• 한국철도학회논문집
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• 제12권6호
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• pp.829-834
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• 2009

자갈비산에 대한 위험성을 평가하는 한 방법으로 열차 하부 각 지점에서 다양한 자갈 종류 및 열차 속도에 따라 자갈 비산 확률을 파라메타로 제시하였다. 이를 위하여 풍동실험 결과를 바탕으로 한 확률계수 BFPF를 이용하였으며, 다양한 조건의 열차 하부 영역에 대한 수치해석을 수행하여 각 조건에 따른 각 지점의 자갈비산확률을 검토하였다. 열차 속도증가에 따라 비산확률이 급격히 증가하고, 속도가 350 km/h가 되면 자각비산 확률이 87%로 증가하였다. 또한 높힘침목을 적용하였을 경우와 비교를 통해, 다양한 조건에서의 자갈비산 확률에 대한 민감도를 분석하여 자갈형태 및 높힘침목 형태에 따른 변화 특성을 분석하고 높힘침목이 자갈비산 위험을 억제할 수 있음을 확인하였다.

• 한국철도학회논문집
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• 제8권1호
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• pp.6-14
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• 2005

The mechanism of ballast-flying phenomena by strong wind induced by high-speed trains has extensively been investigated by conducting wind tunnel test and field-measuring of wind velocity in the vicinity of the track. The ballast gathered from the Seoul-Busan high-speed railway track has been classified by mass and shape to find relationship between those properties and the characteristic of movement in high wind and 16-channel Kiel-probe array has been used to examine the detailed flow structure above the surface of the track. The probability of ballast-flying during the passage of the high-speed train has been assessed comparing the results from wind tunnel test and that from field-measuring. The results shows that when the G7 train runs well as the KTX train runs at 300km/h, about 25m/s wind gust is induced just above the tie and the probability far small ballast under 50g to fly is about 50％ when it is on the tie. If the G7 train runs at 350km/h, the wind gust just above the tie increases to 30m/s, therefore radical countermeasure seems to be needed.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 춘계학술대회 논문집
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• pp.369-373
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• 2005

To investigate the mechanism of ballast-flying phenomena by strong wind induced by high-speed trains, wind velocity in the vicinity of the track has been measured using 16-channel Kiel-probe array and detailed flow structure near the surface of the track has been analyzed. The position at which the underflow fully develop has been examined in order to assess the driving force of the turbulent flow under train and the results yields that the turbulent flow owing to the cavity of the inter-car as well as the friction force at the underbody of the train is the main reason of the strong wind under high-speed train. The preceding wind tunnel test results has been introduced to assess the probability of ballast-flying during the passage of the high-speed train by comparing the results from field-measuring. The results shows that when the G7 train as well as the KTX train runs at 300km/h, about 25m/s wind gust is induced just above the tie and the probability for small ballast under 50g to fly is about 50% when it is on the tie. If the G7 train runs at 350km/h, the wind gust just above the tie increases to 30m/s, therefore more radical countermeasure seems to be needed.