Session 2

Training School for Young Researchers Fire Engineering Research – Key Issues for the Future Design methods – codified, prescriptive or performance-based Paulo Vila Real

COST Action TU0904 Malta, 11-14 April 2012

Scope  Introduction  Thermal Actions  Mechanical Actions  Thermal Analysis  Mechanical Analysis  Design procedures  Examples using different design procedures: prescriptive and performance-based

Introduction Question

 Prescriptive or performance-based approach?

Introduction Two type of regulations or standards

 Each country has its own regulations for fire safety of buildings where the requirements for fire resistance are given

 Standards for checking the structural fire resistance of the buildings - in Europe the structural EUROCODES

Introduction Fire Resistance  Classification criteria

R – Load bearing criterion; E – Integrity criterion; I – Insulation criterion

R

Load

RE

REI

Load heat

Load heat flames

flames

hot g

-

hot g ases

as es

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

Introduction -Fire Resistance Criteria R, E and I - UK Approved document B

R E I

Introduction Fire Resistance – Criteria R, E and I  Standard fire curve Fire resistance is the time since the begining of the standard fire curve ISO 834 until the moment that the element doesn’t fulfill the functions for that it has been designed (Load bearing and/or separating functions)

T  345 log10 8t  1  20 Curva ISO 834 ISO 834 curve ºC 1200 1000 800 600 400 200 0 0

20

40

60 min

80

100

120

Introduction Regulations for fire safety of buildings  Normally the risk factors are: 

Height of the last occupied storey in the building (h) over the reference plane



Number of storeys below the reference plane (n)



Total gross floor area



Number of occupants (effective)

R30, R60, R90, ... or REI30, REI60. REI90, ... h

n

Reference plane

Introduction. Example Regulations for fire safety – UK Approved document B

9

Introduction. Example Regulations for fire safety – UK Approved document B

10

Introduction. Example Portuguese regulation for fire safety of buildings  Required fire resistance - The load-bearing or/and separating function should be maintained during the complete duration of the fire including the decay phase (this means that natural fires can be used), or alternatively during the required time of standard fire exposure given in the table below: Standard fire resistance of structural members in buildings Risk categories Classification according to the occupancy

Function of the structural member 1.º

2.º

3.º

4.º

I, III, IV, V, VI ,VII ,VIII ,IX ,X

R30 REI30

R60 REI60

R90 REI90

R120 REI120

Only load bearing Load bearing and separating

II, XI and XII

R60 REI60

R90 REI90

R120 REI120

R180 REI180

Only load bearing Load bearing and separating

Type I «Dwelling»: Type II «Car parks»; Type III «Administrative»; Type IV «Schools»; Type V «Hospitals»; Type VI «Theatres/cinemas and public meetings»; Type VII «Hotels and restaurants»; Type VIII «Shopping and transport centres»; Type IX «Sports and leisure»; Type X «Museums and art galleries»; Type XI «Libraries and archives»; Type XII «Industrial, workshops and storage»

Introduction Prescriptive or performance-based - The load-bearing function is ensured when collapse is prevented during the complete duration of the fire including the decay phase or alternatively during the required period of time under standard fire exposure.

Natural fire

Sandard fire ISO 834



 or

t Performance-based approach

t Prescriptive approach

Introduction Codes for fire design in Europe: Structural Eurocodes Eurocodes EN 1990

Eurocode:

Basis of Structural Design

EN 1991

Eurocode 1:

Actions on structures

EN 1992

Eurocode 2:

Design of concrete structures

EN 1993

Eurocode 3:

Design of steel structures

EN 1994

Eurocode 4:

Design of composite steel and concrete structures

EN 1995

Eurocode 5:

Design of timber structures

EN 1996

Eurocode 6:

Design of masonry structures

EN 1997

Eurocode 7:

Geotechnical design

EN 1998

Eurocode 8:

Design of structures for earthquake resistance

EN 1999

Eurocode 9:

Design of aluminium structures

Fire design Parts 1-2

Except EN 1990, EN 1997 and EN 1998, all the Eurocodes have Part 1-2 for fire design

Fire Design of Structures Four steps

1. Definition of the thermal loading - EC1 2. Definition of the mechanical loading - EC0 +EC1 3. Calculation of temperature evolution within the structural members – All the Eurocodes

4. Calculation of the mechanical behaviour of the structure exposed to fire – All the Eurocodes

Eurocode 1: Actions on Structures S

W

Actions for temperature analysis G

A C T I O N S

Q

Thermal Action

FIRE Actions for structural analysis Mechanical Action Dead Load Imposed Load Snow Wind

G Q S W

Fire 15

Eurocode 1: Actions on Structures S

W

Actions for temperature analysis G

A C T I O N S

Q

Thermal Action

FIRE

Fire 16

Thermal actions Heat transfer at surface of building elements

hnet ,d  hnet ,c  hnet ,r

Total net heat flux

hnet ,d

hnet ,d

hnet ,d

hnet ,d 17

Thermal actions Heat transfer at surface of building elements

hnet ,d  hnet ,c  hnet ,r hnet , c   c ( g  m )

Total net heat flux

Convective heat flux

hnet ,r     f   m    [( r  273) 4  ( m  273) 4 ]  g  r



Radiative heat flux



or

Temperature of the fire compartment

t Nominal fire

t Natural fire

18

Actions on Structures Exposed to Fire EN 1991-1-2 - Prescriptive rules or performance-based approach Design Procedures

Prescriptive Rules (Thermal Actions given

by Nominal Fire)



Performance-Based Code (Physically based Thermal Actions)



t

t

19

Actions on Structures Exposed to Fire EN 1991-1-2 - Prescriptive rules or performance-based approach Nominal temperature-time curves Standard temperature-time curve External fire curve Hydrocarbon curve

Natural fire models Simplified fire models

Compartment fires - Parametric fire Localised fires – Heskestad or Hasemi Advanced fire models

Two-Zones or One-Zone fire or a combination CFD – Computational Fluid Dynamics 20

Actions on Structures Exposed to Fire EN 1991-1-2 - Prescriptive rules or performance-based approach *) Nominal temperature-time curve Standard temperature-, External fire - & Hydrocarbon fire curve

No data needed

*) Simplified Fire Models Localised Fire Fully Engulfed Compartment - HESKESTADT - HASEMI

- Parametric Fire (t) uniform in the compartment

From DIFISEK+

(x, y, z, t)

*) Advanced Fire Models - One-Zone Model - Two-Zone Model - Combined Two-Zones and One-Zone fire

- CFD

Rate of heat release Fire surface Boundary properties Opening area Ceiling height

+ Exact geometry 21

Simplified fire models Nominal Temperature-Time Curve

Gas temperature (°C) 1200 Hydrocarbon Fire 1000 Standard Fire

800

External Fire

600 400 200 0

1200

2400 Time (s)

EC3 and EC9 do not use this external fire curve. A special Annex B on both Eurocodes gives a method for evaluating the heat transfer to external steelwork

3600 22

List of Physical Parameters needed for Natural Fire Models

Boundary properties Ceiling height

Geometry

Opening Area Fire area Rate of heat release

Fire

Fire load density

23

Characteristics of the Fire Compartment Natural Fire Model Fire resistant enclosures defining the fire compartment according to the national regulations

From DIFISEK+

Material properties of enclosures: c

Definition of openings 24

Characteristics of the Fire Load from EN 1991-1-2 Natural Fire Model

Occupancy Dwelling Hospital (room) Hotel (room) Library Office School Shopping Centre Theatre (movie/cinema) Transport (public space)

Fire Growth Rate Medium Medium Medium Fast Medium Medium Fast Fast Slow

RHRf

Fire Load qf,k 80% fractile

[kW/m²]

[MJ/m²]

250 250 250 500 250 250 250 500 250

948 280 377 1824 511 347 730 365 122 25

Design value of the fire load density Natural Fire Model

q f ,d  q f ,k  m   q1   q2  n

[MJ/m2]

m – Combustion factor. Its value is between 0 and 1. For mainly cellulosic materials a value of 0.8 may be taken. Conservatively a value of 1 can be used q1 – factor taking into account the fire activation risk due to the size of the compartment q2 – factor taking into account the fire activation risk due to the type of occupancy n – factor taking into account the different fire fighting measures 10

n 

 i1

ni

 n1  n2    n9  n10 26

Characteristics of the Fire Load from EN 1991-1-2 Natural Fire Model Compartment floor area Af [m²]

Danger of Fire Activation

Examples of Occupancies

Danger of Fire Activation

Fire Load Density 

q2

q1

25

1,10

0,78

Art gallery, museum, swimming pool

250

1,50

1,00

Residence, hotel, office

2500

1,90

1,22

5000

2,00

1,44

Manufactory for machinery & engines Chemical laboratory, Painting workshop Manufactory of fireworks or paints

q f ,d   q1 .  q2 .   ni . m . q f ,k 2,13

10000

ni

From DIFISEK+

Automatic Fire Suppression Automatic Water Extinguishing System

Independent Water Supplies





n1

0,61

0

1

2

n2

1,0 0,87 0,7

1,66

Function of Active Fire Safety Measures

Automatic Fire Detection Automatic fire

Automatic Alarm Detection Transmission & Alarm to by by Heat Smoke Fire Brigade   n3  n4 n5 0,87 or 0,73

0,87

Manual Fire Suppression Work Fire Brigade

Off Site Fire Brigade





n6

0,61

or

n7

0,78

Safe Access Routes



n8

0,9 or 1 1,5

Fire Fighting Devices



n9

Smoke Exhaust System 

n10

1,0

1,0 1,5

27

1,5

Rate of Heat Release Curve from EN 1991-1-2 Natural Fire Model

RHR [MW]

 t Q( t )    t

   

2

Qmax = Afi x RHRf

Decay phase 70% (qf,d • Afi) 0

tdecay From DIFISEK+

Time [min] 28

Rate of Heat Release of a class 3 car. Experimental evaluation Natural Fire Model

Car of class 3

Demonstration of real fire tests in car parks and high buildings – Contract no. 7215 PP 025, Projecto Europeu

An idealized Rate of Heat Release Curve for a car burning Natural Fire Model

From ECSC Project: Demonstration of real fire tests in car parks and high buildings. 30

Localised Fire: HESKESTAD Method Natural Fire Model Annex C of EN 1991-1-2: • Flame is not impacting the ceiling of a compartment (Lf < H) • Fires in open air

(z) = 20 + 0,25 (0,8 Qc)2/3 (z-z0)-5/3  900°C Flame axis

The flame length Lf of a localised fire is given by :

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

H Lf z

D 31

Localised Fire:HASEMI Method Natural Fire Model Annex C of EN 1991-1-2: • Flame is impacting the ceiling (Lf > H)

32

Localised fires in a car park Five fire scenarios

START

START

Fire Scenario 2

Fire Scenario 4 Fire Scenario 3

Fire Scenario 5

16.00 m

Fire Scenario 1 START

START

20 x 2.40 m

Height: H = 2.7 m Diameter of flame: D = 3.9 m Steel Beams: IPE 500

33

Localised fire Rate of heat release of four burning cars Curve of the rate of heat release of each car. A delay of 12 minutes between each burning car. 1st 2nd 3rd 4th 9 8 7

Q (MW)

6

1st car 2nd car 3rd car 4th car

5 4 3 2 1 0 0

10

20

30

40

50

60

70

80

90

100

Time (min)

From ECSC Project: Demonstration of real fire tests in car parks and high buildings.

34

Two Localised fire models Flame length Heskestad Method if Lr  H

 Hasemi method has to be used

if Lr < H

 Heskestad method has to be used

Hasemi Method

Program Elefir-EN

35

Hasemi method Horizontal distances

r3

r2

r1

ri d1

Program Elefir-EN 2

1



d



d

ri

ri

d2

2

2 36

Temperature development Gas and steel temperture Scenario 1: unprotected steel (a,max = 710.9 ºC)

Scenario 3 ( a,max = 466.7 ºC)

Scenario 1: protected steel (a,max = 527 ºC)

Scenario 4 ( a,max = 510.9 ºC)

Scenario 2 (a,max = 466.7 ºC)

Scenario 3 ( a,max = 528.5 ºC)

37

Parametric fire. Needed parameters Natural Fire Model

Fire load density -

qf ,d

Opening factor -

O  Av h / At

Temperature  = (t)

b  c Wall factor Av - area of vertical openings; At - total area of enclosure Limitations : • Afloor  500 m² • No horizontal openings •H4m • Wall factor from 1000to 2200 • Fire load density, qt,d from 50 to 1000 MJ/m²

38

Parametric Fire Natural Fire Model Annex A of EN 1991-1-2 1000

O  0.07 m1 / 2

O  0.06 m1 / 2

O  0.05m1 / 2

800

O  0.02 m1 / 2

600 [º C] 400

O  0.14 m1 / 2 200

O  0.20 m1 / 2

O  0.1 m1 / 2

0 0

10

20

30

40

50

60

70

80

90

100

110

[min]

Ventilation controlled fires

Fuel controlled fires

Parametric fire curves function of - O For a given qf,d, b, At and Af

39

Parametric Fire - Influence of the Actives Fire Safety Measures Natural Fire Model 1567 = 511x0,8x1,14x1x 1x1x1x1x1x1x1x1,5x1,5x1,5

No Fire Active Measures Off Site Fire Brigade

815 = 511x0,8x1,14x1x 1x1x1x1x1x1x0,78x1x1,5x1,5

Safe access routes Automatic Fire Detection & Alarm by Smoke

397 = 511x0,8x1,14x1x 1x1x1x0,73x1x1x0,78x1x1x1,5

Fire fighting devices Automatic water extinguishing system - Sprinklers

210 = 511x0,8x1,14x1x 0,61x1x1x0,73x0,87x1x0,78x1x1,5x1,5

Automatic akarm transmission to fire brigade qf,d (MJ/m2)

Office

1567 815 397 cçõe 210 Influência das prote s activ as

1400

1200

O = 0,08 m1/2 qf,k = 511 m = 0,8

MJ/m2

1000 Temperatura (ºC)

Af = 45,0

m2

800

q f ,d= m  q1 q2

600



ni

q f ,k

i

400

200

40

0 0

10

20

30

40 Time [min] Tem po (m in)

50

60

70

80

Fire Design of Steel Structures Four steps

1. Definition of the thermal loading - EC1 2. Definition of the mechanical loading - EC0 +EC1 3. Calculation of temperature evolution within the structural members - EC3

4. Calculation of the mechanical behaviour of the structure exposed to fire - EC3

Actions on Structures S

W

Actions for temperature analysis G

A C T I O N S

Q

Thermal Action

FIRE Actions for structural analysis Mechanical Action Dead Load Imposed Load Snow Wind

G Q S W

Fire 42

Actions on Structures S

W

Actions for temperature analysis G

A C T I O N S

Q

Thermal Action

FIRE Actions for structural analysis Mechanical Action Dead Load Imposed Load Snow Wind

G Q S W

Fire 43

Combination Rules for Mechanical Actions EN 1990: Basis of Structural Design • At room temperature (20 ºC)

 G    Q     Q j 1

G, j

k,j

Q ,1

k ,1

i 1

Q ,1

0 ,i

k ,i

• In fire situation 1. Fire is an accidental action. 2. The simultaneous occurrence of other independent accidental actions need not be considered

 G  ( ou  )  Q    Q  A j 1

k ,1

1,1

2 ,1

k ,1

i 1

2 ,i

k ,i

d

1,1 Qk,1 – Frequent value of the representative value of the variable action Q1 2,1 Qk,1 – Quasi-permanent value of the representative value of the variable action Q1 Ad – Indirect thermal action due to fire induced by the restrained thermal expansion44 may be neglected for member analysis

Combination Rules for Mechanical Actions EN 1990: Basis of Structural Design

 G  ( ou  )  Q    Q  A j 1

k ,1

1,1

k ,1

2 ,1

i 1

Action

1

2

Imposed loads in buildings, category (see EN 1991-1-1)

0.5

0.3

Imposed loads in congregation areas and shopping areas

0.7

0.6

Imposed loads in storage areas

0.9

0.8

vehicle weight  30 kN

0.7

0.6

0.5

0.3

Imposed loads in roofs

0.0

0.0

Snow (Norway, Sweden …)

0.2

0.0

Wind loads on buildings

0.2

0.0

30 kN  vehicle weight

 160 kN

2 ,i

k ,i

d

In some countries the National Annex recommends 1,Q1, so that wind is always considered and so horizontal actions are always taken into 45 account

Fire Design of Steel Structures Four steps

1. Definition of the thermal loading - EC1 2. Definition of the mechanical loading - EC0 +EC1 3. Calculation of temperature evolution within the structural members - EC3

4. Calculation of the mechanical behaviour of the structure exposed to fire - EC3

Thermal response Heat conduction equation

                  Q  c p x  x  y  y  t Boundary conditions

qc  hc (   )

convection

qr   (4  4a )   (2  a2 )(  a )(  a )  hr (  a )  

radiation

hr

47

Thermal response Temperature field by Finite Element Method – After 30 min. ISO               Q   c     p x  x  y  y  t Concrete (30x30 cm2)

Note: this equation can be simplified for the case of current steel profiles

48

48

Temperature increase of unprotected steel Simplified equation of EC3 Temperature increase in time step t: Fire temperature A V

a.t  k sh

Steel temperature

h net,d t

m

c aa

Steel

Heat flux h net,d has 2 parts: Radiation:



4 4 h net,r  5,67 x10 8  f  m r  273   m  273 

Convection:



h net,c   c  g  m



 49

Section factor Am/V Unprotected steel members

 a.t  k sh

Am V  hnet,d t c aa b

h

perimeter c/s area

exposed perimeter c/s area

2(b+h) c/s area

50

Correction factor for the Shadow effect ksh For I-sections under nominal fire: ksh = 0.9 [Am/V]b/[Am/V] In all other cases: ksh = [Am/V]b/[Am/V]

]b V / m A [

For cross-sections convex shape: ksh = 1 - Section factor as the profile has a hollow encasement fire protection

b

b

h

2(b+h) c/s area

h

2h+b c/s area

51

Nomogram for temperature Unprotected steel profiles Nomogram for unprotected steel members subjected to the ISO 834 fire curve, for different values of ksh · Am/V [m-1] 800

700

600

Temperature [ºC]

500 400 m-1

400

300 m-1 200 m-1 100 m-1

300

60 m-1 40 m-1

200

30 m-1 25 m-1 20 m-1

100

15 m-1 10 m-1

52

0 0

10

20

30 Time [min.]

40

50

60

Structural fire protection Passive Protection Insulating Board Gypsum, Mineral fibre, Vermiculite. Easy to apply, aesthetically acceptable. Difficulties with complex details. Cementitious Sprays Mineral fibre or vermiculite in cement binder. Cheap to apply, but messy; clean-up may be expensive. Poor aesthetics; normally used behind suspended ceilings. Intumescent Paints Decorative finish under normal conditions. Expands on heating to produce insulating layer. Can be done off-site.

53

Structural fire protection

Columns:

Beams:

54

Structural fire protection Intumescent paint

55

Structural fire protection Cementitious Sprays

56

Structural fire protection Insulating Board

57

Temperature increase of protected steel Simplified equation of EC3 Fire temperature

• Some heat stored in protection layer.

Steel temperature

• Heat stored in protection layer relative to heat stored in steel



c p p c aa

dp

Ap Steel

V

Protection • Temperature rise of steel in time increment t

 a.t

dp





 p / dp A p  1     g.t   a.t t  e  / 10  1  g.t  c aa V  1   / 3 





58

Section factor Ap/V Protected steel members

a.t





 p / dp A p  1    g.t  a.t t  e  / 10  1  g.t   c aa V  1   / 3 





b

h

Steel perimeter steel c/s area

inner perimeter of board steel c/s area

2(b+h) c/s area

59

Nomogram for temperature Protected steel profiles Nomogram for unprotected steel members subjected to the ISO 834 fire curve, for different values of [Ap/V][λp/dp] [W/Km3] 800

700

Temperature [ºC]

600

500

2000 W/Km3 1500 W/Km3

400

1000 W/Km3 800 W/Km3

300

600 W/Km3 400 W/Km3 300 W/Km3

200

200 W/Km3 100 W/Km3

100

0 0

60

120 Time [min.]

180

240 60

Fire Design of Steel Structures Four Steps

1. Definition of the thermal loading - EC1 2. Definition of the mechanical loading - EC0 +EC1 3. Calculation of temperature evolution within the structural members - EC3

4. Calculation of the mechanical behaviour of the structure exposed to fire - EC3

Degree of simplification of the structure

a) a)

b) b)

c) c)

Analysis of: a) Global structure; b) Parts of the structure; c) Members 62

Mechanical properties of carbon steel Stress-strain relationship at elevated temperatures

Stress



f y,

f p,

E a, = tan 

 p,

 y,

= 2%

 t,

 u,

Strain

= 15% = 20%

 63

Mechanical properties of carbon steel Stress-strain relationship at elevated temperatures Stress (N/mm2) 



Strength/stiffness reduction factors for elastic modulus and yield strength (2% total strain). Elastic modulus at 600°C reduced by about 70%.

300 250 200

20°C 200°C 300°C 400°C 500°C

150 600°C 100



Yield strength at 600°C reduced by over 50%.

700°C

50

800°C 0

0.5

1.0 1.5 Strain (%)

2.0 64

Reduction factors for stress-strain relationship of carbon steel at elevated temperatures Reduction factors at temperature a relative to the value of fy or Ea at 20 C Reduction factor Reduction factor Reduction factor Steel (relative to fy) (relative to fy) (relative to Ea) Temperature for effective yield for proportional limit for the slope of the strength linear elastic range a ky, = fy, / fy

kp, = fp, / fy

kE, = Ea, / Ea

20 C

1,000

1,000

1,000

100 C

1,000

1,000

1,000

200 C

1,000

0,807

0,900

300 C

1,000

0,613

0,800

400 C

1,000

0,420

0,700

500 C

0,780

0,360

0,600

600 C

0,470

0,180

0,310

700 C

0,230

0,075

0,130

800 C

0,110

0,050

0,090

900 C

0,060

0,0375

0,0675

1000 C

0,040

0,0250

0,0450

1100 C

0,020

0,0125

0,0225

1200 C

0,000

0,0000

0,0000

% of the value at 20 ºC 1

Yield Strength

.8

k y ,  f y , / f y

.6 .4 .2 0

Young Modulus k E ,  Ea , / Ea 300

600 900 1200 65 Temperature (°C)

Checking Fire Resistance: Strategies with nominal fires R, E

22

Rfi,d

Efi,d

11 t fi,requ

1. Time: tfi,d > tfi,requ

t

t fi,d

2. Load resistance: Rfi,d,t > Efi,d

 d  cr,d

33 t

3. Temperature:

d cr,d

66

Checking Fire Resistance: Strategies with natural fires 1. Load resistance: Rfi,d,t > Efi,d

R, E Rfi,d

1

Efi,d

t 

 cr,d d

2 t

collapse is prevented during the complete duration of the fire including the decay phase or during a required period of time.

2. Temperature: d cr,d collapse is prevented during the complete duration of the fire including the decay phase or during a required period of time. Note: With the agreement of authorities, verification in the time domain can be also performed. The required periodo of time 67 defining the fire resistance must be accepted by the authorities.

Checking Fire Resistance: Strategies with natural fires The Load-bearing function is ensured if collapse is prevented during the complete duration of the fire including the decay phase, or during a required period of time. R, E

R, E

Rfi,d, t

Rfi,d, t

Efi,d

Efi,d

t

Collapse is prevented during the complete duration of the fire including the decay phase.

t1fi,requ t fi,d

t2fi,requ

t

Collapse is prevented during a required period of time, t1fi,req. 68

Design procedures

 Tabulated data (EC2, EC4, EC6)  Simple calculation models (All the Eurocodes)  Advanced calculation models (All the Eurocodes)

Eurocode 2: Tabulated data Fire resistance of a RC beam

a) a) R 60

b)

b) R 180

70

Eurocode 4: Tabulated data Fire resistance of a RC column

80 c

c 80 300

hc u45 s bc 300

us 45

R 120

71

Design procedures

 Tabulated data (EC2, EC4, EC6)  Simple calculation models (All the Eurocodes)  Advanced calculation models (All the Eurocodes)

Eurocode 4: Simple calculation model Sagging moment resistance of a composite beam Compression beff hu

hc

F

fay, /  M, fi,a

b2

2

2

e2 h

fc,20 C /  M , fi,c

c(x)

ew

hw 1

e1 b1

w

fay, /  M, fi,a w

fay,1 / M,fi,a

T





yF

yT

Tension

M

fi,Rd +

 T (y F - yT )

73

Eurocódigo 2 - Vigas Métodos simplificados Eurocode 2: Simplified calculation model 500°C isotherm method Damaged concrete, i.e. concrete with temperatures in excess of 500°C, is assumed not to contribute to the load bearing capacity of the member, whilst the residual concrete cross-section retains its initial values of strength and modulus of elasticity.

74

Eurocode 2: Simplified calculation model 500°C isotherm method – RC beam 300

500ºC

Temperature profiles from Annex A

280 260 240 220

Effective section

200 180

T = 100 ºC

160

T = 300 ºC

140 120 100

T = 200 ºC

100 80

200

60

300 400

40

500 700 600 800

20 0

R60

900

0

20

40

60

80

100 120 140

75

Eurocódigo 2 - Vigas Métodos simplificados Eurocode 2: Simplified calculation model Sagging moment resistance of a RC beam

fcd,fi(20) x

x

As' z' As

dfi

Fs = As'fscd,fi(m)

xbfifcd,fi(20)

z As1fsd,fi(m)

Mu1

+

z'

Mu2

Fs = As2fsd,fi(m)

bfi

76

Eurocode 3: Fire Resistance: Tension members - 1

• The design resistance of a tension

member with uniform temperature a is:

% of the value at 20 ºC Factor de 1 redução .8 k y ,  f y , / f y .6 .4 .2

Nfi,,Rd  k y, Af y /  M,fi or

0

300

600 900 1200 Temperature (°C)

Nfi,,Rd  k y,NRd [  M0 /  M,fi ] NRd = design resistance of the cross-section Npl,Rd for normal temperature design

77

Eurocode 3: Fire Resistance: Compression members with Class 1, 2 or 3 cross-sections - 1 • Design buckling resistance of a compression member with uniform 1 temperature a is With 1  fi  2 2     

 



1 2 1      2



Nb,fi,,Rd   fi Ak y, f y

 M,fi

Bracing system lfi=0,7L

  0.65 235 / f y (Curves a, b, c, d, a0)

• Non.dimensional slenderness:

    k y , / k E ,

lfi=0,5L 78

Eurocode 3: Fire Resistance: Laterally restrained beams with Class 1, 2 or3 cross-sections with uniform temperature - 1

• The design moment resistance of a Class 1, 2 or Class 3 cross-section with a uniform temperature a is:

Mfi,,Rd

  M0    MRdk y,     M,fi 

MRd = Mpl,Rd – Class 1 or 2 cross-sections MRd = Mel,Rd – Class 3 cross-sections 79

Eurocode 3: Fire Resistance: Laterally restrained beams with Class 1, 2 or 3 cross-sections with non-uniform temperature - 2 Adaptation factors to take into account the non-uniform temperature distribution Moment Resistance:

Mfi,,Rd

  M0  1   MRdk y,      M,fi  1 2

1 is an adaptation factor for non-uniform temperature across the cross-section Temp

1=1,0 for a beam exposed on all four sides 1=0,7 for an unprotected beam exposed on three sides 1=0,85 for a protected beam exposed on three sides 80

Eurocode 3: Fire Resistance: Laterally restrained beams with Class 1, 2 or 3 cross-sections with non-uniform temperature - 3 Adaptation factores to take into account the non-uniform temperature distribution Temp

Temp

Temp

Moment Resistance:

Mfi,,Rd

  M0  1   MRdk y,      M,fi  1 2

2 is an adaptation factor for non-uniform temperature along the beam.

2=0,85 at the supports of a statically indeterminate beam 2=1.0 in all other cases 81

Eurocode 3: Fire Resistance: Laterally unrestrained beams - 1 Fixed

Unloaded position Buckled position

Applied load

Lateral-torsional buckling 82

Eurocode 3: Fire Resistance: Laterally unrestrained beams - 2 • Design lateral torsional buckling resistance moment of a laterally unrestrained beam at the max. temp. in the comp. flange •

a.com is

LT.fi the reduction factor for lateraltorsional buckling in the fire design situation.

LT . .com  LT k y . .com / k E . .com LT 

Wy f y M cr

M b. fi. .Rd   LT . fiW y k y. .com f y  LT , fi 

 LT , ,com

1

 M . fi

1  LT ,,com  [ LT ,,com ]2  [  LT ,,com ]2



1  1  LT , ,com  (LT , ,com ) 2 2



  0.65 235 / f y (Curves a, b, c, d)

83

Eurocode 3: Fire Resistance Shear Resistance Design shear resistance

Vfi,t,Rd

  M,0  k y,,web VRd    M,fi

   

VRd

is the shear resistance of the gross cross-section for normal temperature design, according to EN 1993-1-1.

web

is the average temperature in the web of the

section.

ky,,web is the reduction factor for the yield strength of steel at the steel temperature web. 84

Eurocode 3: Members with Class 1, 2 or 3 cross-sections, subject to combined bending and axial compression - 1 Without lateral-torsional buckling Class 1 and 2

Nfi,Ed  min,fi A k y,

fy  M,fi

k y My,fi,Ed k z Mz,fi,Ed   1 fy fy Wpl,z k y, Wpl,y k y,  M,fi  M,fi

Class 3

Nfi,Ed  min,fi A k y,

fy  M,fi



k y My,fi,Ed Wel,y k y,

fy  M,fi

k z Mz,fi,Ed  1 fy Wel,z k y,  M,fi 85

Eurocode 3: Members with Class 1, 2 or 3 cross-sections, subject to combined bending and axial compression - 2 With lateral-torsional buckling Class 1 and 2 Nfi,Ed  z,fi A k y,

fy



k LT M y,fi,Ed LT,fi Wpl,y k y,

 M,fi

fy  M,fi

k z Mz,fi,Ed  1 fy Wpl,z k y,  M,fi

Class 3 Nfi,Ed  z,fi A k y,

fy  M,fi



k LT My,fi,Ed LT,fi Wel,y k y,

fy  M,fi

k z Mz,fi,Ed  1 fy Wel,z k y,  M,fi 86

Eurocode 3: Fire Resistance Members with Class 4 cross-sections Two procedures: 1. In the absence of calculation a critical temperature of 350 ºC should be considered (conservative results). 2. Alternatively use Annex E, considering the effective area and the effective section modulus determined in accordance with EN 1993-1-3 and EN 1993-1-5, i.e. based on the material properties at 20°C. For the design under fire conditions the design strength of steel should be taken as the 0,2 percent proof strength instead of the strength corresponding to 2% total strain. 87

Eurocode 3: Fire Resistance Design yield strength to be used with simple calculation models Cross-sectional Class 1, 2 and 3 Tensão  f y,

fp0.2, 

Crosssectional Class 4

Annex E of EN 1993-1-2

f p,



0,2% p,

E a, = tan   y,

= 2%

 t,

 u,

Extensão  88

Eurocode3: Fire Resistance Concept of critical temperature - 1

crit,2 < crit,1

crit,1

crit,2

The designer should provide the owner with value of the critical temperature, so that the thickness of the fire protection material can be defined in a more economical way.

Note: the concept of critical temperature should only be used if uniform temperature in the cross-section is 89 adopted.

Eurocode 3: Fire Resistance Concept of critical temperature - 2 The best fit curve to the points of this table can be obtained as: Reduction factors at temperature a relative to the value of fy or Ea at 20C Reduction Reduction factor Reduction Reduction Steel factor (relative to fy) factor factor Temperature (relative to (relative to for the design (relative to Ea) f y) strength of f y) for the slope of hot rolled and welded for effective for a the linear thin walled sections yield proportional elastic range (Class 4) strength limit ky,=fy,/fy kp,=fp,/fy kE,=Ea,/Ea k0.2p,=f0.2p, / fy 20 ºC 1.000 1.000 1.000 1.000 100 ºC 1.000 1.000 1.000 1.000 200 ºC 1.000 0.807 0.900 0.890 300 ºC 1.000 0.613 0.800 0.780 400 ºC 1.000 0.420 0.700 0.650 500 ºC 0.780 0.360 0.600 0.530 600 ºC 0.470 0.180 0.310 0.300 700 ºC 0.230 0.075 0.130 0.130 800 ºC 0.110 0.050 0.090 0.070 900 ºC 0.060 0.0375 0.0675 0.050 1000 ºC 0.040 0.0250 0.0450 0.030 1100 ºC 0.020 0.0125 0.0225 0.020 1200 ºC 0.000 0.0000 0.0000 0.000 NOTE: For intermediate values of the steel temperature, linear interpolation may be used.

k y ,

   0.9674  e   

 a  482 39.19

  1   

1

3.833

1

90

Eurocode 3: Fire Resistance Concept of critical temperature - 3

k y ,

   0.9674  e   

 a  482 39.19

   1   

1

3.833

1

 a ,cr  k y , 1

 a ,cr

  1  39.19 ln   1  482 3,833   0,9674k y , 91

Fire Resistance: Concept of critical temperature for a member in tension -1 R, E

Nfi,Rd,t

Nfi,Rd,t = Nfi,Ed Collapse Nfi,Ed



tfi,d

t

cr,d

tfi,d

Nfi,Ed 92

t

Eurocode 3: Fire Resistance Concept of critical temperature for a member in tension - 2 - Resistance at normal temperature:

NRd = Afy/M0 - Resistance in fire situation:

Nfi,Rd = Aky,fy/M,fi e = 0,402 mm More than 50% cr = 500ºC => e = 0.605 mm 117

Examples using different methodologies. Fire resistance of steel structures

 Using tables from the suppliers of the fire protection material Prescriptive approach  Comparison between simplified calculation methods and advanced calculation models – Prescriptive / Performance-based approach  Cases where it is not possible to use simplified calculation method Performance-based approach

118

BARREIRO RETAIL PARK

Required fire resistance 90 minutes (R90) 119

Different zones for fire scenarios

C

B

L K D

S275

120

Temperature development for different fire scenarios

ºC

1200 1000 Jumbo 800

Escritórios Decathlon AKI

600

Unidade D Unidade K

400

ISO834 200 0 0

10

20

30

40

50

60

70

80

90

100

110

120

Tempo[min] [min] Time

Temperatures obtained using the program Ozone 121

Unit B - Jumbo

1.0Gk   1,1Qk ,1  1.0Gk  0.0Qk ,1  Gk

Combination of actions:

L

cr

tfi,d

(m)

(ºC)

(min)

1.0

7.3

672.9

19.25

45

1.0

7.3

593.5

15.23

0.0

-

-

682.8

17.92

NEd

M1

(kN)

(kN. m)

(kN.m)

HEA 260

80

0.00

23

HEA 240

34

0.00

IPE 360

0.00

76.0

cr

ISO

M2 lfi/L

Natural Fire Simplified Method

Natural Fire Advanced Method (min)

(ºC)

(min)

(min)

HEA 260

672.9

> 90

> 90

HEA 240

593.5

80.8

> 90

IPE 360

682.8

> 90

> 90

Without fire protection

With fire protection for R60 and a critical temperature of 500ºC

> 90 122

Deformed shape Obtained with Advanced Calculation Methods Deformed shape of Unit B (Jumbo supermarket) after 117 minutes of exposure to a natural fire DIAMOND 2007 for SAFIR FILE: jc2 NODES: 17117 BEAMS: 8253 TRUSSES: 0 SHELLS: 0 SOILS: 0 DISPLACEMENT PLOT ( x 1) TIME: 7036.35 sec

Z

X

Y

Software: GiD (for the numerical model mesh); SAFIR (for the analysis)

5.0 E+01 m

123

Examples using different methodologies. Fire resistance of steel structures

 Using tables from the suppliers of the fire protection material Prescriptive approach  Comparison between simplified calculation methods and advanced calculation models – Prescriptive / Performance-based approach  Cases where it is not possible to use simplified calculation method Performance-based approach

124

EXHIBITION CENTRE

Required fire resistance 120 minutes (R120) 125

Choice of the structural analysis

The main structure is made of non-uniform class 4 elements. There are no simplified methods, for the time being, for such type of elements. Two options were possible: - Using a prescriptive approach, protect the structure for a citical temperature of 350ºC; - Using performance-based approach with advanced claculation methods.

126

Required fire resistance 120 minutes (R120)

Fire scenarios 6 fire scenarios

Zona C Zona B

Fire load density reduced by 39% due to the sprinklers

Zona A

Zona C

Fire resistance (R120)

Zona C 9m Zona B

Zona A

Zona C

13m 127

Fire scenarios Evolução da temperatura no aço

Zone C 600

C4Zone B C5 C1

Temperatura (ºC)

500

C2

Zone A

C3 Zone C C6

Auditório grande

300

C4

200

100

Zone B

0

Evolução da temperatura no aço

0

800

30

60

90

120

150

180

210

Tempo (min)

700

Salão grande Salão pequeno

600 Temperatura (ºC)

Auditório pequeno

C5

400

Salões em simultâneo

C1

500 400

C3

C2

300

C1-5 - Software OZone C6 is a localized fire in Zone C - Elefir-EN

200

Zone A

100 0 0

30

60

90

120 Tempo (min)

150

180

210

240

128

240

Main Structure

Zona C 9m Zona B

Zona A

Zona C

13m

60.0 m Main Portal Frame

30.0 m 129

Structural Analysis Main structure – portal frame with built-up non-uniform class 4 steel elements

Transverse stiffner

Software: GiD (for the numerical model mesh); SAFIR (for the analysis)

130

Structural Analysis Diamond 2009.a.5 for SAFIR FILE: o NODES: 6849 BEAMS: 0 TRUSSES: 0 SHELLS: 6663 SOILS: 0

Software: SAFIR

SHELLS PLOT DISPLACEMENT PLOT ( x 20) TIME: 7229.51 sec Shell Element

Z Y

X

5.0 E-01 m

131

Deformed shape at Zone A, for the combination of actions 1, after 120 minutes (x20)

Conclusions A performance-based analysis, demonstrated in this study that, protecting the structure for a standard fire resistance of 60 minutes (R60), considering a critical temperature of 500ºC, the load-bearing function is ensured during the complete duration of the fire, including the cooling phase. The steel structure of the Center for Exhibitions and Fairs in Oeiras consists of class 4 cross section profiles. In a prescriptive approach and without making any calculation, this structure should have been protected for a critical temperature of 350ºC and for R120.

132

Fire resistance of the steel roof of the Shopping Centre Dolce Vita in Braga, Portugal SUA KAY

SUA KAY

SUA KAY

SUA KAY

133

Roof structure in Steel

Study based on a Fire Resistance of 60 minutes (R60)

SUA KAY

134

Scenario 2 Fire in the compartment D2, C1 and C2

D1 D2

135

It was assumed that the fire would developed in all the 3 parts D2, C1 and C2.

Scenario 2 Fire in the compartment D2, C1 and C2

Maximum area: Af,max = 7560 m2 Fire area: Afi = 7560 m2 Openings: the openings area was 554.4 m2, located at 10.50 m above the floor level, plus an area of 762 m2 in a glass façade. It was assumed that 10% of the openings would be opened until 400ºC, 50% between 400ºC and 500ºC and 100% for temperatures higher 500ºC (stepwise variation). Compartment height: 12.67 m Walls: concrete blocks Ceiling: Sandwich panels with 0.75 mm thickness steel plate and rock wool of 40 mm thickness and 125 kg/m3 density. Rate of Heat Release: RHRf = 250 kW/m2 Fire growth rate: high, t = 150 s Fire load density: qf,k = 730 MJ/m2 Combustion factor: m = 1.0 136

Gas Temperature

OZONE

Peak: 558 °C at: 98 min

600

Scenario 2

500

Fire in the compartment D2, C1 and C2

400 300

Hot Zone Cold Zone

200 100 0

0

20

40

60 Time [min]

80

100

120

Zones Interface Elevation 12.7

10.1

7.6 Elevation

5.1

2.5

0.0 0.0

2.0

4.0

6.0

8.0

10.0 12.0 Time [min]

14.0

16.0

18.0

20.0

h = 2.55 m at: 20.00 min

137

Scenario 4 Localise fire at floor level 1 of part C2

D1 D2

138

I was considered a localise fire at the floor level 1 of part C2.

Scenario 4 Localise fire at floor level 1 of part C2

Fire diameter: dfi = 10 m Temperature calculated at different heights Compartment height: 36 m Rate of Heat Release: RHRf = 250 kW/m2 Fire growth rate: high, t = 150 s Fire load density: qf,k = 730 MJ/m2 Combustion factor: m = 1.0

139

Localised fire Scenario 4

Temperaturas AT a diferentes alturas HEIGHTS FIRE TEMPERATURE DIFFERENT

Localise fire at floor level 1 of part C2

900 0m

800

1m 2m

700

3m 4m

Temperatura (ºC) Temperature

600

5m 6m

500

7m 8m

400

9m

300 200 100 0 0

20

40

60

80

100

120

Tempo (min) Time 140

Program ELEFIR-EN

DIAMOND 2007 for SAFIR FILE: IPE120 NODES: 84

SAFIR

ELEMENTS: 82 SOLIDS PLOT T EMPERATURE PLOT

IPE120 (60 min)

Commercial profiles

TIME: 3600 sec 310.80 310.40 310.00 309.60 309.20 308.80 308.40 308.00 307.60

Y

DIAMOND 2007 for SAFIR

X

FILE: SHS150x5

Z

NODES: 124 ELEMENTS: 124

DIAMOND 2007 for SAFIR SOLIDS PLOT FILE: HEA160

T EMPERATURE PLOT

NODES: 74

SHS150x5 (60 min)

ELEMENTS: 74

TIME: 3600 sec 298.10 298.03 297.95 297.88 297.80 297.73 297.65 297.58 297.50

SOLIDS PLOT T EMPERATURE PLOT

Y X

TIME: 3600 sec 304.20 303.53 302.85 302.18 301.50 300.83 300.15 299.48 298.80

HEA160 (60 min)

Z

Temperature evolution

Y X

600

Z

DIAMOND 2007 for SAFIR

500

FILE: CHS183.7x5 ELEMENTS: 214 SOLIDS PLOT T EMPERATURE PLOT

CHS183.7x5 (60 min)

TIME: 3600 sec 272.60 272.54 272.48 272.41 272.35 272.29 272.23 272.16 272.10

node 15

Temperature (ºC)

NODES: 214

400 300 200 Compartment Scenario 2

100 Steel temperature (node 15)

Y X

Z

0 0

1200

2400

3600 Time (sec)

4800

6000

141

7200

UB356x171x51 (60min)

SAFIR

DIAMOND 2007 for SAFIR FILE: UB356x171x51 NODES: 90 ELEMENTS: 88

node 13

Commercial profiles

SOLIDS PLOT TEMPERATURE PLOT TIME: 3600 sec 648.90 646.40 643.90 641.40 638.90 636.40 633.90 631.40 628.90

Y

Compartment Scenario 1

Temperature evolution

X

Z

Steel temperature without protection (node 13) Steel temperature with protection (node 13)

700

600

UB356x171x51 protected for R30 (60min) DIAMOND 2007 for SAFIR

Temperature (ºC)

500

FILE: UB356x171x51prot NODES: 252 ELEMENTS: 378 SOLIDS PLOT TEMPERATURE PLOT

400

TIME: 3600 sec 610.30 585.28 560.25 535.23 510.20 485.18 460.15 435.13 410.10

300

200

100

Y X

Z

0 0

1200

2400

3600 Time (sec)

4800

6000

7200

142

SAFIR

DIAMOND 2007 for SAFIR FILE: pil arClasse4-2010 NODES: 4502 BEAM S: 0 T RUSSES: 0 SHELLS: 4496 SOILS: 0

Temperature evolution

900

Localized fire in the first m heigth Steel temperature (node 16) Steel temperature with protection (node 16)

800

Temperature (ºC)

Built-up section profiles

700 600

SHELLS PLOT

ME.tsh piso1-1m.tsh piso2-9m.tsh piso1-2m.tsh piso1-3m.tsh piso1-4m.tsh piso1-5m.tsh piso1-6m.tsh piso1-7m.tsh piso2-8m.tsh 8mm.tsh 12mm .tsh piso2M9-8mm.tsh piso2M9-12mm.ts

500 400 300 200 100 0 0

DIAMOND 2007 for SAFIR

1200

2400

3600 Time (sec)

4800

6000

7200

Steel plate section node 16

Z

X FILE: piso1-1mp NODES: 42 ELEMENTS: 20

DIAMOND 2007 for SAFIR

SOLIDS PLOT TEMPERATURE PLOT

272

FILE: piso1-1m NODES: 22 ELEMENTS: 10

TIME: 3600 sec 451.90 437.99 424.08 410.16 396.25 382.34 368.43 354.51 340.60

14

SOLIDS PLOT TEMPERATURE PLOT TIME: 3600 sec 515.50 515.29 515.08 514.86 514.65 514.44 514.23 514.01 513.80

Y X

Y

h

Z

Y

Steel shell element with protection for R60 (60min)

X

Z

Steel shell element (60min)

8

8 [mm]143

Mechanical actions 1.0Gk   1,1Qk ,1  1.0Gk  0.7Qk ,1

Permanent loads: 77 kN/m3 - dead weight of the steel profiles; 0.5 kN/m2 - dead weight of the roof; 0.3 KN/m2 - others permanent loads. Imposed load: 0.5 kN/m2 - publicity panels and other supended objects from the ceiling.

144

Part C1 with the Fire scenario 2 SAFIR

DIAMOND 2007 for SAFIR

DIAMOND 2007 for SAFIR

FILE: blococ1trel 4 NODES: 682 BEAM S: 292 T RUSSES: 0 SHELLS: 0 SOILS: 0

FILE: blocoC1trel 2 NODES: 1176 BEAM S: 515 T RUSSES: 0 SHELLS: 0 SOILS: 0

BEAM S PLOT DISPLACEMENT PLOT ( x 1) T IME: 4239.177 sec Beam Element

BEAM S PLOT DISPLACEMENT PLOT ( x 1) T IME: 5243.58 sec Beam Element Z Y X 5.0 E+00 m

Truss structure 4 Collapse at 71 min DIAMOND 2007 for SAFIR FILE: blococ1trel 3 NODES: 658 BEAM S: 280 T RUSSES: 0 SHELLS: 0 SOILS: 0 BEAM S PLOT DISPLACEMENT PLOT ( x 1) T IME: 3865.782 sec Beam Element

Z Y 5.0 E+00 m

X

Z Y X

5.0 E+00 m

Truss structure 3 Collapse at 65 min

Truss structure 2 Collapse at 87 min

SAFIR DIAMOND 2007 for SAFIR FILE: blococ1trel 1 NODES: 1461 BEAM S: 638 T RUSSES: 0 SHELLS: 0 SOILS: 0

Part C1 with the Fire scenario 2

BEAM S PLOT DISPLACEMENT PLOT ( x 1) T IME: 7196.441 sec Beam Element

DIAMOND 2007 for SAFIR FILE: blocoC1trel 5 NODES: 1278 BEAM S: 549 T RUSSES: 0 SHELLS: 0 SOILS: 0

Truss structure 1 Z Y

No collapse

X

BEAM S PLOT DISPLACEMENT PLOT ( x 1)

1.0 E+01 m

T IME: 4905.083 sec Beam Element

Z Y X

Truss structure 5 Collapse at 82 min 5.0 E+00 m

SAFIR

Frame of Part C2 with the Fire scenario 2

No collapse

Class 4 collumn with non-uniform cross-section

SAFIR 272

14

h

DIAMOND 2007 for SAFIR

DIAMOND 2007 for SAFIR

FILE: pil arClasse4-2010 NODES: 4502 BEAM S: 0 T RUSSES: 0 SHELLS: 4496 SOILS: 0

FILE: pil arClasse4-2010 NODES: 4502 BEAM S: 0 T RUSSES: 0 SHELLS: 4496 SOILS: 0

SHELLS PLOT DISPLACEMENT PLOT ( x 10)

SHELLS PLOT DISPLACEMENT PLOT ( x 10)

T IME: 3863.182 sec

T IME: 7106.25 sec

Shel l El ement

8

ME.tsh piso1-1mp60.tsh piso2-9mp60.tsh piso1-2mp60.tsh piso1-3mp60.tsh piso1-4mp60.tsh piso1-5mp60.tsh piso1-6mp60.tsh piso1-7mp60.tsh piso2-8mp60.tsh 8mm.tsh 12mm .tsh piso2M9-8mm.tsh piso2M9-12mm.ts

8 [mm]

Z

Z 5.0 E-01 m

X

Y

Fire scenario 2

Collapse at 64 min

5.0 E-01 m

X

Y

Fire scenario 4

Without protection - collapse at 14 min With protection of R60 (500ºC) in the first 9 m height - no collapse

Class 4 collumn with non-uniform cross-section DIAMOND 2007 for SAFIR FILE: pil arClasse4-2010 NODES: 4502 BEAM S: 0 T RUSSES: 0 SHELLS: 4496 SOILS: 0 SHELLS PLOT DISPLACEMENT PLOT ( x 10)

Program Elefir-EN

T IME: 7106.25 sec ME.tsh piso1-1mp60.tsh piso2-9mp60.tsh piso1-2mp60.tsh piso1-3mp60.tsh piso1-4mp60.tsh piso1-5mp60.tsh piso1-6mp60.tsh piso1-7mp60.tsh piso2-8mp60.tsh 8mm.tsh 12mm .tsh piso2M9-8mm.tsh piso2M9-12mm.ts

Temperaturas a diferentes alturas 900 0m

800

1m 2m

700

3m 4m

Temperatura (ºC)

600

5m 6m

500

7m 8m

400

9m

300 200

Z

100

5.0 E-01 m

0

Fire scenario 2 0

20

40

60

Tempo (min)

Localised fire

80

100

120

X

Y

Fire scenario 4

Without protection - collapse at 14 min With protection of R60 (500ºC) in the first 9 m height - no collapse

Class 4 collumn with non-uniform cross-section DIAMOND 2007 for SAFIR FILE: pil arClasse4-2010 NODES: 4502 BEAM S: 0 T RUSSES: 0 SHELLS: 4496 SOILS: 0

Built up Box cross-section of class 4 272

14

SHELLS PLOT DISPLACEMENT PLOT ( x 10) T IME: 3863.182 sec Shel l El ement

h

8

8 [mm]

Z 5.0 E-01 m

X

Y

Fire scenario 2

Collapse at 64 min

Note: In a prescriptive approach and without making any calculation, this structure should have been protected for a critical temperature of 350ºC and for R60

Parts of the structure / fire scenarios Part D1 without protection under fire scenario 1 Part D1 with protection in the purlins of R30 under fire scenario 1

Result tcollapse = 53 min No collapse

Frame of part D2 under fire scenario 2

tcollapse = 78 min

Truss structure 1 of part D2 under fire scenario 2

tcollapse = 70 min

Truss structure 2 of part D2 under fire scenario 2

tcollapse = 77 min

Beam of part D2 under fire scenario 2

No collapse

Truss structure 1 of part C1 under fire scenario 2

No collapse

Truss structure 2 of part C1 under fire scenario 2

tcollapse = 87 min

Truss structure 3 of part C1 under fire scenario 2

tcollapse = 65 min

Truss structure 4 of part C1 under fire scenario 2

tcollapse = 71 min

Truss structure 5 of part C1 under fire scenario 2

tcollapse = 82 min

Frame of part C2 under fire scenario 2

No collapse

Collumn with non-uniform cross-section without protection under fire scenario 2

tcollapse = 64 min

Collumn with non-uniform cross-section without protection under fire scenario 4

tcollapse = 14 min

Collumn with non-uniform cross-section with protection of R60 in the first 9 m height under fire scenario 4

No collapse

153

References

• Fire Design of Steel Structures, Jean-Marc Franssen and Paulo Vila Real (2010) – ECCS ed and Ernst & Sohn a Wiley Company ed. www.steelconstruct.com. • Elefir-EN V1.2.2 (2010), Paulo Vila Real and Jean-Marc Franssen, http://elefiren.web.ua.pt. • The ESDEP (1995), (European Steel Design Education Programme) Society, The Steel Construction Institute. • DIFISEK + (2008), Dissemination of Fire Safety Engineering Knowledge +. • Ozone V2.2.6, (2009), http://www.arcelormittal.com/sections/. • SAFIR - A Thermal/Structural Program Modeling Structures under Fire, Jean-Marc Franssen, http://www.s2v.be/portfolio/safir/. • Vila Real, P. M. M.; Lopes, N. “Shopping Centre Dolce Vita em Braga, Portugal”, to Martifer, S.A., LERF - Laboratório de Estruturas e Resistência ao Fogo, Universidade de Aveiro, Junho de 2009. • Vila Real, P. M. M.; Lopes, N. “Barreiro Reatail Park, Portugal”, to Martifer, S.A., LERF Laboratório de Estruturas e Resistência ao Fogo, Universidade de Aveiro, Junho de 2009. • Vila Real, P. M. M.; Lopes, N. “Shopping Centre Oeiras, Portugal”, to Martifer, S.A., LERF Laboratório de Estruturas e Resistência ao Fogo, Universidade de Aveiro, Junho de 2009.

154

Thank you for your attention [email protected]

155