• International Journal of Railway
• /
• 제6권3호
• /
• pp.112-119
• /
• 2013

A mid-size RC test apparatus (MRCA) equipped with a program is developed that can test samples up to D=10 cm diameter and H=20 cm height which are larger than usual samples used in practice. Using the developed RC test apparatus, two types of crushed trackbed foundation materials were tested in order to get the shear modulus reduction curves of the materials with changing of shear strain levels. For comparison purpose, large repetitive triaxial compression tests (LRT) with samples of height H=60cm and diameter D=30 cm were performed also. Resilient modulus obtained from the LRT was converted to shear modulus by considering elastic theory and strain level conversion and were compared to shear modulus values from the MRCA. It is found from this study that the MRCA can be used to test the trackbed foundation materials properly. It is found also that strain levels of $E_{v2}$ mostly used in the field should be verified considering the shear modulus reduction curves and proper values of $E_{v2}$ of trackbed foundation must be used considering the strain level verified.

• 문화기술의 융합
• /
• 제4권3호
• /
• pp.165-170
• /
• 2018

본 연구에서는 전문대학의 창업인프라와 학생들의 기업가적 역량, 태도, 창업의도를 분석하였다. 이를 통해 일반대학과는 다른 전문대학의 차별화된 창업교육 방법론을 제안하는 것을 목적으로 하고 있다. 연구 방법은 첫째, 수도권 전문대학의 창업 기반을 파악하기 위해 창업진흥원에서 제시한 기준을 바탕으로 담당자와 인터뷰를 실시하여 평가하였다. 둘째, 전문대학 재학생을 대상으로 설문을 실시하여 기업가적 역량, 기업가적 태도, 창업의도에 대한 분석을 실시하였다. 이를 통해 다음과 같이 시사점을 도출하였다. 전문대학은 일반대학에 비해 교육기간이 짧기 때문에 4년제 대학과는 같은 인프라를 갖출 수 없다 따라서 차별화된 인프라의 기준이 제시되어야 한다. 학생들의 창업의지는 역량과 태도에 비해 낮게 나타나고 있다. 따라서 교육과정에서 이론적인 내용보다는 실무 중심의 교육과정과 창업동아리와 같은 비교과 과정을 통해 창업의도를 높일 수 있는 방법을 모색해야 한다.

• 상하수도학회지
• /
• 제34권1호
• /
• pp.23-33
• /
• 2020

With growing expectations for economic cooperation between the two Koreas, there is much interest in participating in the construction of infrastructure in North Korea. In particular, water and sewage infrastructure is the four major social infrastructures in addition to housing, transportation, electricity and telecommunications. North Korea is known to have severe water pollution and ecosystem destruction in major rivers, water pollution and soil pollution in mining areas are serious, and water and sewage infrastructures in cities other than Pyongyang are known to be weak. Preemptive investment in water supply and drainage in North Korea is the foundation for securing the quality of life of the North Korean and is the foundation of public health and industry. It is a leading investment to reduce the cost of unification and is a new growth engine for the water reloded industry. In this study, we proposed a plan to exchange and cooperate in water environment for building water infrastructure of North Korea by examining the data related to water quality, water resources, water disaster, related legal system and human resources exchange situations in North Korea.

• Geomechanics and Engineering
• /
• 제24권4호
• /
• pp.371-388
• /
• 2021

A novel flexibility-based beam-foundation model for inelastic analyses of beams resting on foundation is presented in this paper. To model the deformability of supporting foundation media, the Winkler-Pasternak foundation model is adopted. Following the derivation of basic equations of the problem (strong form), the flexibility-based finite beam-foundation element (weak form) is formulated within the framework of the matrix virtual force principle. Through equilibrated force shape functions, the internal force fields are related to the element force degrees of freedom. Tonti's diagrams are adopted to present both strong and weak forms of the problem. Three numerical simulations are employed to assess validity and to show effectiveness of the proposed flexibility-based beam-foundation model. The first two simulations focus on elastic beam-foundation systems while the last simulation emphasizes on an inelastic beam-foundation system. The influences of the adopted foundation model to represent the underlying foundation medium are also discussed.

• Geomechanics and Engineering
• /
• 제13권5호
• /
• pp.757-774
• /
• 2017

The subgrade reaction modulus of a large mat foundation was investigated by using a numerical analysis and a field case study. The emphasis was on quantifying the appropriate method for determining the subgrade reaction modulus for the design of a flexible mat foundation. A series of 3D non-linear FE analyses are conducted with special attention given to the subgrade reaction modulus under various conditions, such as the mat width, mat shape, mat thickness, and soil condition. It is shown that the distribution of the subgrade reaction modulus is non-uniform and that the modulus of subgrade reaction at both the corners and edges should be stiffer than that at the center. Based on the results obtained, a simple modification factor for the subgrade reaction modulus is proposed depending on the relative positions within the foundation in weathered soil and rocks.

• 전기학회논문지
• /
• 제63권9호
• /
• pp.1192-1198
• /
• 2014

With an increase in the penetration of offshore wind farm, the need of an accurate economic evaluation of offshore wind farm has become crucial. This paper presents an economic evaluation method of offshore wind farm in Korea reflecting the cost of offshore wind farm infrastructure (offshore substation, submarine cable and foundation) in its cost model. Each cost of offshore substation, submarine cable, and foundation is represented as a function of installed capacity, distance to shore, and water level, respectively. We have applied the method to the case study of offshore in Jeju Island and analyzed the economics under various conditions. The results show that the distance to shore is of importance in economics of offshore wind farm.

• 국제초고층학회논문집
• /
• 제6권2호
• /
• pp.131-138
• /
• 2017

There is no easy answer to ensuring the world's rapid urban population growth is managed sustainably and in a manner that promotes economic growth, social cohesion, and health and wellbeing. However, densification of existing urban areas is increasingly recognised as an effective and socially responsible way for cities to accommodate growing populations and still operate as vital, vibrant spaces. The Future Spaces Foundation's Vital Cities: Transport Systems Scorecard explores how well-networked, safe and sustainable transport networks equip densifying cities to meet the needs of their rising and fast-changing populations. This paper uses data from the scorecard to examine the transport infrastructure and associated data networks of three large, rapidly densifying cities - Beijing, Mumbai and $S{\tilde{a}}o$ Paulo - and highlight the successful measures and policies implemented between them. It includes an in-depth explanation of the scorecard's methodology, and concludes with an appeal for people-focused transport design that values safety, urban vibrancy and individual wellbeing over corporate efficiency.

• 한국전산구조공학회논문집
• /
• 제30권1호
• /
• pp.77-86
• /
• 2017

Industry Foundation Classes(IFC)는 Building Information Modeling(BIM)을 위한 표준 데이터 스키마로 정보의 상호운용성 확보를 위한 핵심이지만, 건물만을 대상으로 하고 있어 토목 시설물에 적용하기에는 한계가 있다. 이에 따라 기존 IFC에 토목 시설물을 위한 새로운 요소를 추가하는 연구가 진행되었지만, 상용 소프트웨어가 해당 기능을 추가하기 전에는 새로운 스키마를 활용할 수 없다. 본 연구에서는 토목 시설물에 적용하기 위한 IFC 데이터 스키마 활용 방안을 제시하고, 토목시설물을 위한 확장 요소와 기존 IFC 요소와의 정보 매핑을 통한 확장 IFC기반의 토목 시설물 정보모델링 방법을 제시하였다. 그리고 철도의 궤도 및 침목에 대한 IFC 확장 스키마를 제시하고 제시한 방법을 적용하여 그 활용성을 검증하였다.

• Geomechanics and Engineering
• /
• 제38권4호
• /
• pp.397-408
• /
• 2024

Buried box culverts are crucial elements of transportation infrastructure. However, their behavior under foundation loads is not well understood, indicating a significant gap in existing research. This study aims to bridge this gap by conducting a detailed numerical analysis using the Finite Element Method and Abaqus software. The research evaluates the behavior of buried box culverts by examining their interaction with surrounding soil and the pressures from surface foundation loads. Key variables such as embedment depth, culvert wall thickness, concrete material properties, foundation pressure, foundation width, soil elastic modulus, and friction angle are altered to understand their combined effects on structural response. The methodology employs a validated 2D numerical model under plane strain conditions. Parametric studies highlight the critical role of culvert depth (H) in influencing earth pressure and bending moments. Foundation pressure and width demonstrate complex interdependencies affecting culvert behavior. Variations in culvert materials' elastic modulus show minimal impact. It was found that the lower wall of the buried culvert experiences higher average pressure compared to the other two walls, due to the combined effects of the culvert's weight and down drag forces on the side walls. Furthermore, while the pressure distribution on the top and bottom walls is parabolic, the pressure on the side walls follows a different pattern, differing from that of the other two walls.

• 국제초고층학회논문집
• /
• 제9권4호
• /
• pp.369-376
• /
• 2020

Given the importance of quickly recovering livelihoods and economic activity after an earthquake, the seismic performance of the pile foundation is becoming more critical than before. In order to promote seismic retrofit of the pile foundations, it is necessary to develop a method for evaluating the seismic performance of the pile foundation based on the experimental data. In this paper, we focus on the building that was suffered severe damage to the pile foundation, conduct simulation analyses of the building, and report the results of evaluating the dynamic characteristics when piles are damaged using a system identification method. As a result, an analysis model that can accurately simulate the behavior of the damaged building during an earthquake was constructed, and it was shown that the system identification method could extract dynamic characteristics that may damage piles.