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one-storey and two-storey plane frame structures
under possible future earthquakes are presented.
Earthquakes continue to claim thousands of
lives and to damage structures every year (Comar-
tin et al, 2004). Each earthquake brings out new
surprises and lessons with it. In fact, the unexpected
loss of lives and the severe damage of infrastruc-
tures and buildings during past strong earthquakes
(e.g., 1994 Northridge, 1995 Kobe, 2010 Haiti and
the most recent 2011 Tohoku earthquakes) have
raised significant concern and questions on life
safety and performance of engineering structures
under possible future earthquakes. The occurrence
of strong earthquakes in densely populated regions,
especially in developing countries with vulnerable
building stock and fragile infrastructure, could
lead to catastrophic consequences. A notable
example is the 2010 Haiti earthquake that killed
250,000 people and left a long-term suffering for
the residents of this developing country (USGS/
EERI 2010). On the other hand, the severe dam-
age caused by the 2011 Tohoku earthquake and
associated tsunami in Japan has raised significant
challenges to one of the most developed countries
as well (Takewaki et al, 2011). Hence, the assess-
ment of seismic performance of structures under
strong ground motions is an important problem in
earthquake engineering. Structures need to resist
unknown future earthquakes which adds more
complexity to the problem (Moustafa 2011, 2009,
Moustafa & Takewaki 2010a, Abbas & Manohar
2007, Takewaki 2002a, 2007). The consideration
of the earthquake inherent uncertainty, the vari-
ability in the structure parameters and modeling
the nonlinear behavior of the structure is essential
for the accurate prediction of the actual response
of the structure. Earthquake uncertainties include
time, location, magnitude, duration, frequency
content and amplitude, referred to as aleatory
uncertainties.
The earthquake-resistant design of structures
has been an active area of research for many
decades (e.g., Penelis & Kappos 1997). The struc-
tural engineer aims to ensure safe performance of
the structure under possible future earthquakes
while maintaining optimal use of the construc-
tion material. The design objectives in current
seismic building codes are to ensure life safety
and to prevent damage of the structure in minor
and moderate frequent earthquakes, and to control
local and global damage (prevent total collapse)
and reduce life loss in a rare major earthquake.
This can be achieved through: (1) robust predic-
tion of expected future strong ground motions
at the site, (2) accurate modeling of the material
behavior under seismic loads, and (3) optimal
distribution of the construction material.
Early works on seismic design have dealt
with the specification of earthquake loads using
the response spectrum method, the time history
of the ground acceleration or using the theory of
random vibrations. The nonlinear time-history
analysis method is recognized as the most accurate
tool for dynamic analysis of structures (Pinho,
2007). Many researchers have also established
deterministic and probabilistic hazard spectra
for the site (Reiter, 1990, McGuire, 1995). The
development of mathematical models to describe
the hysteretic nonlinear behavior of the structure
during earthquakes has also been pursued in
several studies (e.g., Takeda et al, 1970, Otani,
1981, Akiyama, 1985). New design concepts
and methods, such as energy-, performance- and
displacement-based design, base-isolation and
structural control have been recently developed
(Priestely et al, 2007, Takewaki, 2009, Fardis,
2010). Similarly, the optimal design of the struc-
tures under earthquake loads has been investigated
in several studies (Fardis, 2010, Elishakoff &
Ohsaki, 2010, Plevris, 2009, Haldar, 2006, Liang,
2005). The evaluation of the current procedures
and new practical procedures for ground motion
selection and modification are provided in the
recent special issue on earthquake ground motion
selection and modification for nonlinear dynamic
analysis of structures (Kalkan & Luco, 2011). The
two edited topics by Papadrakakis et al (2009)
and Tsompanakis et al. (2008) and the doctoral
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