Most of systems and components in nuclear power plants (NPPs) are anchored to the concrete structure and other components by means of post installed anchors. In order to develop more accurate seismic analysis model of equipment in NPPs, a deep consideration of concrete-anchor connection behavior is required. In this paper, the nonlinear finite element analysis was conducted for the concrete-anchor connection zone details. From the analysis results including strength and load-displacement relation was derived according to design variables including geometry and material properties.

In this study, the natural frequencies of long-span truss bridges with LRB were analyzed and compared. As a result of the mode analysis, a similar mode shape was shown irrespective of whether LRB was applied or not. The natural frequency analysis using the measurement data, the natural frequencies of the first to third transverse modes could not be analyzed due to the small dynamic response, and the natural frequency of the fourth vertical mode was analyzed to be similar to the mode analysis results. As a result of comparing the natural frequency of the vertical direction mode of 18 truss bridges in the past, the bridge with LRB was analyzed to have smaller natural frequency than the bridge without LBR.

2016년 경주지진 이후로 국내에서도 본격적으로 건축물의 지진대책 강구가 시급한 시점에서 국내에 널리 보급되어 있는 R/C 건축 물의 효율적인 내진성능 평가 및 내진보강을 포함한 내진대책을 위한 기초적인 자료를 얻고자, 2016년 경주지진에서 지진피해를 받은 R/C 저 층 학교건축물(M학교)을 대상으로 지진피해도구분판정법을 이용하여 잔존내진성능과 지진피해정도를 평가함과 동시에, 부재수준의 비선형 동적해석을 수행하여 지진피해정도와의 상관관계를 검토하였다. 지진피해도구분판정에 의한 손상도-I로 분류된 기둥은 2개, 손상도-Ⅱ가 1 개, 손상도-III으로 분류된 기둥이 3개로 각각 평가되어, 최종적으로 평가한 내진성능잔존율(R)은 88.2%로 피해분류는 소규모 피해로 판정되 었으며, 또한 비선형동적해석 결과 1층 X방향의 최대응답을 나타낸 기둥의 휨변위는 0.7 mm, 전단변위는 6 mm로 전단균열은 발생하였지만, 전단파괴는 발생하지 않았다. 경주지진에서 지진피해를 입은 M학교의 지진피해가 1층의 X방향에 집중되어 있다는 사실, 휨균열보다는 전단 균열이 발생하였다는 사실을 고려한다면 본 연구에서 수행한 비선형동적해석 결과는 2016년 경주지진에서 지진피해를 받은 M학교의 지진피 해상황을 잘 반영하고 있다고 사료되며, 국내 기존 저층 R/C 건축물의 효율적인 내진성능 평가 및 내진보강을 포함한 내진대책을 위한 기초적 인 자료로서 활용가능하다고 사료된다.

Numerical behavior of reinforced concrete(RC) column with GFRP seismic reinforcement was evaluated through the finite element analysis in this study. For the numerical analysis, a experimental test results was used to develop a nonlinear three dimensional finite element model of RC column with GFRP seismic reinforcement. The developed the nonlinear three dimensional finite element model of RC column with GFRP seismic reinforcement was well predicted the behavior, maximum strength and initial stiffness, of RC column with GFRP seismic reinforcement.

Due to the enlargement and high-rise of reinforced concrete structure, the application of high functional material is required. However, high-strength bar is recently introduced to the country and the material is insufficient to measure the variation of quantity of rebar quantitatively when using high-strength bar. For these reasons, this study is to provide useful data in cost decision making when applying high-strength bar at a stage of architectural project planning. For residence-commerce complex buildings, we set up six types of conditions such as in case of using only rebar, in case of using only high-strength bar, in case of using rebar mixed with high-strength bar and so on. With the standard of study model 1 that applies only SD400 regardless of rebar diameter, the analyzed result of rebar variation and the cost change of construction in other study model is as follows. When the rebar amount and cost in study model I was 100%, each ratio was 88.3% and 90.5% in study model II, 80.2% and 83.4% in study model III, 91.9% and 93.5% in study model IV, 88.9% and 87.7% in study model V and 82.4% and 85.5% in study model VI. Therefore, in case of rebar amount and construction cost, study model III was evaluated as the best that was applied only SD600.

본 연구의 목적은 비선형 동적해석을 통한 국내 비보강 조적조의 내진성능을 평가하는데 있다. 보다 정밀한 내진성능 평가를 위해 조적벽체의 파괴모드를 고려한 비선형 이력모델을 이용하고자 하나, 선행연구의 비선형 이력모델은 정적반복가력해석에 대한 검증만이 수행 되었다. 이에 본 연구에서는 진동대실험과 동적해석 결과를 비교하여 제안한 비보강 조적조 비선형 해석모델의 신뢰성을 검증한 다음, 국내 비 보강 조적조 건축물의 비선형 동적해석을 수행하고 결과를 분석하여 내진성능을 평가하였다. 그 결과, 1층의 조적조 건축물의 경우 개구부율 에 관계없이 비교적 지진피해가 작은 반면, 2층 이상의 국내 비보강 조적조 건축물의 대부분이 국내에 발생가능한 지진에 취약하였다.

Structural engineers needs know-how about using nonlinear analysis softwares for seismic performance evaluation of existing building. In this study, it’s compared with several softwares, nonlinear analysis are available.

In this present study to investigate the seismic response of an offshore wind turbine, incorporating with bottom fixed Jacket support structure using semi-coupled analysis method. Fully coupled, aero-servo-hydro-elastic simulations and uncoupled seismic simulation have been done to carry out this investigation. The fully coupled simulation is accomplished and executed by FAST 8 (NREL, USA) to determine the global loads, which consists of six components of forces and moments at x-y-z directions of the tower base. In the uncoupled case, transient analysis has been done using the tower base loads as well as seismic loads by ANSYS. This paper presents a precise dynamic analysis, which can evaluate the dynamic response of three crucial points (tower top, tower base and mud line of substructure) under seismic load to make better decision in the case of structural design of wind turbine.

Damage states of an underground tunnel structure need to be defined in the estimation of its seismic fragility. They are identified in this paper by applying pushover analyses of an typical tunnel structure. Latin Hypercube sampling (LHS) technique is used to explicitly consider uncertainties in the associated design variables.

The purpose of this study is to determine the force and deformation of the ceiling system according to the characteristics seismic wave and damping through the seismic response analysis. Assuming the ceiling system to Single Degree of Freedom(SDF) uses the CANNY in an analysis program. Period divided by the range based on the predominant period of seismic analysis is performed. Variables are seismic wave and damping. If the seismic wave in predominant period of less than 1 second is getting longer than predominant period of more than 1 second response acceleration was significantly reduced. Also, the larger the damping was found that the response acceleration and the displacement decreases.

In order to evaluate the seismic safety of weir structure subjected to seismic ground motions, simple linear elastic 2D plane strain Finite Model (FE) was developed in ABAQUS platform. Also, the 1994 Northridge earthquake as a ground motion uncertainty was selected. The numerical results showed that the compressive stress was significantly increased in comparison to the results from the design spectrum analysis but the horizontal displacement was reduced about 28%.

최근 대형 지진으로 인한 인적 물적 손실을 방지하기 위한 면진설계의 유용성이 입증되면서 교량, 건물 등 대형구조물을 중심으로 면진받침의 적용 사례가 증가하고 있다. 주요 면진받침 형식 중의 하나인 미끄럼식의 경우 복원력을 제공하기 위하여 스프링 등이 사용되며, 지진과 같은 급격한 하중 작용 시 이러한 스프링의 역학적 특성은 면진받침 뿐 아니라 받침이 적용된 구조물의 거동에 영향을 미치므로 정확한 파악이 중요하다. 이 연구에서는 미끄럼식 면진받침에 적용되는 폴리우레탄 스프링에 대한 실험 결과를 이용하여 역학적 특성을 분석하였다. 역학적 거동 특성에 대한 모델링을 위하여 기존 초탄성체에 대한 해석 모델을 분석하고 각 모델의 적절성을 실험 결과와의 비교를 통하여 검토하였다. 검토는 상용 유한요소해석 프로그램인 LUSAS를 이용하여 수행하였다.

본 연구에서는 지진 발생 시, 진앙으로부터 원거리 지역에 위치하거나 연약지반에 위치한 구조물에 영향을 줄 수 있는 장주기 성분 지진에 대한 예측 거리산정식을 분석하였다. 장주기 성분 지진에 관한 대표적인 피해 사례로는 멕시코시티지진(1985), 토카치오키지진(2003), 동일본대지진(2011) 등이 있으며, 일반 지진의 경우에서 볼 수 없는 다른 피해 양상이 나타났다. 이러한 장주기 성분 지진에 대해서는 연구된 바가 거의 없는 실정으로, 본 연구에서는 세계 각지에서 발생한 실제 지진기록에 대한 DB를 구축하고, 이를 분석하여 장주기 성분 지진의 도달거리 범위, 도달거리에 따른 최대지반가속도의 변화 등에 관한 분석을 실시하였다.

The purpose of this study is to analyse site natural period for estimating resonance of soil-structure. The natural period of seismic accelerometer installed site is calculated with HVSR(Horizontal to Vertical Spectral Ratio) proposed by Nakamura. To analyze natural period, a micro tremor is used at several sites. The result can be used for the study of soil-structure resonance, site classification and the site amplification effects.

The objectives of this research are to compute performance point using capacity spectrum analysis, and to use structural damage states classification and damage state criteria through interstory drift angle presented in HAZUS. Seismic fragility curve is drawn by seismic fragility parameter and predict damage probability about non seismic reinforced concrete buildings according to building shapes.

The LH seismic system is composed of structure, brace, and LH damper designed high damping rubber. The dynamic test with shaking table was performed to analyze the vibration characteristic of the RC Frame and LH seismic system.

1994년 미국 서부지역을 강타한 Northridge 지진의 발생 이후로, 캘리포니아 주 정부는 꾸준히 기존 건축물의 내진보강 프로젝트를 발주해왔다. 특히, 지진에 대하여 안전하다고 여겨지던 철골모멘트골조의 내진 취약성이 Northridge 지진을 통해 드러남에 따라, 90년대 중후반부터 2000년대 초반 까지 강구조 접합부의 내진성능 검증 및 개선을 위한 연구가 활발히 진행되었다. 본 기사에서 다루고 있는 캘리포니아 교통국 제4구역 본청(Caltrans District 4) 건물 역시 철골모멘트골조로 지어졌으며, 150년 주기로 대규모 지진을 발생시키고 있는 헤이워드 단층(Hayward Fault)으로부터 불과 9km 떨어진 곳에 위치해있다. 따라서 캘리포니아 교통국에서는 본 건물의 내진보강설계 및 시공 프로젝트를 발주하였고, 샌프란시스코에 있는 건축구조설계사인 Degenkolb Engineers에서 전반적인 보강설계 프로젝트를 수행하였다.본 기사에서는 내진보강설계 대상건물의 개요 및 캘리포니아 내진기준에 대하여 간략하게 소개하고 있으며, Degenkolb Engineers에서 수행한 대상건물의 내진보강계획 수립과정 및 구체적인 내진해석방법에 대하여 설명하고 있다. 또한, 내진보강설계를 위해 수행한 실물대 실험에 대해서도 소개하고 있다.

In this paper a computationally efficient methodology to establish the seismic fragility curve for underground tunnel structures is developed by integrating the response acceleration method and the maximum likelihood approach with a large set of artificial ground motion time-histories. It is elaborated with an illustrative numerical example.

Generally, levee design is performed through deterministic methods. However, deterministic methods, which are unable to take into account the heterogeneity of a physical system, is limited to overcome variable uncertainties taking place in the natural phenomena. Accordingly, structure design based on reliability analysis considering the uncertainty of variables are getting spotlight. Climate changes and global warming occurring all over the world, are ground to frequent natural disasters, such as earthquakes, which can lead to serious damages based on their magnitude. In this research, a seismic safety assessment method for levees is introduced, adopting the concept of reliability analysis methods.

Recent earthquake events arising all over the world, cause serious damages to material/ human resources every year. South Korea, categorized to be relatively safe from earthquakes, recently became subject to frequent seismic events, which made it essential to prepare for damages caused by such events. Failure of hydraulic structures, such as dams, can cause serious damages to resources in the lower reaches of a river. In this study, as a counterproposal for deterministic safety assessment for seismic events on dams, which cannot take into account the uncertainty of various parameters, a method is introduced which constructs a safety chart by creating an artificial seismic wave considering uncertainties of seismic sources, propagation paths and site effects.