 600 800 1000 1200 1400

TEST [C]

OZone[C]

UNPROTECTED STEEL TEMPERATURE

Steel Temp

Calibration of Software OZone:OZ V T t


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62

Comparison BRE Test 4 - OZone Design fire

0100200300400500600700800900

10001100120013001400

0 600 1200 1800 2400 3000 3600 4200 4800 5400 6000 6600 7200Time [sec]

GasTemp

[C]]

OZone Office FastOZone Office Medium

Test AverageTest MaxTest Min

qf,d=511MJ /m2

RHRf= 250kW/m2

OZone Vs Test

Calibration of Software OZone:OZ V Ul t T t


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63

15 m 9 m

OZone Vs Ulster Test

Calibration of Software OZone:OZ V Ul t T t


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Fire load energy density was700MJ/m2

The fire load can be achieved us ing 45 standard wooden cribs(1m x 1m x0.5 m high), positioned evenly around the compartment(9.0m x 15.0m).

WOODEN CRIBS LOCATION


Calibration of Software OZone:OZone Vs Ulster Test


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65


Calibration of Software OZone:OZone Vs Ulster Test


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66

Computer Fluid Dynamics:Soft are Sofie


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Griddefinition

Software Sofie

67

Sofie Results: Gas Temperatures


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p

68

Computer Fluid Dynamics:Free Software FDS


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Free Software FDS

69



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Definition of the mesh

Free Software FDS



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Free Software FDS

71

Resistance to Fire - Chain of Events


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72

4: Thermal

response

time

R

5:Mechanical

response

6:Possible

collapse

time

2: Thermal action 3: Mechanical actions

Loads

Steelcolumns

1: Ignit ion

Basis of Design andActions on Structures


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73

Actions on Structures

S

G

Q

Fire

W

ACT

IONS

Actions for temperature analysis

Thermal Action

FIRE

Actions for structural analysisMechanical Action

Dead Load GImposed Load QSnow SWind W

Combination Rules for Mechanical ActionsEN 1990: Basis of Structural Design


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74

Room temperature

= iQ,i0,i1Q,1Gd QQGE

f.i. : Offices area with the imposed load Q,

the leading variable action

Ed = 1,35 G + 1,5 Q + 0,6 1,5 W + 0,5 1,5 S

EN 1990: Basis of Structural Design

i >1

Combination Rules for Mechanical ActionsEN 1990: Basis of Structural Design


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75

Fire conditions Accidental situation

f.i. : Offices area with the imposed load Q,

the leading variable action

Efi,d= G + 0,3 Q

Offices area with the wind W, the leading variable action

Efi,d = G + 0,0 W + 0,3 Q

+= 1fi,d i >1 i1or2,i

QQGE 1or2,1

EN 1990: Basis of Structural Design

Values of factors for buildings


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76

Action 0 1 2Imposed loads in buildings, category (see EN 1991-1.1)

Category A :domestic, residential areasCategory B :offi ce areasCategory C :congregation areasCategory D :shopping areasCategory E :storage areasCategory F :traffic area

vehicle weight 30kN

Category G :traff ic area,30kN < vehicle weight 160kN

0,70,70,70,71,0

0,7

0,7

0,50,50,70,70,9

0,7

0,5

0,30,30,60,60,8

0,6

0,3

Snow loads on buildings (see EN1991-1.3)Finland, Iceland, Norway, Sweden

Remainder of CEN Member States, for s ites located at altitudeH > 1000 m a.s.l.

Remainder of CEN Member States, for s ites located at altitudeH1000 m a.s.l.

0,700,70

0,50

0,500,50

0,20

0,200,20

0

Wind loads on buildings (see EN1991-1.4) 0,6 0,2 0

Temperature (non-fire) in buildings (see EN1991-1.5) 0,6 0,5 0

( Reference : EN1990 - February 2002)

Category H :roofs 0 0 0


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Worked examples of EN1991-1-2

Fire part of Eurocode 1

The Building (R+5)


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3.4m

14 m

30 m

78

The Building (R+5)


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What do we need for the calculation ?

Size of the compartment

Boundary properties

Ceiling height

Opening Area

Fire surface


Geometry

Fire

79

Size of the compartment


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1

A

C

14m

630 m

80

Ceiling height : 3.05 m


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3.4m

14 m

30 m

81

OZone Software


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82

The Software Package that will be used to perform this

calculation is OZone.This Software package has been developed by the Universityof Lige (Cadorin-Franssen) and is available for freedownload on:

http://www.argenco.ulg.ac.be/logiciel.phphttp://www.arcelormittal.com/sections

OZone Software


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83

OZone Software


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84

Boundaries


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85

Typical floor will be chosen:

- Exterior walls : 20 cm of normal concrete

- Slab : 15 cm of Normal concrete

- Ceiling : 15 cm of normal concrete

Boundaries


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86

Boundaries


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87

Opening Factors


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88

This point is one critical point.

The Eurocode is not providing the scenario that must bechosen to take into account the openings.

Openings can be doors, windows and general porosity ofthe building.

If no opening is taken into account from the beginning of thefire, the amount of oxygen in the compartment will be toosmall and the fire will not develop.

Opening Factors


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89

Here are some information to help for definition of the

scenario for the breaking of the windows:

In the literature, it can be found that:

-Normal glazing will start to break with a T of 40C on theglass

-Tempered glazing will start to break with a T of 120C onthe glass

-Tempered glazing with reinforcement will start to break with aT of 120C on the glass (The reinforcement will melt at300C)

Opening Factors


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90

Luxembourgish authorities have realized a guide that needs

to be followed when FSE is used. This guide will becomeofficial soon. But here is some extract for the non fire resistantglazing:

-Scenario 1 : 90% of the glazing is open since the beginning

-Scenario 2:

-Simple glazing : 100C : 50% and 250C: 90%

-Double glazing: 200C : 50% and 400C: 90%

-Triple glazing: 300C : 50% and 500C: 90%

Opening Factors


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91

Assumptions for the faade:

-Ex. 1: 0.8m open all around the building

-Ex. 2: 1.5m open all around the building

-Ex. 3: full glazing Faade

Opening Factors Ex.1


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92

Opening Factors


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93

Opening Factors


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94

Definit ion of the fire


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95

Occupancy Fire GrowthRate

RHRf[kW/m]


[MJ/m]



Hotel (room) Medium 250 377Library Fast 500 1824



Shopping Centre Fast 250 730

Theatre (movie/cinema) Fast 500 365




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96

Occupancy Fire GrowthRate

RHRf[kW/m]


[MJ/m]



Hotel (room) Medium 250 377Library Fast 500 1824



Shopping Centre Fast 250 730

Theatre (movie/cinema) Fast 500 365




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97

1,90

2,00

2,13

Danger ofFire Activation

Compartment

floor area Af [m]

1,50

1,1025

250

2500

5000

10000

q10,78

1,00

1,22

1,44

1,66

Danger ofFire Activation

q2Examples

of

OccupanciesArt gal lery, museum,

swimming pool

Residence, hotel, office

Manufactory for machinery& engines

Chemical laboratory,Painting workshop

Manufactory of fireworks

or paints

Automatic

Water

Extinguishing

System

Independent

Water

Supplies

Automatic fi re

Detection

& Alarm

byHeat

bySmoke

Automatic

Alarm

Transmission

toFire Brigade

Function of Active Fire Safety Measuresni

0 1 2

Automatic Fire Suppression Automatic Fi re Detect ion

n1 n2 n3 n4 n5

0,61 0,87 or 0,73 0,871,0 0,87 0,7

Work

Fire

Brigade

Off Site

Fire

Brigade

Safe

Access

Routes

Fire

Fighting

Devices

Smoke

Exhaust

System

n10

Manual Fire Suppressi on

n6

n7

n8

n9

0,61 or 0,780,9 or 1

1,5

1,0

1,5

1,0

1,5

kfniqqdf qmq ,21, .... =



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98

Results for 0.8m windows


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99

0

100

200

300

400

500

600

700

800

900

0 20 40 60 80 100 120

Time [min]

Hot Zone

Analysis Name:

Gas Temperature



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100

0.0

50.0

100.0

150.0

200.0

250.0

300.0

350.0

400.0

0 20 40 60 80 100 120

Time [min]

Oxygen Mass

Analysis Name:

Oxygen Mass

Results for IPE450


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101

0

100

200

300

400

500

600

700

800

900

0 20 40 60 80 100 120

Time [min]

Hot Zone

Steel

Analysis Name:

Steel Temper ature

02

Opening Factors Ex. 2


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102

W k h St t l Fi D i f B ildi di t th E d B l 27 28 N b 2012 103



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103

0

100

200

300

400

500

600

700

800

0 20 40 60 80 100 120

Time [min]

Hot Zone

Analysis Name:

Gas Temper ature

W k h St t l Fi D i f B ildi di t th E d B l 27 28 N b 2012 104



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104

0.0

50.0

100.0

150.0

200.0

250.0

300.0

350.0

400.0

0 20 40 60 80 100 120

Time [min]

Oxygen Mass

Analysis Name:

Oxygen Mass

Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels 27 28 November 2012 105

Results for IPE450


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105

0

100

200

300

400

500

600

700

800

0 20 40 60 80 100 120

Time [min]

Hot Zone

Steel

Analysis Name:

Steel Temper ature

Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels 27 28 November 2012 106

Opening Factors Ex. 3


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106

Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels 27-28 November 2012 107

Results for full windows


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107

0

50

100

150

200

250

300

350

400

450

500

0 20 40 60 80 100 120

Time [min]

Hot Zone

Analysis Name:

Gas Temperature

Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels 27-28 November 2012 108

Results for full windows


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Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels, 27 28 November 2012 108

108

50.0

100.0

150.0

200.0

250.0

300.0

350.0

400.0

0 20 40 60 80 100 120

Time [min]

Oxygen Mass

Analysis Name:

Oxygen Mass


Results for IPE450


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Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels, 27 28 November 2012 109

109

0

50

100

150

200

250

300

350

400

450

500

0 20 40 60 80 100 120

Time [min]

Hot Zone

Steel

Analysis Name:

Steel Temper ature


Fire resistance assessment ofsteel structures


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p g g g ,


Fire part of Eurocode 1 : Localised Fire


Hasemi method for localised fires


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p g g g

111

EN 1991-1-2 : 2002; Annex C

Horizontal length on the ceiling:

Non-dimensional parameters:

Virtual vertical coordinate:

Heat flux:

Net Heat flux:


Localised fireParameters


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Car park Auchan,Luxembourg

Undergroundcar park

H = 2.7 m

r = 0.0 m

D = 2.0 m

IPE 550

Building:

Type:

Height:

Horizontal distance from flame axis to beam:

Diameter of flame:

Steel Beam:


Localised fireStatic system and section of the beam


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Localised fireHypothesis


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114

Diameter of the fire: D = 2.0 m

Vertical distance between fire source and ceiling:H = 2.7 m

Horizontal distance between beam and flame axis:r = 0.0 m

Emissivity of the fire: f = 1.0

Configuration factor: = 1.0Stephan Boltzmann constant: = 5.67 10-8

W/m2K4Coefficient of the heat transfer: c = 25.0 W/m

Steel profile: IPE 550Section factor: Am/V = 140.1/mUnit mass: a = 7850 kg/mSurface emissivity: m = 0.7


Localised fireRate of Heat Release


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Curve of the rate of heat release of one car

From ECSC project: Development of design rulesfor steel structures subjected to natural fires in

closed car parks.


Localised fireFlame Length


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if Lr H Model A has to be used

if Lr < H Model B has to be used

2 5 2 51.02 0.0148 2.04 0.0148fL D Q Q= + = +


1st case:The flame is not impacting the ceiling


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The net heat flux is calculated according to Section 3.1 of EN

1991-1-2.

( )( ) ( )( ) ( )

( )( ) ( )( ) ( )

4 4

4 48

273 273

25.0 3.969 10 273 273

net c m m f mz z

m mz z

h

= + + +

= + + +


1st case:The flame is not impacting the ceiling


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The gas temperature is calculated to:

where:z is the height along the flame axis (2.7 m)z0 is the virtual origin of the axis [m]

( ) ( ) ( )

( ) ( )

2 3 5 3

0

5 32 3 2 5

20 0.25 0.8 900 C

20 0.25 0.8 4.74 0.0052 900 C

zQ z z

Q Q

= +

= +

2 5 2 5

01.02 0.0052 2.04 0.0052z D Q Q= + = +


2nd case:The flame is impacting the ceiling


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119

Net heat flux, if the flame is impacting the ceiling, is given by:

( ) ( ) ( )

( )( ) ( ) ( )( )

4 4

4 48

20 273 293

25.0 20 3.969 10 273 293

net c m m f m

m m

h h

h

= +

= +




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The heat flux depends on the parameter y. For different

dimensions of y, different equations for determination of theheat flux have to be used.

ify 0.30:

if 0.30 < y < 1.0:

if y 1.0:

where:

100,000h =

136,300 121,000h y=

3.715,000h y

=

' 2.7 '

' 2.7 'h h

r H z zy

L H z L z

+ + += =

+ + + +



' 2 7 'H


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The horizontal flame length is calculated by:

where:

The vertical position of the virtual heat source isdetermined by:

ifQD* < 1.0:

ifQD* 1.0:where:

' 2.7 '

' 2.7 'h h

r H z zy

L H z L z

+ + += =

+ + + +

( )( ) ( )( )0.33 0.33

* *2.9 7.83 2.7h H HL H Q H Q= =

( ) ( )* 6 2.5 6 2.5

1.11 10 1.11 10 2.7HQ Q H Q= =

( ) ( )( ) ( ) ( )( )2 5 2 3 2 5 2 3

* * * *' 2.4 4.8

D D D Dz D Q Q Q Q= =

( )( ) ( )( )2 5 2 5

* *' 2.4 1.0 4.8 1.0D Dz D Q Q= =

( ) ( )* 6 2.5 6 2.51.11 10 1.11 10 2.0DQ Q D Q= =


Localised fireSteel temperatures


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Temperature-time curve for the unprotected steel beam:

=

=a,max

,max

770 C

at t 31.07 min

2

,

1.78 10ma t m sh net m net

a a a

A Vk h t h

c c

= + = +


Localised fireSteel temperatures


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Temperature-time curve for the unprotected steel beam:

=

=a,max

,max

770 C

at t 31.07 min

2

,

1.78 10ma t m sh net m net

a a a

A Vk h t h

c c

= + = +


Excel SpreadsheetCapafi


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Excel SpreadsheetCapafi


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0

50

100

150

200

250

300

350

400

450

500

550

600

650

700

750

800

850

0 600 1200 1800 2400 3000 3600 4200 4800 5400 6000 6600 7200

AxisTitle

Axis Title

Chart Title

Pos 1

Pos 2

Pos 3

Pos 4

Pos 5



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Example of Application of buildingscalculated with

Natural Fire Safety Concept


Switzerland


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Braun Building in CrissierProduction of Medical Material


Switzerland


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BOBST Building in LausanneOffices + Production


Switzerland


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Congress centre of EPFL in LausanneCrdit Suisse / HRS / Richter-Dahl&Rocha


France


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EADS Airbus


France


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Car park of Toulouse Blagnac Airport


Belgium


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Greich Office Building in Lige


Portugal


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BARREIRO RETAIL PARK


Portugal


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Exhibition Center


Cyprus


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IKEA shopping center in Lefkosia


United Kingdom


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Heron Tower Arup Fire London


Luxembourg


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Fonds du Logement, 17 rue de Hollerich Luxembourg VilleShopping centreResidential


Luxembourg


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Chambre de Commerce LuxembourgOffice Building


Luxembourg


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Dexia-Bil in Esch sur AlzetteOffice Building


Luxembourg


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ArcelorMittal Office Building in Esch sur Alzette


Luxembourg


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ArcelorMittal Office Building in Esch sur Alzette



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Thank you for your attention

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