• Journal of the Earthquake Engineering Society of Korea
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• v.7 no.5
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• pp.1-9
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• 2003

The seismic design of the domestic concrete dams has done by seismic coefficient method considering inertia force, but this method has defect not reflect dynamic properties, as a conservative design method. Therefore, it is necessary for seismic design of dam to consider dynamic properties. Also, concrete dam evaluation of seismic performance has done by seismic coefficient method - in fact, it may done by dynamic analysis - that has many problems when applied to the domestic criteria. This study make a comparative analysis for result from seismic design and evaluation of seismic performance by seismic coefficient method, modified seismic coefficient method, and dynamic analysis method.

• Journal of the Earthquake Engineering Society of Korea
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• v.2 no.2
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• pp.69-75
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• 1998

Because the collapse of liquid-storage tank structures under earthquakes brings out substantially more damages by indirect effects(continuous losses of economy and environmental disruption due to the spillage of toxic contents or pollutants) than direct economic losses of tanks and contents, it is an urgent matter to provide earthquake resistant design criteria in order to minimize such direct/indirect damages. In this paper, as fundamental works to prepare earthquake resistant design criteria for cylindrical liquid-storage tanks, analysis methods given in the Recommendations of New Zealand and Austria are reviewed and the applicabilities and problems of the two methods are set forth by comparison of the analysis results with a numerical example.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.13 no.2
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• pp.111-120
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• 1993

This paper summarizes an experimental and analytical study on the application of viscoelastic dampers as energy dissipation devices in structural applications. It can be concluded the viscoelastic dampers are effective in reducing excessive vibrations of structures under strong earthquake ground motions. It is also found that the modal strain energy method can be used to reliably predict the equivalent structural damping, and the seismic response of a viscoelastically damped structure can be accurately estimated by conventional modal analysis techniques. Based on the above studies, a design procedure for viscoelastically damped structures is presented. This design procedure fits naturally into the conventional structural design flow chart by including damping ratio as an additional design parameter.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.11
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• pp.5306-5313
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• 2011

Most previous studies for finding optimal design parameters of a tuned mass damper(TMD) have been focused on the harmonic excited single-degree-of freedom system. In this study, optimal values of damping ratio and tuning frequency ratio of a TMD applied to control a seismically excited structure are investigated through numerical analyses. Considering that the structural responses due to earthquake loads are strongly dependent on the soil condition, the site effects on the optimal parameters of the TMD are studied and compared to those presented by previous studies. Numerical analyses results indicate that better control performance can be obtained by using the parameters proposed by this study in the seismic application of the TMD.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.5A
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• pp.399-406
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• 2010

In this paper, the optimization of frictional bearings that applied to improve the seismic performance of conventional bridges were conducted. The nonlinear dynamic analysis of steel bridges and concrete bridges are carried out with the El Centro and artificial earthquake motions, and the reponses of the bridges were optimized by genetic algorithm. The object functions were considered with two parameters, such as shear forces and displacements at bearing, and the optimum object functions were searched by varying the weighting factors of the two parameters. As results, in case of the steel bridges, the optimum results were obtained when larger weight factor was imposed to the shear force. However, in case of concrete bridges, larger weight factor was need to the displacement for optimum results.

• Journal of the Earthquake Engineering Society of Korea
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• v.11 no.1 s.53
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• pp.21-27
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• 2007

In this study, an approach that installs seismic isolation bearings was proposed for the seismic retrofit of the existing bridges. The method that replaces all existing bearings with seismic isolators was proposed already. However, in this study, we recommend to utilize the existing bearings for the benefit of safety and cost. According to our proposal, the seismic isolators do not support vertical loads but they Just function as the period shifter and the horizontal damper. To verify this approach experimentally, the real scale bearings and lead rubber bearings far the real highway bridges were designed and fabricated. And the responses of this isolated bridges to the assumed earthquakes were determined by the pseudo dynamic test scheme. The test results were also compared to the responses computed by the well known structural analysis software to check the reliability of the test. From the test results, we found that the retrofitted bridges using the proposed method showed stable performances under earthquakes.

• Journal of the Korean Geotechnical Society
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• v.37 no.5
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• pp.33-46
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• 2021

After the Gyeongju earthquake, which was the largest in the history of measuring instruments in Korea in 2016, and after the Pohang earthquake, where the pillars of pallet structures were destroyed in 2017, the seismic design standards for all domestic facilities have been revised and supplemented. In particular, during the investigation of the Pohang Earthquake damage cases, liquefaction damage that occurs mainly in countries with strong earthquakes such as the United States, Japan, and New Zealand was found, so studies are being conducted in depth to improve seismic design standards. In this study, the liquefaction potential assessment in the recently revised seismic design standard for port and harbor was reviewed, and an applicability review was conducted focusing on the newly cited liquefaction potential index (LPI). At this time, by varying the thickness and location of the sandy soil where liquefaction can occur, the LPIs for various cases were calculated and compared. Also, 22 LPI values in the practical port area were compared and reviewed along with performance of the liquefaction assessment based on the site response analysis using the boring-hole data of the actual 22 port sites.

• Journal of the Earthquake Engineering Society of Korea
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• v.5 no.2
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• pp.13-22
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• 2001

지진하중을 받는 다경간 단순형교의 낙교방지대책으로 적용되는 cable restrainer를 적절하게 설계하기 위해서는 restrainer의 보강효과에 대한 분석이 우선적으로 이루어져야한다. 본 연구에서는 단순지지 다경간 교량시스템을 중심으로 restrainer로 보강된 교량의 보강효과와 다양한 교량의 영향 요소를 고려할 수 있는 단순화된 해석모형을 개발하였으며, 이를 바탕으로 대상교량의 인접 진동계간의 상대거리, 충돌력, 하부교각으로 전달되는 전단역과 휨모멘트의 변화 등의 동적거동특성을 조사하여 restrainer의 보강효과를 분석하였다. 또한, restrainer의 여유길이 변화, 강성변화, 그리고 restrainer 길이변화에 따른 응답특성을 분석하였다.

• Proceedings of the Korean Nuclear Society Conference
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• 1995.05a
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• pp.989-994
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• 1995

본 연구의 목적은 국내에서 개발중인 액체금속로의 면진설계를 위하여 면진층과 원자로용기 사이에 있는 내진벽의 강성이 면진시스템의 지진응답에 미치는 영향을 분석하는 것이다. 이를 위하여 내진벽강성을 고려한 모우드해석을 수행하여 내진벽의 강성변화에 따른 동특성해석을 수행하였으며 면진 및 비면진시스템의 경우에 대하여 지진해석을 수행하였다. 면진 및 비면진시스템에 대한 지진해석결과에서 비면진시스템의 경우에 내진벽강성은 지진응답에 영향을 주지만 면진시스템의 경우에는 그 영향이 매우 작은 것으로 나타났다.

• Proceedings of the Korea Water Resources Association Conference
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• 2010.05a
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• pp.57-61
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• 2010

국내 지진해일에 관한 연구는 범람 여부의 예측과 이에 대한 대비에 관하여 중점적으로 이루어지고 있다. 하지만 구조물에 직접적으로 피해를 주는 파력에 관한 연구는 거의 전무한 실정이다. 특히, 지진해일 1차 대피소는 지진해일 내습에 의한 파력에 대하여 안정하게 설계되어야 한다. 이를 연구하기 위한 방법으로 수리모형실험과 3D 모형을 이용한 수치모형실험의 두 가지 방법이 있으나 시간과 비용이 많이 소요되고 실제 지형에 적용하기에 곤란하다는 단점이 있다. 따라서 본 연구에서는 장파에 의한 파력식과 기존의 2D 수치모형을 이용하여 실용적으로 파력을 계산할 수 있는 방법을 제시하고, 이를 국내 무역항 중 하나인 동해항에 적용하였다.