Approccio sistemico per la sicurezza delle gallerie in caso di incendioe problemi strutturali specifici.
Lezione del 2 dicembre 2015 al corso di Progettazione Strutturale Antincendio - Prof. Ing. Franco Bontempi,
Facolta' di Ingegneria Civile e Industriale
Universita' degli Studi di Roma La Sapienza
TEST CASE GENERATION GENERATION BLOCK BOX APPROACH
PSA - Sicurezza delle gallerie in caso di incendio
1. Approccio sistemico per la sicurezza
delle gallerie in caso di incendio
e problemi strutturali specifici
Prof. Ing. Franco Bontempi
Ordinario di Tecnica delle Costruzioni
Facolta’ di Ingegneria Civile e Industriale
Universita’ degli Studi di Roma La Sapienza
Corso di
PROGETTAZIONE STRUTTURALE ANTINCENDIO
A.A. 2015/16
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2. Scopo della presentazione
• Far vedere gli aspetti piu’ generali della
progettazione strutturale antincendio:
Complessita’ del problema;
Approccio sistemico;
Natura accidentale dell’azione incendio;
Progettazione prestazionale/prescrittiva;
Aspetti specifici delle gallerie stradali.
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20. Piston effect
• Is the result of natural induced draft caused by
free-flowing traffic (> 50 km/h) in uni-directional
tunnel thus providing natural ventilation.
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21. Mechanical ventilation
• “forced” ventilation is required where piston
effect is not sufficient such as in
– congested traffic situations;
– bi-directional tunnels (piston effect is neutralized by
flow of traffic in two opposite directions);
– long tunnels with high traffic volumes.
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22. Longitudinal ventilation system
• employs jet fans suspended under tunnel roof; in
normal operation fresh air is introduced via
tunnel entering portal and polluted air is
discharged from tunnel leaving portal.
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25. Semi-transverse ventilation system
• employs ceiling plenum connected to central fan
room equipped with axial fans; in normal
operation fresh air is introduced along the tunnel
trough openings in the ventilation plenum while
polluted air is discharged via tunnel portals.
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26. Transverse ventilation system
• employs double supply and exhaust plenums
connected to central fan rooms equipped with
axial fans; in normal operation fresh air is
introduced and exhausted via openings in
double ventilation plenums.
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30. Attachments
• Dispersion stack and fan room combined with
longitudinal ventilation: may be required in order
to reduce adverse effect on environment of
discharge of polluted air from tunnel, where
buildings are located in proximity (< 100m) to
tunnel leaving portal.
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38. Prescrittivo (1)
APPROCCIO
PRESCRITTIVO
1) BASI DEL PROGETTO,
2) LIVELLI DI SCUREZZA,
3) PRESTAZIONI ATTESE
NON ESPLICITATI
1) REGOLE DI
CALCOLO E
2) COMPONENTI
MATERIALI
SPECIFICATI E
DETTAGLIATI
QUALITA' ED AFFIDABILITA'
STRUTTURALI
ASSICURATI IN MODO
INDIRETTO
GARANZIA DIRETTA DELLE PRESTAZIONI
E DELLA SICUREZZA STRUTURALI
INSIEME DI
STRUMENTI
LOGICI E
MATERIALI #3
INSIEME DI
STRUMENTI
LOGICI E
MATERIALI #1
INSIEME DI
STRUMENTI
LOGICI E
MATERIALI #2
OBIETTIVI
PRESTAZIONALI E
LIVELLI DI
SICUREZZA
ESPLICITATI
APPROCCIO
PRESTAZIONALE
NUMERICAL
MODELING
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40. Prestazionale (1)
APPROCCIO
PRESCRITTIVO
1) BASI DEL PROGETTO,
2) LIVELLI DI SCUREZZA,
3) PRESTAZIONI ATTESE
NON ESPLICITATI
1) REGOLE DI
CALCOLO E
2) COMPONENTI
MATERIALI
SPECIFICATI E
DETTAGLIATI
QUALITA' ED AFFIDABILITA'
STRUTTURALI
ASSICURATI IN MODO
INDIRETTO
GARANZIA DIRETTA DELLE PRESTAZIONI
E DELLA SICUREZZA STRUTURALI
INSIEME DI
STRUMENTI
LOGICI E
MATERIALI #3
INSIEME DI
STRUMENTI
LOGICI E
MATERIALI #1
INSIEME DI
STRUMENTI
LOGICI E
MATERIALI #2
OBIETTIVI
PRESTAZIONALI E
LIVELLI DI
SICUREZZA
ESPLICITATI
APPROCCIO
PRESTAZIONALE
NUMERICAL
MODELING
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48. Factors for Coupling
MECHANICAL
STATE
(Strain and Stress
Fields and
Mechanical related
Properties)
TERMAL
STATE
(Temperature Field
and Termic Related
Properties)
INFORMATION
FLOW DIRECTION
time
tK
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49. Fully Coupled Scheme
time
tK
TERMAL
STATE
(Temperature Field
and Termic Related
Properties)
MECHANICAL
STATE
(Strain and Stress
Fields and
Mechanical related
Properties)
time
tK
TERMAL
STATE
(Temperature Field
and Termic Related
Properties)
MECHANICAL
STATE
(Strain and Stress
Fields and
Mechanical related
Properties)
time
tK
TERMAL
STATE
(Temperature Field
and Termic Related
Properties)
MECHANICAL
STATE
(Strain and Stress
Fields and
Mechanical related
Properties)
time
tK
TERMAL
STATE
(Temperature Field
and Termic Related
Properties)
MECHANICAL
STATE
(Strain and Stress
Fields and
Mechanical related
Properties)
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50. Staggered Coupled Scheme
time
tK
TERMAL
STATE
(Temperature Field
and Termic Related
Properties)
MECHANICAL
STATE
(Strain and Stress
Fields and
Mechanical related
Properties)
time
tK
TERMAL
STATE
(Temperature Field
and Termic Related
Properties)
MECHANICAL
STATE
(Strain and Stress
Fields and
Mechanical related
Properties)
time
tK
TERMAL
STATE
(Temperature Field
and Termic Related
Properties)
MECHANICAL
STATE
(Strain and Stress
Fields and
Mechanical related
Properties)
time
tK
TERMAL
STATE
(Temperature Field
and Termic Related
Properties)
MECHANICAL
STATE
(Strain and Stress
Fields and
Mechanical related
Properties)
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51. Temperature Driven Scheme
time
tK
TERMAL
STATE
(Temperature Field
and Termic Related
Properties)
MECHANICAL
STATE
(Strain and Stress
Fields and
Mechanical related
Properties)
time
tK
TERMAL
STATE
(Temperature Field
and Termic Related
Properties)
MECHANICAL
STATE
(Strain and Stress
Fields and
Mechanical related
Properties)
time
tK
TERMAL
STATE
(Temperature Field
and Termic Related
Properties)
MECHANICAL
STATE
(Strain and Stress
Fields and
Mechanical related
Properties)
time
tK
TERMAL
STATE
(Temperature Field
and Termic Related
Properties)
MECHANICAL
STATE
(Strain and Stress
Fields and
Mechanical related
Properties)
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52. Scheme With No Memory
time
tK
TERMAL
STATE
(Temperature Field
and Termic Related
Properties)
MECHANICAL
STATE
(Strain and Stress
Fields and
Mechanical related
Properties)
time
tK
TERMAL
STATE
(Temperature Field
and Termic Related
Properties)
MECHANICAL
STATE
(Strain and Stress
Fields and
Mechanical related
Properties)
time
tK
TERMAL
STATE
(Temperature Field
and Termic Related
Properties)
MECHANICAL
STATE
(Strain and Stress
Fields and
Mechanical related
Properties)
time
tK
TERMAL
STATE
(Temperature Field
and Termic Related
Properties)
MECHANICAL
STATE
(Strain and Stress
Fields and
Mechanical related
Properties)
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59. Analysis Strategy #1:
Sensitivity governance of priorities
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60. Analysis Strategy #2:
Bounding behavior governance
p
(p)
p
(p)
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63. ATTRIBUTES
THREATS
MEANS
RELIABILITY
FAILURE
ERROR
FAULT
FAULT TOLERANT
DESIGN
FAULT DETECTION
FAULT DIAGNOSIS
FAULT MANAGING
DEPENDABILITY
of
STRUCTURAL
SYSTEMS
AVAILABILITY
SAFETY
MAINTAINABILITY
permanent interruption of a system ability
to perform a required function
under specified operating conditions
the system is in an incorrect state:
it may or may not cause failure
it is a defect and represents a
potential cause of error, active or dormant
INTEGRITY
ways to increase
the dependability of a system
An understanding of the things
that can affect the dependability
of a system
A way to assess
the dependability of a system
the trustworthiness
of a system which allows
reliance to be justifiably placed
on the service it delivers
SECURITY
High level / active
performance
Low level / passive
performance
Visions, I., Laprie, J.C., Randell, B.,
Dependability and its threats:
a taxonomy,
18th IFIP
World Computer Congress,
Toulouse (France) 2004.
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65. Structural Robustness (2)
• Capacity of a construction to show a
regular decrease of its structural quality
due to negative causes. It implies:
a) some smoothness of the decrease of
structural performance due to
negative events (intensive feature);
b) some limited spatial spread of the
rupture (extensive feature).
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66. Levels of Structural Crisis
UsualULS&SLS
VerificationFormat
Structural Robustness
Assessment
1st level:
Material
Point
2nd level:
Element
Section
3rd level:
Structural
Element
4th level:
Structural
System
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67. Bad vs Good Collapses
STRUCTURE
& LOADS
Collapse
Mechanism
NO SWAY
“IMPLOSION”
OF THE
STRUCTURE
“EXPLOSION”
OF THE
STRUCTURE
is a process in which
objects are destroyed by
collapsing on themselves
is a process
NOT CONFINED
SWAY
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68. Design Strategy #1: Continuity
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69. Design Strategy #2: Segmentation
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70. AZIONE
Natura dell’azione incendio
Carattere accidentale
Carattere estensivo
Carattere intensivo
3
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71. Aspetti caratteristici dell’incendio
• Carattere estensivo
(diffusione nello spazio):
1.wildfire
2.urbanfire
3.all’esterno di una costruzione
4.all’interno di una costruzione
• Carattere intensivo
(andamento nel tempo).
• Natura accidentale.
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76. F
L
A
S
H
O
V
E
R
passive
Create fire
compartments
Prevent damage
in the elements
Prevent loss of
functionality in
the building
active
Detection measures
(smoke, heat, flame
detectors)
Suppression
measures (sprinklers,
fire extinguisher,
standpipes, firemen)
Smoke and heat
evacuation system
prevention protection robustness
Limit ignition
sources
Limit hazardous
human behavior
Emergency
procedure and
evacuation
Prevent the
propagation of
collapse, once
local damages
occurred (e.g.
redundancy)
Fire Safety Strategies
systemic structural
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81. SVILUPPO
Dinamica degli incendi in galleria
Effetti della ventilazione
4
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82. FIRE DYNAMICS IN TUNNELS
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91. Smoke development
• A smoke layer may be created in tunnels at the early stages
of a fire with essentially no longitudinal ventilation. However,
the smoke layer will gradually descend further from the fire.
• If the tunnel is very long, the smoke layer may descend to the
tunnel surface at a specific distance from the fire depending
on the fire size, tunnel type, and the perimeter and height of
the tunnel cross section.
• When the longitudinal ventilation is gradually increased, the
stratified layer will gradually dissolve.
• A backlayering of smoke is created on the upstream side of
the fire.
• Downstream from the fire there is a degree of stratification of
the smoke that is governed by the heat losses to the
surrounding walls and by the turbulent mixing between the
buoyant smoke layers and the normally opposite moving cold
layer.
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94. Maximum gas temperatures in the ceiling area of
the tunnel during tests with road vehicles
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95. Maximum gas temperatures in the ceiling area of
the tunnel during tests with road vehicles
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96. Maximum gas temperatures in the cross section
of the tunnel during tests with road vehicles
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99. • It can be sufficient in short, level tunnels
where smoke stratification allows for
escape in clear/tenable conditions.
Natural smoke venting
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100. Smoke filling long tunnel
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101. Emergency ventilation with
longitudinal system
• It can be employed in unidirectional, medium length
tunnels, with free flowing traffic conditions. Smoke is
mechanically exhausted in direction of traffic circulation,
clear tenable conditions for escape are obtained on
upstream side of fire.
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104. k size factor for small pool fire
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105. k size factor for HGV fire
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106. Emergency ventilation with semi-
transverse “point extraction” system
• Smoke is mechanically exhausted from single ceiling
opening (reverse mode) leaving clear tenable escape
conditions on both sides of fire.
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108. Observation: goal
• The purpose of controlling the spread of smoke
is to keep people as long as possible in a
smoke-free environment.
• This means that the smoke stratification must be
kept intact, leaving a more or less clear and
breathable air underneath the smoke layer.
• The stratified smoke is taken out of the tunnel
through exhaust openings located in the ceiling
or at the top of the sidewalls.
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109. Observation: longitudinal velocity
• With practically zero longitudinal air velocity, the
smoke layer expands to both sides of the fire.
The smoke spreads in a stratified way for up to
10 min.
• After this initial phase, smoke begins to mix over
the entire cross section, unless by this time the
extraction is in full operation.
• The longitudinal velocity of the tunnel air must
be below 2 m/s in the vicinity of the fire
incidence zone. With higher velocities, the
vertical turbulence in the shear layer between
smoke and fresh air quickly cools the upper
layer and the smoke then mixes over the entire
cross section.
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110. Observations: turbulence
• With an air velocity of around 2 m/s, most of the
smoke of a medium-size fire spreads to one side
of the fire (limited backlayering) and starts
mixing over the whole cross section at a
distance of 400 to 600 m downstream of the fire
site. This mixing over the cross section can also
be prevented if the smoke extraction is activated
early enough.
• Vehicles standing in the longitudinal air flow
increase strongly the vertical turbulence and
encourage the vertical mixing of the smoke.
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111. Observation: fresh air
• In a transverse ventilation system, the fresh air
jets entering the tunnel at the floor level induce a
rotation of the longitudinal airflow, which tends to
bring the smoke layer down to the road.
• No fresh air is to be injected from the ceiling in a
zone with smoke because this increases the
amount of smoke and tends to suppress the
stratification.
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112. Observation: smoke extraction
• In reversible semi-transverse ventilation with the
duct at the ceiling, the fresh air is added through
ceiling openings in normal ventilation operation.
• If a fire occurs, as long as fresh air is supplied
through ceiling openings, the smoke quantity
increases by this amount and strong jets tend to
bring the smoke down to the road surface. The
conversion of the duct from supply to extraction
must be done as quickly as possible.
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113. Observation: traffic conditions
• For a tunnel with one-way traffic, designed for
queues (an urban area), the ventilation design
must take into consideration that cars can likely
stand to both sides of the fire because of the
traffic. In urban areas it is usual to find stop-and-
go traffic situations.
• For a tunnel with two-way traffic, where the
vehicles run in both directions, it must be taken
into consideration that in the event of a fire
vehicles will generally be trapped on both sides
of the fire.
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115. Smoke extraction
• Continuous extraction into a return air duct is
needed to remove a stratified smoke layer out of
the tunnel without disturbing the stratification.
• The traditional way to extract smoke is to use
small ceiling openings distributed at short
intervals throughout the tunnel.
• Another efficient way to remove smoke quickly
out of the traffic space is to install large openings
with remotely controlled dampers. They are
normally in an open position where equal
extraction is taking place over the whole tunnel
length.
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116. Tunnel with a single-point
extraction system
The usual way to control the longitudinal velocity is to provide several
independent ventilation sections.
When a tunnel has several ventilation sections, a certain longitudinal
velocity in the fire section can be maintained by a suitable operation of the
individual air ducts.
By reversing the fan operation in the exhaust air duct, this duct can be
used to supply air and vice versa.
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137. Design Process - ISO 13387
A. Design constraints and possibilities
(blue),
B. Action definition and development
(red),
C. Passive system and active response
(yellow),
D. Safety and performance
(purple).
3/22/2011
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138. SS0a
PRESCRIBED
DESIGN
PARAMETERS
SS0b
ESTIMATED
DESIGN
PARAMETERS
SS1
initiation and
development
of fire and
fire efluent
SS2
movement of
fire effluent
SS3
structural response
and fire spread
beyond enclosure
of origin
SS4
detection,
activitation and
suppression
SS5
life safety:
occupant behavior,
location and
condition
SS6
property
loss
SS7
business
interruption
SS8
contamination
of
environment
SS9
destruction
of
heritage
(0)
DESIGN
CONSTRAINTS
AND
POSSIBILITIES
(1+2)
ACTION
DEFINITION
AND
DEVELOPMENT
(3+4)
SYSTEM
PASSIVE
AND ACTIVE
RESPONSE
BUSOFINFORMATION
RESULTS
DESIGN
ACTION
RESPONSE
SAFETY&PERFORMANCE
FSEwww.francobontempi.org
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141. FIRE DETECTION
& SUPPRESSION
active
structural
characteristics
threats
ORGANIZATION &
FIREFIGHTERS
No
Yes
threats
MAINTENANCE
& USE
No
Yes
threats
No
alive
structural
characteristics
Yes
STRUCTURAL
CONCEPTION
STRUCTURAL
TOPOLOGY
&
GEOMETRY
threats
No
Yes
threats
STRUCTURAL
MATERIAL
& PARTS
No
Yespassive
structural
characteristics
threats
FIRE DETECTION
& SUPPRESSION
No
Yes
active
structural
characteristics
threats
ORGANIZATION &
FIREFIGHTERS
No
Yes
threats
MAINTENANCE
& USE
No
Yes
threats
No
alive
structural
characteristics
Yes
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147. Fire safety concepts tree (NFPA)
1
2
3
4
5
6
7
8
9
Buchanan,2002
Strategie per
la gestione
dell'incendio
1
Prevenzione
2
Gestione
dell'evento
3
Gestione
dell'incendio
4
Gestione delle
persone e
dei beni
15
Difesa sul posto
16
Spostamento
17
Disposibilità
delle vie
di fuga
18
Far avvenire
il deflusso
19
Controllo
della quantità
di
combustibile
5
Soppressione
dell'incendio
10
Controllo
dell'incendio
attraverso il
progetto
13
Automatica
11
Manuale
12
Controllo dei
materiali
presenti
6
Controllo
del movimento
dell'incendio
7
Resistenza e
stabilità
strutturale
14
Contenimento
9
Ventilazione
8
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148. 1
2
3
4
5
6
7
8
9
Strategie per
la gestione
dell'incendio
1
Prevenzione
2
Gestione
dell'evento
3
Gestione
dell'incendio
4
Gestione delle
persone e
dei beni
15
Difesa sul posto
16
Spostamento
17
Disposibilità
delle vie
di fuga
18
Far avvenire
il deflusso
19
Controllo
della quantità
di
combustibile
5
Soppressione
dell'incendio
10
Controllo
dell'incendio
attraverso il
progetto
13
Automatica
11
Manuale
12
Controllo dei
materiali
presenti
6
Controllo
del movimento
dell'incendio
7
Resistenza e
stabilità
strutturale
14
Contenimento
9
Ventilazione
8
Fire safety concepts tree (NFPA)
Buchanan,2002
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149. Basis of tunnel fire safety design
• The first priority identified in the literature for fire
design of all tunnels is to ensure:
1. Prevention of critical events that may endanger
human life, the environment, and the tunnel structure
and installations.
2. Self-rescue of people present in the tunnel at time of
the fire.
3. Effective action by the rescue forces.
4. Protection of the environment.
5. Limitation of the material and structural damage.
• Furthermore, part of the objective is to reduce
the consequences and minimize the economic
loss caused by fires.
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153. Option 1 Risk avoidance, which usually means not
proceeding to continue with the system; this is not
always a feasible option, but may be the only
course of action if the hazard or their probability of
occurrence or both are particularly serious;
Option 2 Risk reduction, either through (a) reducing the
probability of occurrence of some events, or (b)
through reduction in the severity of the
consequences, such as downsizing the system, or
(c) putting in place control measures;
Option 3 Risk transfer, where insurance or other financial
mechanisms can be put in place to share or
completely transfer the financial risk to other
parties; this is not a feasible option where the
primary consequences are not financial;
Option 4 Risk acceptance, even when it exceeds the criteria,
but perhaps only for a limited time until other
measures can be taken.
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158. SCENARIOS
DEFINE SYSTEM
(the system is usually decomposed into
a number of smaller subsystems and/or
components)
HAZARD SCENARIO ANALYSIS
(what can go wrong?
how can it happen?
waht controls exist?)
ESTIMATE
CONSEQUENCES
(magnitude)
ESTIMATE
PROBABILITIES
(of occurrences)
DEFINE
RISK SCENARIOS
SENSITIVITY
ANALYSIS
RISK
ANALYSIS
FIRE
EVENT
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160. EVENT TREE
Triggering
event
Fire
ignition
1. Fire
extinguished
by personnel
2. Intrusion of
fire fighters
Arson
Explosion
Short
circuit
Cigarette
fire
YES (P1)
NO (1-P1) YES (P2)
NO (1-P2)
Scenario
Other
A1
A2
A3
A4
A5
3. Fire
suppression
YES (P3)
NO (1-P3)
YES (P3)
NO (1-P3)
Fire
location
AREA A
(PA)
YES (P1)
NO (1-P1) YES (P2)
NO (1-P2)
B1
B2
B3
B4
B5
YES (P3)
NO (1-P3)
YES (P3)
NO (1-P3)
AREA B
(PB)
YES (P1)
NO (1-P1) YES (P2)
NO (1-P2)
C1
C2
C3
C4
C5
YES (P3)
NO (1-P3)
YES (P3)
NO (1-P3)
AREA C
(PC)
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160
161. DEFINE SYSTEM
(the system is usually decomposed into
a number of smaller subsystems and/or
components)
HAZARD SCENARIO ANALYSIS
(what can go wrong?
how can it happen?
waht controls exist?)
ESTIMATE
CONSEQUENCES
(magnitude)
ESTIMATE
PROBABILITIES
(of occurrences)
DEFINE
RISK SCENARIOS
SENSITIVITY
ANALYSIS
RISK
ANALYSIS
NUMERICAL
MODELING
SIMULATIONSwww.francobontempi.org
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165. F (frequency) – N (number of fatalities) curve
• An F–N curve is an alternative way of describing
the risk associated with loss of lives.
• An F–N curve shows the frequency (i.e. the
expected number) of accident events with at
least N fatalities, where the axes normally are
logarithmic.
• The F–N curve describes risk related to large-
scale accidents, and is thus especially suited for
characterizing societal risk.
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166. FN-curves UK Road Rail Aviation Transport, 67-01
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167. Persson, M. Quantitative Risk Analysis Procedure for
the Fire Evacuation of a Road Tunnel - An Illustrative
Example. Lund, 2002
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168. Risk acceptance – ALARP (1)
RISK MAGNITUDE
INTOLERABLE
REGION
As
Low
As
Reasonably
Practicable
BROADLY ACCEPTABLE
REGION
Risk cannot be justified
in any circumstances
Tolerable only if risk
reduction is impracticable
or if its cost is greatly
disproportionate to the
improvement gained
Tolerable if cost of
reduction would exceed
the improvements gained
Necessary to maintain
assurance that the risk
remains at this level
As
Low
As
Reasonably
Achievable
RISK MAGNITUDE
INTOLERABLE
REGION
As
Low
As
Reasonably
Practicable
BROADLY ACCEPTABLE
REGION
Risk cannot be justified
in any circumstances
Tolerable only if risk
reduction is impracticable
or if its cost is greatly
disproportionate to the
improvement gained
Tolerable if cost of
reduction would exceed
the improvements gained
Necessary to maintain
assurance that the risk
remains at this level
As
Low
As
Reasonably
Achievable
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169. Risk acceptance – ALARP (2)
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172. Monetary values – cost of human life (!)
What is the maximum amount the society (or the
decisionmaker) is willing to pay to reduce
the expected number of fatalities by 1?
Typical numbers for the value of a statistical life used in
cost-benefit analysis are 1–10 million euros.
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172
174. The burnt out interior
of the Mont Blanc Tunnel
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175. Curve temperatura - tempo
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176. Types of fire exposure
for tunnel analysis
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177. Cellulosic curve
• Defined in various national standards, e.g. ISO 834, BS 476: part 20, DIN
4102, AS 1530 etc.
• This curve is the lowest used in normal practice.
• It is based on the burning rate of the materials found in general building
materials.
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178. Hydrocarbon (HC) curve
• Although the cellulosic curve has been in use for many years, it soon became
apparent that the burning rates for certain materials e.g. petrol gas, chemicals
etc, were well in excess of the rate at which for instance, timber would burn.
• The hydrocarbon curve is applicable where small petroleum fires might occur,
i.e. car fuel tanks, petrol or oil tankers, certain chemical tankers etc.
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179. Hydrocarbon mod. (HCM) curve
• Increased version of the hydrocarbon curve, prescribed by the French
regulations.
• The maximum temperature of the HCM curve is 1300ºC instead of the
1100ºC, standard HC curve.
• However, the temperature gradient in the first few minutes of the HCM fire is
as severe as all hydrocarbon based fires possibly causing a temperature
shock to the surrounding concrete structure and concrete spalling as a result
of it.
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180. RABT ZTV curves
• The RABT curve was developed in Germany as a result of a series of test
programs such as the EUREKA project. In the RABT curve, the temperature
rise is very rapid up to 1200°C within 5 minutes.
• The failure criteria for specimens exposed to the RABT-ZTV time-temperature
curve is that the temperature of the reinforcement should not exceed 300°C.
There is no requirement for a maximum interface temperature.
RABT-ZTV (train)
Time (minutes) T (°C)
0 15
5 1200
60 1200
170 15
RABT-ZTV (car)
Time (minutes) T (°C)
0 15
5 1200
30 1200
140 15
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181. RWS (Rijkswaterstaat) curve
• The RWS curve was developed by the Ministry of Transport in the
Netherlands. This curve is based on the assumption that in a worst case
scenario, a 50 m³ fuel, oil or petrol, tanker fire with a fire load of 300MW could
occur, lasting up to 120 minutes.
• The failure criteria for specimens is that the temperature of the interface
between the concrete and the fire protective lining should not exceed 380°C
and the temperature on the reinforcement should not exceed 250°C.
RWS, RijksWaterStaat
Time
(minutes)
T
(°C)
0 20
3 890
5 1140
10 1200
30 1300
60 1350
90 1300
120 1200
180 1200
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184. Lönnermark, A. and Ingason, H., “Large Scale Fire Tests in the Runehamar
tunnel – gas temperature and Radiation”,
Proceedings of the International Seminar on Catastrophic Tunnel Fires,
Borås, Sweden, 20-21 November 2003.
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188. Mechanical Analysis
• The mechanical analysis shall be performed for the
same duration as used in the temperature analysis.
• Verification of fire resistance should be in:
– in the strength domain: Rfi,d,t ≥ Efi,requ,t
(resistance at time t ≥ load effects at time t);
– in the time domain: tfi,d ≥ tfi,requ
(design value of time fire resistance ≥
time required)
– In the temperature domain: Td ≤ Tcr
(design value of the material temperature ≤
critical material temperature);
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189. Verification of fire resistance (3D)
R = structural resistance
T = temperature
t = time
T=T(t)
R=R(t,T)=R(t,T(t))=R(t)
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190. Verification of fire resistance (R-safe)
R = structural resistance
T = temperature
t = time
Rfi,d,t
Efi,requ,t
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191. Verification of fire resistance (R-fail)
R = structural resistance
T = temperature
t = time
Efi,requ,t
Rfi,d,t
Failure !
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192. Verification of fire resistance (t)
R = structural resistance
T = temperature
t = time
Efi,requ,t
Rfi,d,t
Failure !
tfi,d ≥ tfi,requ
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193. Verification of fire resistance (T)
R = structural resistance
T = temperature
t = time
Efi,requ,t
Rfi,d,t
Failure !
Td ≤ Tcr
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194. Verification of fire resistance (T)
R = structural resistance
T = temperature
t = time
Efi,requ,t
Rfi,d,t
Failure !
Td ≤ Tcr
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202. Resilience
• Resilience is defined as “the positive
ability of a system or company to adapt
itself to the consequences of a
catastrophic failure caused by power
outage, a fire, a bomb or similar” event or
as "the ability of a system to cope with
change".
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204. ACKNOWLEDGEMENTS
• Dr. Konstantinos GKOUMAS – Uniroma1
• Dr. Francesco PETRINI – Uniroma1
• Ing. Alessandra LO CANE – MIT
• Dr. Filippo GENTILI – Coimbra (PT)
• Mr. Tiziano BARONCELLI – Uniroma1
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