Computation of Seepage and Exit Gradient through a Non-Homogeneous Earth Dam without Cut-off Walls by using Geo-Slope (SEEP/W) Software

Author's: Imran Arshad, Mohammed Muneer Babar, Clea Anne E. Vallejera
Authors' Affiliations
Article Type: Research Article     Published: Jan. 31, 2019 Pages: 40-50
DOI:        Views 1933       Downloads 0


In this study, SEEP/W was used to develop a finite element model of a non-homogenous earth dam and for this purpose Hub dam was selected. Two different cases i.e. (i) with cut-off wall and (ii) without cut-off wall were studied to check the behaviour of the dam in terms of seepage flux and exit gradient respectively. The software was also used to simulate the phreatic line behaviour for both cases. The outcome of the simulated results showed that the dam is safe against piping, at its original design as the installation of a cut-off wall found working effectively in reducing internal pore water pressure within the dam and its foundation. For case (i), the phreatic line showed a normal trend as it is falling into the filter drain after passing the core with overall minimum seepage flux of order 2.1130 x 10-4 ft3/sec/ft (21.54 LPH) and exit gradient at downstream toe was recorded 0.099 respectively. However, for case (ii) the dam showed an irregular behaviour as the internal pore water pressure at the subsurface region of the dam foundation was continuously increasing due to unavailability of the cut-off wall and the flow vectors move towards toe drain with high velocity and seepage flux. The overall maximum seepage flux and exit gradient was recorded for the maximum pond level without cut-off wall of order 4.6355 x 10-3 ft3/sec/ft (472.54 LPH) and 0.865 respectively. The comparison results showed that without cut-off walls the seepage flux may increase about (87.314% – 87.493%) and the variation in exit gradient may increase about (48.705% – 63.353%) respectively.


Non-Homogeneous Dam, Seepage Flux, Exit Gradient, Phreatic Line, SEEP/W, Geo-Slope Software.


Arshad, I., Babar, M.M., Vallejera, C.A.E., 2019. Computation of Seepage and Exit Gradient through a Non-Homogeneous Earth Dam without Cut-off Walls by using Geo-Slope (SEEP/W) Software. PSM Biol. Res., 4(1): 40-50.


Aasma, A.J.J., 2016. Analysis and Estimation of Seepage through Homogenous Earth Dam without Filter. Diyala J. Eng. Sci., 9(2): 83-94.

Al-Damluji, O.A., Fattah, M., Al-Adthami, R.A., 2004. Solution of Two-Dimensional Steady-State Flow Field Problems by the Boundary Element Method. J. Eng. Tech., 23(12): 750-766.

Arshad, I., Babar, M.M., 2017. Finite Element Analysis of Seepage and Exit Gradient through a Non-Homogeneous Earthen Dam without Filter Drain. Int. J. Altern. Fuels. Energy., 1(1): 1-8.

Arshad, I., Babar, M.M., Javed, N., 2017. Numerical Analysis of Seepage and Slope Stability in an Earthen Dam by Using Geo-Slope Software. PSM Biol. Res., 2(1): 13-20.

Arshad, I., Baber, M.M., Javed, N., 2016. Numerical Analysis of Drawdown in an Unconfined Aquifer due to Pumping Well by SIGMA/W and SEEP/W Simulations. Adv. Sci. Tech. Eng. Sys. J., 1(1): 11-18.

Arshad, I., Babar, M.M., Sarki, A., 2015. Computation of Seepage Quantity in an Earthen Watercourse by SEEP/W Simulations Case Study: “1R Qaiser Minor” – Tando Jam-Pakistan. Adv. J. Agric. Res., 3(1): 82-88.

Arshad, I., 2015. Numerical Analysis of Phosphate Movement through the Sandy Loamy Clayey Soil by CTRAN/W Simulations. Adv. J. Agric. Res., 3(1): 89-97.

Arshad, I., Baber, M.M., 2014. Finite Element Analysis of Seepage through an Earthen Dam by using Geo-Slope (SEEP/W) software. Int. J. Res., 1(8): 612-619.

Arshad, I., Baber, M.M., 2014. Comparison of SEEP/W Simulations with Field Observations for Seepage Analysis through an Earthen Dam. Int. J. Res., 1(7): 67-79.

Arshad, I., 2013. Finite Element Analysis of seepage through Hub Dam by using Geo-Slope Software. M.E Thesis, (IWREM), MUET Jamshoro, Pakistan.

Baghalian, S., Nazari, F., Malihi, S.S., 2012. Analysis and Estimation of Seepage Discharge in Dams. Int. J. Eng. App. Sci., 4(3): 49-56.

Doherty, D., 2009. Design and Construction of Earth Dams: A Primer on Dam Design. Retrieved from, October 03.

Gokmen, T., Swiatek, D., Wita, A., 2005. Finite Element Method and Artificial Neural Network Models for Flow through Jeziorsko Earth-fill Dam in Poland. J. Hyd. Eng., 131(6): 431-440.

Garg, S.K., 2006. Irrigation Engineering and Hydraulic Structures. 19th Edition, Khanna Publishers, Delhi.

Khattab, S.A.A., 2010. Stability Analysis of Mosul Dam under Saturated and Unsaturated Soil Conditions. Al- Rafidain Eng. J., 18(1): 95-102.

Moayed, R.Z., Rashidian, V.R., Izadi, E., 2012. Evaluation of Phreatic Line in Homogenous Earth Dams with Different Drainage Systems. Civ. Eng. Dept.  Imam Khomeini Int. Uni. Qazvin, Iran.

Nasim, S., 2007. Seepage Analysis of Earth Dams by Finite Elements. M.Sc. Thesis, Collage of Engineering, University of Kufa, Iraq.

Osuji, S.O., Adegbemileke, S.A., 2015. Phreatic Line and Pore Pressure Stresses in Zoned Rockfill Dam. Asian J. Sci. Tech., 6(5): 1447-1454.

WAPDA., 2009. 4th Periodic Inspection Report of Hub Dam. Published by ACE – WAPDA.