• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2010년도 춘계학술대회 논문집
• /
• pp.1697-1702
• /
• 2010

It has been recognized for decades that the spherical bearing which is sliding on curved surface in the intrinsic behavior is optimized for the railway bridge requiring a large slope deflection. However, the spherical bearing is easily corrosived at the PSC girder bridge which is exposed to the outside so the normal function of bridge bearing is not fulfilled fully. It is common that the corrosion is happened at the operating plate of steel bridge bearing and generally it is necessary to replace the bridge bearing after 20~25 years. Accordingly, It costs multi billion dollars for maintenance each year and the necessity of improvement become a issue. Korea Rail Network Authority(KR) suggested to apply the Elastomeric bearing instead of Spherical bearing through the task of construction site of 2006. But the normal Elastomeric bearing is optimized for the Highway bridge so it needs the special consideration to satisfy each design condition required by railway bridge. As the result of examination of Elastomeric bearing at the railway bridge construction site, the stress is decreased by effective dispersion of earthquakes and the maintenance fee is also decreased.

• 전기학회논문지
• /
• 제65권3호
• /
• pp.511-519
• /
• 2016

This paper is proposed control algorithm for the using thyristor of the parallel dual converter for Urban railway power supply in order to return the regenerative power generated by regenerative braking in urban railway train. Conventional control algorithm of Thyristor dual converter for urban railway power supply has voltage variation within a control range of hysteresis band. The purposed control algorithm of the parallel thyristor dual converter is to maintain a constant voltage without voltage variation in accordance with variable load through the Sequential mode change. And the control algorithm need calculating optimum initial firing angle to consider magnitude of the load current slope. For this purpose, Proposed algorithm for sequential conversion mode of the dual converter was verified by applying for the simulation.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2004년도 춘계학술대회 논문집
• /
• pp.290-295
• /
• 2004

Electrification of existing railroad as well as extension of double track, need a large amount of electric energy. Especially, increase in energy consumption of high cost causes much problems in domestic economy. It is neccessary to save energy for the crisis of exhaust of fossil energy. About $20{\~}25\%$ of regenerated energy of an electric railcar is lost on down slope run or on braking. In order to save energy in electric railway system, Therefor, application of energy regeneration system is proposed and introduced in the present paper.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2000년도 추계학술대회 논문집
• /
• pp.666-673
• /
• 2000

This paper describes the full load test results of IGBT VVVF inverter for the railway propulsion system. The 1,650kVA IGBT VVVF inverter has been developed. Therefore, the field test is performed in SMG 6 Line to confirm its the reliability and performance. The train consists of 4M4T(4 Motor car 4 Trailer Car) and the electrical equipment for field test are as follows VVVF inverter 4 sets, 16 traction motors and 2 SIVs. The propulsion system is composed with IC4M(1-Controller 4-Motors). The results of propulsion system which have the excellent acceleration/deceleration and the jerk characteristics as well as starting ability on slope are taken through the field test.

• 한국측량학회지
• /
• 제35권4호
• /
• pp.281-290
• /
• 2017

Transportation plays a vital role in sustainable development, and moreover, bulk transportation provides cost effective movement of goods and human beings with less environmental issues. Nepal is a developing country with increasing urbanization and transportation demands. The growing interest of China to connect with Southeast Asia through Nepal has led to ambitious project proposal of Rasuwa Gadhi to Birgunj Railways, which is the shortest route from China to India. Lack of updated geospatial data has lead the concerned authorities in Nepal to be dependent on analysis and proposals from donor nations. Taking such considerations, based on GIS and free data, this study explores optimal routes to connect cites using slope and land cover. Based on reclassified slope, two shortest optimal routes were found. One passing through Baireni in Dhading and another through Kathmandu towards Birgunj with length of around 172 Kilometers. The study shows that available open source data can be used of preliminary feasibility studies and yet shows limitations for detailed economy based planning. Development and use of high resolution updated geospatial data is of high necessity for Nepal to become self-sustained in planning of development works.

• 대한토목학회논문집
• /
• 제44권1호
• /
• pp.109-116
• /
• 2024

초속경 복합매트(Rapid Hardening Composite Mat)는 기존 GCCM의 초기 강도 발현 속도를 향상시킨 제품으로, 시공기면이 부족한 철도 비탈면에서 신속한 시공기면 확보가 가능하고 비탈면 유실 방지 및 식생억제가 가능한 장점이 있다. 본 연구에서는 실험을 통해 초속경 복합매트의 철도 현장 적용성을 분석하였다. 현장 적용성은 내화성, 내구성, 안정성으로 구분하여 난연 시험, 접지압 실험, 일일 변위량 분석을 통해 분석하였다. 국토 대부분이 산림구조로 이루어진 국내의 경우 비탈면 화재 예방이 필수적이며, 초속경 복합매트의 내화성을 분석하기 위해 난연 시험을 수행하였다. 내구성은 시공기면에 불가피하게 투입되는 중·소형 장비에 의한 초속경 복합매트의 변형 및 파괴 여부를 분석하기 위해 접지압 실험을 수행하였다. 또한 일일 변위량 분석은 초속경 복합매트 적용 시 발생되는 변위 및 거동을 철도 비탈면 관리기준과 비교·분석하여 구조적 안정성을 평가하기 위해 수행하였다. 실내시험 결과, 초속경 복합매트는 열방출률 및 가스유해성 판정기준에 충족하는 것으로 분석되었으며 재령 4시간~24시간 초속경 복합매트의 접지압은 모든 조건에서 약 50 kPa 이상인 것으로 나타났다. 또한 현장실험을 통해 분석한 일일 변위량은 -1.7 mm~1.01 mm로 나타나, 기준치에 만족하는 것을 확인하였다.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2009년도 춘계학술대회 논문집
• /
• pp.1016-1019
• /
• 2009

암반사면의 설계, 사공, 유지보수를 위해서는 암반의 지질구조에 대한 정밀한 조사가 이뤄져야 하나 한정된 노출면에서 행하여지는 조사는 한계가 있으며, 물리탐사 등의 보조 조사 역시 충분한 정보를 획득 하는데는 한계가 있다. 이러한 문제를 보완하기 위한 조사방법으로 입체사진을 이용한 원격조사방법 (Surface Mapper)과 시추공 자료의 투영을 위한 S/W (Fracjection)를 개발하였다. 입체사진을 이용한 원격 조사가법은 사진측량의 원리를 응용하여 암반 절취면에 분포하는 절리, 단층, 엽리 등의 면구조를 3차원으로 측정하고 데이터베이스화 하는 것이며 시추공 자료의 투영기법은 BIPS, Televideo 혹은 DOM 시추 등을 이용하여 시추공내에서 측정된 면구조의 배열을 예상 절취면에 투영하는 기법이다. 이 기법들은 면구조의 3 차원 배열과 절취면의 위치를 실제 3 차원으로 분석할 수 있는 새로운 사면의 조사, 설계, 사공 및 유지관리의 방안을 제시하고 있다.

• Geomechanics and Engineering
• /
• 제28권4호
• /
• pp.335-346
• /
• 2022

Buckling failure is a typical slope instability mode that should be paid more attention to. It is difficult to provide systematic guidance for the monitoring and management of such slopes due to unclear mechanism. Here we examine buckling failure as the potential instability mode for a slope above a railway tunnel in southwest China. A comprehensive model test system was developed that can be used to conduct buckling failure experiments. The displacement, stress, and strain of the slope were monitored to document the evolution of buckling failure during the experiment. Monitoring data reveal the deformation and stress characteristics of the slope with different slipping mass thicknesses and under different top loads. The test results show that the slipping mass is the main subject of the top load and is the key object of monitoring. Displacement and stress precede buckling failure, so maybe useful predictors of impending failure. However, the response of the stress variation is earlier than displacement variation during the failure process. It is also necessary to monitor the bedrock near the slip face because its stress evolution plays an important role in the early prediction of instability. The position near the slope foot is most prone to buckling failure, so it should be closely monitored.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2011년도 춘계학술대회 논문집
• /
• pp.707-716
• /
• 2011

It has been applied using cranes or insertion methods to install heavy structures to strengthen existing railway bridges. These methods are uneconomical because of two reasons. The first one is it is required to construct approach roads for heavy equipment and/or working yard. The second one is the electric lines shall be cutoff during construction. Both require additional construction cost and duration. In this study, new transport equipment was developed which can be applied to heavy structures up to 100 ton. Using this method, the heavy structure can be loaded into the new transport equipment at working yard and transported to the working site. This method can be applied, but not limited to railway bridge or roadbed rehabilitation. It was found that the precious construction can be achieved to install heavy structure using this method. The experimental construction to make non-ballast girder bridge composite with new pc deck slab using this method was carried out for Jewon bridge. The example bridge is in extreme condition because it locates above national road #38 within extreme transition curve and has 10 ‰ slope and skew. The experimental construction results were satisfactory both for safety and construction precision.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2011년도 춘계학술대회 논문집
• /
• pp.368-376
• /
• 2011

도시철도의 전동차는 변전설비로부터 전력을 공급받아 지상, 지하부의 다양한 선로조건(구배)를 지닌 선로를 운행하며, 열차 제동 시 많은 회생전력이 발생하고 있다. 회생제동은 에너지를 재활용 할 뿐만 아니라 기계식 브레이크의 사용을 줄이는 매우 이상적인 시스템이라고 할 수 있다. 또한 중요한 점은 회생제동이 가능한 시스템은 발생된 에너지가 어떤 정해진 흐름을 가지고 소모되고 재활용 가능하다는 것이다. 본 연구에서는 서울도시철도 선로구배도 검토 및 전동차 운행기록 분석, 전력공급소(변전소)의 전동차용 전력 공급반 전력분석 등으로 진행 되었다. 현재 운용중인 시스템 데이터의 분석을 통해 최적의 회생에너지 저장 시스템의 구축을 목표로 재활용 가능 에너지의 예측 및 분석을 시행 하였다.