Risk analysis for fire: the case of civil structures

Analisi del rischio: il caso dell’incendio di strutture civili

CORSO DI PROGETTAZIONE STRUTTURALE ANTINCENDIO

1October 28 2014www.francobontempi.org

Konstantinos Gkoumas, Ph.D., P.E.

Franco Bontempi, Ph.D., P.E.

Facoltà di Ingegneria

Sapienza Università di Roma

http://www.francobontempi.org/

Index

• System approach to fire safety design

• Risk/fire risk/risk analysis

• Risk assessment process

• Risk analysis

• Hazard analysis

• Risk acceptance

• Risk reduction

• References

www.francobontempi.org


2ANALISI DEL RISCHIO:

IL CASO DELL’INCENDIO DI STRUTTURE CIVILI




3ANALISI DEL RISCHIO:

IL CASO DELL’INCENDIO DI STRUTTURE CIVILI


• System approach to fire safety design

• Risk

- fire risk

- risk types

- risk analysis



ANALISI DEL RISCHIO:IL CASO DELL’INCENDIO

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System approach to fire safety design



MINORSPREAD

FIRE SPREADSTOP FIRE

suppressionY

MAJORSPREAD

STRUCTURAL INTEGRITY

AVOID CASUALITIES

LOCALISED DAMAGE

STRUCTURAL FAILURES

N

mitigation

Y

N

fire safe design

Y

N

FIRE

robust design

Y

N

MAJOR COLLAPSE

AVOID DIRECT

DAMAGE

AVOID COLLAPSE

1

2

3

4

0 preventionOBJECTIVE

fire safety design -structural

fire safety design -non structural

GLOBAL SAFETY

LOSS OF GLOBAL SAFETY

AVOID INDIRECT DAMAGE

NY

The fire safety is framed in different “safety levels”, corresponding to different safety objectives.




(Fire) Risk Estimation*

*(following SFPE Handbook of Fire Protection Engineering)

Provide answer to the following questions

1. What could happen?

2. How bad would it be if it did happen?

3. How likely is it to happen






What is risk?Risk can be defined as the probability that the harm or damage from a particular hazard is realized.

Risk is measured in terms of consequences and likelihood (a qualitative description of probability or frequency). In mathematical terms risk can be defined as:

risk = f (frequency or probability, consequence) (1)

In the case of an activity with only one event with potential consequences, a risk (R) is the probability (P) that this event will occur multiplied with the consequences (C) given the event occurs:

R = PC (2)

The risk of a system is the sum of the risks of all harmful events of that system:

(3)




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𝑅𝑆 = 𝑅𝑖𝑛

𝑖=1

7


Risk types• Life safety risks are normally presented in two ways:

- Individual risk and

- Societal risk

• Individual risk:The purpose of the individual risk is to ensure that individuals in the society are not exposed to unacceptably high risks. It can be defined as the risk to any occupant on the scene for the event/hazard scenario i.e. it is the risk to an individual and not to a group of people.

• Societal risk:

Societal risk is not looking at one individual but is concerned with the risk of multiple fatalities. People are treated as a group, there are no considerations taken to the individuals within the group i.e. the definition of the risk is from a societal point of view.




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Source: Jönsson, 2007

8


What is risk analysis?

• A big family of different approaches, methods and complex models combining various methododical components for specific tasks

• Systematic analysis of sequences and interaction effects in potential accidents, thereby identifying weak points in the system and recognizing possible improvement measures

• Risk analysis makes the quantification of risks feasible






The risk assessment process






The risk assessment process




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Start

Definition of the system

Hazard identification

Probability analysis Consequence analysis

Additional safety measures

Risk estimation

Risk evaluation Risk criteria

Acceptable risk?

Stop

Risk analysis

Risk evaluation

YES

NO

Risk reduction

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Definition of the system (context establishment)




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Define the operational environment and the context of the risk assessment process

– Definition of the scope or the risk assessment process• This includes determining the timeframe (e.g. from planning to dismantling),

the required resources and the depth of analysis required.

– Definition of the strategic and organizational context• The nature of the organization in charge of the risk management and the

environment in which it operates is established

– Identification of the stakeholders and objectives• The relationships that are interdependent with the organization are defined, the

impacts that might occur are accounted for, as well as and what each is wanting out of the relationship

– Determination of the evaluation criteria• Decide what level of risk the organization is prepared to accept

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a. What can happen

b. How can it happen

Means for hazard identification:• Decomposition of the system into a number of

components and/or subsystems• Identification of possible states of failure for the

considered system and sub-systems• Identification of how the hazards might be realized

for the considered system and subsystems Source: Faber, 2008

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Hazard identification – system decomposition

A. Structure

1. Main components

(d) Foundations

(c) Towers

(b) Anchor systems

(a) Main cables

(h) Cable saddle

(e) Railway girder (f) Highway girders (g) Expansion joints

(e) Non str.elements

(a) Steel (b) Concrete (c) Prestressed c. (d) Alluminium/iron

3. Materials

(f) Coating

4. Systems

(a) Electrical

(c) Hydraulics

(b) Mechanical

(e) Bitumen (e) Plastic

2. Secondary comp.

(d) H.R. attachments

(c) TMD

(b) Buffers

(a) Hanger ropes

B. Users

1. Highway traffic

(b) Commercial

(a) Private

2. Railway traffic

(b) Commercial

(a) Private

(a) Heavy (b) Hazard mat. (c) Military

3. Exceptional traffic

C. Facilities

1. Over the bridge

(b) Railway

(a) Highway

2. By the bridge

(a) Highway (b) Railway (c) Toll booths (d) Control center (e) Parking

(a) Maritime traffic

3. Under the bridge

D. Dependencies

1. Power

3. Financial

2. Communications

4. Supplies

5. Emerg. Responce

(a) First aid (b) Police (c) Fire brigade (d) Hospitals

6. Ext. Contractors

E. Linkage

1. Economy

3. Military

2. Social

F. Operation

1. Authorities

(b) Management

2. Aspects

(a) Bridge authorities (b) Goverment (c) Region

5. Personnel

(c) Maintenance

(a) Financial

(b) Other

(a) Technical

G. Technology

(a) GPS (b) Accelerometers (c) Strain gauges

(e) Thermometers

(g) CCTV

(f) WIM

(d) Seismographs

(h) Field equipment

1. Monitoring

2. Control

(a) Cable control

(d) Railway traffic

(c) Highway traffic

(b) TMD

3. Data transmission

(b) Wireless

(a) Cable

4. Computer center

(b) Software

(a) Hardware

(d) Internet/LAN

(c) Data bases

4. Regulations

3. Policies

4. Location

(c) External

Hie

rarc

hic

al H

olog

rap

hic

Mod

els

(HH

M)

(Def

ined

in

Hai

mes

, 198

1)

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Risk analysis: hazard identification




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• Qualitative methods

Studies based on the generic experience of personnel and do not involve mathematical estimations.

• Quantitative methods

Mathematical estimations that rely upon historical evidence or estimates of failures to predict the occurrence of an event.

• Semi-quantitative methods

Combination of the above (mostly, qualitative methods with applied numerical values).

Source: Nolan, D. P. Handbook of Fire and Explosion Protection Engineering Principles for Oil, Gas, Chemical, and Related Facilities, 1986

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Source: Aven, T. Risk Analysis: Assessing Uncertainties beyond Expected Values and Probabilities. John Wiley & Sons, 2008

Risk analysis: hazard identification

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Hazard identification. Qualitative Methods




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Checklist or Worksheet A standardized listing which identifies common protection features required for typical facilities is compared against the facility design and operation. Risks are expressed by the omission of safety systems or system features.

Preliminary Hazard Analysis (PHA) Each hazard is identified with potential causes and effects. Recommendations or known protective measures are listed.

What-If analysisA safety study which by which “What-If’ investigative questions (brainstorming approach) are asked by an experienced team of a hydrocarbon system or components under examination. Risks are normally expressed in a qualitative numerical series (e.g., 1 to 5).

HAZOP - HAZard and OPerability analysis (analisi di pericolo e operabilità) A formal systematic critical safety study where deviations of design intent of each component are formulated and analyzed from a standardized list. Risks are typically expressed in a qualitative numerical series (e.g., 1 to 5) relative to one another.

Source: Nolan, D.P. 1986. Handbook of Fire and Explosion Protection Engineering Principles for …. Noyes, New Jersey

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Hazard identification. Qualitative Methods




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Event Trees (ET) –albero degli eventi

A mathematical logic model that mathematically and graphically portrays the combination of events and circumstances in an accident sequence, expressed in an annual estimation.

Fault Trees (FT) – alberi dei guasti

A mathematical logic model that mathematically and graphically portrays the combination of failures that can lead to a specific main failure or accident of interest, expressed in an annual estimation.

Failure Modes and Effects Analysis (FMEA)

A systematic, tabular method of evaluating the causes and effects of known types of component failures, expressed in an annual estimation.

Source: Nolan, D.P. 1986. Handbook of Fire and Explosion Protection Engineering Principles for …. Noyes, New Jersey

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• Risk analysis

• Qualitative risk analysis

• Quantitative risk analysis









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Risk analysis• Risk analysis

– Probability- as the likelihood of the risk occurrence– Impact - consequences if the risk occurs

• risk proximity, meant as the point in time during which a risk will impact

• Risk analysis - methods– Qualitative Risk Analysis, in which numbers and

probabilities are used not extensively or at all– Quantified Risk Analysis (QRA)– Probabilistic Risk Analysis (PRA), in which the system risk

is represented as a probability distribution

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Risk analysis and system complexity

High-Probability/Low-Consequences

(HPLC)

Low-Probability/High-Consequences

(LPHC)


(HPLC)


(LPHC)


(HPLC)


(LPHC)


(HPLC)

Stochastic

Complexity

Deterministic

AnalysisMethods

QualitativeRisk

Analysis

Quantitative/ProbabilisticRisk

Analysis

PragmaticRisk

Scenarios

Stochastic

Complexity

Deterministic

AnalysisMethods

QualitativeRisk

Analysis

Quantitative/ProbabilisticRisk

Analysis

PragmaticRisk

Scenarios

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Qualitative Risk analysis• Qualitative Risk Analysis is the simplest method of risk analysis, and

generally is used during the preliminary analysis phases.

• It consists in using subjective assessments of risks, and consequently, in ranking them in a subjective manner.

• Sources for information to be used in the analysis can be drown from previous experiences, history of events and consultation of experts.

• The ranking of risks is qualitative, e.g. risk (1) > risk (2) > risk (3), while a description can be added. Eventually, a likelihood-consequence matrix can be constructed.

• The biggest drawback of QRA is that there is neither a clear indication of the risk’s magnitude nor an absolute scale of how serious the risk might be, so, for a comprehensive risk analysis of more complex systems, quantitative methods should be preferred.

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Qualitative risk analysis methods: risk matrix• A risk matrix typically provides a discrete partitioning of relative

consequences along one dimension and relative likelihood along the other.

• The entry in each matrix cell may include a description of hazards known or believed to have that combination of consequence severity and likelihood.

Source: NFPA, SFPE Handbook of Fire Protection Engineering,

3rd edition, 2002

Source: Furness, A., Muckett, M. Introduction to Fire Safety

Management. Elsevier, 2007.

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Qualitative risk analysis methods: SWOT analysis

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Strengths: characteristics of the business or project that give it an advantage over others.

Weaknesses: characteristics that place the business or project at a disadvantage relative to others

Opportunities: elements that the project could exploit to its advantage

Threats: elements in the environment that could cause trouble for the business or project





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Quantitative Risk analysis

• Quantified (or quantitative) Risk Analysis (QRA) combines the consequences and frequencies of accident scenarios to estimate the level of risk.

• In respect to the Qualitative method, QRA implicates the acquaintance of probabilities that describe the likelihood of the outcomes and their consequences.

• QRA started with the chemical industries from the 70s and the offshore industry from the 80s.

• QRA is traditionally expressed through the decomposition of the system. This frequently is done by the use of event trees and fault trees.

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FTA and ETA

• ETA (event tree analysis) provides a structure for postulating an initiating event and analyzing the potential outcomes

• FTA (fault tree analysis) begins with a failure and provides a structure to look for potential causes

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Event tree analysis

• Event trees pictorially represent the logical order in which events in a system can occur. Event trees begin with an initiating event, and then the consequences of the event are followed through a series of possible paths.

• Each path is assigned a probability of occurrence. Therefore, the probability of the various possible outcomes can be calculated.

• Event tree analysis is based on binary logic, in which an event has either happened or not, or a component has failed or has not.

• It is valuable to analyze the consequences arising from a failure or undesired event.

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Event tree analysis: illustration (1)

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Event trees are helpful in considering all the possible outcomes (on the right-hand side) from an initiating event (on the left-hand side), which is usually ignition for fire risks.

The frequency of the initiating event can be estimated from fire report data, and the conditional probabilities of the sub-events can be quantified from fire report data or fault trees.





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Event tree analysis: illustration (2)

Source: Fire Risk in Metro Tunnels and Stations Hyder Consulting

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Fault tree analysis

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Fault trees are helpful in quantifying the probability of a top event of concern (such as the failure of a fire protection system) from all the potential root causes (at the bottom), again quantified from fire report data.





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Fault tree analysisgeneral conclusion (event)

• Fault trees look like a complement to event trees.

• The idea is to begin with a general conclusion (event) and, using a top-down approach, to generate a logic model that provides for both qualitative and quantitative evaluation of the system reliability.

Source: google pictures search “Fault tree”

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Fault tree analysis - symbolsBasic event - failure or error in a system component or element (example: switch stuck in open position)

Initiating event - an external event (example: bird strike to aircraft)

Undeveloped event - an event about which insufficient information is available, or which is of no consequence

Conditioning event - conditions that restrict or affect logic gates (example: mode of operation in effect)

Intermediate event: can be used immediately above a primary event to provide more room to type the event description.

Source: Fault Tree Handbook. Nuclear Regulatory Commission. NUREG–0492

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Fault tree analysis – gate symbols

OR gate - the output occurs if any input occurs

AND gate - the output occurs only if all inputs occur (inputs are independent)

Exclusive OR gate - the output occurs if exactly one input occurs

Priority AND gate - the output occurs if the inputs occur in a specific sequence specified by a conditioning event

Inhibit gate - the output occurs if the input occurs under an enabling condition specified by a conditioning event

Source: Fault Tree Handbook. Nuclear Regulatory Commission. NUREG–0492

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Advantages and disadvantages of FTA

• Disadvantages1. There is a possibility of oversight and omission of significant failure

modes.

2. It is difficult to apply Boolean logic to describe failures of system components that can be partially successful in operation and thereby affect the operation of the system, e.g. leakage through a valve.

3. For the quantitative analysis there is usually a lack of pertinent failure data. Even when there are data they may have been obtained from a different environment.

• Advantages1. It provides a systematic procedure for identifying faults that can exist

within a system.

2. It forces the analyst to understand the system thoroughly.Source: Hasofer et al. 2007, Risk Analysis in Building Fire Safety Engineering

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Cause – consequence diagrams• The combination of fault trees and event trees leads to the creation of

cause-consequence diagrams.

Time

Revealed from the Monitoring system

S3

S2

S1

Consequences

Infraction of traffic law

Improper speedRoad condition

Vehicle flowblocked

YES

YES

NO

NO

Other

Iniziative event

RoadAccident

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SCENARIO PROBABILITY

A1 PA*P1

A2 PA*(1-P1) *P2 *P3

A3 PA*(1-P1) *P2*(1-P3 )

A4 PA*(1-P1) *(1-P2)*P3

A5 PA*(1-P1) *(1-P2)*(1-P3)

B1 PB*P1

B2 PB*(1-P1) *P2 *P3

B3 PB*(1-P1) *P2*(1-P3 )

B4 PB*(1-P1) *(1-P2)*P3

B5 PB*(1-P1) *(1-P2)*(1-P3)

C1 PC*P1

C2 PC*(1-P1) *P2 *P3

C3 PC*(1-P1) *P2*(1-P3 )

C4 PC*(1-P1) *(1-P2)*P3

C5 PC*(1-P1) *(1-P2)*(1-P3)

Triggering event

Fireignition

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)

Firelocation

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)

Quantified Risk Analysis: cause – effect diagrams

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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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Source: NFPA, SFPE Handbook of Fire Protection Engineering, 3rd edition, 2002

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Index

• Risk acceptance

- ALARP

- Human life (!)









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Risk acceptance

Source: Persson, M. Quantitative Risk Analysis Procedure for the Fire Evacuation of a Road Tunnel -An Illustrative Example. Lund, 2002

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Risk acceptance – ALARP (1)

RISK MAGNITUDE

INTOLERABLEREGION

AsLowAsReasonablyPracticable

BROADLY ACCEPTABLEREGION

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

AsLowAsReasonablyAchievable

RISK MAGNITUDE

INTOLERABLEREGION

AsLowAsReasonablyPracticable

BROADLY ACCEPTABLEREGION

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

AsLowAsReasonablyAchievable

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Risk acceptance – ALARP (2)

Source: google pictures search “ALARP”

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Monetary values – cost of human life (!)

• What is the maximum amount the society (or the decision-maker) 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. The Ministry of Finance in Norway has arrived at a value at approximately 2 million euros.


Guideline values for the cost to avert a statistical life (euros), used by an oil company

Source: Aven, T. Risk Analysis: Assessing Uncertainties beyond Expected Values and

Probabilities. John Wiley & Sons, 2008

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F-N diagrams: case study on a 180m road tunnel

www.francobontempi.org 45

1 20MW Fire [fat+inj/year] 0.00E+002 100MW Fire [fat+inj/year] 0.00E+003 Bleve of 50kg propane cylinder [fat+inj/year] 0.00E+004 Motor spirit pool fire [fat+inj/year] 0.00E+005 VCE of motor spirit [fat+inj/year] 0.00E+006 Chlorine release [fat+inj/year] 0.00E+007 BLEVE of 18t propane tank [fat+inj/year] 0.00E+008 VCE of propane [fat+inj/year] 0.00E+009 Propane torch fire [fat+inj/year] 0.00E+00

10 Ammonia Release [fat+inj/year] 0.00E+0011 Acrolein in bulk release [fat+inj/year] 0.00E+0012 Acrolein in cylinder release [fat+inj/year] 0.00E+0013 BLEVE of a 20t CO2 tank [fat+inj/year] 0.00E+00

All scenarios [fat+inj/year] 0.00E+001+2 20MW - 100MW FIRES [fat+inj/year] 0.00E+00

3+13 BLEVE (except propane in bulk) [fat+inj/year] 0.00E+004+5 Flammable liquids [fat+inj/year] 0.00E+00

6+10+11+12 Toxic products [fat+inj/year] 0.00E+007+8+9 Propane in bulk [fat+inj/year] 0.00E+00




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𝐹𝑁=∑𝑖=1

𝑛

𝑓 𝑖

𝐸𝑉=∑𝑖=1

𝑛

𝑓 𝑖 ∙𝑁 𝑖

EVENTEvent

FrequencyEvent

ConsequenceCumulative Frequency

(per year)

E1 f1 N1

F1 = f1

E2 f2 N1 F2 = f1 + f2

E3 f3 N2 F3 = f1 + f2 + f3

E4 f4 N4 F3 = f1 + f2 + f3 + f4

..... ..... ..... .....

En fn Nn Fn = f1 + f2 + f3 + f4+.....+ fn

F-N diagrams: case study on a 180m road tunnel




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Case study: 180m road tunnel

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Trial 1 BASIS calculation

Trial 2 Total traffic [veh/h] 7200 72000HGV ratio [-] 0.01 0.99

TrDen (traffic density) [-] 0.78 3.79Bus/Coaches ratio [-] 0.01 0.99

TrDen (traffic density) [-] 0.78 3.79HGV ratio [-] 0.01 0.99Bus/Coaches ratio [-] 0.01 0.99

TrDen (traffic density) [-] 0.78 3.79

Trial 6 Light vehicles average speed [km/h] 80 179Trial 7 HGV/Bus average speed [km/h] 60 119Trial 8 Delay for stopping approaching traffic [s] 9000 1Trial 9 Area (Urban/Rural) [-] urban ruralTrial 10 Average density of population [hab/km2] 0.01 999000Trial 11 DG-HGV traffic [veh/h] 5 10000Trial 12 Average number of people in a light vehicle [-] 2 10Trial 13 W (effective width) [m] 10 5Trial 14 H (effective height) [m] 6 3Trial 15 VnN (volume flow rate along tunnel at nodes) [m3/s] 120 0Trial 16 VnE (volume flow rate along tunnel at nodes) [m3/s] 210 0Trial 17 tE (Time taken to activate emergency ventilation) [mins] 0.2 60Trial 18 Xe (average spacing between emergency exits) [m] 90 1000Trial 19 Cam (camber) [%] 0 100Trial 20 Ad (open area of discrete drains) [m2] 0.075 0Trial 21 Ecom (emergency coms) → 1, 2 o 3 [-] 3 1

Type of construction → 1 o 2 [-] 2 1

trad (internal radius) [m] - 6

dlin (lining thickness) [m] - 0.3

trad (wall thickness) [m] 0.2 -

dlin (roof slab thickness) [m] 0.2 -Ns (Number of segments) [-] 6 15

Xs (Segment lengths) [m] 30 12Nsub (number of sub-segments per segment) [-] 3 2total number of sub-segments [-] 18 30Xsub (actual sub-segment lengths) [m] 10 6

Trial 24 Number of lanes [-] 2 5

Trial 4

Trial 3

Trial 22

Trial 5

Trial 23

1 20MW Fire [fat+inj/year]2 100MW Fire [fat+inj/year]3 Bleve of 50kg propane cylinder [fat+inj/year]4 Motor spirit pool fire [fat+inj/year]5 VCE of motor spirit [fat+inj/year]6 Chlorine release [fat+inj/year]7 BLEVE of 18t propane tank [fat+inj/year]8 VCE of propane [fat+inj/year]9 Propane torch fire [fat+inj/year]

10 Ammonia Release [fat+inj/year]11 Acrolein in bulk release [fat+inj/year]12 Acrolein in cylinder release [fat+inj/year]13 BLEVE of a 20t CO2 tank [fat+inj/year]

All scenarios [fat+inj/year]1+2 20MW - 100MW FIRES [fat+inj/year]

3+13 BLEVE (except propane in bulk) [fat+inj/year]4+5 Flammable liquids [fat+inj/year]

6+10+11+12 Toxic products [fat+inj/year]7+8+9 Propane in bulk [fat+inj/year]

Societal Risk EV (Expected Value of the dead)

Societal Risk

30m (distance from the route) [fat+inj/year]80m [fat+inj/year]200m [fat+inj/year]500m [fat+inj/year]30m [fat+inj/year]80m [fat+inj/year]200m [fat+inj/year]500m [fat+inj/year]

Individual Risk

Direction A

Direction B

Individual Risk

4 analysis for every trial

Grouping


Risk reduction









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Risk reduction

Source: Brussaard et al. 2004. The Dutch Model for the Quantitative Risk Analysis of Road Tunnels.

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Risk reduction (2) - monitoring and system response

Time

1

3

2

Accident Accident evolutionPre-accident

situation

Pre-accidentMonitoring

Pre-accidentSystem Response

AccidentLocalization

Evolution of System Response

Accident evolution Monitoring

SystemResponse

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• NFPA, SFPE Handbook of Fire Protection Engineering, 3rd edition, 2002

• Jönsson, J. Combined Qualitative and Quantitative Fire Risk Analysis – Complex Urban Road Tunnel. Arup partners, 2007.

• Faber, M.H. (2008) Risk and Safety in Civil, Environmental and Geomatic Engineering. ETH Zürich, lecture notes, available online on 01/2011 at: http://www.ibk.ethz.ch/fa

• Haimes, Y. Y. (1981). Hierarchical holographic modeling. IEEE Transactions on Systems, Man, and Cybernetics, 11(9), pp. 606– 617.

• Nolan, D.P. 1986. Handbook of Fire and Explosion Protection Engineering Principles for Oil, Gas, Chemical, and Related Facilities. Noyes, New Jersey

• Aven, T. Risk Analysis: Assessing Uncertainties beyond Expected Values and Probabilities. John Wiley & Sons, 2008

• Furness, A. , Muckett, M. Introduction to Fire Safety Management. Elsevier, 2007.

• Fire Risk in Metro Tunnels and Stations, Hyder Consulting, available on 05.2011 at http://hkarms.myftp.org/web_resources/Conference_Presentation/Fire_Risk_Metro_Tunnels_Stations.pdf

• Fault Tree Handbook. Nuclear Regulatory Commission. NUREG–0492

• Hasofer et al. 2007, Risk Analysis in Building Fire Safety Engineering

• Persson, M. Quantitative Risk Analysis Procedure for the Fire Evacuation of a Road Tunnel -An Illustrative Example. Lund, 2002

• Brussaard et al. 2004. The Dutch Model for the Quantitative Risk Analysis of Road Tunnels. Available on 05.2011 at http://www.rws.nl/rws/bwd/home/Tunnelveiligheid/dutch%20model.pdf

• Gkoumas, K. 2008. Basic aspects of risk-analysis for civil engineering structures. Handling Exceptions in Structural Engineering: Robustezza Strutturale, Scenari Accidentali, Complessità di Progetto, Roma, 13-14 novembre. http://www.francobontempi.org/handling_papers.php

References

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http://www.ibk.ethz.ch/fa

http://hkarms.myftp.org/web_resources/Conference_Presentation/Fire_Risk_Metro_Tunnels_Stations.pdf

http://www.rws.nl/rws/bwd/home/Tunnelveiligheid/dutch%20model.pdf

http://www.francobontempi.org/handling_papers.php

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