The effect of changes in sealing wall and horizontal drainage of Golfaraj dam on the values of lifting pressure parameters and maximum outlet gradient

Document Type : Research Paper

Authors

1 Civil Engineering of Geotechnics, Tabriz Branch, Islamic Azad University, Tabriz, Iran.

2 Civil Engineering, Tabriz Branch, Islamic Azad University, Tabriz, Iran.

Abstract

Dams are always considered as infrastructure structures and have vital value. An earthen dam is a body consisting of discontinuous soil particles of various sizes that need to be placed in front of a stream of water to store it. As water is stored behind the dam and its surface area increases, the potential energy of the water particles increases and due to its porous nature, it begins to move in it. Today, the main problem that has attracted the attention of engineers is the issue of seepage. So that the presence of seepage in earthen dams is inevitable. The aim of the present study was to investigate the different positions of the sealing wall and to select the best angle, length, number and distance, as well as to select the appropriate length for horizontal drainage. Due to the geotechnical conditions, it is against the phenomenon of rug and lifting force. GeoStudio software is a collection of soil mechanics software based on finite element methods through which various modellings and analyzes can be examined. This software includes various models such as SEEP / W which is used for flow analysis and seepage. In the present study, the SEEP / W model of this software package has been used. The SEEP / W model is based on the Darcy relation, which expresses the passage of water flow through the soil in both saturated and unsaturated states. The results showed that for the sealing wall located above the core, an angle of 20 degrees and for the sealing wall located downstream of the core, an angle of 100 degrees are suitable. Also, the optimal length of the sealing wall is 24 meters and its optimal number is 2. Increasing the distance between the two vertical sealing walls has increased the lifting pressure and reduced the maximum outlet gradient. Increasing the horizontal drainage length reduced the maximum output gradient, while having little effect on the uplift pressure.

Keywords

[1] A. Abdulhadi, A. Delewy,K. Abdul-Hassan, and H. Al-Musawi, Optimum design of control devices for safe seepage under hydraulic structures. Journal of Engineering and Development, 10, 1, (2006), 66-87.
[2] I. Arshad, , M. M. Babar and C. A. E. Vallejera, Computation of seepage and exit gradient through a nonhomogeneous earth dam without cutoff walls by using Geo-Slope (SEEP/W) Software. PSM Biological Research,4, 1,(2019), 40-50.
[3] A. Asadi Sakhmarsi ,H. Akhbari,P. Naeimi and A. Kiapey, The effect of the cutoff wall conditions on the seepage
characteristics of homogeneous earth-fill dams using SEEP/W. WALIA Journal, 30, S2, (2014), 176-182.
[4] B. R. Chahar, Determination of length of horizontal drain in homogenous earth dams. Journal of Irrigation and Drainage Engineering, 130, 6, (2004), 530-536.
[5] B. M.Das, Principal of geotechnical engineering fifth edition. Thomas Learning. (2001).
[6] K. E. Fadaei,S. Shojaee and R. Memarzadeh, Numerical simulation of seepage flow through dam foundation using smooth particle hydrodynamics method (RESEARCH NOTE). International Journal of Engineering, 32,4, (2019), 484-488.
[7] B. Goharnejad, M. Noury,A. Noorzad, A. Shamsaie and A. Goharnejad, The effect of clay blanket thickness to prevent seepage in dam reservor. Research Journal of Environmental Sciences, 4, 6,(2010), 558-565.
[8] Y. M. A. Hashash, J. J. Hook, B.Schmidt, and J. Yao, Seismic design and analysis of underground structures. Tunnelling and Underground Space Technology, 16, 4, (2001), 247-293.
[9] A. A. Hekmatzadeh,F. Zarei, A. Johari and A. Torabi Haghighi, Reliability analysis of stability against piping and sliding in diversion dams, considering four cutoff wall configurations. Computers and Geotechnics, 98, (2018),217-231.
[10] M. A. M. Ismail, and I. Abustan, Parametric study of horizontal drains for slope stability measure: A case study in Putrajaya, Malaysia. KSCE Journal of Civil Engineering, 21, 6, (2017), 2162-2167.
[11] M. Javanmard, R. Mottaghi and S. M. M. Hosseini, Investigating the influence of penetration length of cutoff wall on its dynamic interaction with core and foundation of earth dam. Civil Engineering Journal. 4, 12, (2018),3019-3026.
[12] V. J. Johnson, Mechanics of cavitation. Journal of the Hydraulics Division, 89, 3, (1963), 251-275.
[13] A. Kamanbedast and A. Delvari,Analysis of earth dam: Seepage and stability using Ansys and Geo-Studio softwares. World Applied Sciences Journal, 17, 9, (2013), 1087-1094.
[14] H. Khalili Shayan and E. Amiri, Effects of blankets, drains and cutoff wall on reducing uplift pressure, seepge and exit gradient under hydraulic structures. International Journal of Civil Engineering, 13, 4,(2015), 486-500.
[15] A. Malekpour, D. Farsadizadeh, A. Hosseinzadeh Dalir, and J. Sadrekarimi, Effect of horizontal drain size on the stability of an embankment dam in steady and transient seepage conditions. Turkish Journal of Engineering and Environmental Sciences, 36, 2,(2012),139-152.
[16] B. Mansuri and F. Salmasi, Effect of horizontal drain length and cutoff wall on seepage and uplift pressure in heterogeneous earth dam with numerical simulation. Journal of Civil Engineering and Urbanism, 3, 3,(2013), 114-121.
[17] G. C. Mishra,and A. K. Singh, Seepage through a levee. International Journal of Geomechanics, 5, 1, (2005), 74-79.
[18] A. Moharrami , G. Moradi,M. H. Bonab, J. Katebi and G. Moharrami, Performance of cutoff walls under hydraulic structures against uplift pressure and piping phenomenon. Geotechnical and Geological Engineering, 33, 1, (2014), 95-103.
[19] M. Mortazavi and S. Soleimani, Leakage analysis of embankment dams using SEEP/W, SEEP/3D software. Journal of Applied Environmental and Biological Sciences, 5, 10,(2015), 122-128.
[20] Y. Ninomiya,R. Hagiwara, and T. Azuma, Rise of excess pore water pressure and uplift of underground structures due to liquefaction. Earthquake Geotechnical Engineering-International Conference, Rotterdam, the Netherlands: Balkema, 2 (1995), 1023-1030.
[21] J. Niec, P. Zawadzhi, Z. Walczak and M. Spychala, Calculating earth dam seepage using HYDRUS software applications. Acta Scientiarum Polonorum, 16, 3, (2017), 43-56.
[22] V. Nourani, E. Sharghi,and M. H. Aminfar, Integrated ANN model for earthfill dams seepage analysis: Sattarkhan Dam in Iran. Artificial Intelligence Research, 1, 2, (2012), 22-37.
[23] B. M. A. Noori, and S. I. Khaleel, Evaluation of seepage and stability of Duhok Dam. Al-Rafidain Engineering, 19, 1, (2010), 42-58.
[24] M. S. Pakbaz, A. Dardaei and J. Salahshoor , Evaluation of performance of plastic concert cutoff wall in Karkheh Dam using 3-D seepage analysis and measurement. Journal of Applied Sciences, 9, 4, (2009), 724-730.
[25] B. Schmidt, and Y. M. A. Hashash, Preventing tunnel floatation due to liquefaction. In: Proceedings of the 2nd international conference on earthquake geotechnical engineering, Lisbon, Portugal, 3, (1999), 509-512.
[26] A. Ullah, A. Kassim, I. Alam, M. Junaid, and I. S. Ahmad, Efficiency analysis of seepage of Baz Ali small dam, Kurram Agency using clay blanket and cutoff wall with sand filter. Bulletin of the Geological Society of Malaysia, 67, (2019), 113 118.
Volume 12, Issue 1
May 2021
Pages 419-432
  • Receive Date: 30 June 2020
  • Revise Date: 05 October 2020
  • Accept Date: 04 January 2021