• Proceedings of the Korea Concrete Institute Conference
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• 2001.11a
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• pp.965-970
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• 2001

The object of this research is to evaluate the seismic performance of existing RC bridge piers that were constructed before the adoption of the seismic design provision of Korea Bridge Design Specification in 1992. In this research, adopted test parameters were limited ductile design or non-seismic design, aspect ratio, confinement steel type, loading pattern, lap-spliced ratio for longitudinal reinforcement. This study has been performed to verify the effect of test parameter by quasi-static test. Quasi-static test has been done to investigate the physical seismic performance of RC bridge piers, such as lateral force-displacement hysteretic curve, envelope curve etc. It has been observed that seismic performance of lap-spliced test specimen, non-seismically designed specimens, was significantly reduced.

• Steel and Composite Structures
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• v.14 no.2
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• pp.155-171
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• 2013

This study analytically evaluated the seismic performance of wind-designed diagrid tall steel buildings in regions of moderate/low seismicity and strong winds. To this end, diagrid tall steel buildings with varying wind exposure and slenderness ratio (building height-to-width ratio) conditions were designed to satisfy the wind serviceability criteria specified in the Korean Building Code and the National Building Code of Canada. A series of seismic analyses were then performed for earthquakes having 43- and 2475- year return periods utilizing the design guidelines of tall buildings. The analyses demonstrated the good seismic performance of these wind-designed diagrid tall steel buildings, which arises because significant overstrength of the diagrid system occurs in the wind design procedure. Also, analysis showed that the elastic seismic design process of diagrid tall steel buildings might be accepted based on some wind exposures and slenderness ratios.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2001.09a
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• pp.187-193
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• 2001

The object of this research is to evaluate the seismic performance of existing circular reinforced concrete bridge piers by the Quasi-static test. Existing reinforced concrete bridge piers, which were non-seismical]y designed in accordance with the conventional provisions of Korea Highway Design Specification, are needed to rating evaluate seismic performance fur probable earthquake motions in future by developing a seismic analysis computer program with estimation algorithm. This study has been performed to verify the effect of lap spliced longitudinal steel, confinement steel type and confinement steel ratio for the seismic behavior of reinforced concrete bridge piers. Quasi-static test has been done to investigate the physical seismic performance of RC bridge piers, such as displacement ductility, energy absorption, strength degradation etc.

• Journal of the Earthquake Engineering Society of Korea
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• v.3 no.2
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• pp.97-106
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• 1999

In order to check the necessity of seismic reinforcement for a great number of existing structures effectively, it might be desirable to introduce the multi-step seismic evaluation system. This paper presents close relationships between shear-to-moment capacity ratio of a member and seismic performance of structures concerned through the failure mechanism investigation in the view of geological and structural characteristics. Based on it, the simple seismic performance evaluation method has been proposed and its effectiveness was verified by comparing with the damage condition of structures damaged under Hyogo-Ken Nambu Earthquake.

• Nuclear Engineering and Technology
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• v.40 no.4
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• pp.285-298
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• 2008

This study evaluates the performance of a coil spring-viscous damper system for the vibration and seismic isolation of an Emergency Diesel Generator (EDG) by measuring its operational vibration and seismic responses. The vibration performance of a coil spring-viscous damper system was evaluated by the vibration measurements for an identical EDG set with different base systems - one with an anchor bolt system and the other with a coil spring-viscous damper system. The seismic performance of the coil spring-viscous damper system was evaluated by seismic tests with a scaled model of a base-isolated EDG on a shaking table. The effects of EDG base isolation on the fragility curve and core damage frequency in a nuclear power plant were also investigated through a case study.

• Steel and Composite Structures
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• v.39 no.5
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• pp.645-664
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• 2021

There is a growing need of seismic retrofit of existing non-seismically designed structures in Korea after the 2016 Gyeongju and 2017 Pohang earthquakes, especially school buildings which experienced extensive damage during those two earthquakes. To this end, a steel multi-slit damper (MSD) was developed in this research which can be installed inside of partition walls of school buildings. Full-scale two-story RC frames were tested with and without the proposed dampers. The frames had structural details similar to school buildings constructed in the 1980s in Korea. The details of the experiments were described in detail, and the test results were validated using the analysis model. The developed seismic retrofit strategy was applied to a case study school building structure, and its seismic performance was evaluated before and after retrofit using the MSD. The results show that the developed retrofit strategy can improve the seismic performance of the structure to satisfy a given target performance level.

• Journal of the Korean Society of Industry Convergence
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• v.25 no.4_2
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• pp.611-619
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• 2022

In this study, the seismic performance of low - rise piloti buildings with concentric core (shear wall) position is analysed and reviewed based on KDS 41. The prototype is selected among the constructed low - rise piloti buildings with concentric core designed based on KBC 2005 which was used for many low - rise piloti buildings construction. The seismic performance of the building shows plastic behavior in X-direction and elastic behavior in Y-direction. The inter-story drift is lager than that of concentric core case and is under the maximum allowed drift ratio. The displacement ratio of first story is much lager the that of upper stories, and the frame structure in the first story is evaluated as vulnerable to lateral force. Therefore, low - rise piloti buildings with concentric core need the diminishment of lateral displacement and reinforcement of lateral resistance capacity in seismic design and seismic retrofit.

• Earthquakes and Structures
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• v.14 no.5
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• pp.389-398
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• 2018

The seismic isolation system makes a structure isolated from ground motions to protect the structure from seismic events. Seismic isolation techniques have been implemented in full-scale buildings and bridges because of their simplicity, economic effectiveness, inherent stability and reliability. As for the responses of an isolated structure due to seismic events, it is well known that the most uncertain aspects are the seismic loading itself and structural properties. Due to the randomness of earthquakes and uncertainty of structures, seismic response distributions of an isolated structure are needed when evaluating the seismic fragility assessment (or probabilistic seismic safety assessment) of an isolated structure. Seismic response time histories are useful and often essential elements in its design or evaluation stage. Thus, a large number of non-linear dynamic analyses should be performed to evaluate the seismic performance of an isolated structure. However, it is a monumental task to gather the design or evaluation information of the isolated structure from too many seismic analyses, which is impractical. In this paper, a new methodology that can evaluate the seismic fragility assessment of an isolated structure is proposed by using stochastic response database, which is a device that can estimate the seismic response distributions of an isolated structure without any seismic response analyses. The seismic fragility assessment of the isolated nuclear power plant is performed using the proposed methodology. The proposed methodology is able to evaluate the seismic performance of isolated structures effectively and reduce the computational efforts tremendously.

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.35 no.10
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• pp.143-153
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• 2019

In this study, a full scale 3-axes shake table test for M-bar and T-bar type ceilings commonly used in the country was conducted. Through damage inspection during the test, seismic performance of ceilings according to variables, such as clearance between wall mold and ceiling as well as existence of facilities, was evaluated. A test frame consisted of square hollow section members was used for the shake table test. The experimental method was performed as a fragility test using required response spectrum described in ICC-ES AC156. In the case of architectural nonstructural component that contain ceilings, it mainly is evaluated the performance by post-test visual inspection. For the evaluation of seismic performance of ceilings, this study classified and defined damaged items for targeted ceiling system referring to illustrative damage according to nonstructural performance levels accordance with ASCE 41 and previous studies. And proposed illustrative damage items classification was utilized to compare the degree of the damage according to experimental variables. The experiment results confirmed that differences in boundary conditions due to the clearance at wall mold and the installation of facilities had a significant effect on the seismic performance of the ceiling.

• Structural Engineering and Mechanics
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• v.48 no.2
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• pp.257-274
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• 2013

In this study, seismic performance of one story hinged precast buildings, which represents the majority of existing lightweight industrial building stock of Turkey, was assessed. A lot of precast buildings, constructed in one of the important seismic zones of western Turkey, were investigated and building inventories were prepared. By this method, structural properties of inventory buildings and damaged precast buildings in recent earthquakes were compared. Damage estimations based on nonlinear analysis methods have shown that estimated damage levels of inventory buildings and observed damage levels in recent earthquakes are similar. Accuracy of damage estimation study and the simplicity of the one story precast building models implied that rapid seismic performance assessment method for these buildings can be developed. In this assessment method, capacity curves and vibration periods of precast buildings were calculated by using structural properties of precast buildings. The proposed assessment method was applied to inventory buildings by using two different seismic demand scenarios which reflect moderate and soft soil conditions. Comparison of detailed analysis and rapid assessment methods have indicated that reliable seismic performance estimations can be performed by using proposed method. It is also observed that distribution of damage estimations is compatible in both scenarios.