Seismic risk models for aging and deteriorating buildings and civil infrastructure - Seismic Risk Analysis and Management of Civil Infrastructure Systems - page 380

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Seismic risk models for aging and
deteriorating buildings and civil infrastructure
M. SÁNCHEZ-SILVA and J. RIASCOS-OCHOA,
Universidad de Los Andes, Colombia
DOI : 10.1533/9780857098986.3.387
Abstract : The design, operation and maintenance of structures and
infrastructure systems depend highly on their performance throughout
their service life. In adverse environmental conditions structures
deteriorate with time as a result of, for instance, corrosion and fatigue.
Furthermore, in seismic regions structures are subjected to earthquakes
of various intensities causing damage to accumulate further during their
service life. Because the structural conditions change over time,
modeling the deterioration process is central for reliability assessment
and cost-based optimization. This chapter presents an overview of
structural deterioration models (graceful and shock-based) and provides
a discussion about the associated uncertainties. Furthermore, the chapter
discusses the case of structures abandoned after failure and
reconstructed successively after failure. The results highlight the
importance of selecting the appropriate deteriorating model for the
problem at hand. The importance of including deterioration within the
lifetime assessment of structures is illustrated with several examples.
Key words : structural deterioration models, shock-based models,
progressive deterioration, graceful deterioration models, stochastic
models, life-cycle performance, reliability assessment.
15.1 Introduction
Studying and modeling degradation of structures and critical infrastructure
systems are essential for life-cycle analysis, reliability estimations and defi n-
ing optimum maintenance and operation strategies. This is particularly
important for structures located in aggressive environments (high/low tem-
perature, humidity, etc.) or subjected to frequent extreme events (e.g.,
earthquakes). In practice, structural design does not usually take into
account changes in the structural condition (e.g., deterioration) over time,
underestimating the reliability and the operation costs. In order to under-
stand damage accumulation mechanisms it is necessary to take into account
the time-dependence of the structural properties as a result of the dynamic
interaction with the external (e.g., environmental) demands. The main chal-
lenges in modeling deterioration are to manage the damage accumulation
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