• Journal of the Computational Structural Engineering Institute of Korea
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• v.24 no.3
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• pp.289-294
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• 2011

In this study, the seismic analysis of traveling sea water screen for nuclear power plant was performed using finite element model. For qualification of traveling sea water screen, the response spectrum analysis was performed using the given operating basis earthquake(OBE) and safe shutdown earthquake(SSE) floor response spectrum. Dynamic analysis of water sea traveling screen was performed using finite element method. The analytical maximum displacements of traveling sea water screen were 2.5 mm under OBE condition and 4.6 mm under SSE condition. The maximum stresses of traveling sea water screen were 24 MPa under OBE condition and 44 MPa under SSE condition, that this results were 18 %, 27% of yield strength of material. Thus, it can shown that the structural integrity of traveling sea water screen has a stable structure for seismic load conditions.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.13 no.4
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• pp.65-75
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• 1993

Presented is a method for nonstationary response analysis of an offshore guyed tower subjected to strong earthquake motions under moderate random waves and current loadings. By taking the time varying envelope function and the auto-correlation function of the ground acceleration in terms of complex exponential functions, an analytical procedure is developed for computing time varying variances of the tower response. The stationary responses due to small random waves are obtained by using frequency domain method, and the results are combined with the nonstationary results due to earthquakes. Finally, the expected maximum responses are estimated. Through the example analyses, the nonstationary method developed in this study is verified, and the contributions of the earthquake, wave and current loadings to the total maximum response are investigated.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.27 no.6
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• pp.501-508
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• 2014

In this paper, a method on deducing the capacity spectrum based on nonlinear earthquake response analysis will be introduced. Damage assessment of general building draws the capacity spectrum through the Push-over analysis and the intersection point of capacity spectrum and demand spectrum is seen as performance point. Push-over analysis is the way to perform static analysis by using the equivalent static load changed from the effect of earthquake and predict the behavior of structures by earthquake. But, this method can not be taken into account in the effects of higher mode and the dynamic characteristic. Therefore, in order to calculate the capacity spectrum under dynamic properties of building. A capacity spectrum from going ahead with the nonlinear earthquake response analysis is suggested.

• 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.

• Journal of Korean Society of Steel Construction
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• v.22 no.1
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• pp.13-20
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• 2010

Seismic risk assessment of railway bridges is an important issue for a transportation network, because loss of functionality of railway bridges could result in severe disruption of the railway line, as no redundant routing systems generally exist. Although many studies have been conducted by numerous researchers regarding fragility analyses of bridge structure, little or no studies have been done for fragility analyses of a class of bridge structures considering their geometric variability. This study performs a fragility analysis for Track-on Steel-Plate-Girder (TOSPG) railway bridges in Korea considering their span variability. Seismic fragility curves are developed for a series of bridges with different spans varying from 2 to 15. At last, the fragility curves for the whole TOSPG bridges in Korea are also developed using the total probability theorem. This study is expected to effectively contribute to the seismic risk assessment of railway lines, where a number of bridges are present.

• Journal of the Earthquake Engineering Society of Korea
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• v.12 no.6
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• pp.25-33
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• 2008

Fires that result from the excessive leakage of gas due to earthquakes cause enormous loss of property as well as numerous human casualties. To prevent such disasters, an emergency gas shut-off system is considered to be one of the effective and rational methods. Considering the seismicity, the earthquake frequency and the gas-supply system of Korea, mass gas shut-off by a gas company is determined to be more cost-effective than individual gas shut-off by customers. In this study, an emergency response system was proposed that would shut off the gas supply immediately. Two different reference seismicities were proposed, to specify rapid response according to the measured seismicity. The gas supply area was divided into several gas shut-off blocks in order to facilitate the shut-off of gas supply in damaged blocks. This proposed system was implemented in the actual gas supply area with reference seismicities on the basis of seismic damage analysis.

• Land and Housing Review
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• v.1 no.1
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• pp.51-57
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• 2010

The importance of seismic design is greatly emphasized recently in Korea, resulting in an increase in the number of dynamic analysis being performed. One of the most important input parameters for the dynamic seismic analysis is input ground motion. However, it is common practice to use recorded motions from U.S. or Japan without considering the seismic environment of Korea or synthetic motions generated in the frequency domain. The recorded motions are not suitable for the seismic environment of Korea since the variation in the duration and energy with the earthquake magnitude cannot be considered. The artificial motions generated in frequency domain used to generated design response spectrum compatible ground motion has the problem of generating motions that have different frequency characteristics compared to real recordings. In this study, an algorithm that generates target response spectrum compatible ground motions in time domain is used to generate a suite of input ground motions. The generated motions are shown to preserve the non-stationary characteristics of the real ground motion and at the same, almost perfectly match the design response spectrum.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.35 no.3
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• pp.149-158
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• 2022

As a bridge ages, its mechanical properties and structural performance deteriorate, degrading its seismic performance during a strong earthquake. In this study, the aging of piers and bridge bearings was quantified in several stages and reflected in the analysis model, enabling the evaluation of the member-level seismic fragility of these bearings. Moreover, by assuming that the failure mechanism of a bridge system is a series system, a method for evaluating the system-level seismic fragility based on the member-level seismic fragility analysis result is formulated and proposed. For piers with rubber and lead-rubber bearings (members vulnerable to aging effects), five quantitative degrees of aging (0, 5, 10, 25, and 40%) are assumed to evaluate the member-level seismic fragility. Then, based on the result, the system-level seismic fragility evaluation was implemented. The pier rather than the bridge bearing is observed to have a dominant effect on the system-level seismic fragility. This means that the seismic fragility of more vulnerable structural members has a dominant influence on the seismic fragility of the entire bridge system.

• The Journal of Engineering Geology
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• v.25 no.2
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• pp.265-272
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• 2015

Finite element analyses were performed on large-sized (>5000 ton) stainless steel circular water reservoirs subjected to earthquake loading for different stainless steel materials. The earthquake load inputs for the analyses were selected by the guidelines in the Korean Standards Association specification KS B 6283. Seismic effects can be heavily dependent on water capacity, especially for large reservoirs. The numerical results show the interactions between the different load combinations and other parameters such as the water capacity and stainless steel materials. Structural performance is also evaluated for the various load combinations.

• 한국공간정보시스템학회:학술대회논문집
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• 2007.06a
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• pp.293-299
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• 2007

자연재해 중 시설 파괴 규모나 인위적 경제적 피해정도에 있어서 지진은 직접적인 피해가 엄청난 재난이다. 특히 현대사회의 산업화로 도시는 인구가 집중되고 시설물이 대형화되면서 그 기능이 복잡다양해지고 있어 지진이 발생할 경우 도시의 사회 경제활동이 장기간 마비되는 사태가 발생하기도 한다. 본 논문에서는 건축물 구조해석에 의한 내진평가체계를 수립하고 내진평가에 필요한 다양한 자료들을 GIS DB화하여 건물의 내진성능평가를 수행함으로써, 개별 건물의 지진위험등급 산정과 GIS기반으로 지진위험도를 체계적으로 평가할 수 있는 정보체계를 구축하여 지진발생시 피해규모 및 범위를 추정할 수 있는 정보체계구축의 가능성을 제시하였다.