• Journal of the Korean Society of Safety
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• v.27 no.1
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• pp.44-48
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• 2012

The seismic safety of long-period cable-stayed bridges is assessed by probabilistic finite element analysis and reliability analysis under NFE. The structural response of critical members of cable-stayed bridges is evaluated using the developed probabilistic analysis algorithm. In this study, the real earthquake recording(Chi-Chi Earthquake; 1997) was selected as the input NFE earthquake for investigating response characteristics. The probabilistic response and reliability index shows the different aspect comparing the result from FFE earthquake. Therefore, the probabilistic seismic safety assessment on NFE earthquakes should be performed for the exact evaluation of long-period cable-stayed bridges and the earthquake resistant design criteria should be complemented.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.36 no.4
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• pp.337-346
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• 2000

Earthquake is a natural disaster accompanied by damage of human and properties caused by the ground motion, crustal movements, faults as well as tidal wave. The earthquake is known to occur mostly in earthquake-prone areas and the Korean Peninsula is known to be relatively safe in terms of geological characteristics. In order to withstand on severe environmental dynamic random load such as an earthquake, the large structure need to be designed to withstand the anticipated seismic tremor. The seismetic design is essential for building structures, bridges, and large structures which is handles explosive gases. Thus, the necessity of earthquake resistant analysis for large structure is growing and the capability of dynamic analysis should be obtained. In this thesis, dynamic responses of a high building(height 60m, width 18) which subjected to random earthquake load are presented which responses are derived using dynamic analysis methods such as response spectrum analysis, mode superposition and direct integration. Each results are also compared to review the merit of each methods.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 1999.10a
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• pp.37-44
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• 1999

Spectral characteristic of Kyeongju earthquake occurred on the June 2, 1999 with magnitude 3,4 is analyzed. It is guessed that the stress energy release of source within relatively short period caused the ground near the epicenter to vibrate with large amplitude for the magnitude and predominantly high frequency. The cumulative absolute velocity and average spectrum acceleration are 0.034 gsec and 0.118g, respectively lower than threshold values of potential earthquake damage which is consistent with the investigation of damage in field. The analysis of the acceleration records of Kyeongju earthquake shows the need to develop the ration criterion for the determining the operating basis earthquake of nuclear power plant.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 1999.04a
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• pp.61-68
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• 1999

In the nonlinear dynamic structural analysis the given ground excitation as an input should be well defined. Because of the lack of recorded accelerograms in Korea it is required to generate an artificial earthquake by a stochastic model of ground excitation with various dynamic properties rather than recorded accelerograms. It is well known that earthquake motions are generally non-stationary with time-varying intensity and frequency content. Many researchers have proposed non-stationary random process models. Yeh and Wen (1990) proposed a non-stationary modulation function and a power spectral density function to describe such non-stationary characteristics. Satio and Wen(1994) proposed a non-stationary stochastic process model to generate earthquake ground motions which are compatible with design reponse spectrum at sites in Japan. this paper shows the process to modify power spectrum compatible with target design response spectrum for generating of nonstationary artificial earthquake ground motions. Target reponse spectrum is chosen by ATC14 to calibrate the response spectrum according to a give recurrence period.

• Earthquakes and Structures
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• v.6 no.4
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• pp.375-392
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• 2014

Time history analyses have been preferred commonly in earthquake engineering area to determine earthquake performances of structures in recent years. Advances in computer technology and structural analysis have led to common usage of time history analyses. Eurocode 8 allows the use of real earthquake records as an input for linear and nonlinear time history analyses of structures. However, real earthquake records with the desired characteristics sometimes may not be found, for example depending on soil classes, in this case artificial and synthetic earthquake records can be used for seismic analyses rather than real records. Selected earthquake records should be scaled to a code design spectrum to reduce record to record variability in structural responses of considered structures. So, scaling of earthquake records is one of the most important procedures of time history analyses. In this paper, four real earthquake records are scaled to Eurocode 8 design spectrums by using SESCAP (Selection and Scaling Program) based on time domain scaling method and developed by using MATLAB, GUI software, and then scaled and real earthquake records are used for linear time history analyses of a six-storied building. This building is modeled as spatial by SAP2000 software. The objectives of this study are to put basic procedures and criteria of selecting and scaling earthquake records in a nutshell, and to compare the effects of scaled earthquake records on structural response with the effects of real earthquake records on structural response in terms of record to record variability of structural response. Seismic analysis results of building show that record to record variability of structural response caused by scaled earthquake records are fewer than ones caused by real earthquake records.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 1998.04a
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• pp.39-43
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• 1998

The objective of the study is to develop attenuation equations of groud motions in the southern part of the Korean Peninsula. The earthquake source characteristics and the medium properties were estimated from available instrumental earthquake records and used as input parameters. The peak ground accelerations (PGA) and pseudo-velocty response spectra(PSV) were simulated by the random vibration theory. The attenuation equations for the PGA were constructed in terms of local magnitudes and hypocentral distances.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 1999.04a
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• pp.41-48
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• 1999

Small earthquake records with magnitude 2.7-4.8 recorded in Kyungsang Basin during 1995-1997 were analysed. Total of 87 records consisted of 16 events instrumented at 11 stations,. Mean dominant period at each station mean zero period acceleration of each component and the acceleration response spectra were analysed. Spectral value increases as magnitude increases and the predominant frequency band expands to low frequency zone as magnitude increases.

• Journal of the Earthquake Engineering Society of Korea
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• v.20 no.3
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• pp.171-180
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• 2016

Earthquake event keeps increasing every year, and the recent cases of earthquake hazards invoke the necessity of seismic study in Korea, as geotechnical earthquake hazards, such as strong ground motion, liquefaction and landslides, are a significant threat to structures in industrial hub areas including coastal facilities. In this study, systemized framework of integrated assessment of earthquake-induced geotechnical hazard was established using advanced geospatial database. And a visible simulation of the framework was specifically conducted at two coastal facility areas in Incheon. First, the geospatial-grid information in the 3D domain were constructed with geostatistical interpolation method composed of multiple geospatial coverage mapping and 3D integration of geo-layer construction considering spatial outliers and geotechnical uncertainty. Second, the behavior of site-specific seismic responses were assessed by incorporating the depth to bedrock, mean shear wave velocity of the upper 30 m, and characteristic site period based on the geospatial-grid. Third, the normalized correlations between rock-outcrop accelerations and the maximum accelerations of each grid were determined considering the site-specific seismic response characteristics. Fourth, the potential damage due to liquefaction was estimated by combining the geospatial-grid and accelerations correlation grid based on the simplified liquefaction potential index evaluation method.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2002.09a
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• pp.83-90
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• 2002

There are few earthquake records in Korea and the Japanese or American representative earthquake records have been generally used in the seismic design. In this study, some earthquake records which the range of earthquake magnitudes varies from 5.3 to 7.9 were collected and analyzed to assess which record can rationally reflect Korean seismic characteristics. In this assessment, each seismic energy and acceleration spectrum were analyzed with the unified maximum ground acceleration. Several numerical analyses on Korean representative caisson structures were also carried out to compare each dynamic displacement. In these numerical analyses, soil conditions and the dimension of structure such as height and width were changed. Through this assessment, it is found that the compatible earthquake magnitude in Korea is lower than 7. From the result of numerical analyses, it is shown that horizontal dynamic displacements corresponding to earthquake magnitudes over than 7 are quite larger than those below earthquake magnitude 7. Based on this study, it is necessary that Korean seismic design guideline will refer earthquake magnitude criteria for the construction of the economical aseismic structure.

• Geomechanics and Engineering
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• v.37 no.3
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• pp.279-291
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• 2024

The "Korea Institute of Geoscience and Mineral (KIGAM) Quake" is a web-based open platform developed for publicly serving seismological data from 61 stations operated by KIGAM in Korea. The service provides meta-information related to observatory sites, sensors, and recorders necessary for utilizing the seismological data, as well as mainly observed continuous and strong-motion waveforms. The data is available through both the web and International Federation of Digital Seismograph Networks (FDSN) web services (open API), a unified data-providing interface in seismology. The platform aims to strengthen its open nature by offering a signal processing function for strong ground motions that can be controlled by user requests. The processed results can be downloaded in ASCII format, designed to meet the increased demands and accessibility in the earthquake engineering field. The platform also offers earthquake research information produced by KIGAM, such as recent major earthquake source information and academic annual report of earthquakes. Additionally, a site flat file was constructed for the geotechnical characteristics of 61 KIGAM station (KGNET) sites based on direct investigations and estimations.