Abstract: The steel-concrete hybrid structure has been extensively employed in high-rise buildings and super high-rise buildings. The light gauge steel-concrete hybrid structure, including light gauge steel structure and concrete hybrid structure, is a type of steel-concrete hybrid structure, which possesses some advantages of light gauge steel structure and concrete hybrid structure. The seismic behavior and loss assessment of three high-rise buildings with three different concrete hybrid structures were investigated through finite element software. The three concrete hybrid structures are reinforced concrete column-steel beam (RC-S) hybrid structure, concrete-filled steel tube column-steel beam (CFST-S) hybrid structure, and tubed concrete column-steel beam (TC-S) hybrid structure. The nonlinear time-history analysis of three high-rise buildings under 80 earthquakes was carried out. After simulation, it indicated that the seismic performances of three high-rise buildings were superior. Under extremely rare earthquakes, the maximum inter-story drifts of three high-rise buildings are significantly lower than 1/50. The inter-story drift and floor acceleration of high-rise building with CFST-S hybrid structure were bigger than those of high-rise buildings with RC-S hybrid structure, and smaller than those of high-rise building with TC-S hybrid structure. Then, based on the time-history analysis results, the post-earthquake repair cost ratio and repair time of three high-rise buildings were predicted through an economic performance analysis method proposed in FEMA-P58 report. Under frequent earthquakes, basic earthquakes and rare earthquakes, the repair cost ratio and repair time of three high-rise buildings were less than 5% and 15 days, respectively. Under extremely rare earthquakes, the repair cost ratio and repair time of high-rise buildings with TC-S hybrid structure were the most among three high rise buildings. Due to the advantages of CFST-S hybrid structure, it could be extensively employed in high-rise buildings subjected to earthquake excitations.
Abstract: In the current research structural health
monitoring is considered for addressing the critical issue of
post-earthquake damage detection. A non-standard approach
for damage detection via acoustic emission is presented -
acoustic emissions are monitored in the low frequency range
(up to 120 Hz). Such emissions are termed high-frequency
transients. Further a damage indicator defined as the
Time-Ratio Damage Indicator is introduced. The indicator
relies on time-instance measurements of damage initiation and
deformation peaks. Based on the time-instance measurements
a procedure for estimation of the maximum drift ratio is
proposed. Monitoring data is used from a shaking-table test
of a full-scale reinforced concrete bridge pier. Damage of the
experimental column is successfully detected and the proposed
damage indicator is calculated.
Abstract: The ultimate load analysis of RC pile groups has assumed a lot of significance under liquefying soil conditions, especially due to post-earthquake studies of 1964 Niigata, 1995 Kobe and 2001 Bhuj earthquakes. The present study reports the results of numerical simulations on pile groups subjected to monotonically increasing lateral loads under design amounts of pile axial loading. The soil liquefaction has been considered through the non-linear p-y relationship of the soil springs, which can vary along the depth/length of the pile. This variation again is related to the liquefaction potential of the site and the magnitude of the seismic shaking. As the piles in the group can reach their extreme deflections and rotations during increased amounts of lateral loading, a precise modeling of the inelastic behavior of the pile cross-section is done, considering the complete stress-strain behavior of concrete, with and without confinement, and reinforcing steel, including the strain-hardening portion. The possibility of the inelastic buckling of the individual piles is considered in the overall collapse modes. The model is analysed using Riks analysis in finite element software to check the post buckling behavior and plastic collapse of piles. The results confirm the kinds of failure modes predicted by centrifuge test results reported by researchers on pile group, although the pile material used is significantly different from that of the simulation model. The extension of the present work promises an important contribution to the design codes for pile groups in liquefying soils.
Abstract: The use of eccentrically braced frame (EBF) is increasing day by day as EBF possesses high elastic stiffness, stable inelastic response under cyclic lateral loading, and excellent ductility and energy dissipation capacity. The ductility and energy dissipation capacity of EBF depends on the active link beams. Recently, there are two types EBFs; these are conventional EBFs and EBFs with replaceable links. The conventional EBF has a disadvantage during maintenance in post-earthquake. The concept of removable active link beam in EBF is developed to overcome the limitation of the conventional EBF in post-earthquake. In this study, a replaceable link with reduced web section is introduced and design equations are suggested. In addition, nonlinear finite element analysis was conducted in order to evaluate the proposed links.
Abstract: In nearly all earthquakes of the past century that
resulted in moderate to significant damage, the occurrence of postearthquake
fire ignition (PEFI) has imposed a serious hazard and
caused severe damage, especially in urban areas. In order to reduce
the loss of life and property caused by post-earthquake fires, there is
a crucial need for predictive models to estimate the PEFI risk. The
parameters affecting PEFI risk can be categorized as: 1) factors
influencing fire ignition in normal (non-earthquake) condition,
including floor area, building category, ignitability, type of appliance,
and prevention devices, and 2) earthquake related factors contributing
to the PEFI risk, including building vulnerability and earthquake
characteristics such as intensity, peak ground acceleration, and peak
ground velocity. State-of-the-art statistical PEFI risk models are
solely based on limited available earthquake data, and therefore they
cannot predict the PEFI risk for areas with insufficient earthquake
records since such records are needed in estimating the PEFI model
parameters. In this paper, the correlation between normal condition
ignition risk, peak ground acceleration, and PEFI risk is examined in
an effort to offer a means for predicting post-earthquake ignition
events. An illustrative example is presented to demonstrate how such
correlation can be employed in a seismic area to predict PEFI hazard.
Abstract: The rapid growth of the human population and the
environmental degradation associated with increased consumption of
resources raises concerns on sustainability. Social sustainability
constitutes one of the three dimensions of sustainability together with
environmental and economic dimensions. Even though there is not an
agreement on what social sustainability consists of, it is a well known
fact that it necessitates user participation. The fore, this study aims to
observe and analyze the role of user participation on social
sustainability. In this paper, the links between user participation and indicators of
social sustainability have been searched. In order to achieve this, first
of all a literature review on social sustainability has been done;
accordingly, the information obtained from researches has been used
in the evaluation of the projects conducted in the developing
countries considering user participation. These examples are taken as
role models with pros and cons for the development of the checklist
for the evaluation of the case studies. Furthermore, a case study over
the post earthquake residential settlements in Turkey have been
conducted. The case study projects are selected considering different building
scales (differing number of residential units), scale of the problem
(post-earthquake settlements, rehabilitation of shanty dwellings) and
the variety of users (differing socio-economic dimensions). Decisionmaking,
design, building and usage processes of the selected projects
and actors of these processes have been investigated in the context of
social sustainability. The cases include: New Gourna Village by
Hassan Fathy, Quinta Monroy dwelling units conducted in Chile by
Alejandro Aravena and Beyköy and Beriköy projects in Turkey
aiming to solve the problem of housing which have appeared after the
earthquake happened in 1999 have been investigated. Results of the
study possible links between social sustainability indicators and user
participation and links between user participation and the
peculiarities of place. Results are compared and discussed in order to find possible
solutions to form social sustainability through user participation.
Results show that social sustainability issues depend on communities'
characteristics, socio-economic conditions and user profile but user
participation has positive effects on some social sustainability
indicators like user satisfaction, a sense of belonging and social
stability.
Abstract: From the past earthquake events, many people get hurt at the exit while they are trying to go out of the buildings because of the exit doors are unable to be opened. The door is not opened because it deviates from its the original position. The aim of this research is to develop and evaluate a new type safety door that keeps the door frame in its original position or keeps its edge angles perpendicular during and post-earthquake. The proposed door is composed of three components: outer frame joined to the wall, inner frame (door frame) and circular hollow section connected to the inner and outer frame which is used as seismic energy dissipating device.
Abstract: Earthquake is considered as one of the most catastrophic disasters in Iran, in terms of both short-term and long-term hazards. Due to the particular financial and time constraints in Iran, quickly constructed post-earthquake houses (PEHs) do not fulfill the minimum requirements to be considered as comfortable dwellings for people. Consequently, people often transform PEHs after they start to reside. However, lack of understanding about process, motivation, and results of housing transformation leads to construction of some houses not suitable for future transformations, hence resulting in eventually demolished or abandoned PEHs. This study investigated housing transformations in a natural bed of post-earthquake Lar. This paper reports results of the conducted survey for comparing normal condition housing transformation with post-earthquake housing transformation in order to reveal the factors that affect post-earthquake housing transformation in Iran. The findings proposed the use of a combination of ‘Temporary’ and ‘Permanent’ housing reconstruction models in Iran to provide victims with basic but permanent post-disaster dwellings. It is also suggested that needs for future transformation should be predicted and addressed during early stages of design and development. This study contributes to both research and practice regarding post-earthquake housing reconstruction in Iran by proposing new design approaches and guidelines.
Abstract: In recent years, the number of natural disasters in the world has occurred frequently. After a strong earthquake occurs, multiple disasters due to tsunami, strong aftershocks or heavy snow can possible to occur. To prevent a secondary disaster and to save a life, the quick inspection of the damaged building is necessary. This paper investigated on a possibility of post earthquake quick inspection of damaged building by ordinary people which used the European Macro- Seismic Scale 1998 (EMS-98).