• Structural Engineering and Mechanics
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• v.71 no.1
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• pp.1-12
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• 2019

This study investigates optimum designs of steel space truss towers under seismic loading by using Jaya optimization algorithm. Turkish Earthquake Code (2007) specifications are applied on optimum designs of steel space truss towers under the seismic loading for different local site classes depending on different soil groups. The proposed novel algorithm does not have any algorithm-specific control parameters and depends only a simple revision equation. Therefore, it provides a practical solution for structural optimization problems. Optimum solutions of the different steel truss examples are carried out by selecting suitable W sections taken from American Institute of Steel Construction (AISC). In order to obtain optimum solutions, a computer program is coded in MATLAB in corporated with SAP2000-OAPI (Open Application Programming Interface). The stress and displacement constraints are applied on the design problems according to AISC-ASD (Allowable Stress Design) specifications. Firstly, a benchmark truss problem is examined to see the efficiency of Jaya optimization algorithm. Then, two different multi-element truss towers previously solved with other methods without seismic loading in literature are designed by the proposed algorithm. The first space tower is a 582-member space truss with the height of 80 m and the second space tower is a 942-member space truss of about 95 m height. The minimum optimum designs obtained with this novel algorithm for the case without seismic loading are lighter than the ones previously attained in the literature studies. The results obtained in the study show that Jaya algorithm is a practical and robust optimization method for structural optimization problems. Moreover, incorporation of the seismic loading causes significant increase in the minimum design weight.

• Journal of the Korea Concrete Institute
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• v.15 no.5
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• pp.705-714
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• 2003

Even though Korean peninsula is located in regions of moderate seismic risks, current seismic design provisions of the roadway bridge design code have adopted the AASHTO code which is based on the requirements for high seismic regions. The objective of this research is to investigate the seismic performance of circular reinforced concrete (RC) bridge piers with limited ductility, which may be desirable in low or moderate seismic regions, such as in Korea. Four test specimens were designed and constructed. The reference specimen was designed with longitudinal steel ratio as 1.01% and the confinement reinforcement ratio as 0.13% without considering earthquake, and three other test specimens were designed in accordance with a limited-ductility concept as 0.3% for the confinement steel ratio. This confinement ratio is 0.32 times of minimum lateral reinforcement specified in current seismic design provisions, and 2.3 times of lateral reinforcement required in nonseismic design provisions. The pseudo-dynamic test was carried out to evaluate the seismic performance of full-scale specimens in size of 1.2m diameter and 4.8m height. Judging from the experiment, the reference specimen was not satisfactory for the demand displacement ductility ${\mu}$=5.0, but three limited-ductility specimens appeared to have the displacement ductility of more than 5.

• Proceedings of the Safety Management and Science Conference
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• 2011.11a
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• pp.75-84
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• 2011

In this paper various numerical analyses are carried out according to behavior characteristics of structures and types of seismic design methods as a study on the seismic analysis for underground structures. Equivalent Static Force Procedure and Response Displacement Method commonly used in practiral design are adopted and Time History Method regarded as the most accurate analysis method is selected to verify the results of two practical methods above. 3-D modelling for seismic analysis of structures is introduced to consider Structure Soil Interaction and all analyses are based on Korea Structural Concrete Design Code. After numerical analyses, Equivalent Static Force Procedure and Response Displacement Method showed relatively lager values than those of Time History Method, so it is identified that above two methods are suitable for practical design purpose.

• Earthquakes and Structures
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• v.6 no.5
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• pp.561-580
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• 2014

After strong earthquakes conventional frames used worldwide in multi - story steel buildings (e.g. moment resisting frames) are not well positioned according to reparability. Two innovative systems for seismic resistant steel frames incorporated with dissipative fuses were developed within the European Research Program "FUSEIS" (Vayas et al. 2013). The first, FUSEIS1, resembles a vertical Vierendeel beam and is composed of two closely spaced strong columns rigidly connected to multiple beams. In the second system, FUSEIS2, a discontinuity is introduced in the composite beams of a moment resisting frame and the dissipative devices are steel plates connecting the two parts. The FUSEIS system is able to dissipate energy by means of inelastic deformations in the fuses and combines ductility and architectural transparency with stiffness. In case of strong earthquakes damage concentrates only in the fuses which behave as self-centering systems able to return the structure to its initial undeformed shape. Repair work after such an event is limited only to replacing the fuses. Experimental and numerical investigations were performed to study the response of the fuses system. Code relevant design rules for the seismic design of frames with dissipative FUSEIS and practical recommendations on the selection of the appropriate fuses as a function of the most important parameters and member verifications have been formulated and are included in a Design Guide. This article presents the design and performance of building frames with FUSEIS 1-1 based on models calibrated on the experimental results.

• Proceedings of the Korea Concrete Institute Conference
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• 2005.05a
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• pp.295-298
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• 2005

Coupled shear wall(CSW) has been adopted as a lateral force resisting system in building frame structures. New Zealand code recommends the capacity design in designing the CSW. Capacity design based on using moment redistribution of member force may provide the economical benefit to designer. In this study, CSW's are designed by both capacity design and strength -based design. The design results and the seismic performance are compared by using nonlinear static analyses. The amount of reinforcement of shear wall and the section area of steel coupling beams by capacity design appear to be reduced by 19$\%$ and 17$\%$, respectively. Also CSW designed by capacity design shows good seismic performance at the ultimate state.

• Journal of the Society of Disaster Information
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• v.11 no.4
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• pp.487-492
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• 2015

Recently, apartment designs are tend to be changed from the standard pattern by many causes and the beam-column structures are getting popular instead of wall structure system. Therefore, for the effective use of planed space the heights of apartment are tend to be higher and higher. According to Korea Building Code, earthquake resistance designs or seismic design for those high rise apartments must be more attentive and accurate, especially, dynamic periods of structures must be exactly measured, because those are very important for equivalent static analysis. The important subject of this study is to investigate the safety factors and seismic performance for natural period of high rise buildings by comparing the natural periods getting from ambient vibration method with those of Korea Building Code.

• Journal of the Earthquake Engineering Society of Korea
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• v.16 no.5
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• pp.33-40
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• 2012

To reduce the vulnerability of torsional irregular buildings caused by seismic loads, the torsional amplification factor was introduced by the seismic code. This factor has been applied differently in a variety of seismic codes. In this study, the final static eccentricity, and the lateral and torsional stiffness ratios of buildings designed with different design eccentricities were compared. The increment of the torsional amplification factor resulted in a decrement of the final static eccentricity of the building. However, after reaching the maximum value of this factor, the final static eccentricity of the building increased again. The final static eccentricity of the building designed by multiplying the sum of the inherent and accidental eccentricity by the torsional amplification factor was zero or had a minus value, depending to the position of the vertical element.

• Structural Engineering and Mechanics
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• v.26 no.6
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• pp.617-634
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• 2007

Algeria is a country with a high seismic activity. During the last decade, many destructive earthquakes occurred, particularly in the northern part, causing enormous losses in human lives, buildings and equipments. In order to reduce this risk in the capital and avoid serious damages to the strategic existing buildings, the government decided to invest into seismic upgrade, strengthening and retrofitting of these buildings. In doing so, seismic vulnerability study of this category of buildings has been considered. Structural analysis is performed on the basis of site investigation (inspection of the building, collecting data, materials, general conditions of the building, etc), and existing drawings (architectural plans, structural design, etc). The aim of these seismic vulnerability studies is to develop guidelines and a methodology for rehabilitation of existing buildings. This paper will provide insight to the vulnerability assessment and strengthening of the telecommunication centre, according to the new code RPA 99/version 2003. Both, static equivalent method and non linear dynamic analysis are performed in this study.

• Structural Engineering and Mechanics
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• v.33 no.3
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• pp.261-284
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• 2009

The seismic behavior of a framed structure with chevron-type buckling restrained braces was investigated and their behavior factors, such as overstrength, ductility, and response modification factors, were evaluated. Two types of structures, building frame systems and dual systems, with 4, 8, 12, and 16 stories were designed per the IBC 2003, the AISC LRFD and the AISC Seismic Provisions. Nonlinear static pushover analyses using two different loading patterns and incremental dynamic analysis using 20 earthquake records were carried out to compute behavior factors. Time history analyses were also conducted with another 20 earthquakes to obtain dynamic responses. According to the analysis results, the response modification factors turned out to be larger than what is proposed in the provision in low-rise structures, and a little smaller than the code-values in the medium-rise structures. The dual systems, even though designed with smaller seismic load, showed superior static and dynamic performances.

• Journal of the Earthquake Engineering Society of Korea
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• v.13 no.3
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• pp.51-65
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• 2009

The seismic design concept of RC bridges is to attain the proper ductility of piers, yielding a ductile failure mechanism. Therefore, seismic design force for moment is determined by introducing a response modification factor (R), and lateral reinforcements to confine core concrete are specified in the current design code. However, these design provisions have irrationality, which results in excessive amounts of lateral reinforcements for columns in Korea, which are generally designed with large sections. To improve on these provisions, a new design method based on seismic performance has been proposed. To apply this to hollow sectional columns, however, further investigations and improvements must be performed, due to the different seismic behaviors and confinement effects. In this study, hollow sectional columns with different lap-splice of longitudinal bars and lateral reinforcements have been tested. Seismic characteristics and performance were investigated quantitatively. These research results can be used to derive a performance-based design for hollow sectional columns.