• 대한토목학회논문집
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• 제10권3호
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• pp.1-6
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• 1990

다지점지진하중(多支點地震荷重)을 받는 사경문(四徑問) 연속철도교양(連續鐵道橋梁)의 동적거동(動的擧動)을 응답(應答)스펙트럼법(法)에 의하여 조사(調査)하였다. 소진복(小振福)의 진동(振動)과 재료(材料)의 선형(線形)-탄성거동(彈性擧動)을 가정(假定)하였으며, 지반(地盤)-구조물(構造物) 상호작용(相互作用) 효과(效果)는 무시(無視)하였고, 교량(橋梁)의 횡방향(橫方向) 등답(應答)만을 고려(考慮)하였다. 응답(應答)스펙트럼해석(解析)의 결과(結果)는 시간이력해석결과(時間履歷解析結果)와 비교(比較)되었으며 모우드 최대치(最大値)와 지지점운동(支持點運動)의 중량(重量)은 여러가지 조합법칙(組合法則) 즉(卽), Square-Root-Of-Sum-Squares, Double Sum, 그리고 P-Norm Rule을 적용(適用)하였다.

• 한국소음진동공학회논문집
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• 제17권1호
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• pp.88-94
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• 2007

Structures with additional frictional damping system have strong nonlinearity that the dynamic behavior is highly affected by the relative magnitude between frictional force and excitation load. In this study, normalized response spectra of the structures with non-dimensional friction force are obtained through nonlinear time history analyses of the mass-normalized single degree of freedom systems using 20 ground motion data recorded on rock site. The variation of the control performance of frictional damping system is investigated in terms of the dynamic load and the structural natural period, of which effects were not considered in the previous studies. Least square curve fitting equations are presented for describing those normalized response spectrum and optimal non-dimensional friction forces are obtained for controlling the peak displacement and absolute acceleration of the structure based on the derivative of the curve-fitted design spectrum.

• 한국지진공학회논문집
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• 제7권2호
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• pp.39-48
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• 2003

반응수정계수의 핵심구성요소인 연성계수에 대하여 통계적 분석을 수행하였다. 연성계수의 체계적인 산정을 위하여 총 1,860개의 지진기록을 수집하였다. 수집된 지진기록을 지반 전단파의 평균속도에 따라 4가지로 분류하고, 탄소성 이력거동을 가지는 단자유도 구조물에 대하여 비탄성 스펙트럼을 작성하였다. 작성된 비탄성 스펙트럼으로부터 연성계수를 구하고, 변위연성비, 토질조건, 규모 및 진앙거리가 연성계수에 미지는 영향을 분석하였다. 토질 조건별로 평균연성계수를 구하고, 산정된 연성계수의 산포도를 검토하기 위하여 변동계수를 산정하였다.

• Nuclear Engineering and Technology
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• 제49권4호
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• pp.825-837
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• 2017

Due to the severe impacts of recent earthquakes, the use of seismic isolation is paramount for the safety of nuclear structures. The diversity observed in seismic events demands ongoing research to analyze the devastating attributes involved, and hence to enhance the sustainability of base-isolated nuclear power plants. This study reports the seismic performance of a seismically-isolated nuclear reactor containment building (NRCB) under strong short-period ground motions (SPGMs) and long-period ground motions (LPGMs). The United States Nuclear Regulatory Commission-based design response spectrum for the seismic design of nuclear power plants is stipulated as the reference spectrum for ground motion selection. Within the period range(s) of interest, the spectral matching of selected records with the target spectrum is ensured using the spectral-compatibility approach. NRC-compliant SPGMs and LPGMs from the mega-thrust Tohoku earthquake are used to obtain the structural response of the base-isolated NRCB. To account for the lack of earthquakes in low-to-moderate seismicity zones and the gap in the artificial synthesis of long-period records, wavelet-decomposition based autoregressive moving average modeling for artificial generation of real ground motions is performed. Based on analysis results from real and simulated SPGMs versus LPGMs, the performance of NRCBs is discussed with suggestions for future research and seismic provisions.

• 한국지진공학회:학술대회논문집
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• 한국지진공학회 1998년도 추계 학술발표회 논문집 Proceedings of EESK Conference-Spring 1998
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• pp.297-303
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• 1998

The uniform hazard spectrum of Wolsong Nuclear Power plant Site is computed in order to estimate probabilistically the characteristics of spectral ground response. The spectral hazard values calculated from the seismic zoning maps proposed by eight seismologist are combined with equal weight to produce a uniform hazard spectrum. The uniform hazardd spectra corresponding to reference probabilities of 1.0 $\times$10-4/year and 1.0$\times$10-5/year are presented, which largely depend on the spectral attenuation relation. The computational results of this study contribute to verify the conservatism of the design ground spectrum of Wolsong Nuclear Power Plant.

• Earthquakes and Structures
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• 제23권2호
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• pp.115-128
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• 2022

One common method to select input ground motions to predict dynamic behavior of structures subjected to seismic excitation requires spectral acceleration (S_a) match target mean response spectrum. However, dispersion of ground motions, which explicitly affects the structural response, is rarely discussed in this method. Generally, selecting ground motions matching target mean and variance has been utilized as an appropriate method to predict reliable seismic response. The goal of this paper is to investigate the impact of target spectra variance of ground motions on structural seismic response. Two sets of ground motions with different target variances (zero variance and minimum variance larger than inherent variance of the target spectrum) are selected as input to two different structures. Structural responses at different heights are compared, in terms of peak, mean and dispersion. Results show that increase of target spectra variance tends to increase peak floor acceleration, peak deformation and dispersions of response of interest remarkably. To short-period structures, dispersion increase ratios of seismic response are close to that of S_a of input ground motions at the first period. To long-period structures, dispersions of floor acceleration and floor response spectra increase more significantly at the bottom, while dispersion increase ratios of IDR and deformation are close to that of S_a of input ground motions at the first period. This study could further provide useful information on selecting appropriate ground motion to predict seismic behavior of different types of structures.

• 한국지진공학회논문집
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• 제12권1호
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• pp.1-9
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• 2008

건축물의 지진응답해석에서 입력지진동은 구조물의 비선형 응답에 중요한 영향을 미치는 요소이다. 지진동의 특성은 표층지반의 성질과 국부적인 지반 조건에 따른 여러 가지 인자에 의해 그 특성이 결정되기 때문에 구조물의 지진응답해석에서 일반성을 갖는 입력지진동을 선정하는 것은 매우 어려운 문제이다. 본 논문은 내진설계용 스펙트럼에 적합한 인공지진동파형을 작성한 후, 작성된 인공지진동에 의한 철근콘크리트 다층 골조구조물의 탄소성 응답특성을 분석한 것이다. 여기서 작성된 인공지진동파형은 과거 비교적 큰 규모의 지진에서 얻어진 기록지진동과 동일한 위상각을 가지며, 감쇠정수 h=5%일 때의 내진설계용 스펙트럼과 거의 일치하도록 작성하였다. 입력지진동의 탄성 가속도 응답스펙트럼이 동일한반면, 각 입력지진동띄 위상특성이 다른 인공지진동을 입력하여 다자유도 골조 구조물의 지진응답을 분석하여 건축물의 내진설계용 지진동으로서 타당성을 확인하는 것이 목적이다. 본 논문에서 작성된 인공지진동은 기록지진동에 비해 지진응답치가 안정된 값을 나타내는 것을 확인할 수 있었다. 그러므로 다층 골조구조물의 비선형 지진응답해석용 입력지진동으로 타당성이 높다고 사료되며, 비선형 지진응답해석용 입력지진동의 강도를 탄성 가속도 응답스펙트럼으로 규준화 하는 것이 합리적이라고 사료된다.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회B
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• pp.3497-3500
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• 2007

The internal structure is subjected to dynamic analysis due to the structural integrity. The internal structure shall be installed in the vertical hole call IR1 of reactor core. In order to verify the deflection of the internal structure, the mode and response spectrum analysis of the internal structure was performed. The natural frequency of the internal structure is 11.6 Hz(mode 1 and 2) and deflections of the internal structure are less than values of allowable design (3.2 mm).

• 한국지진공학회:학술대회논문집
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• 한국지진공학회 2000년도 추계 학술발표회 논문집 Proceedings of EESK Conference-Fall 2000
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• pp.91-97
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• 2000

Once a response spectrum is estimated for the site, if there is a need of generating realistic earthquakes time histories considering seismic sources and path effects, one alternative is to use statistical phase characteristics based on real earthquake records other than assuming arbitrary duration and envelope curves. In this study, statistics of group delay times derived from Japanese strong earthquake data were used for phase generation to fully capture the stochastic property of earthquakes. The result shows that simulated earthquake time histories can be generated according to earthquake magnitude and distances with target response spectrum.

• 한국지진공학회:학술대회논문집
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• 한국지진공학회 2003년도 춘계 학술발표회논문집
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• pp.69-76
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• 2003

Near-field ground motions exhibit special characteristics that are different from ordinary far-field ground motions. This paper first briefly examines the characteristics of near-field ground motions associated with fault directivity and fling-step effects. Then evaluation of near-field ground motions by inelatstic response spectrum analysis is performed and analyzed. As a result, ductility demand in near-field ground motions is larger in hanging wall than in foot wall in long period regions. Also in long period regions ductility demand in soil site is larger than that in rock site.