A Numerical Modeling of Piping Phenomenon in Earth Dams

To estimate the risks of dam failure phenomenon, it is necessary to understand this phenomenon and the involved governing factors. Overtopping and piping are the two main reasons of earthdam failures. In the piping context, the piping is determined as a phenomenon which is occurred between two phases, the water liquid and the solid soil. In this investigation, the onset of piping and its development, as well as the movement of water in soil, are numerically approached. In this regard, a one-dimensional numerical model based on the mass-conserving finite-volume method is developed and applied in order to simulate the piping phenomenon in a continuous circular tunnel of given initial length and radius, located between upstream and downstream. The simulation result includes the time-variations of radius along the tunnel until the radius value reaches its critical and the piping phenomenon converts to overtopping.

• N. Zaki Alamdari
• M. Banihashemi
• A. Mirghasemi

• Earth dam
• dam break
• piping
• internal erosion

[1] Bonelli S., Brivois O.(2008) The scaling law in the hole erosion test with
a constant pressure drop, International Journal for Numerical and
Analytical Methods in Geomechanics, in press.
Int.J.Numer.Anal.Meth.32.pp.1573-1595
[2] Fell, R., MacGregor, P., Stapledon, D. & Bell, G. (2005). Geotechnical
engineering of dams. Balkema, Leiden, ISBN 041536440x.
[3] Fread, D. L. (1988). BREACH: an Erosion Model for Earthen Dam
Failures. Model description and User Manual, US National Weather
Service.
[4] Lachouette D., Golay F., Bonelli S. (2008). One-dimensionnal modeling
of piping flow erosion, C. R. Mécanique, 336: 731-736.
[5] Mijala,T.(2001). Development of rescue actions based on dam-break
flood analysis. RESCDAM, Final report.
[6] Richards K.S., Reddy K.R. (2007). Critical appraisal of piping
phenomena in earth dams. Bulletin of Engineering Geology and the
Environment. Vol. 66, No 4, pp. 381-402.
[7] Wan. C, Fell. R. (2004). Investigation of rate of erosion of soils in
embankment dams, J. Geotech. Geoenviron. Eng. 130(4), 373-380.
[8] Wang Z., Bowles D.S. (2007). A numerical method for simulating onedimensional
headcut migration and overtopping breaching in cohesive
and zoned embankments. Water Resources Research. Vol. 3, W05411.