• Korean Journal of Construction Engineering and Management
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• v.17 no.4
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• pp.87-94
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• 2016

The necessity to consider stability of underground structures constructed below or adjacent ammunition depots has been increased since the expansion of urban area and construction of infrastructure. However, there are a few studies on influence of accidental explosion on underground structures. In this study, the process of assessing the stability of underground structures is suggested and its applicability is verified through the case study. AUTODYN and SPACECLAIM are used to execute the structure and geotechnical modelling, and explosion effect is simulated and vibration velocities are calculated. According to the result of this case study, it is concluded that underground structure constructed 70m below ground might be rarely influenced by the simulated explosion. The process used in this study could be used to design the underground ammunition complex and analyse the stability of underground facilities being influenced by periodical vibration.

• Proceedings of the Korea Water Resources Association Conference
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• 2008.05a
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• pp.519-523
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• 2008

하천의 보와 같은 횡방향 구조물은 홍수시 구조물에 의한 세굴이 발생하고, 그로인해 구조물의 불안정을 초래한다. 본 연구에서는 apron 하류에 하상보호공을 설치하였을 때 하상보호공의 안정성과 하류의 세굴양상에 대해 연구하였다. Apron 상류로부터 유사의 유입이 없도록 apron 하류에 체결된 블록을 설치한 개수로에서 블록의 설치길이와 채움재를 변화시켜 수리모형 실험을 실시하여 블록의 설치길이와 채움재에 따른 안정성과 하류세굴양상을 평가하였다. Apron하류의 블록 내부에서 세굴 깊이는 블록의 설치길이, 채움재의 직경, 유량, Reynolds 수, Froude 수 등에 따라 달라진다. 세굴에 대한 블록의 안정성은 블록의 설치길이와 채움재의 직경에 가장 큰 영향을 받는다. 블록의 설치 길이와 채움재의 직경을 증가시킴으로써 블록의 안정성을 확보할 수 있다. 실험결과 블록의 설치길이가 13.35m이상일 때 블록의 안정성이 확보될 수 있는 것으로 나타났다.

• Journal of the Korean GEO-environmental Society
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• v.24 no.5
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• pp.5-12
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• 2023

Recently, due to urban development and expansion, construction plans have been increasing adjacent to existing tunnel structures such as subways, roads, and large pipelines. Structural plans adjacent to existing tunnels have different effects on tunnel stability depending on the construction method, degree of proximity, and location of new structures. In particular, the pressure water tunnel shows a very large difference from other road tunnels and railway tunnels in geotechnical characteristics and operation characteristics. Therefore, it is necessary to review the safety zone due to adjacent construction in consideration of the geotechnical characteristics of the water tunnel and the new sturure construction method. In this study, the existing tunnel safety zone standards were investigated. A stability evaluation performed numerical analysis considering the deterioration of concrete lining in operation and the characteristics of water tunnel. In addition, the impact of vibration caused by pile construction and blasting excavation of new structures was reviewed. Based on this, a pressure water tunnel safety zone was proposed in consideration of adjacent construction.

• Composites Research
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• v.26 no.4
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• pp.259-264
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• 2013

This study manufactured the radiating element of multi-band antenna skin structure which satisfy electrical and mechanical performance and is made by double injection molding process. Structural test including impact and buckling test is carried out and stress analysis is simulated to evaluate safety of radiating element for the axial and shear loads, when changing of the skin structure is occurred by the external force. To predict allowable load of structure and evaluate safety on impact and buckling, experimental and analytic method is used in strength analysis of structure.

• Journal of the Korean GEO-environmental Society
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• v.16 no.9
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• pp.13-21
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• 2015

Recently, land subsidence and sinkhole are generated due to a change in the groundwater level in the city. For this reason, the necessity for management of stable underground water level is on the rise. In this study, it was conducted for the underground structure that passes through the lower of bus transfer center construction site to examine the influence on the stability for underground structures to changes in the groundwater level and effective stress, the coupled finite element analysis and structural analyses were performed to evaluate stability for underground structure. It is to secure stability for underground structures according to underground water level declines. In this way, effective construction management will be made by previewing and forecasting the influence on the ground behavior and adjacent structures due to changes in the groundwater level.

• Proceedings of the Korea Water Resources Association Conference
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• 2019.05a
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• pp.357-357
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• 2019

최근 한반도에서 예측하기 어려운 지진현상 및 가뭄, 폭우 등 이상기후현상이 지속적으로 발생하고 있다. 댐과 같은 수공구조물의 치수능력부족은 구조물의 파손이나 붕괴로 직결되며, 대규모 재산피해와 인명피해를 야기한다. 이에 댐의 안전성 위험요인들로부터 구조적 안전성을 평가하기 위한 방법에 대한 관심이 높아지고 있다. 비상방류시설은 여수로와 함께 저수지의 저류수를 안전하게 배제시킬 수 있는 구조물로서, 댐 비상상황 발생 시 가능한 빠른 시간 내 댐 수위를 낮춰 댐 손상을 최소화 시킨다. 이러한 점에서 비상방류시설의 적정성 평가하기 위한 방법의 도입이 필요할 것으로 판단되며, 본 연구에서는 비상방류시설의 수위강하율을 산정하여 댐 축조재에 따른 적합성을 평가하는 방법을 제시하였다. 필댐의 경우 5가지, 콘크리트, 석괴댐의 경우 3가지 사항에 대한 수위강하율의 적합성을 고려하였으며, 각각의 고려사항에 대한 결과의 점수화를 통해 비상방류시설의 적정성을 평가하였다. 최종적으로 경과연수가 50년 이상된 필댐을 선정하여 비상방류시설 수위강하율의 고려사항에 대한 적합성 평가를 수행하였다. 본 연구방법은 댐의 안정성 개선을 위한 노후화된 댐의 현황 파악 및 비상방류시설의 적정 운영방안을 수립하는데 있어 보다 합리적인 기준을 제시할 수 있을 것으로 판단된다.

• Journal of Navigation and Port Research
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• v.29 no.6 s.102
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• pp.561-566
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• 2005

This study was carried out to amlyze and compare the stability of a 50ton container crane according to various wind load design codes. The wind load was evaluated according to 'The Specification of Port Facilities and Equipments / Specification for the design of crane structures (KS A 1627)' and 'Load Criteria of Building Structures' effected by the ministry of construction & transportation And the uplift forces qf a container crane under this wind load were estimated by amlyzing reaction forces at each supporting point and compared each other. From this study, we noticed that the design wind velocity criteria need to be defined specifically when the wind load is evaluated to design a container crane. And we verified the necessity of the estimation of the uplift forces at each supporting point to analyze a structural stability of a container crane and the maximum compressive force in order to consider the stability of the ground foundation of the berth.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.38 no.4
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• pp.311-320
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• 2014

Rotor blades are important devices that affect the power performance, efficiency of energy conversion, and loading and dynamic stability of wind turbines. Therefore, considering the characteristics of a wind turbine system is important for achieving optimal blade design. When a design is complete, a design evaluation should be performed to verify the structural integrity of the proposed blade in accordance with international standards or guidelines. This paper presents a detailed exposition of the evaluation items and acceptance criteria required for the design certification of wind turbine blades. It also presents design evaluation results for a 2-MW blade (KR40.1b). Analyses of ultimate strength, buckling stability, and tip displacement were performed using FEM, and Miner's rule was applied to evaluate the fatigue life of the blade. The structural integrity of the KR40.1b blade was found to satisfy the design standards.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.38 no.11
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• pp.1283-1290
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• 2014

Recently, a wide variety of simulation techniques such as structure analysis and structure-fluid interaction analysis are being employed in the field of forensic engineering for resolving the problem of legal liability for accidents and disasters. In this study, we performed a forensic engineering investigation of a sinking accident of a DCM (deep cement mixing) vessel. The accident vessel was built as a dedicated SCP (sand compaction pile) vessel at the time of vessel building, and the DCM vessel was structurally modified, e.g., by increasing the leader height and constructing for leader expansion, without a stability review. To determine the effects of expansion and modification of structures in this sinking accident, structural stability evaluation was performed using commercial software for structural analysis, ADINA software. Through an analysis and comparison of simulation results obtained using ADINA software with the results of the structural modification and expansion, we could determine the exact cause of the sinking accident of the DCM vessel.

• 한국HCI학회:학술대회논문집
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• 2008.02a
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• pp.59-64
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• 2008

In this paper, stability and transparency analysis for client/server haptic-based networked virtual environment (NVE) is introduced. From this analysis the appropriate communication structure for the more stable and transparent haptic interactions can be derived. Also, it is possible to expect and compensate the quality deterioration of haptic interactions according to certain network conditions In order to verify the usefulness of the analysis, simple haptic-based NVE application is implemented. For the stability verification, the vibration or strange movement of haptic interface and virtual object are measured under various network states. In addition, the usefulness of the proposed transparency analysis and network delay compensation scheme is verified by comparing distorted and compensated force feedbacks with real force feedback.