Environmental Engineering Reference
In-Depth Information
-
Industrial plants: New fragility curves are investigated in order to predict the
vulnerability of metal industrial tanks (for oil storage or process) when they are
hit by tsunamis. Tank failure may result from buoyancy (uplift), overturning,
sliding (shear effect), excessive bending (and stress), or buckling. However, any
possible perforation by debris such as containers, ships or cars, structural frag-
ments, or boulders is not investigated in this study. As the recovery process or
protection against products escaping after damage depends on the capacity of the
plant and its components to resist tsunami effects, vulnerability and fragility
curves are developed for small and large size tanks.
16.2.1.3
Resilience Evolution and Disasters
A capacity of a system such as its mechanical capacity, serviceability, sheltering or
power supply, can be described by utility functions, F(t), along the time t. Loss of
an utility function i.e. damage, D, can result from a hazard which occurs at an
instant t
0
. The post-disaster capacity equation becomes:
( )
=
()(
)
Ft Ft D ith tt
.
1
−
,
:
≥
.
(16.1)
0
0
If there is no evolution, at post-disaster stage, the residual capacity remains con-
stant. In the case of evolutionary conditions, variations of residual capacity depend
on resources available (potential energy, plastic capacity, external supply and inward
flows, external demand or outward flows). Depending closely on interactions
between the different constitutive parts of a system and the exchanges at its
frontiers, the system can then evolve towards a worse or a better state, (Fig.
16.2
).
It is therefore vitally important to develop and identify adequate recovery and
evolution functions for each system (Cimellaro et al.
2010
; Steen and Aven
2011
).
Some parameters governing resilience can be easily evaluated in terms of quantity,
whereas others are not easy to measure, for example determination, confidence, past
experience and history, education, good, suitable management and adequate,
intelligent decision making. For this second group of parameters, probabilistic
distributions and statistical analysis may help in constructing and defining adequate
forms and measures of their effect on the evolution of the utility function.
16.2.1.4
Resilience as a Governing Indicator for Post-disaster Analysis
Resilience may concern a simple system (one construction) as well as a complex
system such as sets of constructions (neighborhoods, industrial plants, urban sets,
cities, regions, states, or continents). It can be described by:
(
)
()
=
()
−
(
)
+
() ()
∫∫∫
Ft
Ft
.
1
D
.
1 Φ χ
t
.
t
.
dv
(16.2)
R
T
r
r
ref
V
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