Mh Mohammad Hossein Jowkar, M Mashalah Khamehchiyan, M Mohammad Salehi, A Ehsan Mahmoudian Barzi,
Volume 0, Issue 0 (Accepted Articles 2025)
One of the major challenges in tunnel engineering is the estimation and prediction of water inflow into tunnels. Although numerous methods have been proposed to evaluate hydraulic behavior and to estimate the permeability of soil and rock masses depending on their geological structures, these methods still lack sufficient accuracy and certainty. Therefore, in this study, the amount of water seepage into different sections of the Sarploe Zahab water transfer tunnel (T4), as part of the Sirvan river water transfer project to the tropical regions of Kermanshah and Ilam provinces, was evaluated using analytical (Goodman, Karlsrud, and El Tani), empirical (SGR and TIC), and numerical (SEEP/W) methods. The tunnel has a total length of 3.4 km, a diameter of 8.6 m, and inlet and outlet elevations of 552.51 m and 549.50 m above sea level, respectively. The results indicate that the water inflow into different tunnel sections varies from <1 to 161 L/s based on analytical methods, from <1 to 8 L/s and from <1 to 35 L/s according to the SGR and TIC empirical methods, respectively, while values ranging from <1 to 19 L/s are obtained from numerical modeling. Furthermore, the hydraulic flow components, the influence of the river on water inflow into the tunnel, and the differences resulting from considering layer-by-layer hydraulic conductivity instead of equivalent hydraulic conductivity were modeled. Finally, by correlating the results with the geological conditions of the study area, it was determined that water inflow may pose a risk at chainages 0+239 and 1+829, and these sections of the tunnel should receive special attention during construction.
