• Journal of the Earthquake Engineering Society of Korea
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• v.20 no.7_spc
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• pp.461-472
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• 2016

Damage potential has been investigated for a domestic metropolitan railway bridge subjected to 2016 Gyeongju earthquake which has been reported as the strongest earthquake in Korea. For this purpose, nonlinear static pushover analyses for the bridge piers have been carried out to evaluate ductility capacities. Then, the capacities have been compared with those suggested by Railway Design Standards of Korea. This comparison shows that all piers possess enough safety margins. Nonlinear dynamic time-history analysis has also been conducted to estimate both displacement and shear force demands for the bridge subjected to ground motions recorded at stations in near of Gyeongju. Maximum demands reveal that response under the ground motions remains essentially in elastic. In addition, for a further assessment of the bridge under the Gyeongju earthquake, fragility analyses have been performed using those ground motions. The fragility results indicate that the recorded earthquakes do not significantly affect the damage exceedance probability of the bridge piers.

• Nuclear Engineering and Technology
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• v.54 no.1
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• pp.386-400
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• 2022

Seismic fragility analysis, a part of seismic probabilistic risk assessment (SPRA), is commonly used to establish the relationship between a representative property of earthquakes and the failure probability of a structure, component, or system. Current guidelines on the SPRA of nuclear power plants (NPPs) used worldwide mainly reflect the earthquake characteristics of the western United States. However, different earthquake characteristics may have a significant impact on the seismic fragility of a structure. Given the concern, this study aimed to investigate the effects of earthquake characteristics on the seismic fragility of concrete containments housing the OPR-1000 reactor. Earthquake time histories were created from 30 ground motions (including those of the 2016 Gyeongju earthquake) by spectral matching to the site-specific response spectrum of Hanbit nuclear power plants in South Korea. Fragility curves of the containment structure were determined under the linear response history analysis using a lumped-mass stick model and 30 ground motions, and were compared in terms of earthquake characteristics. The results showed that the median capacity and high confidence of low probability of failure (HCLPF) tended to highly depend on the sustained maximum acceleration (SMA), and increase when using the time histories which have lower SMA compared with the others.

• Nuclear Engineering and Technology
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• v.30 no.3
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• pp.212-221
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• 1998

In the present study, a method for the dynamic analysis of a reactor core is developed. Peak responses for the motions induced from earthquake are obtained for a core model. The dynamic responses such as fuel assembly shear force, bending moment, axial force and displacement, and spacer grid impact loads are investigated. Prediction of fuel assembly stress during an earthquake requires development of a fuel assembly stress analysis model capable of interfacing with the models and results discussed in the dynamic analysis of a reactor core. This analysis uses beam characteristics which describe the overall fuel assembly response. The stress analysis method and its application for the case of an increased seismic level are also presented.

• Journal of the Earthquake Engineering Society of Korea
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• v.10 no.5 s.51
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• pp.63-71
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• 2006

In seismic response analysis of building structures, the input ground accelerations have considerable effect on the nonlinear response characteristics of structures. The characteristics of soil and the locality of the site where those ground motions were recorded affect on the contents of earthquake waves. Therefore, it is difficult to select appropriate input ground motions for seismic response analysis. This study describes a generation of artificial earthquake wave compatible with seismic design spectrum, and also evaluates the nonlinear response spectra by the simulated earthquake motions. The artificial earthquake wave are generated according to the previously recorded earthquake waves in past earthquake events. The artificial wave have identical phase angles to the recorded earthquake wave, and their overall response spectra are compatible with seismic design spectrum with 5% critical viscous damping. Each simulated earthquake wave has a identical phase angles to the original recorded ground acceleration, and match to design spectra in the range of period from 0.02 to 10.0 seconds. The seismic response analysis is performed to examine the nonlinear response characteristics of SDOF system subjected to the simulated earthquake waves. It was concluded that the artificial earthquake waves simulated in this paper are applicable as input ground motions for a seismic response analysis of building structures.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 1998.10a
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• pp.345-352
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• 1998

Free-field ground motion during earthquake is significantly affected by the local site conditions and the behavior of structure is influenced by ground motion, it is essential to perform the reliable site characterization and to determine the site specific earthquake response. In this study, case study of site specific ground response evaluation was performed at Inchon area. Step by step procedures for site characterization and one-dimensional site response analysis were introduced and the importance of site specific analysis was verified.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 1999.04a
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• pp.292-299
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• 1999

In order to investigate dynamic behaviors of marine cables under wave and earthquake forces a geometric nonlinear. F, E formulation of marine cables is presented and tangent stiffness and mass matrices for the isoparametric cable element are derived, The initial equilibrium state of cables subjected to self -weights and current forces is determined and free vibration and dynamic nonlinear analysis of cable structures under additional environmental loads are performed based on the initial configuration Challenging examples are presented and discussed in order to demonstrate the feasibility of the present finite element method and investigate dynamic nonlinear behaviors of marine cables.

• Journal of Ocean Engineering and Technology
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• v.19 no.1 s.62
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• pp.26-32
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• 2005

Recent earthquakes, measuring over a magnitude of 5.0, on the eastern coast of Korea, have aroused interest in earthquake analyses and the seismic design of caisson-type breakwaters. Most earthquake analysis methods, such as equivalent static analysis, response spectrum analysis, nonlinear analysis, and capacity analysis, are deterministic and have been used for seismic design and performance evaluation of coastal structures. However, deterministic methods are difficult for reflecting on one of the most important characteristics of earthquakes, i.e. the uncertainty of earthquakes. This paper presents results of probabilistic seismic hazard assessment(PSHA) of an actual caisson-type breakwater, considering uncertainties of earthquake occurrences and soil properties. First, the seismic vulnerability of a structure and the seismic hazard of the site are evaluated, using earthquake sets and a seismic hazard map; then, the seismic risk of the structure is assessed.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2006.03a
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• pp.284-291
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• 2006

This paper presents a seismic response analysis of bridge structures considering foundation-soil interaction and multi-support input motion. In the earthquake analysis of structures it is usually assumed that the input ground motion is the same at all supports. However, this assumption is not justified for long structures like bridges, because observations have shown the earthquake ground motion can vary considerably within relatively small distances. When the soil under the foundation is relatively soft and deep, analysis for foundation-soil interaction always must be peformed. To consider foundation-soil interaction, soil response analysis is preceded, and after determining the material characteristics of foundation element obtained by foundation-soil interaction analysis at the frequency domain, the seismic response analysis of bridge superstructure with the equivalent spring and damper is performed. Finally, influences of multi-support input motion, which are affected by different soil characteristics, are also considered in this paper.

• Journal of the Earthquake Engineering Society of Korea
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• v.5 no.5
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• pp.1-11
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• 2001

The purpose of this study is to develop the main program and pre/post processor for the geometric and plastic non-linear analysis of steel jacket structures subjected to wave and earthquake loadings. In this paper, steel jackets are modelled using geometric non-linear space frames and wave loadings re evaluated based on Morrison equation using the linear Airy theory and the fifth Stokes theory. Random wave is generated using JONSWAP spectrum. For earthquake analysis, dynamic analysis is performed using artificial earthquake time history. Also the plastic hinge method is presented for limit analysis of steel jacket. In the companion paper, the pre/post processor is developed and the numerical examples are presented for linear and non-linear dynamic analysis of steel jackets.

• Journal of Cadastre & Land InformatiX
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• v.47 no.1
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• pp.251-265
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• 2017

On the Korean peninsula, which has been recognized as a safe haven from earthquakes, A magnitude 5.8 earthquake occurred. It has been confirmed that the Korean Peninsula is no longer a safe zone from an earthquake. The purpose of this study is to examine the state of the earthquake preparedness in our society and to grasp the properties of the building which is a direct damage object in the event of an earthquake and to help the decision making of the earthquake disaster prevention policy through the construction of the earthquake safety map. There is a purpose. Earthquake safety maps are created through spatial analysis using GIS tools. The construction of an earthquake safety map is not the whole of the earthquake disaster prevention policy, but it means that it is a starting point to effectively replace the earthquake disaster prevention system.