Evaluation of Underground Water Flow into Tabriz Metro Tunnel First Line by Hydro-Mechanical Coupling Analysis

One of the main practical difficulties attended with tunnel construction is related to underground water. Uncontrolled water behavior may cause extra loads on the lining, mechanical instability, and unfavorable environmental problems. Estimating underground water inflow rate to the tunnels is a complex skill. The common calculation methods are: empirical methods, analytical solutions, numerical solutions based on the equivalent continuous porous media. In this research the rate of underground water inflow to the Tabriz metro first line tunnel has been investigated by numerical finite difference method using FLAC2D software. Comparing results of Heuer analytical method and numerical simulation showed good agreement with each other. Fully coupled and one-way coupled hydro mechanical states as well as water-free conditions in the soil around the tunnel are used in numerical models and these models have been applied to evaluate the loading value on the tunnel support system. Results showed that the fully coupled hydro mechanical analysis estimated more axial forces, moments and shear forces in linings, so this type of analysis is more conservative and reliable method for design of tunnel lining system. As sensitivity analysis, inflow water rates into the tunnel were evaluated in different soil permeability, underground water levels and depths of the tunnel. Result demonstrated that water level in constant depth of the tunnel is more sensitive factor for water inflow rate to the tunnel in comparison of other parameters investigated in the sensitivity analysis.

[1] Javadi, M., M. Sharifzadeh, and K. Shahriar, Uncertainty analysis of groundwater inflow into underground excavations by stochastic discontinuum method: Case study of Siah Bisheh pumped storage project, Iran. Tunneling and Underground Space Technology, 2016. 51: p. 424-438.
[2] Goodman, R.E., et al., Ground water inflows during tunnel driving. 1964: College of Engineering, University of California.
[3] Zhang, L. and J. Franklin. Prediction of water flow into rock tunnels: an analytical solution assuming a hydraulic conductivity gradient. In International journal of rock mechanics and mining sciences & geomechanics abstracts. 1993. Elsevier.
[4] Heuer, R.E. Estimating rock tunnel water inflow. In Proceedings of the rapid excavation and tunneling conference. 1995. Society for Mining, Metallogy & Exploration, INC.
[5] Lei, S., An Analytical Solution for Steady Flow into a Ttonnel. Ground water, 1999. 37(1): p. 23-26.
[6] Karlsrud, K., Water control when tunneling under urban areas in the Olso region. NFF publication, 2001. 12(4): p. 27-33.
[7] Raymer, J. Predicting groundwater inflow into hard-rock tunnels: estimating the high-end of the permeability distribution. In 2001 Rapid Excavation and Tunneling Conference. 2001.
[8] El Tani, M., Circular tunnel in a semi-infinite aquifer. Tunneling and underground space technology, 2003. 18(1): p. 49-55.
[9] Park, K.-H., A. Owatsiriwong, and J.-G. Lee, Analytical solution for steady-state groundwater inflow into a drained circular tunnel in a semi-infinite aquifer: a revisit. Tunneling and Underground Space Technology, 2008. 23(2): p. 206-209.
[10] Schweiger, H., R. Pottler, and H. Steiner, Effect of seepage forces on the shotcrete lining of a large undersea cavern. Computer Method and Advances in Geomechanics, Rotterdam, 1991: p. 1503-1508.
[11] Katzenbach, R. The influence or soil strength and water load to the safety of tunnel driving. In International conference on numerical methods in geomechanics. 1985.
[12] Daito, K. and K. Ueshita. Prediction of tunneling effects on groundwater condition by the water balance method. In Proc., 6th Int. Conf. on Numerical Methods in Geomechanics. 1988. Innsbruck.
[13] Ueshita, K., T. Sato, and K. Daito. Prediction of tunneling effect on groundwater condition. In International conference on numerical methods in geomechanics. 1985.
[14] Gunn, M. and R. Taylor, Discussion on Atkinson and Mair (1983). Géotechnique, 1984. 35(1): p. 73-75.
[15] Shin, J., D. Potts, and L. Zdravkovic, Three-dimensional modelling of NATM tunneling in decomposed granite soil. Geotechnique, 2002. 52(3): p. 187-200.
[16] Shin, J., T. Addenbrooke, and D. Potts, A numerical study of the effect of groundwater movement on long-term tunnel behavior. Geotechnique, 2002. 52(6): p. 391-403.
[17] Yoo, C. and S. Kim, Soil and lining responses during tunneling in water-bearing permeable soil–3D stress-pore pressure coupled analysis. 2006.
[18] Shin, Y.-J., et al., The ground reaction curve of underwater tunnels considering seepage forces. Tunneling and Underground Space Technology, 2010. 25(4): p. 315-324.
[19] Shin, Y.-J., et al., Interaction between tunnel supports and ground convergence—Consideration of seepage forces. International Journal of Rock Mechanics and Mining Sciences, 2011. 48(3): p. 394-405.
[20] Wang, M. and G. Wang, A stress-displacement solution for a pressure tunnel with impermeable liner in elastic porous media. Latin American Journal of Solids and Structures, 2012. 9(1): p. 95-110.
[21] Preisig, G., F. Joel Cornaton, and P. Perrochet, Regional Flow Simulation in Fractured Aquifers Using Stress‐Dependent Parameters. Ground water, 2012. 50(3): p. 376-385.
[22] Prassetyo, S.H. and M. Gutierrez, Effect of transient coupled hydro-mechanical response on the longitudinal displacement profile of deep tunnels in saturated ground. Tunneling and Underground Space Technology, 2018. 75: p. 11-20.
[23] Lewis, R. and H. ghafouri, a novel finite element double porosity model for multiphase flow through deformable fractured porous media. International Journal for Numerical and Analytical Methods in Geomechanics, 1997. 21(11): p. 789-816.
[24] Lewis, R. and Y. Sukirman, Finite element modelling of three‐phase flow in deforming saturated oil reservoirs. International Journal for Numerical and Analytical Methods in Geomechanics, 1993. 17(8): p. 577-598.
[25] Osorio, J.G., H.-Y. CHE, and L.W. Teufel. Numerical simulation of the impact of flow-induced geomechanical response on the productivitv of stress-sensitive reservoirs. In SPE symposium on reservoir simulation. 1999.
[26] Fredrich, J., et al. Three-dimensional geomechanical simulation of reservoir compaction and implications for well failures in the Belridge Diatomite. In SPE Annual Technical Conference and Exhibition. 1996. Society of Petroleum Engineers.
[27] Minkoff, S.E., et al., Coupled fluid flow and geomechanical deformation modeling. Journal of Petroleum Science and Engineering, 2003. 38(1): p. 37-56.
[28] Reynolds, O., Experiments showing dilatancy, a property of granular material, possibly connected with gravitation. Proc. R. Inst. GB, 1886. 11(354363): p. 12.
[29] King, F.H., Observations and Experiments on the Fluctuations in the Level and Rate of Movement of Ground-water on the Wisconsin Agricultural Experiment Station Farm and at Whitewater, Wisconsin. 1892: Weather Bureau.
[30] Neuzil, C., Hydromechanical coupling in geologic processes. Hydrogeology Journal, 2003. 11(1): p. 41-83.
[31] Organization, T.c.t., Report of geological and geotechnical investigations result of the Tabriz metro first line, 2004: Archives of Tabriz city train organization.
[32] ITASCA, Manual, FLAC User’s, 2002.
[33] Lee, K. and X. Ge, The equivalence of a jointed shield-driven tunnel lining to a continuous ring structure. Canadian Geotechnical Journal, 2001. 38(3): p. 461-483.