Training School for Young Researchers

Transcription

1 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, April 2012

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

3 Introduction Question Prescriptive or performance-based approach?

4 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

5 Introduction Fire Resistance Classification criteria R Load bearing criterion; E Integrity criterion; I Insulation criterion R Load RE Load REI Load heat heat flames flames hot gases hot gases - Load bearing only: mechanical resistance (criterion R) - Load bearing and separating: criteria R, E and when requested, I

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

7 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 8t log10 ºC Curva ISO 834 ISO 834 curve min

8 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) h R30, R60, R90,... or REI30, REI60. REI90,... Reference plane n

9 Introduction. Example Regulations for fire safety UK Approved document B 9

10 Introduction. Example Regulations for fire safety UK Approved document B 10

11 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 Classification according to the occupancy Risk categories 1.º 2.º 3.º 4.º Function of the structural member 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»

12 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

13 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

14 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

15 Eurocode 1: Actions on Structures S W G Q A C T I O N S Actions for temperature analysis Thermal Action FIRE Actions for structural analysis Mechanical Action Dead Load G Imposed Load Q Snow S Wind W Fire 15

16 Eurocode 1: Actions on Structures S W G Q A C T I O N S Actions for temperature analysis Thermal Action FIRE Fire 16

17 Thermal actions Heat transfer at surface of building elements h net, d hnet, c hnet, r Total net heat flux h net, d h net, d h net, d h net, d 17

18 Thermal actions Heat transfer at surface of building elements h net, d hnet, c hnet, r Total net heat flux h ( net, c c g m ) Convective heat flux h net 4, r f m [( r 273) ( m 273) 4 ] Radiative heat flux g r Temperature of the fire compartment Nominal fire t or Natural fire t 18

19 Actions on Structures Exposed to Fire EN 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

20 Actions on Structures Exposed to Fire EN 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

21 Actions on Structures Exposed to Fire EN 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 (x, y, z, t) - Parametric Fire (t) uniform in the compartment Rate of heat release Fire surface Boundary properties Opening area Ceiling height From DIFISEK+ *) Advanced Fire Models - Two-Zone Model - One-Zone Model - Combined Two-Zones and One-Zone fire -CFD + Exact geometry 21

22 Simplified fire models Nominal Temperature-Time Curve Gas temperature ( C) 1200 Hydrocarbon Fire Standard Fire External Fire 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 22

23 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

24 Characteristics of the Fire Compartment Natural Fire Model Fire resistant enclosures defining the fire compartment according to the national regulations Material properties of enclosures: c From DIFISEK+ Definition of openings 24

25 Characteristics of the Fire Load from EN Natural Fire Model Occupancy Fire Growth Rate RHR f [kw/m²] Fire Load q f,k 80% fractile [MJ/m²] Dwelling Medium Hospital (room) Medium Hotel (room) Medium Library Fast Office Medium School Medium Shopping Centre Fast Theatre (movie/cinema) Fast Transport (public space) Slow

26 Design value of the fire load density Natural Fire Model q f,d qf,k m q1 q2 n [MJ/m 2 ] 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 n 10 i1 ni n1 n2 n9 n10 26

27 Characteristics of the Fire Load from EN Natural Fire Model Compartment floor area A f q f,d [m²] Automatic Fire Suppression Danger of Fire Fire Load Activation Density ni q1. q1 1,10 1,50 1,90 2,00 2,13 q2 Danger of Fire Activation q2 0,78 1,00 1,22 1,44 1,66 Function of Active Fire Safety Measures Automatic Fire Detection. ni. Examples of Occupancies Art gallery, museum, swimming pool Residence, hotel, office Manufactory for machinery & engines Chemical laboratory, Painting workshop Manufactory of fireworks or paints m. q Manual Fire Suppression f,k From DIFISEK+ Automatic fire Independent Water Detection Supplies & Alarm by Heat by Smoke n1 n2 n3 n4 n5 Automatic Water Extinguishing System Automatic Alarm Transmission to Fire Brigade 0,61 0,87 or 0,73 0,87 1,0 0,87 0,7 Work Fire Brigade Off Site Fire Brigade Safe Access Routes Fire Fighting Devices n6 n7 n8 n9 0,61 or 0,78 0,9 or 1 1,5 1,0 1,5 Smoke Exhaust System 1,0 n10 1,5 27

28 Rate of Heat Release Curve from EN Natural Fire Model RHR [MW] Q(t) t t 2 Q max = A fi x RHR f 70% (q f,d A fi ) Decay phase 0 From DIFISEK+ t decay Time [min] 28

29 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 PP 025, Projecto Europeu

30 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

31 Localised Fire: HESKESTAD Method Natural Fire Model Annex C of EN : Flame is not impacting the ceiling of a compartment (L f < H) Fires in open air Flame axis (z) = ,25 (0,8 Q c ) 2/3 (z-z 0 ) -5/3 900 C The flame length L f of a localised fire is given by : H L f = -1,02 D + 0,0148 Q 2/5 L f z D 31

32 Localised Fire:HASEMI Method Natural Fire Model Annex C of EN : Flame is impacting the ceiling (L f >H) 32

33 Localised fires in a car park Five fire scenarios START START Fire Scenario 2 Fire Scenario 4 Fire Scenario 3 Fire Scenario m Fire Scenario 1 START START 20 x 2.40 m Height: Diameter of flame: H = 2.7 m D = 3.9 m Steel Beams: IPE

34 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 Q (MW) st car 2nd car 3rd car 4th car Time (min) From ECSC Project: Demonstration of real fire tests in car parks and high buildings. 34

35 Two Localised fire models Flame length if L r H Hasemi method has to be used if L r < H Heskestad method has to be used Heskestad Method Hasemi Method Program Elefir-EN 35

36 ridmethod Horizontal distances r 3 r r 1 2 d 1 rhasemi id 2 d2 1 r i Program Elefir-EN

37 Temperature development Gas and steel temperture Scenario 1: unprotected steel Scenario 1: protected steel Scenario 2 ( a,max = ºC) ( a,max = 527 ºC) ( a,max = ºC) Scenario 3 ( a,max = ºC) Scenario 4 ( a,max = ºC) Scenario 3 ( a,max = ºC) 37

38 Parametric fire. Needed parameters Natural Fire Model Fire load density - Opening factor - Wall factor - q f, d O A h / v A t b c Temperature = (t) A v - area of vertical openings; - total area of enclosure A t Limitations : A floor 500 m² No horizontal openings H 4 m Wall factor from 1000to 2200 Fire load density, q t,d from 50 to 1000 MJ/m² 38

39 Parametric Fire Natural Fire Model O 0.07m 1 / 2 Annex A of EN O 0.06m 1/ 2 O 0.05m 1 / 2 O 0.02m 1/ 2 [º C] O 0.20m 1/ 2 O 0.14m Ventilation controlled fires [min] 1/ 2 O 0.1m 1/ 2 Fuel controlled fires Parametric fire curves function of - O For a given q f, d, b, A t and A f 39

40 Parametric Fire - Influence of the Actives Fire Safety Measures Natural Fire Model No Fire Active Measures Off Site Fire Brigade Safe access routes Automatic Fire Detection & Alarm by Smoke Fire fighting devices Automatic water extinguishing system - Sprinklers Automatic akarm transmission to fire brigade 1567 = 511x0,8x1,14x1x 1x1x1x1x1x1x1x1,5x1,5x1,5 815 = 511x0,8x1,14x1x 1x1x1x1x1x1x0,78x1x1,5x1,5 397 = 511x0,8x1,14x1x 1x1x1x0,73x1x1x0,78x1x1x1,5 210 = 511x0,8x1,14x1x 0,61x1x1x0,73x0,87x1x0,78x1x1,5x1,5 Office A f = 45,0 m 2 O = 0,08 m 1/2 q f,k = 511 MJ/m 2 m = 0,8 Temperatura (ºC) Influência das protecções activas q f,d (MJ/m 2 ) q m f,d= q1 q Time [min] Tempo (min) i ni q f,k 40

41 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

42 Actions on Structures S W G Q A C T I O N S Actions for temperature analysis Thermal Action FIRE Actions for structural analysis Mechanical Action Dead Load G Imposed Load Q Snow S Wind W Fire 42

43 Actions on Structures S W G Q A C T I O N S Actions for temperature analysis Thermal Action FIRE Actions for structural analysis Mechanical Action Dead Load G Imposed Load Q Snow S Wind W Fire 43

44 Combination Rules for Mechanical Actions EN 1990: Basis of Structural Design At room temperature (20 ºC) G Q G, j k, j Q,1 k,1 j1 i1 Q In fire situation 1. Fire is an accidental action. 2. The simultaneous occurrence of other independent accidental actions need not be considered Q,1 0, i k, i G ou ) Q k, 1 1,1 2,1 k,1 j1 i1 ( Q 2, i k, i A d 1,1 Q k,1 Frequent value of the representative value of the variable action Q 1 2,1 Q k,1 Quasi-permanent value of the representative value of the variable action Q 1 A d Indirect thermal action due to fire induced by the restrained thermal expansion44 may be neglected for member analysis

45 Combination Rules for Mechanical Actions EN 1990: Basis of Structural Design G ( Q Q ou ) k, 1 1,1 2,1 k,1 j1 i1 2, i k, i A d Action 1 2 Imposed loads in buildings, category (see EN ) Imposed loads in congregation areas and shopping areas Imposed loads in storage areas vehicle weight 30 kn kn vehicle weight 160 kn Imposed loads in roofs Snow (Norway, Sweden ) Wind loads on buildings In some countries the National Annex recommends 1,Q 1, so that wind is always considered and so horizontal actions are always taken into 45 account

46 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

47 Thermal response Heat conduction equation Boundary conditions x x y y Q c p t q c h c ( ) convection q r ( 4 4 a ) 2 2 ( a )( a )( h r a ) h r ( a ) radiation 47

48 Thermal response Temperature field by Finite Element Method After 30 min. ISO Concrete (30x30 cm2) x x Q c p y y t Note: this equation can be simplified for the case of current steel profiles 48 48

49 Temperature increase of unprotected steel Simplified equation of EC3 Temperature increase in time step t: a.t k sh A c m a V h a net, d t Fire temperature Steel temperature Heat flux h net,d has 2 parts: Steel Radiation: h net,r , 67x10 f m r m 4 Convection: h net,c c g m 49

50 Section factor A m /V Unprotected steel members a.t k sh A c m a V a h net, d t b h perimeter c/s area exposed perimeter c/s area 2(b+h) c/s area 50

51 [A/VmCorrection factor for the Shadow effect k sh For I-sections under nominal fire: k sh =0.9[A m /V] b /[A m /V] In all other cases: k sh =[A m /V] b /[A m /V] For cross-sections convex shape: k sh =1 ]- Section factor as the profile has a hollow encasement fire protection b bbh h 2(b+h) c/s area 2h+b c/s area 51

52 Nomogram for temperature Unprotected steel profiles Nomogram for unprotected steel members subjected to the ISO 834 fire curve, for different values of k sh Am/V [m-1] Temperature [ºC] m m m m-1 60 m-1 40 m-1 30 m-1 25 m-1 20 m-1 15 m-1 10 m Time [min.] 52

53 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

54 Structural fire protection Columns: Beams: 54

55 Structural fire protection Intumescent paint 55

56 Structural fire protection Cementitious Sprays 56

57 Structural fire protection Insulating Board 57

58 Temperature increase of protected steel Simplified equation of EC3 Some heat stored in protection layer. Heat stored in protection layer relative to heat stored in steel Fire temperature Steel temperature c c p a p a d p A p V Temperature rise of steel in time increment t d p Steel Protection a.t p c a / d a p A p V / / g.t a.t t e 1g. t 58

59 Section factor A p /V Protected steel members a.t p c a / d a p A p V / / g.t a.t t e 1g. t b h Steel perimeter steel c/s area inner perimeter of board steel c/s area 2(b+h) c/s area 59

60 Nomogram for temperature Protected steel profiles Nomogram for unprotected steel members subjected to the ISO 834 fire curve, for different values of [A p /V][λ p /d p ] [W/Km3] Temperature [ºC] W/Km W/Km W/Km3 800 W/Km3 600 W/Km3 400 W/Km3 300 W/Km3 200 W/Km3 100 W/Km Time [min.] 60

61 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

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

63 Mechanical properties of carbon steel Stress-strain relationship at elevated temperatures Stress f y, f p, E = tan a, p, y, t, u, = 2% = 15% = 20% Strain 63

64 Mechanical properties of carbon steel Stress-strain relationship at elevated temperatures Stress (N/mm 2 ) Strength/stiffness reduction factors for elastic modulus and yield strength (2% total strain). Elastic modulus at 600 C reduced by about 70%. Yield strength at 600 C reduced by over 50% C 200 C 300 C 400 C 500 C 600 C 700 C 800 C Strain (%) 64

65 Reduction factors for stress-strain relationship of carbon steel at elevated temperatures Steel Temperature a Reduction factors at temperature a relative to the value of f y or E a at 20 C Reduction factor Reduction factor Reduction factor (relative to f y ) (relative to f y ) (relative to E a ) for effective yield for proportional limit for the slope of the strength linear elastic range k y, = f y, / f y k p, = f p, / f y k E, = E a, / E a 20 C 1,000 1,000 1, C 1,000 1,000 1, C 1,000 0,807 0, C 1,000 0,613 0, C 1,000 0,420 0, C 0,780 0,360 0, C 0,470 0,180 0, C 0,230 0,075 0,130 % of the value at 20 ºC Yield Strength k / y, f y, f y 800 C 0,110 0,050 0, C 0,060 0,0375 0, C 0,040 0,0250 0, C 0,020 0,0125 0, Young Modulus k / E, Ea, E a 1200 C 0,000 0,0000 0, Temperature ( C) 65

66 RE, Checking Fire Resistance: Strategies with nominal fires 2 R fi,d 1 1 E fi,d 1. Time: t fi,d > t fi,requ t fi,requ t fi,d t d 2. Load resistance: R fi,d,t > E fi,d 3 3 cr,d 3. Temperature: d cr,d t 66

67 RE, Checking Fire Resistance: Strategies with natural fires 1 R fi,d Efi,d 1. Load resistance: R fi,d,t > E fi,d collapse is prevented during the complete duration of the fire including the decay phase or during a required period of time. d 2 t cr,d t 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 defining the fire resistance must be accepted 67 by the authorities.

68 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. RE, RE, R fi,d, t R fi,d, t Efi,d Efi,d t t1 2 fi,requ t fi,d t fi,requ t Collapse is prevented during the complete duration of the fire including the decay phase. Collapse is prevented during a required period of time, t 1 fi,req. 68

69 Design procedures Tabulated data (EC2, EC4, EC6) Simple calculation models (All the Eurocodes) Advanced calculation models (All the Eurocodes)

70 Eurocode 2: Tabulated data Fire resistance of a RC beam a) a) R 60 b) b) R

71 Eurocode 4: Tabulated data Fire resistance of a RC column 80 c 80 c u45 s 300 h c u b s c R

72 Design procedures Tabulated data (EC2, EC4, EC6) Simple calculation models (All the Eurocodes) Advanced calculation models (All the Eurocodes)

73 Eurocode 4: Simple calculation model Sagging moment resistance of a composite beam Compression h c b eff b 2 e 2 h e w h w h u c (x) 2 w f ay /, 2 f ay /, w M,fi,a M,fi,a f c,20c / M, fi,c F T y F b 1 e 1 1 f 1 ay, / M,fi,a Tension y T M fi,rd + T (y F - y T ) 73

74 Eurocode 2: Simplified calculation model 500 C isotherm method Eurocódigo 2 - Vigas Métodos simplificados 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

75 Eurocode 2: Simplified calculation model 500 C isotherm method RC beam ºC Temperature profiles from Annex A Effective section T = 100 ºC T = 300 ºC T = 200 ºC R60 75

76 Eurocode 2: Simplified calculation model Sagging moment resistance of a RC beam Eurocódigo 2 - Vigas Métodos simplificados fcd,fi(20) x As' x xbfifcd,fi(20) Fs = As'fscd,fi(m) z' dfi z Mu1 + z' Mu2 As As1fsd,fi(m) Fs = As2fsd,fi(m) bfi 76

77 The design resistance of a tension member with uniform temperature a is: N or Eurocode 3: Fire Resistance: Tension members - 1 fi,,rd k y, Afy / N k M,fi N [ fi,,rd y, Rd M0 / % of the value at 20 ºC 1 Factor de redução.8 k y, f y, / f Temperature ( C) M, fi ] y N Rd = design resistance of the cross-section N pl,rd for normal temperature design 77

78 Eurocode 3: Fire Resistance: Compression members with Class 1, 2 or 3 cross-sections -1 Design buckling resistance of a compression member with uniform temperature a is With 1 fi / (Curves a, b, c, d, a 0 ) f y N b,fi,,rd fi Ak y, Bracing system f y l fi =0,7L 1 M,fi Non.dimensional slenderness: k y, / ke, l fi =0,5L 78

79 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: M fi,,rd M Rd k y, M0 M,fi M Rd = M pl,rd Class 1 or 2 cross-sections M Rd = M el,rd Class 3 cross-sections 79

80 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: M fi,,rd M Rd k y, M0 1 M,fi 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

81 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: M fi,,rd M Rd k y, M0 1 M,fi 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

82 Eurocode 3: Fire Resistance: Laterally unrestrained beams - 1 Fixed Buckled position Unloaded position Applied load Lateral-torsional buckling 82

83 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 M b. fi.. Rd LT. fiwyk y.. com f y 1 M. fi LT.fi the reduction factor for lateraltorsional buckling in the fire design situation. LT..com LT k y..com / k E..com LT, fi LT,, com 1 2 [ 1 LT,, com ] 2 [ LT,, com 2 LT,, com 1LT,, com ( LT,, com) ] 2 LT W y M f cr y / f y (Curves a, b, c, d) 83

84 Eurocode 3: Fire Resistance Shear Resistance Design shear resistance V fi,t,rd k y,,web V Rd M, 0 M,fi V Rd is the shear resistance of the gross cross-section for normal temperature design, according to EN web section. is the average temperature in the web of the k y,,web is the reduction factor for the yield strength of steel at the steel temperature web. 84

85 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 min,fi N fi,ed A k y, f y M,fi W k y pl,y M k y,fi,ed y, f y M,fi W k z pl,z M k z,fi,ed y, f y M,fi 1 Class 3 min,fi N A k fi,ed y, f y M,fi W k y el,y M k y,fi,ed y, f y M,fi W k z el,z M k z,fi,ed y, f y M,fi 1 85

86 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 z,fi N A k fi,ed y, f y M,fi LT,fi k LT W M pl,y y,fi,ed k y, f y M,fi W k z pl,z M k z,fi,ed y, f y M,fi 1 Class 3 z,fi N A k fi,ed y, f y M,fi LT,fi k LT W M el,y y,fi,ed k y, f y M,fi W k z el,z M k z,fi,ed y, f y M,fi 1 86

87 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 and EN , 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

88 Eurocode 3: Fire Resistance Design yield strength to be used with simple calculation models Cross-sectional Class 1, 2 and 3 Tensão f y, f p0.2, Crosssectional Class 4 f p, Annex E of EN ,2% p, E = tan a, y, = 2% t, u, 88 Extensão

89 Eurocode3: Fire Resistance Concept of critical temperature - 1 crit,1 crit,2 < 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 adopted. 89

90 Eurocode 3: Fire Resistance Concept of critical temperature -2 The best fit curve to the points of this table can be obtained as: Steel Temperature a Reduction factors at temperature a relative to the value of f y or E a at 20C Reduction Reduction Reduction factor Reduction factor factor (relative to f factor y ) (relative to (relative to for the design (relative to E f y ) f y ) a ) strength of for the slope of for effective for hot rolled and welded the linear yield proportional thin walled sections elastic range strength limit (Class 4) k y, =f y, /f y k p, =f p, /f y k E, =E a, /E a k 0.2p, =f 0.2p, / f y 20 ºC ºC ºC ºC ºC ºC ºC ºC ºC ºC ºC ºC ºC NOTE: For intermediate values of the steel temperature, linear interpolation may be used. k y a , 1 e 1 90

91 Eurocode 3: Fire Resistance Concept of critical temperature - 3 k y a , 1 e 1 a, cr k 1 y, 1 a, cr ln 1 3,833 0,9674k y,

92 R, E Fire Resistance: Concept of critical temperature for a member in tension -1 N fi,rd,t N fi,rd,t = N fi,ed Collapse N fi,ed t fi,d t cr,d t fi,d t 92 N fi,ed

93 Eurocode 3: Fire Resistance Concept of critical temperature for a member in tension Resistance at normal temperature: N Rd = Af y / M0 - Resistance in fire situation: N fi,rd =Ak y, f y / M,fi < 1 93 N fi,ed

94 Eurocode 3: Fire Resistance Concept of critical temperature for a member in tension - 3 R, E Collapse occurs when: N fi,rd,t = N fi,ed N fi,rd,t N fi,rd,t = N fi,ed N fi,ed Colapso t fi,d t Ak y, f y / M,fi =N fi,ed k y, =N fi,ed / (Af y / M,fi ) a, cr 94 N fi,ed

95 Eurocode 3: Fire Resistance Concept of critical temperature for a member in tension -4 Steel Temperature a By interpolation Reduction factors at temperature a relative to the value of f y or E a at 20C Reduction Reduction Reduction factor Reduction factor factor (relative to f factor y ) (relative to (relative to for the design (relative to E f y ) f y ) a ) strength of for the slope of for effective for hot rolled and welded the linear yield proportional thin walled sections elastic range strength limit (Class 4) k y, =f y, /f y k p, =f p, /f y k E, =E a, /E a k 0.2p, =f 0.2p, / f y 20 ºC ºC ºC ºC ºC a, ºC cr k0.780 y, ºC ºC ºC ºC ºC ºC ºC NOTE: For intermediate values of the steel temperature, linear interpolation may be used. k y, =N fi,ed / (Af y / M,fi ) a, cr or 1 a, cr ln ,833 0,9674k y, 95 N fi,ed

96 Eurocode 3: Fire Resistance Concept of critical temperature for a member in tension -5 1 a, cr ln 1 3,833 0,9674k y, 482 k y, =N fi,ed / (Af y / M,fi ) Eurocode 3 a cr 1, 39.19ln 1 3,833 0, E fi, d 0 k y, R fi, d,0 For the case of tension 0 E R fi, d fi, d,0 Af N y fi, Ed / M, fi 96

97 Checking Fire Resistance in the temperature domain: Strategy for nominal fires. Temperature d ISO 834 Unprotected section crit d Protected section t requ time d crit! 97

98 Temperature Checking Fire Resistance in the temperature domain: Strategy for natural fires Natural fire máx crit máx Unprotected section * Protected section máx crit! time * - or using active fire fighting measures 98

99 Temperature Checking Fire Resistance in the time domain: Strategy for natural fires if accepted by the authorities Natural fire Unprotected section crit * Protected section t fi,d t requ t fi,d t requ t fi,d! time * - or using active fire fighting measures 99

100 Design procedures Tabulated data (EC2, EC4, EC6) Simple calculation models (All the Eurocodes) Advanced calculation models (All the Eurocodes)

101 Advanced calculation models Diamond 2007 for SAFIR FILE: HEA240 NODES: 166 ELEMENTS: 108 TEMPERATURE PLOT TIME: 3970 sec Temperature field in a profile Y X Z Truss without the possibility of expanding longitudinally subjected (colapse time 66.1 min) 101

102 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 102

103 Single storey hall R60 Steel grade S355 6 x 14 = 84 m 2.0 m 1.85 m 8.15 m IPE x 24 = 66 m cr =? Intumescent =? 103

104 Load combinations G Dead load Q Live load in the roof W - Wind Load combination 1: G 1, QQ 2, WW G 0. 0Q 0. 0W G Load combination 2: G, WW 2, QQ G 0. 2W 0. 0Q G 0. 2W 1 104

105 Critical temperature for load combination 1 Section N M 1 M 2 q l fi,y l fi,z - [kn] [knm] [knm] [kn/m] [m] [m] IPE Program Elefir-EN 105

106 Critical temperature for load combination 1 106

107 Critical temperature for load combination 2 Section N M 1 M 2 q l fi,y l fi,z - [kn] [knm] [knm] [kn/m] [m] [m] IPE

108 Critical temperature for load combination 2 108

109 Critical temperature for load combination 2 109

110 Critical temperature of the column IPE 500 a,cr = min(656 ºC; 638 ºC) = 638 ºC 110

111 Critical time with ISO 834 Using Elefir-EN 111

112 Critical time with ISO 834 Using Elefir-EN 112

113 Critical time with ISO 834 Using Elefir-EN t fi,d < t requ = 60 min Fire protection is needed for a critical temperature of a,cr = 638 ºC 113

114 Critical time with ISO 834 Using Nomogram ºC Temperature [ºC] Time [min.] 400 m m m m-1 60 m-1 40 m-1 30 m-1 25 m-1 20 m-1 15 m-1 10 m-1 t fi,d < t requ = 60 min Fire protection is needed for a critical temperature of a,cr = 638 ºC 114

115 ... This Company has sheets for the temperatures: 350, 400, 450, 500, 550, 600, 620, 650 and 700ºC 115

116 Thickness of intumescent painting ºC, 620ºC, 650ºC,... a,cr = 638 ºC A m V m 1 116

117 Thickness of intumescent painting In some Countries default temperatures are suggested if no calculation is made. Normally for columns or other members susceptible of instability phenomena a critical temperature of 500ºC is suggested. If, instead of a critical temperature of 638ºC, a critical temperature of 500ºC was used, a thickness of 0,605 mm would be obtained. cr = 638ºC => e = 0,402 mm cr = 500ºC => e = mm More than 50% 117

118 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

119 BARREIRO RETAIL PARK Required fire resistance 90 minutes (R90) 119

120 Different zones for fire scenarios C B L K D S

121 Temperature development for different fire scenarios ºC Jumbo Escritórios Decathlon AKI Unidade D Unidade K ISO Time Tempo [min] Temperatures obtained using the program Ozone 121

122 Unit B - Jumbo Combination of actions: 1.0G k 1,1Qk,1 1.0Gk 0. 0Qk, 1 G k N Ed M 1 M 2 l fi /L L cr t fi,d (kn) (kn. m) (kn.m) (m) (ºC) (min) HEA Without fire protection HEA IPE cr ISO Natural Fire Simplified Method Natural Fire Advanced Method (ºC) (min) (min) (min) HEA > 90 > 90 With fire protection for R60 and a critical temperature of 500ºC HEA > 90 IPE > 90 > 90 >

123 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: BEAMS: 8253 TRUSSES: 0 SHELLS: 0 SOILS: 0 DISPLACEMENT PLOT ( x 1) TIME: sec Z X Y 5.0 E+01 m Software: GiD (for the numerical model mesh); SAFIR (for the analysis) 123

124 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

125 EXHIBITION CENTRE Required fire resistance 120 minutes (R120) 125

126 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. Required fire resistance 120 minutes (R120) 126

127 Fire scenarios Zona C 6 fire scenarios Zona B Zona A Fire load density reduced by 39% due to the sprinklers Zona C Fire resistance (R120) Zona C Zona A 13m 9m Zona B Zona C 127

128 Fire scenarios 800 Zone C C1 C6 Zone C C4 Zone B Zone A C3 C5 Evolução da temperatura no aço C2 Temperatura (ºC) Evolução da temperatura no aço Auditório grande C5 Auditório pequeno C Zone B Tempo (min) Temperatura (ºC) 700 Salão grande 600 Salão pequeno 500 C1 Salões em simultâneo C2 C Zone A Tempo (min) C1-5 - Software OZone C6 is a localized fire in Zone C - Elefir-EN 128

129 Main Structure Zona C Zona A 13m 9m Zona B Zona C 60.0 m 30.0 m Main Portal Frame 129

130 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

131 Structural Analysis Diamond 2009.a.5 for SAFIR Software: SAFIR FILE: o NODES: 6849 BEAMS: 0 TRUSSES: 0 SHELLS: 6663 SOILS: 0 SHELLS PLOT DISPLACEMENT PLOT ( x 20) TIME: sec Shell Element Z Y X Deformed shape at Zone A, for the combination of actions 1, after 120 minutes (x20) 5.0 E-01 m 131

132 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 R

133 Fire resistance of the steel roof of the Shopping Centre Dolce Vita in Braga, Portugal SUA KAY SUA KAY SUA KAY SUA KAY 133

134 Roof structure in Steel Study based on a Fire Resistance of 60 minutes (R60) SUA KAY 134

135 Scenario 2 Fire in the compartment D2, C1 and C2 D2 D1 135

136 Scenario 2 Fire in the compartment D2, C1 and C2 It was assumed that the fire would developed in all the 3 parts D2, C1 and C2. Maximum area: A f,max = 7560 m 2 Fire area: A fi = 7560 m 2 Openings: the openings area was m 2, located at m above the floor level, plus an area of 762 m 2 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: m Walls: concrete blocks Ceiling: Sandwich panels with 0.75 mm thickness steel plate and rock wool of 40 mm thickness and 125 kg/m 3 density. Rate of Heat Release: RHR f = 250 kw/m 2 Fire growth rate: high, t = 150 s Fire load density: q f,k = 730 MJ/m 2 Combustion factor: m =

137 Scenario 2 OZONE Gas Temperature Peak: 558 C at: 98 min Fire in the compartment D2, C1 and C Hot Zone Cold Zone Time [min] 12.7 Zones Interface Elevation Elevation Time [min] h = 2.55 m at: min 137

138 Scenario 4 Localise fire at floor level 1 of part C2 D2 D1 138

139 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: d fi = 10 m Temperature calculated at different heights Compartment height: 36 m Rate of Heat Release: RHR f = 250 kw/m 2 Fire growth rate: high, t = 150 s Fire load density: q f,k = 730 MJ/m 2 Combustion factor: m =

140 Localised fire Scenario 4 Localise fire at floor level 1 of part C2 Temperature Temperatura (ºC) FIRE TEMPERATURE Temperaturas AT a diferentes DIFFERENT alturas HEIGHTS m 1m 2m 700 3m 4m 600 5m 6m 500 7m 8m 400 9m Program ELEFIR-EN Time Tempo (min) 140

141 DIAMOND 2007 for SAFIR FILE: IPE120 Commercial profiles SAFIR IPE120 (60 min) NODES: 84 ELEMENTS: 82 SOLIDS PLOT TEMPERATURE PLOT TIME: 3600 sec DIAMOND 2007 for SAFIR Y Y X Z SHS150x5 (60 min) FILE: SHS150x5 NODES: 124 ELEMENTS: 124 SOLIDS PLOT TEMPERATURE PLOT TIME: 3600 sec Y X HEA160 (60 min) Z X Z DIAMOND 2007 for SAFIR FILE: HEA160 NODES: 74 ELEMENTS: 74 SOLIDS PLOT TEMPERATURE PLOT TIME: 3600 sec Temperature evolution Y X Z CHS183.7x5 (60 min) DIAMOND 2007 for SAFIR FILE: CHS183.7x5 NODES: 214 ELEMENTS: 214 SOLIDS PLOT TEMPERATURE PLOT TIME: 3600 sec node 15 Temperature (ºC) Time (sec) Compartment Scenario 2 Steel temperature (node 15)

142 Commercial profiles SAFIR node 13 DIAMOND 2007 for SAFIR FILE: UB356x171x51 NODES: 90 ELEMENTS: 88 SOLIDS PLOT TEMPERATURE PLOT TIME: 3600 sec UB356x171x51 (60min) Y Temperature evolution Compartment Scenario 1 Steel temperature without protection (node 13) Steel temperature with protection (node 13) X Z UB356x171x51 protected for R30 DIAMOND 2007 for SAFIR (60min) FILE: UB356x171x51prot NODES: 252 Temperature (ºC) ELEMENTS: 378 SOLIDS PLOT TEMPERATURE PLOT TIME: 3600 sec Y X Z Time (sec) 142

143 Built-up section profiles SAFIR Temperature (ºC) Temperature evolution Localized fire in the first m heigth Steel temperature (node 16) Steel temperature with protection (node 16) DIAMOND 2007 for SAFIR FILE: pilarclasse NODES: 4502 BEAMS: 0 TRUSSES: 0 SHELLS: 4496 SOILS: 0 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 200 piso2m9-8mm.tsh piso2m9-12mm.ts DIAMOND 2007 for SAFIR FILE: piso1-1mp Time (sec) Steel plate section node 16 X Z Y NODES: 42 ELEMENTS: 20 SOLIDS PLOT TEMPERATURE PLOT DIAMOND 2007 for SAFIR FILE: piso1-1m NODES: ELEMENTS: 10 Y TIME: 3600 sec SOLIDS PLOT TEMPERATURE PLOT TIME: 3600 sec h X Z Steel shell element with protection for R60 (60min) Y X Z Steel shell element (60min) 8 8 [mm] 143

144 Mechanical actions 1.0Gk 1,1Qk,1 1.0Gk 0. 7Qk,1 Permanent loads: 77 kn/m 3 - dead weight of the steel profiles; 0.5 kn/m 2 - dead weight of the roof; 0.3 KN/m 2 - others permanent loads. Imposed load: 0.5 kn/m 2 - publicity panels and other supended objects from the ceiling. 144

145

146

147 SAFIR Part C1 with the Fire scenario 2 DIAMOND 2007 for SAFIR FILE: blococ1trel4 NODES: 682 BEAM S: 292 TRUSSES: 0 SHELLS: 0 SOILS: 0 BEAM S PLOT DISPLACEMENT PLOT ( x 1) TIME: sec Beam Element DIAMOND 2007 for SAFIR FILE: blococ1trel2 NODES: 1176 BEAMS: 515 TRUSSES: 0 SHELLS: 0 SOILS: 0 BEAM S PLOT DISPLACEMENT PLOT ( x 1) TIME: sec Z Y Beam Element X Truss structure 4 Collapse at 71 min 5.0 E+00 m DIAMOND 2007 for SAFIR FILE: blococ1trel3 NODES: 658 BEAMS: 280 TRUSSES: 0 SHELLS: 0 SOILS: 0 BEAM S PLOT DISPLACEMENT PLOT ( x 1) TIME: sec Beam Element Z Y X 5.0 E+00 m Z Y X 5.0 E+00 m Truss structure 2 Truss structure 3 Collapse at 87 min Collapse at 65 min

148 SAFIR DIAMOND 2007 for SAFIR FILE: blococ1trel1 NODES: 1461 BEAMS: 638 TRUSSES: 0 SHELLS: 0 SOILS: 0 Part C1 with the Fire scenario 2 BEAM S PLOT DISPLACEMENT PLOT ( x 1) TIME: sec Beam Element DIAMOND 2007 for SAFIR Z Y X Truss structure 1 No collapse 1.0 E+01 m FILE: blococ1trel5 NODES: 1278 BEAM S: 549 TRUSSES: 0 SHELLS: 0 SOILS: 0 BEAM S PLOT DISPLACEMENT PLOT ( x 1) TIME: sec Beam Element Z Y X Truss structure 5 Collapse at 82 min 5.0 E+00 m

149 SAFIR Frame of Part C2 with the Fire scenario 2 No collapse

150 SAFIR Class 4 collumn with non-uniform cross-section DIAMOND 2007 for SAFIR FILE: pilarclasse NODES: 4502 BEAM S: 0 TRUSSES: 0 SHELLS: 4496 SOILS: 0 DIAMOND 2007 for SAFIR FILE: pilarclasse NODES: 4502 BEAMS: 0 TRUSSES: 0 SHELLS: 4496 SOILS: 0 SHELLS PLOT DISPLACEMENT PLOT ( x 10) SHELLS PLOT DISPLACEMENT PLOT ( x 10) 8 8 [mm] h TIME: sec Shell Element TIME: 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 Z Z X Y 5.0 E-01 m Fire scenario 2 X Y Fire scenario 4 Collapse at 64 min 5.0 E-01 m Without protection - collapse at 14 min With protection of R60 (500ºC) in the first 9 m height - no collapse

151 Class 4 collumn with non-uniform cross-section DIAMOND 2007 for SAFIR FILE: pilarclasse NODES: 4502 BEAMS: 0 TRUSSES: 0 SHELLS: 4496 SOILS: 0 Program Elefir-EN Temperatura (ºC) Temperaturas a diferentes alturas m 1m 2m 3m 4m 5m 6m 7m 8m 9m SHELLS PLOT DISPLACEMENT PLOT ( x 10) TIME: 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 Z 0 X Y Fire scenario 2 Fire scenario 4 Tempo (min) Localised fire 5.0 E-01 m Without protection - collapse at 14 min With protection of R60 (500ºC) in the first 9 m height - no collapse

152 Class 4 collumn with non-uniform cross-section DIAMOND 2007 for SAFIR FILE: pilarclasse NODES: 4502 BEAM S: 0 TRUSSES: 0 SHELLS: 4496 SOILS: 0 SHELLS PLOT DISPLACEMENT PLOT ( x 10) Built up Box cross-section of class TIME: sec Shell Element h 8 8 [mm] Z X Y Fire scenario 2 Collapse at 64 min 5.0 E-01 m 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

153 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 Frame of part D2 under fire scenario 2 Truss structure 1 of part D2 under fire scenario 2 Truss structure 2 of part D2 under fire scenario 2 Beam of part D2 under fire scenario 2 Truss structure 1 of part C1 under fire scenario 2 Truss structure 2 of part C1 under fire scenario 2 Truss structure 3 of part C1 under fire scenario 2 Truss structure 4 of part C1 under fire scenario 2 Truss structure 5 of part C1 under fire scenario 2 Frame of part C2 under fire scenario 2 Collumn with non-uniform cross-section without protection under fire scenario 2 Collumn with non-uniform cross-section without protection under fire scenario 4 Collumn with non-uniform cross-section with protection of R60 in the first 9 m height under fire scenario 4 Result t collapse = 53 min No collapse t collapse = 78 min t collapse = 70 min t collapse = 77 min No collapse No collapse t collapse = 87 min t collapse = 65 min t collapse = 71 min t collapse = 82 min No collapse t collapse = 64 min t collapse = 14 min No collapse 153

154 References Fire Design of Steel Structures, Jean-Marc Franssen and Paulo Vila Real (2010) ECCS ed and Ernst & Sohn a Wiley Company ed. Elefir-EN V1.2.2 (2010), Paulo Vila Real and Jean-Marc Franssen, 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), SAFIR - A Thermal/Structural Program Modeling Structures under Fire, Jean-Marc Franssen, 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 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 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

155 Thank you for your attention 155