• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2000.05a
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• pp.191-194
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• 2000

최근의 삼풍백화점 붕괴사고 및 성수대교사고 등 대형사고의 원인을 살펴보면 건물의 안전진단 미비와 구조물의 안전관리 진단판정미비로 건축물의 붕괴를 예측하지 못한 결과이다. 이는 모든 불확실 시스템의 상태를 적당한 항목으로 판정 정규화한 계수값으로 나타내어 예방하지 못한 결과이다. 비단건축물 시스템뿐 아니라 실존 가시물(可視物)과 비가시물(悲歌視物)에 대해서도 비결정 상황의 상태표시계수를 예측하여 정규값으로 나타낼 필요가 있다. 즉, 교통도로의 교통량 특정, 통신신호의 수신율 측정 등을 최적화 예측할 수가 있게된다. 본 논문에서는 환경 및 시스템 출력값에 표시하여 어떤 결과를 가져오는지 확인하기 위하여 평면 상의 임의의 데이터의 조합으로부터 특정 데이타를 선택 최적화하는 과정을 실험화 하였다.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.27 no.4
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• pp.215-222
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• 2014

The objective of this research is to evaluate the seismic performance of steel intermediate moment frames(IMFs) with different heights. The seimic performance is conducted according to ATC-63. Three-, six, nine- and twelve-story IMFs are designed according to KBC 2009. The connection is modeled to have a drift capacity of 0.02rad, which is required for IMF connections. This study shows that the probability of collapse increases with an increase in the height of the frame. Nine- and twelve-story frames did not satisfy the requirement specified in ATC-63.

• Journal of the Korean GEO-environmental Society
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• v.11 no.8
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• pp.83-93
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• 2010

The purpose of this study is to present emergency rehabilitation, cause and the countermeasure of reinforcement about reinforced retaining wall and the slope collapse of the phyllite ground. The study area is broken easily because this area has rock mass discontinuity such as stratification, foliation, joint and fold. And this area consists of the ground where it happens easily to the failure of structure like reinforced retaining wall because of the phyllite ground sensitive to weathering. Counterweight fill in front of reinforced retaining wall was performed as emergency rehabilitation about displacement of reinforced retaining wall and the failure at the rear of slope on phyllite ground. After that, additional displacement didn't occur. Boring and geophysical exploration were launched to present emergency rehabilitation and develop the long-term method of reinforcement. This could grasp anticipated range of the failure section and identify internal and external factors of the cause of the slope collapse. Several methods of reinforcement were suggested by conducting the numerical analysis. When conducting design and construction of major structures at the ground which has complex discontinuities, the precise site investigation should be conducted. During construction, immediate action for over-displacement should be taken by performing the periodic measurement.

• Magazine of the Korea Concrete Institute
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• v.14 no.2
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• pp.24-29
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• 2002

산업화에 따른 인구 집중현상의 결과 도심지의 밀집형 고층주거형 구조물에 발생할 수 있는 화재는 인명과 경제적인 손실을 가져올 수 있으므로 이에 대한 체계적인 방재 시스템을 요구한다. 구조공학적인 측면에서 내화 특성은 화재에 대한 최후의 방어선으로서 구조적인 안정성을 유지하여야 한다. 화재로 인한 구조부재의 파괴는 구조체의 강성 및 강도저하가 주요 원인으로 근처 다른 구조부재의 파괴로 발전하면서 종국적으로 전체 구조물이 붕괴할 수도 있다.(중략)

• Proceedings of the Korea Concrete Institute Conference
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• 2008.11a
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• pp.745-748
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• 2008

The past structures were just required bearing capacity to service load, serviceability, and resistance to corrosion. However this point of view has changed after 9.11 terrorism, capacities which can bear impact loading by explosion, and heat by fire happening at the same time, become to be important as a basic condition. The blast resistance capacity of structures is very important part against all over the world is intimidated by terrorism everyday in current point of time. The target of this research is a development of segmented composites and layered structures with high blast resistance using cementitious composites, concrete and FRP composites, which has high tensile strength and ductility, to apply in not only existing facilities but also new ones. Through the improvement of blast resistance, casualties and economic loss can be minimized, and it is possible to diminish the structure collapse and delay the time of structure collapse by thermal effect, impact loading, dynamic loading and high strain.

• Journal of the Society of Naval Architects of Korea
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• v.28 no.2
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• pp.251-267
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• 1991

Plastic strength analysis using plastic failure mode as a limit state is adopted instead of a conventional elastic structural analysis to predict the ultimate strength of Web frame idealized by a plane frame. Linear programming arid Compact procedure are developed for determining the collapse load factor. It is found that the final results are good agreement with the results of Elasto-plastic analysis. Besides, the redundant structures like Web frame is known to have multiple failure modes. Web frame may collapse under any of the possible failure modes. Thus, the identification of these possible failure modes is necessary and very important in the reliability analysis of Web frame. In order to deal with multiple failure modes, automatic generation method of all failure modes and basic failure modes is used for selecting the dominant failure modes. The probability of failure pastic collapse of Web frame is calculated using these dominant failure modes. The safety of Web frame is asscssed and compared by performing the deterministic and probabilistic analysis.

• Computational Structural Engineering
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• v.8 no.2
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• pp.153-161
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• 1995

The dynamic instability for snapping phenomena has been studied by many researchers. There is few paper which deal with the dynamic buckling under the load with periodic characteristics, and the behavior under periodic excitation is expected the different behavior against step excitation. In this study, the dynamic direct snapping of shallow elliptic paraboloidal shells is investigated under not only step excitation but also sinusoidal and seismic excitations, applied in the up-and-down direction. The dynamic nonlinear responses are obtained by the numerical integration of the geometrically nonlinear equations of motion, and examined by the Fourier spectral analysis in order to get the frequency-dependent characteristics of the dynamic instability for various load levels. The results show that the dynamic instability phenomenon carried out from stable to unstable region reveals considerably different mechanism depending on the characteristics of excitations.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.20 no.3
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• pp.239-246
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• 2007

In this paper a new equivalent static analysis method of dynamic behavior during progressive collapse is presented. The proposed analysis method uses the equivalent nodal load for the element stiffness which represents the dynamic behavior influence caused by the deletion of elements during progressive collapse analysis. The proposed analysis method improves the efficiency of progressive collapse analysis haying the iterative characteristic because the inverse of the structural stiffness matrix is roused in the reanalysis. By comparing the results obtained by this analysis method with those of GSA code analysis and time history analysis, it is shown that the results obtained by this analysis method more closely approach to those of time history analysis than by GSA code analysis.

• Journal of the Korea Concrete Institute
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• v.26 no.6
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• pp.715-722
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• 2014

In this paper, internal blast effect of reinforced concrete core structure were investigated using Ansys Autodyn, which is a specialized hydrocode for the analysis of explosion and impact. It is expected that internal blast case can give additional damage to the structure because it causes rebound of blast loads. Therefore, in this paper, the hazard of internal blast effect is demonstrated using UFC 3-340-02 criteria. In addition, analysis result of Autodyn, experimental result regarding rebound of blast load, and example of UFC 340-02 are compared to verify that Autodyn can analyze internal blast effect properly. Furthermore, progressive collapse mechanism of core structure which is one of the most important parts in high rise buildings is also analyzed using Autodyn. When internal blasts are loaded to core structure, the core structure is mostly damaged on its corner and front part of core wall from explosives. Therefore, if the damaged parts of core wall are demolished, progressive collapse of the core structure can be initiated.

• Magazine of the Korea Institute for Structural Maintenance and Inspection
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• v.17 no.3
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• pp.77-84
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• 2013