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

현장측정을 통한 터널 내 벽면마찰계수 추정 연구

  • Received : 2018.02.01
  • Accepted : 2018.02.26
  • Published : 2018.03.31


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.


Grant : 대심도 복층터널 설계 및 시공기술개발

Supported by : 국토교통과학기술진흥원


  1. 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.
  2. 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.
  3. 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.
  4. MOLIT (Ministry of Land, Infrastructure and Transport) (2011), Road design manual (617. ventilation), pp. 617-45-617-46.
  5. Moody, L.F. (1944), "Friction factor for pipe flow", Transactions of the American Society of Mechanical Engineers, Vol. 66, No. 8, pp. 671-681.
  6. 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).