• Nuclear Engineering and Technology
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• v.37 no.2
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• pp.191-200
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• 2005

Shaking table tests of the seismic behavior of a steel frame structure model were performed. The purpose of these tests was to estimate the effects of a near-fault ground motion and a scenario earthquake based on a probabilistic seismic hazard analysis for nuclear power plant structures. Three representative kinds of earthquake ground motions were used for the input motions: the design earthquake ground motion for the Korean nuclear power plants, the scenario earthquakes for Korean nuclear power plant sites, and the near-fault earthquake record from the Chi-Chi earthquake. The probability-based scenario earthquakes were developed for the Korean nuclear power plant sites using the PSHA data. A 4-story steel frame structure was fabricated to perform the tests. Test results showed that the high frequency ground motions of the scenario earthquake did not damage the structure at the nuclear power plant site; however, the ground motions had a serious effect on the equipment installed on the high floors of the building. This shows that the design earthquake is not conservative enough to demonstrate the actual danger to safety related nuclear power plant equipment.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2006.03a
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• pp.56-63
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• 2006

Facilities of 76skV Substation(S/S) play an important role in electric power supply grids. Various power facilities of 765kV S/S might be damaged enormously if a strong earthquake occurs. In an effort to mitigate possible earthquake disasters, KEPRI (Korea Electric Power Research Institute) set forth plans to verify seismic safety of the facilities of 765kV S/S. To accomplish the task, an earthquake monitoring systems is constructed at four 765kV S/S sites(Shin-AnSung, Shin-TaeBaek, Shin-SeoSan and Shin-GaPyung). Data from these earthquake monitoring stations are being transmitted via satellite communication. Currently, KEPRI is operating an earthquake monitoring system in freefield of Shin-SeoSan S/S (NSS) tentatively, Also, the data from NSS is preliminarily analyzed using the horizontal to vertical (H/V) spectrum ratio method. The method of H/V spectrum ratio has been used to infer site amplification without previous knowledge of near surface geology. The results of data analysis shorts good S/N ratio and amplification of 20-25 Hz by site effect. In the near future, the accumulated data is expected to provide a basis for assessing and predicting any damages to integrity of 765kV S/S facilities by earthquakes.

• Journal of the Earthquake Engineering Society of Korea
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• v.11 no.1 s.53
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• pp.1-9
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• 2007

The purpose of this study is to carry out the quantitative sensitivity analysis on rockfill material influencing the dam crest displacement of CFRD(Concrete-Faced Rockfill Dam) subjected to earthquake loading. The total 105 dynamic numerical analyses (2 input earthquake, 2 magnitudes for each earthquake. 27 rockfill material property combinations obtained from large triaxial tests) on CFR type "D" dam in operation were conducted. The global sensitivity analysis was carried out using the results of numerical analysis. From the results of sensitivity analysis, It was found that the crest settlement of the CFR type dam subjected to earthquake was absolutely affected by the shear modulus of rockfill material irrespective of the input earthquakes and the maximum acceleration of each earthquake. Also, it was found that the horizontal displacement of the dam crest was highly affected by the shear modulus of rockfill material though the extent of effect on that was smaller than the settlement and the extent of effect depended on the input earthquakes and the maximum acceleration of each earthquake. On the contrary, it was found that the effect of friction angle was negligible.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 1999.10a
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• pp.3-14
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• 1999

The Hyogoken-Nambu Earthquake of January 17, 1995 inflicted severe damage in the Hanshin and Awaji areas such as has never been seen in Japan in recent years. The safety inspections of the dams conducted in the area by site offices and dam experts immediately after the earthquake showed that there was no damage affecting the safety of the dams although slight damage was observed in several dams. The investigation also revealed that the peak accelerations at dam sites were much smaller than those at soil sites. The Ministry of construction organized the Committee on Evaluattion of Earthquake Resistance of Dams after the earthquake. The Committee confirmed through dynamic analysis that the dams designed in accordance with the present design criteria in Japan are safe under the magnitude of shaking that occurred close the source fault of the Hyogoken-Nambu Earthquake.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2000.04a
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• pp.233-240
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• 2000

Nuclear power plant structures may be exposed to aggressive environmental effects than may cause their strength and stiffness to decrease over their service lives, Although the physics of these damage mechanisms are reasonably well understood and quantitative evaluation of their effects on time-dependent structural behavior is possible in some instances such evaluations are generally very difficult and remain novel. The assessment of existing RC containment in nuclear power plants for continued service must provide quantitative evidence that they are able to withstand future extreme loads during a service period with an acceptable level of reliability. Rational methodologies to perform the reliability assessment can be developed from mechanistic models of structural deterioration using time-dependent structural reliability analysis to take earthquake loading uncertainties into account. The final goal of this study is to develop the reliability analysis of RC containment structures. The cause of the degrading is first clarified and the reliability assessment has been conducted. By introducing stochastic analysis based on random vibration theory the reliability analysis which can determine the failure probabilities has been established.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2000.10a
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• pp.124-131
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• 2000

Numerical analysis of slop stability is carried out using seismic intensity, modified seismic intensity, and response seismic coefficient methods. It is found by comparing each of method that minimum safety factor precedes the required safety factor. It is also proved during analysis that most conservative method is the earthquake response analysis method, next is the response seismic coefficient method, and last one is the seismic intensity method. Usually, seismic intensity method is applied in analysis of slop stability. However, in view of safety factor, modified seismic intensity method is more conservative than seismic intensity method. Also modified seismic intensity method is appropriate when height of structure analyzed is high enough.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2002.03a
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• pp.220-227
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• 2002

This study introduces the fragility analysis method for the safety evaluation of reinforced concrete pier subject to earthquake. Damage probability is calculated instead of the failure probability from definition of the damage state in the fragility curve. Not only the damage model determined by the response of structure subject to earthquake, but also the plastic-damage model which can represent the local damage is applied to fragility analysis. The evaluation method of damage state by damage variable in global structure is defined by this procedure. This study introduces the fragility analysis method considering the features of nonlinear time history behavior of reinforced concrete element and the plastic behavior of materials. At last, This study gives one of the approach method for seismic margin evaluation with the result of fragility analysis to design seismic load.

• Proceedings of the KSME Conference
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• 2001.11a
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• pp.465-470
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• 2001

In this study, the seismic analysis of rack structure with fluid-structure interaction is performed through use of the Finite Element Method(FEM) code ANSYS. Fluid-structure interaction can specify in terms of an hydrodynamic effect which is defined as the added mass per unit length divided by the area of the cross section. Using the Floor Response Spectrum(FRS) obtained through the time-history analysis, modal analysis and seismic analysis under Operating Basis Earthquake(OBE) and Safe Shutdown Earthquake(SSE) condition is carried out. The fluid-structure interaction effects on the rack structure are investigated.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2005.03a
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• pp.153-160
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• 2005

A new nonlinear static analysis method, Effective Modal Pushover Analysis (EMPA) which can evaluate earthquake responses such as story drift and plastic rotation of plastic hinges addressing higher mode effects was developed. Unlike existing nonlinear static procedure based on properties of fundamental vibration mode, the EMPA performs nonlinear static analysis using multiple effective modes constructed by direct combination of natural vibration modes. Therefore higher mode effects can be efficiently considered. In the present study, procedures of the EPMA evaluating inelastic earthquake responese were established and the results were verified by nonlinear time history analysis. The EMPA can be applied to seismic evaluation of high-rise buildings and irregular buildings where higher mode effects become conspicuous.

• Proceedings of the Korean Geotechical Society Conference
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• 2008.10a
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• pp.820-826
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• 2008

Differ number of seismograph to the composition dam by recently frequent earthquake and analyzed responsiveness. Interest for dam inner place by increase of something wrong flood and inside and outside of the country earthquake appearance according to unusual change of weather is risen, on important urea in dam safety floodgate school register by structural safety divide can. Therefore, by PMP (PMF) of dam and increase of domestic earthquake occurrence, need research about earthquake resistant nature ability estimation of water resources facilities. Because responsiveness analysis applies number 0.154 ~ 0.25 g of seismograph, seismic wave that use in analysis is being suitable in dynamic analysis of construction such as Rockfill dam from representative chapter cycle faction and recommend in domestic internal examination design workbook, and use results applied much Hachinohe wave onions in van abroad.