The estimation of the wall friction coefficient in tunnels by in-situ measurement

Hyo-Gyu   Kim; Pan-Gyu  Choi; Ho-Hyung  Lee; Doo-San  Baek; Kwang-Hoon Na

doi:10.9711/KTAJ.2018.20.2.405

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The estimation of the wall friction coefficient in tunnels by in-situ measurement 현장측정을 통한 터널 내 벽면마찰계수 추정 연구

31 March 2018. pp. 405-421

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Abstract

In most of cases, the wall friction coefficients applied for local tunnel design are quoted directly from foreign data or local design guideline. In the previous studies, the wall friction coefficient was estimated using the velocity decay method. However, it is difficult to estimate the wall friction coefficient when the convergence wind velocity in the tunnel is negative (-) or if there is a change in the natural wind. Therefore, in this study, the wall friction coefficient is estimated by applying the dynamic simulation technique in addition to the conventional the velocity decay method. As a result of the analysis, the coefficient of wall friction in the tunnels for the total of 9 tunnels (18 tubes both directions) was 0.011~0.025, and the mean value was estimated to be 0.020. In addition, the wall friction coefficient obtained quantitatively through this study was compared with the current design criteria.

Keywords

Wall friction coefficient

Total ventilation resistance coefficient

Dynamic simulation

Velocity decay method

In-situ measurement

현재 국내터널에 적용중인 벽면마찰계수는 단순히 외국의 연구결과를 인용하여 사용하 고 있는 실정이다. 또한 기존 선행연구들에서는 속도감쇄법을 이용하여 벽면마찰계수 를 추정하였으나, 터널 내 수렴풍속이 음수(-)이거나 자연풍의 변화가 있는 경우에는 벽 면마찰계수에 대한 추정이 어려운 점이 있었다. 이에 따라 본 연구에서는 기존 속도감쇄법과 더불어 동적 시뮬레이션기법을 적용하여 벽면마찰계수를 추정하였다. 분석결과, 총 9개 터널(양방향 18개 튜브)에 대한 터널 내 마찰계수는 0.011~0.025 정도로 분석되었으며, 평균값은 0.020로 추정되었다. 또한, 본 연구를 통해 정량 적으로 획득한 벽면마찰계수를 현재 적용중인 설계기준과 비교하였다.

키워드

벽면마찰계수

총환기저항계수

동적 시뮬레이션

속도감쇄법

현장측정

References

De Bruin, A.C., Maarsingh, R.A., Swart, L. (1997), “New attempts to solve an old problem: aerodynamic measurements in new vehicle tunnels”, Proceedings of the 9th International Symposium on Aerodynamics and Ventilation of Vehicle Tunnels, Aosta Valley, Italy, pp. 3-23.

Kim, H.G., Choi, P.G., Ryu, J.O., Lee, Y.H. (2018), “Development of a programming logic to estimate the wall friction coefficient in vehicle tunnels with piston effects”, Journal of Korean Tunnelling and Underground Space Association, Vol. 20, No. 1, pp. 39-53.

Lee, K.B., Lee, C.W., Kim, H.G. (2004), “An in-situ study of the wall friction coefficient in road tunnels”, Proceedings of the Korean Society for Rock Mechanics, 2004 Fall Conference, Daejeon , pp. 61-72.

MOLIT (Ministry of Land, Infrastructure and Transport) (2011), Road design manual (617. ventilation), pp. 617-45 - 617-46.

Moody, L.F. (1944), “Friction factor for pipe flow”, Transactions of the American Society of Mechanical Engineers, Vol. 66, No. 8, pp. 671-681.

Park, Y.D. (1989), Fluid mechanics, Bosung-munhwasa, Seoul, pp. 145-188 (Original Edition: John, J.E.A., Haberman, W.L. (1980), Introduction to Fluid Mechanics, 2nd Edition).

Information

Publisher :Korean Tunneling and Underground Space Association
Publisher(Ko) :한국터널지하공간학회
Journal Title :Journal of Korean Tunnelling and Underground Space Association
Journal Title(Ko) :한국터널지하공간학회 논문집
Volume : 20
No :2
Pages :405-421
Received Date : 2018-02-01
Revised Date : 2018-02-22
Accepted Date : 2018-02-26
DOI :https://doi.org/10.9711/KTAJ.2018.20.2.405

Journal of Korean Tunnelling and Underground Space Association ISSN:2233-8292(Print) 2287-4747(Online) 한국터널지하공간학회 논문집

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