Seismic vulnerability analysis of a complex interconnected civil infrastructure - Seismic Risk Analysis and Management of Civil Infrastructure Systems - page 488

Grid point 2

Grid point 1

Component 1
Power source

Overhead line

Dependency
edges

System 1
Electric power
network

Component 2
Sub-station

Component 4
Pipe

Building cells

End-user

Component 3
Pumping station

System 2
Water supply
system

Grid point 4

Grid point 3

18.9 A simple infrastructure made up of two interconnected systems,
each with two components. System 1 is an EPN with a generation
node (point-like component 1) and a sub-station (point-like component
2) which provides power to a pump (point-like component 3) that
inputs water into a pipe (line-like component 4) connected to a
demand node that feeds water to the building in the dependent cells.

multiplication times the variables A i sampled from their distribution at each
site within the amplifi cation model. As part of this process geotechnical IMs,
such as, for example, permanent ground deformation (variable S geo 4 in the
fi gure), are sampled from a geotechnical hazard model for those compo-
nents whose fragility model requires one, such as for instance the pipe in
Fig. 18.9 (component 4).
The simulation run then proceeds with the assessment of the physical
damage state of each component, represented by variables D i , sampled from
their respective fragility models. These can be of two types. Point-like com-
ponents have fragility models consisting of a set of fragility curves associ-
ated with limit-states of increasing severity. The curves express the
probability of exceedance of each limit-state conditional on the local seismic
intensity. Determination of the damage state D i is performed by sampling