Embankment dam foundation analysis for the decrease of internal erosion likelihood
- Marc Smith
- … show all 1 hide
Purchase on Springer.com
$39.95 / €34.95 / £29.95*
Rent the article at a discountRent now
* Final gross prices may vary according to local VAT.
A zoned embankment dam is founded on clay underlain by a sand deposit. Major seepage phenomena were noticed in the foundation downstream from the dam where the vertical seepage forces in the sand layer were expected to exceed the downward forces due to the overlying clay. Modern technologies were applied to delineate critical zones to help design optimal rehabilitation measures. A global electromagnetic survey was carried out to detect and map the main sources, pathways and exits of seepage. Based on these global findings, a more detailed analysis was then conducted to identify zones where thickness of the foundation clay is minimal, pore pressures in sand are higher and thus where the factor of safety against uplift is lower and internal erosion is more likely to occur.
Clay thickness evaluation required the determination of land surface as well as clay-sand contact elevations. A laser airborne survey was performed to model the land surface elevation. Data concerning the clay-sand contact elevation came from the interpreted stratigraphy based on a series of boreholes and cone penetration tests. This data was combined in a geostatistical model along with the measured piezometric levels in the foundation. This resulted in a contour map showing factors of safety against uplift over the entire downstream area.
The use of modern technologies, namely electromagnetic and laser surveys as well as geostatistical tools, was instrumental in defining the limits of an otherwise spread-out problem and to provide an optimal solution, in terms of costs and effectiveness, for the long-term stabilization of the foundation.
- Smith M, Côté A, Noël P, Babin D. Characterizing seepage at the junction of two embankment dams. In: Proceedings of the Canadian DamAssociation Annual Conference,Whistler, Canada, Oct 3–8, 2009
- Olsen M J, Stuedlein A W. Discussion of use of terrestrial laser scanning for the characterization of retrogressive landslides in sensitive clay and rotational landslides in river banks. Canadian Geotechnical Journal, 2010, 47(10): 1164–1168 CrossRef
- Isaaks E H, Srivastava RM. An Introduction to Applied Geostatistics. New York: Oxford University Press, 1989
- Smith M, Konrad J M. Assessing hydraulic conductivities of a compacted dam core using geostatistical analysis of construction control data. Canadian Geotechnical Journal, 2011, 48(9): 1314–1327 CrossRef
- Embankment dam foundation analysis for the decrease of internal erosion likelihood
Frontiers of Structural and Civil Engineering
Volume 6, Issue 4 , pp 431-436
- Cover Date
- Print ISSN
- Online ISSN
- SP Higher Education Press
- Additional Links
- seepage detection
- geostatistical analysis
- dam monitoring
- internal erosion
- LIDAR survey
- Marc Smith (1)
- Author Affiliations
- 1. Hydro Québec, 75 René-Lévesque, West Montreal, Canada