• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2002년도 추계학술대회 논문집(I)
• /
• pp.614-619
• /
• 2002

Since 1980's in U.S.A and Japan, the studies on increasing the bearing capacity of railway roadbed using geocell have been conducted for repair and reinforcement of railways constructed on soft soils. In this study, the railway roadbed system reinforced with geocells has been analyzed and investigated results of the previous studies were conducted in Korea and other nations, And the method for estimating the railway roadbed thickness was developed based on the equivalent method using the multi-layer theory and the deformation modulus Ev.

• International Journal of Railway
• /
• 제3권4호
• /
• pp.113-116
• /
• 2010

In modern conditions of world economic development the integral element of stable social and economic development of the separate countries of the world is the level of their transport infrastructure development, on the one hand capability to effectively provide economic communications between regions inside the country, and capability to integrate into world economic. The condition of a transport infrastructure and its possibility in sphere of maintenance of national participants of foreign trade are reflected in many respects on competitiveness of production, made by them, in the world market and, as consequence, on a country role in economic.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2004년도 하계학술대회 논문집 B
• /
• pp.1406-1408
• /
• 2004

Recently, the load increasement and regenerative system of electrified railway system make a difficult to distinguish between the load current and fault current and it need a new intelligent protection system. In this paper, we proposed intelligent algorithm for discriminating normal and abnormal situation instead of the system being operated abnormally.

• 대한교통학회:학술대회논문집
• /
• 대한교통학회 1998년도 Proceedings The 4th International Transport Symposium
• /
• pp.17-24
• /
• 1998

The article expounds that the speed competition is the motive force of each transportation means. It also analyzes the current condition of the speed of Chinese railways. The developing strategy for Chinese railway is to raise the speed of the existing lines as a primary step and to construct the high-speed railway in selected sections concurrently, which proved that constructing high-speed railway in Beijing-Shanghai area is the best choice.

• 대한교통학회:학술대회논문집
• /
• 대한교통학회 1998년도 Proceedings The 4th International Transport Symposium
• /
• pp.36-42
• /
• 1998

This article analyzes Chinese railways transportation management system, uses the experiences of other countries' railway transportation management system for reference, as well as discusses the necessity of reform of railway transportation management system based on separating train operation with rail equipment management. Moreover, the article also puts forward an imagination on the reform scheme of railway transportation management system based on separating train operation with rail equipment management.

• 동굴
• /
• 제73호
• /
• pp.45-47
• /
• 2006

The modern people spend more time with heir family on weekends, and this changed the perspective toward leisure and tourism. Along with this, the recognition toward tourism resources have underwent various modifications with the increasing number of family tourists. Caves are categorized as lava tube (formed by volcano activity), lime stone cave(formed by absorption of water into underground level), sea cave (formed by wave erosion) and artificial cave that were made for the fluent traffic activity of railways or roads. Caves manifest characteristics of tourism as a natural resources and tourism as a humanity study, so caves are valuable as a multipurpose tourism resource.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 1998년도 추계학술대회 논문집
• /
• pp.96-102
• /
• 1998

The characteristics of roadbed are very important factors in the design of railways. Laboratory model tests were performed to investigate the effectiveness of geogrid placement in the subbase layers on reinforcement. Design parameters of reinforcement were determined through the laboratory model tests. The results indicated that geogrid reinforcement is increased the bearing capacity and reduced the settlement of railway foundation. The optimum length of geogrid reinforcement is about 4B. The effective depth of geogrid placement from the bottom of ballast is about 0.1B-0.2B depended on magnitude of applied load.

• 한국철도학회논문집
• /
• 제17권3호
• /
• pp.210-215
• /
• 2014

도시철도의 표정속도를 증대시키기 위해 여러 가지 방안이 연구되고 있는데 출입문 폭 확장을 통한 정차시간 단축은 이러한 방안 중 하나이다. 그러나, 출입문 폭을 확장하였을 때 단축되는 승객 승하차시간을 예상하기 위해 적합한 국내 모델과 수식은 아직 수립되지 않은 형편이다. 승하차 동작은 사람의 행동 방식에 영향을 많이 받고 이는 국가 별로 상이하다는 점을 고려한다면 승하차시간에 대한 외국 모델을 따른 다는 것은 적합하지 않다. 본 연구에서는 국내에서 측정 및 실험한 데이터를 바탕으로 국내 환경에 적합한 모델을 세우고 관련 수식과 변수를 유도함으로써 출입문 폭 확장 시 승하차시간 단축효과를 예상할 수 있도록 한다.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2011년도 춘계학술대회 논문집
• /
• pp.140-144
• /
• 2011

As a result of that the domestic railway technology has been progressed as times go by, the 1st and the 2nd steps for Gyeongbu HSR at the speed of more than 300km/h, were completed and Honam HSR - its operational speed is 350km/h - is under construction. Additionally, As a part of the expressization project for general lines, the Seoul-Chuncheon route at the speed of more than 180[km/h] is under construction and the Jeolla route is under design. At present, 11 countries (e.g. France, Germany, Belgium, Italy, the Netherlands, Spain, England, Japan, China and Taiwan) including Korea have high speed railways operated at the speed of more than 300[km/h]. As shown in the above, the domestic railway has high speed trains as good as those of countries outside Korea, but the schedule speed, which is calculated by dividing distance to destination by time, is lower than that of overseas trains. For overseas railway, the ratio of schedule speed to the highest speed is above 65%, while that of domestic railways is over 50%. It shows a significant difference between them. It is expected that the schedule speed improvement will increase the number of train operation and line capacities than now, so it shall achieve smooth transportation flow and improve the passengers' satisfaction. In this paper we describe the necessity for the improvement of schedule speed, by analyzing foreign cases related to the improvement of schedule speed in order to satisfy the increasing traffic demand.

• Advances in concrete construction
• /
• 제10권1호
• /
• pp.49-59
• /
• 2020

Precast concrete elements in accelerated bridge construction (ABC) extends from superstructure to substructure, precast pile foundation has proven a benefit for regions with fragile ecological environment and adverse geological condition. There is still a lack of knowledge of the seismic behavior and performance of the precast pile foundation. In this study, a 1/8 scaled model of precast pile foundation with elevated cap is fabricated for quasi-static test. The failure mechanism and responses of the precast pile-soil interaction system are analyzed. It is shown that damage occurs primarily in precast pile-soil interaction system and the bridge pier keeps elastic state because of its relatively large cross-section designed for railways. The vulnerable part of the precast pile with elevated cap is located at the embedded section, but no plastic hinge forms along the pile depth under cyclic loading. Hysteretic curves show no significant strength degradation but obvious stiffness degradation throughout the loading process. The energy dissipation capacity of the precast pile-soil interaction system is discussed by using index of the equivalent viscous damping ratio. It can be found that the energy dissipation capacity decreases with the increase of loading displacement due to the unyielding pile reinforcements and potential pile uplift. It is expected to promote the use of precast pile foundation in accelerated bridge construction (ABC) of railways designed in seismic regions.