Seismic risk and possible maximum loss (PML) analysis of reinforced concrete structures - Seismic Risk Analysis and Management of Civil Infrastructure Systems - page 734

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Seismic risk and possible maximum loss
(PML) analysis of reinforced
concrete structures
H. YOSHIKAWA, Tokyo City University, Japan
DOI : 10.1533/9780857098986.5.741
Abstract : Seismic risk analysis facilitates the quantitative evaluation of
seismic damage and loss, and is an indispensable technique for disaster
prevention planning and risk-based asset management. This chapter
presents an analytical procedure for assessing seismic risk indices, such
as the normal expected loss (NEL) and possible maximum loss (PML).
First, a seismic risk analysis procedure for deriving seismic risk curves
and risk indices is introduced. The method employs a multi-event model
for earthquake scenarios and fragility functions for reinforced concrete
(RC) structures based on nonlinear push-over analysis. Then, several
case studies for reinforced concrete infrastructure, such as railway
viaducts and buildings in Japan, are presented. The importance and
usefulness of seismic risk curves and PML analysis are highlighted from
the viewpoints of catastrophic earthquake risk mitigation and informed
decision-making for asset management.
Key words : seismic risk, normal expected loss (NEL), probable
maximum loss (PML), seismic risk curve, seismic event risk curve,
reinforced concrete structure.
27.1 Introduction
Complex urban infrastructure and structures in Japan are exposed to sig-
nifi cant risk due to exposure to recurrent earthquakes. For example, recent
major events include the 1995 Kobe earthquake, the 2001 Geiyo earth-
quake, the 2003 Tokachi-Oki earthquake, the 2004 Chuetsu earthquake, and
most notably the 2011 Tohoku earthquake. In particular, the casualty losses
in the 1995 Kobe and 2011 Tohoku earthquakes exceeded 6500 and 20 500,
respectively, while the economic losses in these two events were tremen-
dous, exceeding 100 billion and 210 billion US dollars, respectively. There-
fore, quantitative assessment of catastrophic earthquake risk is essential to
mitigate seismic damage and loss in future earthquakes. The quantitative
assessment entails comprehensive understanding of earthquake source
information (e.g. rupture process, propagation, and site effects) as well as
vulnerability of infrastructure (e.g. structural damage mechanism, seismic
loss generation, and societal/economical impact). Such assessment is often
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