• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 춘계학술대회
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• pp.1655-1660
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• 2004

Theoretical study has been conducted to clarify pressure characteristics of KTX(Korea Train eXpress) in tunnel. The external and internal pressure of rolling stock have been measured by using the atmospheric pressure sensors and portable data acquisition system on Seoul-Busan high speed railroad line. These pressure change may give rise to the ear-discomfort for passenger and fatigue for car body. In this study, the tunnels from 200m to 4000m in length have been chosen for the investigation of tunnel length effects. From the results of experiment, the pattern of pressure change generally agrees to RTRI's experimental result for Shinkansen. We found that there are similar patterns of external pressure variation for each critical tunnel length. The critical tunnel lengths are governed by train speed, train length and sonic velocity.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 춘계학술대회 논문집
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• pp.70-77
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• 2011

When a train passes a conventional tunnel at high speed, an environmental noise issue arises by pressure variation and micro-pressure waves at the exit of the tunnel. It is known that this issue can be reduced by using dummy tunnel duct on the tunnel entrance. We studied the variances of micro-pressure waves at the exit of tunnel and pressure variation within the tunnel, by altering surface area and length of the dummy tunnel duct. For analyze this train-tunnel relation problem, axi-simmetric steady compressible flow solver was used. Changing the length of the dummy tunnel duct can adjust pressure variation, changing the surface area of the dummy tunnel duct can adjust volume and pressure variation of the micro-pressure wave. Thus, optimized surface area and length of the dummy tunnel duct can simultaneously reduce environmental noise pollution by micro-pressure wave and issues by the pressure variation.

• 한국철도학회논문집
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• 제7권1호
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• pp.26-31
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• 2004

A study is conducted to clarify internal and external pressure variation of passenger cabin for KTX. These pressure variation may give rise to the ear-discomfort for passenger and fatigue for carbody. In this study, the pressure variation of interior, gangway and exterior of KTX passenger car is measured by using the atmospheric pressure sensors and portable data acquisition system. The tunnel from 4000m to 200m in length are chosen far the investigation of tunnel length effects. From the results of experiment, the pressure variation of interior per second is under the ear-discomfort limitation in all of tunnel. And, We found that there are similar patterns of exterior pressure variation for each critical tunnel length. These results generally agree to RTRI's experimental result fur Shinkansen.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2002년도 추계학술대회 논문집(I)
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• pp.220-224
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• 2002

As the train run through the tunnels, especially at high speed, pressure shock developed by the running train gives the influence on the pressure fluctuation inside the tunnel and consequently, inside the car. This pressure changes and pressure gradient is closely related with the tunnel section, train speed, air tightness of the train, length of the tunnel, etc. This study includes the analysis of the pressure behavior at the varied train speed and tunnel length. The results show that train speed affects the pressure gradient inside the car almost linearly, and that there exist the critical tunnel lengths that gives the maximum value of pressure change and pressure gradient, respectively.

• 화약ㆍ발파
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• 제22권3호
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• pp.65-70
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• 2004

최근 신설되는 도로의 경우 고속화/직선화로 인하여 터널의 연장 및 평균터널 길이, 3차선이상의 대 단면 터널이 날로 증가하고 있어 이에 따른 굴착 효율 극대화가 필요한 시점에 있다. 사패산 터널은 약 4km의 4차선 대단면 도로터널로, 환경문제로 인해 늦춰진 공기를 단축시키기 위하여 터널 굴착 시 굴진효율에 가장 큰 영향요소인 굴진장과 여굴관리, 발파효율의 개선을 위한 다양한 신 공법이 적용되고 있다. 본 논문은 당 현장에서 시도되고 있는 신 공법 중, 새로운 형태의 폭약인 Bulk 폭약에 대하여 소개하고, Bulk 폭약의 대 단면 터널 적용에 대한 효율을 검증하고자 하였다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2008년도 춘계 학술발표회 초청강연 및 논문집
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• pp.778-783
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• 2008

In this paper, numerical method was calculated on evaluation of underground ventilation system to keep servicing a fresh air. The tunnel length for simulation is 18.2 km with various located seven ventilation shaft. Generally, owing to thermal generation in cable tunnel under about 50 m depths, cable tunnel ventilation system is more important than that of other tunnels. So, we conducted that the effects of ventilation systems was simulated depending on the difference of electrical power tunnel length, the number of shaft tunnel, forced ventilation and duct was or not. Test results show that the main conditions in order to enhance the underground cable tunnel are that ventilation systems have to be designed with forced ventilation and with duct.

• 한국터널지하공간학회 논문집
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• 제8권3호
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• pp.219-225
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• 2006

터널시공에 있어서 굴진장은 기술적인 면뿐만이 아니라 경제적인 면에서도 큰 영향을 끼치지만 현재까지 굴진장 결정을 위한 일관된 절차는 연구되지 않았다. 본 연구에서는 수치해석을 통해 굴진장이 연암터널의 거동형태에 끼치는 영향을 알아보았다. 터널 막장과 무지보구간의 거동형태를 막장안전률과 설계차트를 이용해 정량적으로 판단할 수 있도록 하였으며, 설계단계에서의 최적 굴진장을 사이클타임과 공사비 등의 시공자료를 이용해 분석하였다. 비록 본 연구결과가 몇몇 적용한계를 가지고 있지만 설계단계에서 터널 굴착을 최적화하기 위한 정보를 제공할 수 있다.

• 소음진동
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• 제7권6호
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• pp.959-966
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• 1997

In general, the booming noise intensity at tunnel exit is strongly related to the gradient of the compression wave front created by high speed train entering the tunnel. This paper presents some results in relation with the compression wave front produced when the high speed train enters a tunnel. Four kinds of tunnel entrance shape with real dimensions were studied to investigate the formation of compression wave front inside tunnel by train entering tunnel. Computations were carried out using three-dimensional compressible Euler equation with vanishing viscosity and conductivity of fluid. According to the results, the flow disturbances occured at tunnel entrance were eliminated by tunnel hood with same cross sectional area. The compression wave front is formed completely at 30-40m from tunnel entrance. The maximum pressure gradient of compression wave front is reduced by 29.8% for the inclined tunnel hood and reduced by 21.5% for the tunnel hood with holes at the top face with tunnel without hood. The length of the inclined hood is 15m and the length of the hood with holes is 20m.

• International Journal of Railway
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• 제1권4호
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• pp.169-174
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• 2008

Experimental study has been conducted to clarify the internal and external pressure variation characteristics for KTX(Korea Train eXpress) passing through tunnel. Abrupt pressure variation gives rise to the ear-discomfort for passenger and fatigue for car body. In this study, the internal and external pressure variation are measured by using KTX real train experiment and on-board portable data acquisition system in Gyeongbu high speed commercial line. The tunnels from 200 m to 4000 m in length are chosen for the investigation of tunnel length effects. From the results of experiment, the internal pressure variation rate for all the test tunnels is lower than the standard criteria of 200 Pa/s. And, the critical tunnel lengths for pressure wave pattern are classified into 7 groups by using the theoretical L-t diagram analysis.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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• pp.158-164
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• 2011

When a train passes a conventiaonl tunnel at high speed, external pressure variation problem arises. It is known that this issue can be reduced by control the tunnel length. We studied the variances of external pressure variation within the tunnel, by altering length of the dummy tunnel duct. We also studies the variances of micro-pressure waves at the exit of tunnel, by altering surface area of dummy tunnel duct. For analyzing this train-tunnel relation problem, axisymmetric steady compressible flow solver was used.