1.
6th
International Disaster and Risk Conference IDRC 2016
‘Integrative Risk Management – Towards Resilient Cities‘ • 28 Aug – 1 Sept 2016 • Davos • Switzerland
www.grforum.org
Seismic fragility of equipment and support
structure in a unit of an oil complex
A.Kalantari,International Institude fo Earthquake Engineering
and Seismology,Tehran, Iran
D. Abdi, University of Science and Culture, Tehran, Iran

2.
6th
International Disaster and Risk Conference IDRC 2016
‘Integrative Risk Management – Towards Resilient Cities‘ • 28 Aug – 1 Sept 2016 • Davos • Switzerland
www.grforum.org
Support structures are structures in petrochemical, chemical and power plants
that support equipment like pumps, vessels , heat exchangers and pipes

3.
6th
International Disaster and Risk Conference IDRC 2016
‘Integrative Risk Management – Towards Resilient Cities‘ • 28 Aug – 1 Sept 2016 • Davos • Switzerland
www.grforum.org
A heat exchanger is a device that allows heat from a fluid (a liquid or a
gas) to pass to a second fluid (another liquid or gas) without the two
fluids having to mix together or come into direct contact

4.
6th
International Disaster and Risk Conference IDRC 2016
‘Integrative Risk Management – Towards Resilient Cities‘ • 28 Aug – 1 Sept 2016 • Davos • Switzerland
www.grforum.org
Why Refineries?
why Earthquakes?
• Refineries and related industrial facility have shown vulnerable
during the past earthquakes like Kobe(Japan,1995),
Izmit(Turkey,1999), Gujarat(India,2001), Toikachi- Oki(Japan,2003)
and other earthquakes.
• Damage to such facility may have a great economical impact
• Earthquakes are not predictable

5.
6th
International Disaster and Risk Conference IDRC 2016
‘Integrative Risk Management – Towards Resilient Cities‘ • 28 Aug – 1 Sept 2016 • Davos • Switzerland
www.grforum.org
Tow cooling towers , pipeline system and more than ten tanks
were damaged in turkey(1991) earthquake.

6.
6th
International Disaster and Risk Conference IDRC 2016
‘Integrative Risk Management – Towards Resilient Cities‘ • 28 Aug – 1 Sept 2016 • Davos • Switzerland
www.grforum.org
Iranian code of practice for seismic resistance design of buildings
have defined four levels for intensity of earthquakes. Investigations
have shown that more than half of refineries and petrochemical
plants in Iran are located in high and too high hazardous seismic
zones.
Here is the exact result of investigations:
 Seismic zone number1( too high hazardous zone): 12.8 % of
refineries and petrochemical plants
 Seismic zone number2(high hazardous zone): 43.6 % of refineries
and petrochemical plants
 Seismic zone number3(average hazardous zone): 21.3 % of
refineries and petrochemical plants
 Seismic zone number4( low hazardous zone): 22.3 % of
refineries and petrochemical plants

7.
6th
International Disaster and Risk Conference IDRC 2016
‘Integrative Risk Management – Towards Resilient Cities‘ • 28 Aug – 1 Sept 2016 • Davos • Switzerland
www.grforum.org
Fragility:
a fragility function represents the cumulative distribution function
of the capacity of an asset to resist an undesirable limit state.
Capacity is measured in terms of the degree of environment
excitation at which the asset exceeds the undesirable limit state. For
example, a fragility function could express the uncertain level of
shaking that a building can tolerate before it collapses. The chance
that it collapses at a given level of shaking is the same as the
probability that its strength is less than that required to resist that
level of shaking.

8.
6th
International Disaster and Risk Conference IDRC 2016
‘Integrative Risk Management – Towards Resilient Cities‘ • 28 Aug – 1 Sept 2016 • Davos • Switzerland
www.grforum.org
probability density function and cumulative distribution function

9.
6th
International Disaster and Risk Conference IDRC 2016
‘Integrative Risk Management – Towards Resilient Cities‘ • 28 Aug – 1 Sept 2016 • Davos • Switzerland
www.grforum.org
Why the lognormal cumulative distribution function is widely used for
fragility
There is nothing fundamental about the lognormal distribution that makes
it ideal or exact or universal for the applications described here. At least
three reasons justify its use:
1. Simplicity. It has a simple, parametric form for approximating an
uncertainty quantity that must take on a positive value, using only an
estimate of central value and uncertainty;
2. Precedent. It has been widely used for several decades in earthquake
engineering.
3.Often fits data. It often reasonably fits observed distributions of
quantities of interest here, such as ground motion conditioned on
magnitude and distance, the collapse capacity of structures, and the
marginal distribution of loss conditioned on shaking.

10.
6th
International Disaster and Risk Conference IDRC 2016
‘Integrative Risk Management – Towards Resilient Cities‘ • 28 Aug – 1 Sept 2016 • Davos • Switzerland
www.grforum.org
Incremental Dynamic Analysis (IDA):
IDA is a computational analysis method of Earthquake Engineering for
performing a comprehensive assessment of the behavior of structures
under seismic loads.

11.
6th
International Disaster and Risk Conference IDRC 2016
‘Integrative Risk Management – Towards Resilient Cities‘ • 28 Aug – 1 Sept 2016 • Davos • Switzerland
www.grforum.org
To evaluate the dynamic behaviour of the support structure and
equipment which are located on support structure , support structure
have been simulated in ETABS to calculate mass and stiffness of each
story, since the time history analysis in ETABS is time consuming and
based on the fact that for performing Incremental Dynamic Analysis
(IDA) sixty ground motions have been selected, dynamic analysis is
performed in MATLAB software using dynamic equations of structure.

12.
6th
International Disaster and Risk Conference IDRC 2016
‘Integrative Risk Management – Towards Resilient Cities‘ • 28 Aug – 1 Sept 2016 • Davos • Switzerland
www.grforum.org
Created model in Etabs and simplified mass-spring system for vibration analysis in
Matlab

13.
6th
International Disaster and Risk Conference IDRC 2016
‘Integrative Risk Management – Towards Resilient Cities‘ • 28 Aug – 1 Sept 2016 • Davos • Switzerland
www.grforum.org
Failure modes:
To obtain seismic fragility of support structure inter-story drift ratio
have been selected as failure mode. Extensive and moderate
damage states are selected based on Iranian code of design and
construction of steel structures .
In order to analyse seismic behaviour of the non-structural
components, equipment have been assumed as block- type. Failure
modes are selected based on damages caused by past earthquakes.
Shear failure of bolts have been considered as failure mode of
equipment.
the numerical results obtained from dynamic analysis have been
used to develop the fragility curve for each of the considered
frames.

14.
6th
International Disaster and Risk Conference IDRC 2016
‘Integrative Risk Management – Towards Resilient Cities‘ • 28 Aug – 1 Sept 2016 • Davos • Switzerland
www.grforum.org
Performance objectives
The criteria in this document are based on performance
objectives, defined for selected occupancy categories. The
performance objectives are intended to provide different
levels of protection from damage, consistent with the
occupancy categories.

15.
6th
International Disaster and Risk Conference IDRC 2016
‘Integrative Risk Management – Towards Resilient Cities‘ • 28 Aug – 1 Sept 2016 • Davos • Switzerland
www.grforum.org
For purposes of seismic design and/or evaluation, structures and
components at a petrochemical facility are divided into four
occupancy categories: Low hazard to human life (I), Substantial
hazard to human life (III), Essential facilities (IV), and Other
structures (II).

16.
6th
International Disaster and Risk Conference IDRC 2016
‘Integrative Risk Management – Towards Resilient Cities‘ • 28 Aug – 1 Sept 2016 • Davos • Switzerland
www.grforum.org
Occupancy
Categories
Performance Objectives
Qualitative
Seismic Risk
Maintain structural
Integrity
Maintain
Containmen
t of
Hazardous
Materials
Maintain
Functions
Low Hazard Yes N/A No Low
Other Yes No No Low
Substantial Hazard Yes Yes No Very Low
Essential Yes Yes Yes
Extremely
Low
Performance Objectives for Different Occupancy Categories

17.
6th
International Disaster and Risk Conference IDRC 2016
‘Integrative Risk Management – Towards Resilient Cities‘ • 28 Aug – 1 Sept 2016 • Davos • Switzerland
www.grforum.org
fragility curves for support structure

18.
6th
International Disaster and Risk Conference IDRC 2016
‘Integrative Risk Management – Towards Resilient Cities‘ • 28 Aug – 1 Sept 2016 • Davos • Switzerland
www.grforum.org
fragility curves for equipment

19.
6th
International Disaster and Risk Conference IDRC 2016
‘Integrative Risk Management – Towards Resilient Cities‘ • 28 Aug – 1 Sept 2016 • Davos • Switzerland
www.grforum.org
Fragility curves in extensive damage level for support structure and equipment

20.
6th
International Disaster and Risk Conference IDRC 2016
‘Integrative Risk Management – Towards Resilient Cities‘ • 28 Aug – 1 Sept 2016 • Davos • Switzerland
www.grforum.org
Based on the fragility curves developed for support structure and
three equipment located on support structure, by using time
history dynamic analyses and considering inter-story drift ratio
and shear failure of bolts as failure mode of support structure and
equipment, it can be concluded that sixth story equipment is the
most vulnerable component of the unit, this means failure of this
equipment will stop processing of unit and is identification of
most vulnerable component is helpful for risk management
strategies.

21.
6th
International Disaster and Risk Conference IDRC 2016
‘Integrative Risk Management – Towards Resilient Cities‘ • 28 Aug – 1 Sept 2016 • Davos • Switzerland
www.grforum.org
RISK MANAGEMENT PROCESS AND ITS IMPORTANCE IN A
UNIT OF AN OIL COMPLEX
This paper have shown that earthquakes may cause severe
damages in the investigated unit. In this research probability of
failure of equipment and support structure have been evaluated.
The results indicate that probability of failure of the equipment and
support structure can be calculated and therefore oil complex
condition after earthquake can be predictable using fragility curves.
Based on the importance of each equipment and support structure
risk management strategies have to be selected and fragility curves
can be the important factors in risk management strategies.
Seismic risk assessment provides information for decision making
when setting levels of importance factors of the intended facilities.

22.
6th
International Disaster and Risk Conference IDRC 2016
‘Integrative Risk Management – Towards Resilient Cities‘ • 28 Aug – 1 Sept 2016 • Davos • Switzerland
www.grforum.org
Thank you for your attention