• 한국철도학회논문집
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• 제18권6호
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• pp.596-608
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• 2015

지구온난화에 대한 대응으로 철도를 이용한 화물운송의 필요성이 강조되고 있다. 이의 일환으로 본 연구는 벌크화물을 대상으로 철도역 환적저항 감소를 통한 철도이용 활성화 방안을 강구하였다. 우선 화주가 철도운송을 선택하는 과정에서 중요하게 고려하는 환적관련 요인을 파악하였다. 그리고 이들의 상대적 중요도를 비교하고 환적단계에서 영향을 미치는 비중을 평가하였다. 다음으로 환적저항 요인에 대한 분석을 토대로 철도역에서 환적저항을 감소시킬 정책추진 방향을 제안하였다. 정책은 하드웨어적 개선방안과 소프트웨어적 개선방안을 포함한다. 또한 정책 추진을 통해 이끌어내야 할 환적비용과 환적시간의 감소 범위도 제시하였다.

• 한국철도학회논문집
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• 제20권4호
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• pp.500-511
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• 2017

최근 경주지진이 일어나게 되면서 지진의 진동에 의한 구조물의 안정성에 대한 관심이 증가하고 있다. 하지만 국내 앵커분야의 경우 설계하중에 대한 안정성만 고려하고 있을 뿐 진동에 대한 안정성에 대한 연구는 미미한 실정이다. 마찰형 앵커의 경우 시공 중 발생하는 발파진동 등으로 인하여 앵커의 저항능력을 상실한 경우가 종종 보고되고 있다. 이에 반하여 지압형 앵커의 경우 구조적으로 마찰형 앵커에 비하여 진동저항능력이 우수할 것으로 판단되나 이러한 특성에 대한 연구는 거의 진행되지 않았다. 본 연구에서는 새롭게 개발한 지압형 앵커의 발파진동과 지진에 대한 안정성을 검증하기 위하여 현장시험을 수행하였으며 수치해석을 통하여 내진안정성을 검증하였다. 그 결과 현장시험의 경우에는 마찰형 앵커보다 발파진동에 대한 저항성능이 우수하였으며, 수치해석을 이용한 내진해석의 경우 또한 마찰형 앵커에 비하여 저항성능이 우수한 것으로 분석되었다.

• 한국철도학회논문집
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• 제6권3호
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• pp.169-173
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• 2003

Transportation by railroad is superior to other transport in a mass transport, stability, rapid transit, delightfulness and low-pollution etc. But, it need to ensure a track stability that supports the train-load for high-speed in transportation by railroad. Ballast resistance force resists against the buckling of track taking a rail-tie's place. So, it plays an important role in a careful train-service. So, in this papers, we forced on measuring and theorizing about the Ballast Resistance Force that play a key role in track stability and high-speed. And we studied the mechanical property. Finally, we suggested the method of securing Ballast Resistance Force and the report for a careful train-service in high-speed.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집D
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• pp.985-988
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• 2001

Revision and establish of KS(Korean Standards) is currently actively discussed. It is just the time for a new world class standards under the new system with WTO(World Trade Organization). This paper is a part of "Researchs on the Standards in Railway rolling stock Field", as one of KS establish projects. The aim of this study is to define the requirements of railway rolling stock-test methods for running resistance. In the former KS, there is no items matched with this purpose. Therefore a new part of KS is proposed.

• Smart Structures and Systems
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• 제15권4호
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• pp.1085-1101
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• 2015

Changes in substructure conditions, such as ballast fouling and subgrade settlement may cause the railway quality deterioration, including the differential geometry of the rails. The objective of this study is to develop and apply a hybrid cone penetrometer (HCP) to characterize the railway substructure. The HCP consists of an outer rod and an inner mini cone, which can dynamically and statically penetrate the ballast and the subgrade, respectively. An accelerometer and four strain gauges are installed at the head of the outer rod and four strain gauges are attached at the tip of the inner mini cone. In the ballast, the outer rod provides a dynamic cone penetration index (DCPI) and the corrected DCPI (CDCPI) with the energy transferred into the rod head. Then, the inner mini cone is pushed to estimate the strength of the subgrade from the cone tip resistance. Laboratory application tests are performed on the specimen, which is prepared with gravel and sandy soil. In addition, the HCP is applied in the field and compared with the standard dynamic cone penetration test. The results from the laboratory and the field tests show that the cone tip resistance is inversely proportional to the CDCPI. Furthermore, in the subgrade, the HCP produces a high-resolution profile of the cone tip resistance and a profile of the CDCPI in the ballast. This study suggests that the dynamic and static penetration tests using the HCP may be useful for characterizing the railway substructure.

• 한국철도학회논문집
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• 제5권1호
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• pp.1-9
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• 2002

Where the track is continuously welded over the bridge, the longitudinal forces will be distributed interactively between the track and the sub-structure by the rail-bridge interaction mechanism. The ratio between the longitudinal forces transmitted in each elements depends on the magnitude of the ballast resistance and the stiffness of the sub-structures. In this paper, the main factors affect on the longitudinal rail force are discussed and the parametric study for the behavior of CWR(Continuous Welded Rail) track was executed. It is concluded that the horizontal ballast resistance and the stiffness of the bridge sub-structure are the significant parameters affecting the stability of the continuous welded rail track.

• 한국철도학회논문집
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• 제4권2호
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• pp.62-70
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• 2001

Pure copper, Cu-1.1wt%Cd and ACSR(Aluminum Conductor Steel Reinforced) have been used as catenary materials of the electric railway system. Since these materials may be exposed to the corrosive environments like polluted air, acid rain and sea water, it is important to investigate the corrosion rates in various corrosive environments. The aqueous corrosion characteristics of catenary materials in aerated acid, neutral and alkali solutions were studied by using immersion corrosion tests, electrochemical measurements and analytical techniques. In order to examine corrosion characteristics according to the dissolved oxygen content, pH, chloride ion concentration ion, and the addition of Cd to Cu, a series of tests such as potentiodynamic polarization, a.c impedance spectroscopy and galvanic corrosion tests were carried out with these materials. Results showed that the addition of Cd to Cu and chloride ion in the solution have an adverse effects on the resistance to corrosion. Additionally, Galvanic currents between Al and steel wires of ACSR were confirmed by using ZRA(zero resistance ammeter) method.

• 한국철도학회논문집
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• 제5권2호
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• pp.93-103
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• 2002

Reinforced earth structure has been regarded as general structure in order to achieve efficient land utilization as well as securing safety in railway service lines in other countries, but there are no construction actual results in Korea. In this study, the soil-geogrid interaction mechanism was investigated experimentally and numerical analysis was performed to predict Pull-out behaviour of geogrid embedded in reinforced earth body. This experimental data and analysis result can not contribute to understand the soil-geogrid interaction mechanism at soil-geogrid interface but also be used in design practice of the railway reinforced earth structures.

• 한국철도학회:학술대회논문집
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• 한국철도학회 1999년도 추계학술대회 논문집
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• pp.280-287
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• 1999

An automatic train operation(ATO) system executes the operation of constant speed travelling and fixed point parking by using microprocessors instead of drivers manual operation. This paper describes the mathematical model for the train considering unknown disturbances which consist of start resistance, travelling resistance, slope resistance, curve resistance, and so on. The speed controller of ATO system is designed by considering the disturbances. The simulation is executed to verify the speed control and fixed point parking performance and to compare its performance with that of a PID-type ATO control system under disturbances. Simulation results show that the control performance of gain scheduled control scheme fur ATO system is better than that of the conventional PID controller.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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• pp.821-828
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• 2011

A significantly larger lateral load and moment are applied on a high speed railway bridge foundation than other bridge foundations. Therefore most of bridge foundations on Honam high speed railway project were designed by high strength steel pipe piles to resist lateral load and moment, which caused the increase of construction costs. In order to perform optimum design, it is important to estimate accurate lateral resistance when designing this type of structure. Lateral load tests were carried out based on the field design data with the purpose of examining the lateral behavioral characteristics of a railway bridge foundation. The standard load test method(ASTM D 3966) was used for field tests by applying twice of design load. Total four load tests were performed on high speed railway bridge foundations with strain gages installed by every 1m along piles to measure load-resistance characteristics under applied lateral loads. The back-calculated P-y curves from strain gages were compared with estimated P-y curves using theoretical methods based on geotechnical investment data. Back-calculated P-y curves from field tests for sand and clay ground conditions were presented in this paper, which are different from theoretical P-y curves. By using the research results of this study, more accurate estimations of pile design under lateral loads can be available for similar geotechnical conditions.