» Research Note « Investigation of the Effects of Valley Shape and Arc Radius on the Seepage Analysis of Arched Earth Dams using 3D Numerical Modeling

Document Type : Research Article

Authors

1 M.Sc. Graduate, Department of Civil Engineering, Imam Khomeini International University, Qazvin, Iran

2 Assistant Professor, Department of Civil Engineering, Imam Khomeini International University, Qazvin, Iran

Abstract

Earth dams under certain conditions are constructed as arch shaped in plane. This may have different reasons such as foundation problem, stability of the body of the earth dam and seepage. Change in the earth dam shape results in its discharge changes too. This is one of the reasons why this study was made. The main purpose of this study is to examine the numerical analysis for verifying the extent of discharge and hydraulic gradient variations of arch dams. For this purpose, a series of numerical analysis by FLAC 3D software were made, and the impact of parameters such as the shape of the valley, height of the dam and the radius of the arc were examined. The results showed that as the radius of the arc increases, discharge rate of the dam in both types of the valleies decreases. In a valley with a constant cross section at a certain height, discharge rate is more than a narrow valley. The results also showed that discharge and arc length have linear relationship. The analysis also showed that, average of hydraulic gradient downstream of arch dams is greater than the straight dams.

Keywords


Al Jairry, H. (2010). "2D-Flow analysis through zoned earth using finite element approach". Eng. and Tech. Journal, Vol. 28, No. 21: 6315-6324.
Chen, Q. and Zhang, L.M. (2006). "Three-dimensional analysis of water infiltration into Gouhou rockfill Dam using saturated-unsaturated seepage theory". Canadian Geotechnical Journal, 43(5):449-461.
Fakhari, A. and Ghanbari, A. (2013). "A simple method for calculating the seepage from earth dams with clay core". Journal of GeoEngineering, 8(1): 27-32.
FLAC3D. (2012). Finite Difference Analysis Program. Version 5.01 User's Manual.
Jafarzadeh F. Ferdos, F. and Soleimanbeigi A. (2009). "Comparison between two and three dimensional seepage analysis of rock-fill dams constructed in narrow valleys, a case study". Commission internationale des grands barrages, Vingt Trosieme Congres, Des grands barrages, At Brasilia, Brazil.
Jafarzadeh, F. and Shafipour, R. (2003). "Three dimensional seepage analysis of earth dam considering valley shape effects". Proceeding of 6th International Conference of Civil Engineering, Isfahan, Iran.
Jun-feng, Fu and Sheng, J. (2009). "A study on unsteady seepage flow through dam". Journal of Hydrodynamics, 21(4):499-504.
Lam, L. Fredlund, DG. and Barbour, SL. (1988). "Transient seepage model for saturated-unsaturated systems:A geotechnical engineering approach". Canadian Geotechnical Journal, 24(4): 565-580.
Papagianakis, AT. and Fredlund, DG. (1984). "A steady state model for flow in saturated-unsaturated soils". Canadian Geotechnical Journal, 21(3): 419-430.
Rafiezadeh, k. and Ataei-Ashtiani, B. (2014). "Transient free-surface seepage in three dimensional general anisotropic media by BEM". Engineering Analysis with Boundary Elements, 46: 51-56
Rakhshanderoo, G. and Bagherieh, A. (2006). "Three dimensional analysis of seepage in 15-Khordaddam after impoundment". Iranian Journal of Science and Technology, Transaction B, Engineering, 30(B1): 55-68.
Salmasi, F. and Jafari, F. (2013). "Validity of Schaffernak’s and Casagrande’s analytical solutions for Seepage through a homogeneous earth dam". International Journal of Pure Scientific Researches, 1(1): 5-11.
Yarahmadi, N. Khodashenas, S.R. and Ansari, S. (2015). "A comparison between two and three
dimensional seepage analysis results in earth dams using SEEP/W and SEEP/3D (Case study: Shian and Khaan-Abad Dams)". Ecology, Environment and Conservation, 21(1): 509-516.