• Geophysics and Geophysical Exploration
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• v.13 no.3
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• pp.219-226
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• 2010

Current earthquake alert notification for immediate post-earthquake procedures for the critical facilities is exclusively dependent on the ground-motion intensity measures observed at the seismic station located within the site. This practice is prune to false notification due to a noise and problems of missing and poor quality records of the seismic station. The credibility of the earthquake alert notification can be enhanced by utilizing the multiple transformed records of the nearby seismic stations at other sites interconnected to the same earthquake monitoring system by a network. The time-domain transformation of the site-response between the seismic stations is implemented by convoluting the nearby records with a pair of forward and inverse FIR filters designed for the site response relative to a seismic basement. The transformed records from the nearby seismic stations can be used to estimate the ground-motion intensity measures missing at the site or to evaluate the data quality along with other various possible applications in the area of geoscience and earthquake engineering.

• Journal of the Earthquake Engineering Society of Korea
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• v.1 no.1
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• pp.11-17
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• 1997

Seismic analyses of structures were carried out in the past assuming a right base and Ignoring the characteristics of foundations and the properties of the underlying soil. Resent soil-structure interaction studies show that seismic response of structure can be affected significantly by these fators. Typical effects of the soil-structure interaction are the kinematic interaction of a rigid massiess foundation and the inertial interaction between underlying soil and structure. The kinematic interaction effect is particularly important for embedded foundations and can be ignored for surface foundations with vertically propagating waves. In this study, seismic response of structure was investigated with four buildings in Mexico City considering only the inertial interaction effect and using the E-W components of the 1985 Mexico City earthquake records. The study was carried out for surface foundations and pile foundations with linear and nonlinear soil conditions, comparing the results with those of the rigid base.

• Economic and Environmental Geology
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• v.51 no.2
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• pp.185-201
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• 2018

Nuclear power plants(NPP) are constructed and operated to ensure safety against natural disasters and man-made disasters in all processes including site selection, site survey, design, construction, and operation. This paper will introduce a series of efforts conducted in Korea Hydro and Nuclear Power Co. Ltd., to assure the safety of nuclear power plant against earthquakes and other natural hazards. In particular, the present status of the earthquake, fault, and slope safety monitoring system for nuclear power plants is introduced. A earthquake observatory network for the NPP sites has been built up for nuclear safety and providing adequate seismic design standards for NPP sites by monitoring seismicity in and around NPPs since 1999. The Eupcheon Fault Monitoring System, composed of a strainmeter, seismometer, creepmeter, Global Positioning System, and groundwater meter, was installed to assess the safety of the Wolsung Nuclear Power Plant against earthquakes by monitoring the short- and long-term behavioral characteristics of the Eupcheon fault. Through the analysis of measured data, it was verified that the Eupcheon fault is a relatively stable fault that is not affected by earthquakes occurring around the southeastern part of the Korean peninsula. In addition, it was confirmed that the fault monitoring system could be very useful for seismic safety analysis and earthquake prediction study on the fault. K-SLOPE System for systematic slope monitoring was successfully developed for monitoring of the slope at nuclear power plants. Several kinds of monitoring devices including an inclinometer, tiltmeter, tension-wire, and precipitation gauge were installed on the NPP slope. A macro deformation analysis using terrestrial LiDAR (Light Detection And Ranging) was performed for overall slope deformation evaluation.

• Journal of the Earthquake Engineering Society of Korea
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• v.3 no.2
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• pp.77-86
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• 1999

In the previous $paper^{(1),(2)}$, a geometrically non-linear finite element formulation of spatial cables subjected to self-weights and support motions was presented using multiple noded cable elements and how to determine the initial equililbrium state of cables was addressed. In this paper, in order to perform dynamic non-linear analysis of ocean cables subjected to support motions and earthquakes, a numerical method to calculate Morison forces and incorporate effects of earthquake motions is presented based on the Newmark method. Challenging example problems are presented in order to investigate dynamic non-linear behaviors of ocean cables subjected to support motions and earthquake loadings.

• Journal of the Earthquake Engineering Society of Korea
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• v.4 no.4
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• pp.83-91
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• 2000

합리적인 기기의 활률론적 지진위험도 평가를 위해서는 모델의 동특성에 대한 보다 현실적인 정보가 제공되어야 한다. 이 연구에서는 심한 비선형 동적 거동을 보일 것으로 예상되는 철제 전기 캐비넷의 동특성 시험결과 및 분석 절차를 제시하였다. 특히, 이 연구에서는 가진 강도의 크기에 따른 동특성의 비선형 집중분석하고, 그 비선형성의 원인을 고찰하였다. 시험 결과 및 이 논문에 제시된 분석 절차를 이용하여 시험체의 동특성이 효과적으로 도출될 수 있으며, 대상 시험체는 가진 강도에 따라 심한 비선형 거동을 함을 입증하였다. 비선형성의 원인은 일반적인 재료 비선형이라기 보다는 각 부품들의 마찰력과 기하학적인 비선형성에 기인함을 발견하였다. 또한, 캐비넷 형식의 기긱에 대한 합리적인 내진안전성 평가를 위해서는 각 방향별로 서로 다른 감쇠값을 적용할 것을 추천하였다. 또한, 캐비넷 형식의 기기에 대한 합리적인 내진안전성 평가를 위해서는 각 방향별로 서로 다른 감쇠값을 적용할 것을 추천하였다.

• Journal of the Earthquake Engineering Society of Korea
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• v.2 no.4
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• pp.11-22
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• 1998

An axisymmetric shell element which includes the effects of the meridional and circumferential cable prestresses is developed. It is coded for personal computer by the maximum use of axisymmetic properties and the dynamic analysis is performed under the seismic exitations. A ring element is used to fully utilize the characteristics of the axisymmetric shell. The eigenvalue solutions using 20 elements under the initial prestresses are in good agreement with the exact solutions. The results of the seismic analysis show that the radial deflection under the meridional prestress is a little larger than that under the circumferential prestress. The finite element model developed in this study can be very useful to the design applications.

• Water for future
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• v.52 no.5
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• pp.36-41
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• 2019

• Journal of the Earthquake Engineering Society of Korea
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• v.11 no.6
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• pp.33-39
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• 2007

The seismic source parameters of the Uljin earthquake on 29 May 2004, including focal depth, focal mechanism, magnitude, and moment tensor elements for source characteristics, are analysed using moment tensor seismic source inversion. The Green‘s function for 3 crust models representing the southern Korean Peninsula are used. Also 3 kinds of epicenters are used to find optimum solution for seismic source parameters. Results show that seismic source parameters have a little dependency of azimuthal distribution and epicentral distances of seismic stations. Final results show that the event, considering 6 moment tensor elements, is caused by the typical reverse fault with nearly NS strike. The focal mechanism implies that the tectonic force around epicenter area currently has compressive environment, with nearly EW principal axis. The focal depth is estimated to be about 12km. The resultant focal mechanism show fairly good agreement to those of other studies. However, focal depth is much different from that of other studies.

• Proceedings of the Korea Water Resources Association Conference
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• 2018.05a
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• pp.19-19
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• 2018

최근 경주, 울산, 포항 등 경상도 지역에서 잇달아 발생한 대규모 지진으로 인해 사회기반시설물의 내진 안전성이 이슈가 되고 있다. 지진 안전 국가라고 여겨지던 우리나라는 상대적으로 지진에 대한 대비가 매우 부족한 실정이며, 자칫 대규모 피해로 이어질 우려가 있다. 특히 상수관망의 경우, 지중에 매설되어 있는 특성상 지진에 취약하고, 그 피해를 발견하기 어려워 장기적인 피해가 불가피하다. 상수관로의 지진피해는 누수와 파손으로 구분할 수 있으며, 파손관의 경우 용수공급능력을 크게 저하시키기 때문에 신속한 복구가 요구된다. 파손관의 복구는 부근에 위치한 차단밸브를 닫아 피해관로의 통수를 차단한 후에 복구 작업을 진행하는 것이 일반적이다. 이때, 차단밸브의 위치에 따라 단수구역이 광범위하게 발생할 수 있어 시스템 전반의 용수공급능력 저하로 이어질 가능성이 있다. 본 연구에서는 지진 발생 후 피해관로의 효율적인 복구전략 마련을 위한 상수관망 지진피해 복구 시뮬레이션 모형을 개발하였다. 개발 모형은 피해복구에 따른 상수관망 시스템의 용수공급능력을 정량적으로 산정할 수 있으며, 지진 발생과 같은 비정상 상황의 시스템 용수공급능력을 수리학적으로 정확하게 해석하기 위해 압력기반의 해석(Pressure-driven analysis, PDA)을 적용하였다. 또한, 피해관로의 복구 시, 차단밸브에 의해 발생되는 단수구역을 탐색한 후, 수리해석 모의에 적용함으로써 현실적인 용수공급 상황을 모의할 수 있도록 하였다. 본 연구에서는 개발모형을 활용하여 차단밸브의 위치 및 개수가 단수구역의 범위 및 지진복구에 미치는 영향을 정량적으로 비교 분석하였으며, 이를 통해 효율적인 지진피해 복구 전략을 제시하였다.

• Journal of the Earthquake Engineering Society of Korea
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• v.5 no.3
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• pp.9-17
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• 2001

This paper focuses on the earthquake hazard delineation and physical loss estimation for lifelines and utilities. Emphasis is given to geographic information systems(GIS) and their application to pipeline networks in evaluating the spatial characteristics of earthquake effects. The paper examines the GIS databases for water supply performance obtained for the 1994 northridge. Relationships among buried lifeline damage and various seismic parameters are examined, and the parameters that are statistically most significant are identified. Using GIS data from the Northridge earthquake, the relationships among pipeline repair rate, type of pipe, diameter, and various seismic parameters are assessed.