• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2019.05a
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• pp.59-62
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• 2019

인천신항 내 기존 준설토 투기장은 2018년에 수토가 완료 될 예정이므로 향후 항만개발과 운영시 발생되는 준설토의 원활한 처리를 위해서는 신규 준설토 투기장 조성이 필요하다. 투기장 조성을 위해서는 중 장기적인 준설토 처리방안 등을 고려한 항만기능 향상과 경쟁력 강화를 위한 준설토 투기장 호안 축조가 선행되어야 하기 때문에 극동건설 컨소시움에서는 퍼펙트델타라는 설계컨셉을 수립하고 내구성과 안전성을 강화한 설계, 조기수토 공간확보 및 수토용량 증대, 자연과 인간 도시가 함께하는 환경 친화적인 설계, 현장여건에 가장 적합한 설계를 구현하였다.

• Annual Conference of KIPS
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• 2010.04a
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• pp.1034-1037
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• 2010

오늘날 많은 컴퓨터 시스템들이 우리의 삶에 사용이 되고 있다. 컴퓨터 시스템의 사용이 증가함에 따라 오류로 인한 문제들도 커지고 있다. 특히 열차 제어 시스템, 원자력 제어 시스템과 같은 안전필수 시스템에 오류가 발생하면 재산적, 인명적인 피해를 초래할 수 있다. 정형명세 언어 중 하나인 Z notation 은 안전필수 시스템 명세등에 많이 사용이 되고 있으며 Z 를 사용하여 명세하는 방법들이 제시되고 있다. 본 논문에서는 Correctness by Construction 에 기반하여 Z 를 사용하여 시스템을 명세하는 방법을 제안하며 안전필수 시스템인 DCM 을 적용하여 명세한다.

• Journal of Advanced Marine Engineering and Technology
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• v.34 no.6
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• pp.914-921
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• 2010

When industrial structures are constructed on soft ground, ground subsidence is occurred by problems of bearing capacity. To protect ground subsidence have to improve soft ground, and have to predict settlement estimation for reasonable construction. Artificial Neural Networks(ANN) is adopted for prediction of settlement of construction during the initial design. In the study, Artificial Neural Networks are applied to predict the settlement estimation of initial condition ground and ground improved by D.C.M method. Also, this study compares results of Artificial Neural Networks and results of continuum analysis using Mohr-Coulomb models. In result, settlements of initial condition ground decreased over 0.7 times. Also, by comparing ANN and continuum analysis, coefficient of determination was comparatively high value 0.79. Thought this study, it was confirmed that settlements of improvement ground is predicted using laboratory experiment data.

• The Journal of Engineering Geology
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• v.30 no.2
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• pp.131-145
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• 2020

The construction on these flimsy ground, activation of unsymmetrical surcharges, can often cause of the embankment road lateral flow or the destruction of the activities. In this study, the stability of the abutment pile foundation installed on soft ground and its behavior has been evaluated. The behavior of the abutment pile foundation under lateral flow was studied by verifying the behavior and reinforcement effects of the abutment pile foundation of previous studies about horizontal loads acting on the pile due to the lateral flow of the ground by performing finite element analysis. As a result of the consolidation analyses, the undrained cohesion or the strength of the soft ground, was increased by about 1.1 to 1.8 times by the increase in the strength of the soft ground according to the degree of consolidation. It is deemed reasonable to use 3.8 cm of the allowable displacement both economically and constructively, but considering the importance of the structure and the uncertainty of the ground, measurement shall be carried out during construction and thorough safety management of the lateral flow should be done.

• Journal of Environmental Health Sciences
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• v.36 no.5
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• pp.391-401
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• 2010

A reduction in risk of occupational exposure to chemical hazards within the workplace has been the focus of attention both through industry initiatives and legislation. The aims of this study were to develop an exposure matrix by industry and process, and to apply this matrix to control the risk of occupational exposure to Dichloromethane (DCM). The exposure matrix is a tool to convert information on industry and process into information on occupational risk. The exposure matrix comprised industries and processes involving DCM, based on an exposure database provided by KOSHA (the Korean Occupational Safety and Health Agency), which was gathered from a workplace hazards evaluation program in Korea. The risk assessment of the exposure matrix was performed using Hallmark risk assessment tool. The results of the risk assessment were indicated by a Danger Value (DV) calculated from the combination of hazard rating (HR), duration of use rating (DUR), and risk probability rating (RPR) of exposure to the chemical, and were divided into four control bands which were related to control measures. The applicability of the risk assessment of the exposure matrix was evaluated by a field study, and survey of the employees of the exposure matrix groups. Among 45 industries examined, this study found that greater attention should be paid to two industries: the manufacture of other optical instruments and photographic equipment, and the manufacture of printing ink, and to one process among 47 examined, the packing process in the manufacture of printing ink, because these were regarded as carrying the highest risk. This tool of a risk assessment for the exposure matrix can be applied as a general exposure information system for hazard control, risk quantification, setting the occupational exposure limit, and hazard surveillance. The exposure matrix includes workforce data, and it provides information on the numbers of exposed workers in Korea by agent, occupation, and level of exposure and risk.

• Journal of Korean Tunnelling and Underground Space Association
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• v.24 no.2
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• pp.193-215
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• 2022

Recently, ground structures have reached saturation, and underground construction using underground structures such as tunnels has been in the spotlight as a way to solve increasing traffic difficulties and environmental problems. However, due to the increasing number of underground structures, close construction is inevitable for continuous underground development. When a new underground structure is constructed closely, stability may become weak due to the influence on the existing tunnel, which may cause collapse. Therefore, analyzing the stability of existing tunnels due to new structures is an essential consideration. In this study, the effect of excavating new tunnels under parallel tunnels on existing parallel tunnels was analyzed using numerical analysis. Using the Displacement Control Model (DCM), the volume loss generated during construction was simulated into three case (0.5%, 1.0%, and 1.5%). Based on the center of the pillar, the distance where the new tunnel is located was set to 5 m, 6 m, 7 m, 8 m, 9 m, and the space for each distance were set to 5 (0D₁, 0.37D₁, 0.75D₁, 1.13D₁, 1.5D₁). In general, as the volume loss increased and the distance approached, the maximum displacement and angular displacement increased, and the strength/stress ratio to evaluate the stability of the pillar also decreased. As a result, when the distance between the new tunnel and the center of the pillar is 5 m, the space is 0D₁, and the volume loss is 1.5%, the stability of the existing parallel tunnel is the weakest.

• Journal of Korean Tunnelling and Underground Space Association
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• v.19 no.5
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• pp.779-797
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• 2017

Recently, underground road construction is attracting attention because the ground transportation facilities in the urban area have reached the saturation level and traffic volume has increased and the air pollution has risen. Construction of underground roads is not only reduce trafficjam in downtown but also design the city eco-friendly, so existing roads as well as new roads go underground. It is essential to construct divergence tunnels that serve as IC (interchage) and JC (Junction) when constructing underpasses. Therefore, the analysis of the effect of the existing tunnel by the divergence tunnel should be considered. In this study, numerical analysis is performed to analyze the effect of existing tunnel on the excavation of the divergence tunnel. The divergence tunnels were set in 5 cases at $45^{\circ}$ intervals in the clockwise direction starting from the lower part of the existing tunnel. In each case, numerical analyses were carried out by using the DCM (Displacement Controlled Model) for applying the volume loss of 0.5%, 1.0% and 1.5%. As a result, when the volume loss increased, the effect on displacement, fracture range, and effect on stability increased as well. In addition, it was confirmed that the divergence tunnel located directly underneath is the weakest for the stability, and the case where the divergence tunnel is located diagonally rather than the vertical and horizontal direction is found to be vulnerable to displacement and lining destruction.

• Journal of Bio-Environment Control
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• v.30 no.4
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• pp.287-294
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• 2021

In order to expand facility agriculture and reduce greenhouse construction costs in reclaimed land, a greenhouse foundation method that satisfies economic feasibility and structural safety at the same time is required. As an alternative, the allowable bearing capacity and settlement were reviewed when the DCM(Deep cement mixing) method was applied among the soft ground reinforcement methods. To examine the applicability of the greenhouse foundation, the allowable bearing capacity and settlement were calculated by applying the theory of Terzaghi, Meyerhof, Hansen, and Schmertmann. In case of the diameter of 800mm and the width and length of the foundation of 4m, the allowable bearing capacity was 179kN/m² and the settlement was 7.25mm, which satisfies the required bearing capacity and settlement standards. The calculation results were verified through FEM(Finite element method) analysis using the Mohr-Coulomb material model. The allowable bearing capacity was 169kN/m² and the settlement was 2.52mm. The bearing capacity showed an error of 5.6% compared to calculated value, and the settlement showed and error of 65.4%. Through theoretical calculations and FEM analysis, it was confirmed that the allowable bearing capacity and settlement satisfies the design criteria as a greenhouse foundation when the width and length of the foundation were 4m. Based on the verified design values, it is expected to be able to present the foundation design criteria for greenhouses through empirical tests such as bearing capacity tests and long-term settlement monitoring.