Research Article
Seismic Performance Evaluation of Special RC Frames with
Gravity Steel Columns under the Base Level
Amin Zaherdannak,
1
Amirhosein Shabani ,
1,2
and Saeed Erfani
1
1
Department of Civil and Environmental Engineering, Amirkabir University of Technology (Tehran Polytechnic), Tehran, Iran
2
Department of Civil Engineering and Energy Technology, Oslo Metropolitan University, Oslo, Norway
Correspondence should be addressed to Saeed Erfani; sderfani@aut.ac.ir
Received 4 March 2020; Revised 12 April 2020; Accepted 13 May 2020; Published 30 June 2020
Academic Editor: Roberto Palma
Copyright © 2020 Amin Zaherdannak et al. is is an open access article distributed under the Creative Commons Attribution
License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is
properly cited.
In many multistory buildings, basement levels are used as parking spaces. However, dimensions of reinforced concrete columns at
these levels cause them to be unideal parking spaces. An alternative is to replace the RC columns in middle frames with steel
columns that are not a part of seismic force resisting system and only support vertical loads, therefore have smaller sections. Using
simply supported steel columns under the base level is beneficial not only because they have smaller cross-sections which lead to
increasing the parking space but also these steel columns are easier to be replaced after any possible damages and can be
considered as convenient alternatives compared to ordinary RC columns in construction. In this research, seismic performance of
structures implementing the suggested alternative is evaluated using nonlinear static and dynamic analyses and compared to that
of regular counterparts. Results show that these structures pass the acceptability tests proposed by FEMA P695 methodology.
Moreover, seismic performance factors of these two structural systems have been calculated and proposed.
1. Introduction
To minimize casualties in large earthquakes, building codes
provide structural engineers with seismic design require-
ments. is goal can be generally achieved by limiting the
probability of global structural collapse of buildings to
relatively low levels. However, not even total satisfaction of a
building code provisions can necessarily mean that a
building will meet certain performance objectives during
large earthquakes. Compared to the intended performance
objective of the building code, the performance exhibited by
the building may or may not be adequate. erefore, a
methodology is needed for evaluating the performance of
any given building designed based on requirements of a
building code. e methodology introduced in FEMA P695
satisfies this need and it has been used in this study.
In the system, the performance of which is evaluated in
this study, the upper part consists of special RC moment
frames. Several research efforts have focused on developing
methods to improve seismic design procedure of RC frames
beyond minimum code requirements [1–3] and perfor-
mance-based earthquake engineering is used to assess the
effectiveness of these improvements [4, 5]. Seismic collapse
safety of ductile moment frames has been assessed by
Haselton [6] and seismic collapse capacity of nonductile RC
frames is evaluated and compared with ductile moment
frames by Abbie et al. [7].
FEMA P695 introduces a methodology for quantifica-
tion of building seismic performance factors used in seismic
design and for specifying whether a structure satisfies the
seismic performance objectives of building codes using the
probabilistic assessment of collapse risk [8].
According to FEMA P695 methodology, Archetypes for
nonlinear analyses must be selected so that they cover
normal variations of key characteristics of structures [8],
characteristics capable of affecting the overall seismic be-
havior of structures such as height and bay length. en,
archetypes with similarities in their structural behaviors and
characteristics are classified into distinct performance
groups.
Hindawi
Shock and Vibration
Volume 2020, Article ID 8825258, 11 pages
https://doi.org/10.1155/2020/8825258