• 한국지진공학회:학술대회논문집
• /
• 한국지진공학회 2001년도 추계 학술발표회 논문집 Proceedings of EESK Conference-Fall 2001
• /
• pp.139-146
• /
• 2001

The seismic safety analysis were performed for the center-core rockfill dam(CCRD) The static and pseudo-static FEM analysis using seismic coefficient Method, and dynamic FEM analysis using Hachinohe earthquake wave(0.12g) were used for the seismic safety of CCRD. The results of seismic analysis were that the factor of safety of down slope was 1.5, horizontal displacement is about 14.3cm, and vertical displacement is 3.3cm at dam creast. The model dam did not show any seismic stability problems for 0.12g. And much more research is still necessary in seismic safety of CCRD.

• 한국지진공학회논문집
• /
• 제9권4호
• /
• pp.1-10
• /
• 2005

본 연구의 목적은 국내 실정에 적합한 원전 기초지반의 지진안정성을 평가할 수 있는 적절한 해석모델을 제시하는 것이다 입력지진의 작용방향, 경계조건, 해석모델의 폭 및 깊이, 단층연약대의 모델링방법 등의 해석조건에 대하여 활동면해석법, 등가정적해석법, 동적해석법을 적용하였다. 해석결과 측면경계조건은 등가정적 해석시 수평롤러, 동적해석시 전달경계, 해석영역의 폭은 구조물 폭의 5배 이상, 깊이는 구조물 폭의 2배 이상을 적용하는 것이 바람직한 것으로 나타났다.

• 한국지진공학회:학술대회논문집
• /
• 한국지진공학회 2001년도 추계 학술발표회 논문집 Proceedings of EESK Conference-Fall 2001
• /
• pp.147-154
• /
• 2001

In this study, comprehensive seismic performance analysis were performed for the concrete face rockfill dam(CFRD) designed seismic coefficient method(0. 10g). The static and pseudo-static FEM analysis, limited equilibrium method and dynamic FEM analysis were used for the dam safety analysis. The results of the seismic analysis were that the minimum factor of safety of down slope was 1.2 and horizontal displacement increased 8cm and vertical displacement increased 1.2cm at dam crest rather than those of static condition. The model dam did not show any serious tai lure in seismic stabi1ity for 0.13g. And much more research is still necessary in seismic safety of CFRD.

• 한국공간구조학회논문집
• /
• 제14권4호
• /
• pp.89-96
• /
• 2014

Spatial structures as like dome structure have the different dynamic characteristics from general rahmen structures. Therefore, it is necessary to accurately analyze dynamic characteristics and effectively control of seismic response of spatial structure subjected to multi-supported excitation. In this study, star dome structure that is subjected to multi-supported excitation was used as an example spatial structure. The response of the star dome structure under multiple support excitation are analyzed by means of the pseudo excitation method. Pseudo excitation method shows that the structural response is divided into two parts, ground displacement and structural dynamic response due to ground motion excitation. And the application of passive tuned mass damper(TMD) to seismic response control of star dome structures has been investigated. From this numerical analysis, it is shown that the seismic response of spatial structure under multiple support seismic excitation are different from those of spatial structure under unique excitation. And it is reasonable to install TMD to the dominant points of each mode. And it is found that the passive TMD could effectively reduce the seismic responses of dome structure subjected to multi-supported excitation.

• Geomechanics and Engineering
• /
• 제5권1호
• /
• pp.37-55
• /
• 2013

An important issue in the design of soil-nailing systems, as long-term retaining walls, is to assess their stability during seismic events. As such, this study is aimed at simulating the dynamic behavior and failure pattern of nailed structures using two series of numerical analyses, namely dynamic time history and pseudo-static. These numerical simulations are performed using the Finite Difference Method (FDM). In order to consider the actual response of a soil-nailed structure, nonlinear soil behaviour, soil-structure interaction effects, bending resistance of structural elements and construction sequences have been considered in the analyses. The obtained results revealed the efficiency of both analysis methods in simulating the seismic failure mechanism. The predicted failure pattern consists of two sliding blocks enclosed by three slip surfaces, whereby the bottom nails act as anchors and the other nails hold a semi-rigid soil mass. Moreover, it was realized that an increase in the length of the lowest nails is the most effective method to improve seismic stability of soil-nailed structures. Therefore, it is recommended to first estimate the nails pattern for static condition with the minimum required static safety factor. Then, the required seismic stability can be obtained through an increase in the length of the lowest nails. Moreover, placement of additional long nails among lowest nails in existing nailed structures can be considered as a simple retrofitting technique in seismic prone areas.

• 한국지진공학회:학술대회논문집
• /
• 한국지진공학회 2005년도 학술발표회 논문집
• /
• pp.74-81
• /
• 2005

The purpose of this study is to suggest a proper analysis model that can evaluate seismic stability for local rock foundation of nuclear power plant. Sliding Analysis, Pseudo-static Analysis and Danamic Analysis methods are used for analysing NPP rock foundation with the conditions like acting directions of input earthquake, boundary conditions, width and depth of analysing model, and modeling methods of weakness fault zones. As the results of study, Pseudo-static Analysis for lateral roller and dynamic analysis for transfer boundary condition showed good results, and analysing ranges of width and depth were 5 times of structure width and over 2 times of structure depth.

• 한국지반공학회논문집
• /
• 제37권9호
• /
• pp.5-12
• /
• 2021

유사정적해석법은 실무에서 지진 시 사면의 안전계수를 구하기 위하여 널리 사용되고 있다. 반면에 동적해석은 지진 시 지반의 응력-변형관계를 가장 잘 모사할 수 있다는 장점에도 불구하고 설계기준에서 요구되는 안전계수를 산정하기 어려워 실무적으로 그 활용이 많지 않았다. 본 연구에서는 비선형 응답이력해석으로 사면의 동적 안전계수를 산정하는 기법을 구축하였다. 이 방법은 최대가속도를 인위적으로 조절해서 지진계수를 산정하는 유사정적해석법의 문제점을 극복하며 사면 고유의 증폭 특성을 고려할 수 있다. 제안된 방법은 단일 사면에 대해서 적용하였으며 해석 결과를 유사정적해석법과 비교하였다. 본 연구에서 사용한 사면 사례에서는 동적해석결과로부터 계산된 사면의 최소 안전계수는 유사정적해석결과와 유사하게 평가되었으며, 수평방향 지진계수와 활동 토체의 평균 가속도가 최대가 되는 시점에서 동적 안전계수는 최소가 됨을 확인하였다.

• 한국지진공학회논문집
• /
• 제21권2호
• /
• pp.77-85
• /
• 2017

Pseudo-static approach has been conventionally applied for the design of gravity quay walls. In this method, the decision to select an appropriate seismic coefficient ($k_h$) is an important one, since $k_h$ is a key variable for computing an equivalent pseudo-static inertia force. Nonetheless, there is no unified standard for defining $k_h$. Likewise, port structure designers in Korea have a difficulty in choosing an appropriate $k_h$ definition, as there are conflicts in how $k_h$ is defined between the existing seismic code of port structures and the proposed new one. In this research, various seismic design codes for port structures were analyzed to compare the definitions of the seismic coefficient. The results were used for the proposing a unified seismic coefficient definition. Further, two dynamic centrifuge tests were performed with different wall heights (5 m, 15 m) to clarify the reference point of peak acceleration used in determination of $k_h$ according to the wall height. Results from dynamic centrifuge experiments showed that correction factors for the peak ground acceleration considering both the wall height and allowable displacement are needed to calculate $k_h$.

• 한국지진공학회논문집
• /
• 제11권1호
• /
• pp.21-27
• /
• 2007

본 연구에서는 교량의 내진보강을 위하여 기존 교량에 지진격리장치를 추가하는 접근법을 제안하였다. 기존 받침을 지진 격리받침으로 완전히 대체하는 접근법도 이미 제안되어 있지만 본 연구에서는 경제성과 안전성을 고려하여 기존 받침을 제거하지 않고 활용하도록 하였다. 이는 지진격리받침이 상부 수직하중을 분담하지 않고, 수평방향의 지진운동에 대한 주기 이동과 감쇠 역할만 한다. 이 접근법의 실험적 검증을 위해 실제 교량을 대상으로 납-적층고무받침(LRB)을 설계하고 실물크기로 기존 받침과 LRB를 제작하였다. 이 지진격리시스템의 가상 지진입력에 대한 응답은 유사동적실험으로 구하였다. 아울러 범용해석프로그램을 통한 지진응답해석과 비교하여 실험결과의 신뢰성을 확인하였다. 실험결과 제안된 지진격리시스템은 지진시 안정적인 거동을 보였다.

• 콘크리트학회논문집
• /
• 제14권2호
• /
• pp.180-189
• /
• 2002

이 연구의 목적은 유사동적실험에 의한 섬유보강 원형철근콘크리트교각의 내진성능평가를 위한 연구로서 수원시에 위치한 내진설계된 교량인 하갈교를 대상모델로 하였다. 도로교설계기준의 내진설계규정이 적용되지 않은 비내진실험체 2개 및 내진설계 규정에 따라 설계된 내진실험체 2개 그리고 내진성능향상을 위해 비내진실험체를 보강한 섬유보강실험체 4개 즉 총 8개에 대하여 유사동적실험을 수행하였다. 보강공법으로는 유리섬유 및 탄소섬유 보강공법을 사용하였으며, 실험변수로는 내진 및 비내진설계, 하중형식, 섬유보강유무로 하였다. 내진성능평가 방법은 소산에너지, 변위연성도 그리고 능력스펙트럼이 분석되었다. 실험결과로 유리 및 탄소섬유로 보강된 비내진실험체의 변위연성도는 KHC인공지진파에 대하여 7.7~8.7정도의 값으로서 충분한 내진성능을 확보하고 있는 것으로 평가되었다.