Seismic vulnerability analysis of a complex interconnected civil infrastructure - Seismic Risk Analysis and Management of Civil Infrastructure Systems - page 461

The fi nal result is aimed to be a fairly comprehensive model that ideally
includes all component systems and the relations between their compo-
nents, as well as the capability to perform their functional analysis. Such a
model has been termed a hybrid model (Nan and Kröger, 2011), and could
be implemented in a distributed architecture with domain-specifi c sim-
ulators (in charge of performing the disciplinary functional analysis of
each system) contained in an application layer. A communication or inte-
gration layer manages interactions between the simulators. The results
shown later with reference to a simple example have been implemented
and simulated using MATLAB© (The Mathworks, 2010) environment.
The systems added are buildings, electric power networks (EPN), water
supply systems (WSS) and road networks (RDN); further systems will
be added. Only physical/functional and geographic dependencies are
considered.

18.4 Object-oriented model (OOM) of the

infrastructure and hazards

Figure 18.2 illustrates the class diagram describing the main classes defi ned
to assess vulnerability of an Infrastructure subjected to multiple man-made
and natural hazards. Only class names, without their attributes and methods,
are shown for simplicity. Readers not familiar with the Unifi ed Modelling
Language (UML) graphical notation should consult Booch et al . (2007). In
this, as well as in the following Fig. 18.5, classes are represented by rect-
angles (and classes grouped together for clarity, are shown with rectangles
with rounded vertices) and lines connecting rectangles indicate a relation-
ship between classes. Three types of relationships are used: the generalisa-
tion which means that a class is the generalisation of those below, i.e. an
abstraction of their common features (and the class is called abstract),
the composition which means that the class is made up of component
classes, and the association which means that classes can call each other's
methods.
As shown in the top portion of the fi gure, an Analysis is carried out within
the Environment that is where Hazards act upon the Infrastructure , under
certain Weather conditions. The Infrastructure class is the composition of
three classes, the two abstract classes Network (line-like systems) and Criti-
calFacility (point-like systems), and the InhabitedArea class (area-like
systems).
Networks can be either directed or undirected, and hence the Network
class is composed of two abstract sub-classes Directed and Undirected . The
former includes the Road Network ( RDN ) and the Railway Network
( RWN ), while the latter includes the Electric Power Network ( EPN ), Oil