Abstract
The resilience of a dike is quantified in this research as the residual strength, which is the time between initial damage to a dike and dike breach. Unique experiments have been carried out in the Delta Flume of Deltares with a 8.5 m high dike with a clay liner and sand core. Below the still water level the dike was protected with a concrete block revetment and above the water level there was grass on the clay. The tests were carried out with large waves: Hs = 1.6 m. A formula to quantify the erosion of the clay layer as a function of time is derived by combining present and previous experimental results. A formula to quantify the erosion rate of the sand core is derived by combining the present experimental results with existing dune erosion models. The derived formulas make it possible to calculate the probability of failure of the typical Dutch coastal dike with wave attack. This is an important step in the understanding of dike safety.References
Burger; Stability of Oosterschelde dikes under wave action (in Dutch); Delft Hydraulics, report M2036, 1985.
Coeveld et al; Residual strength of dike after failure of cover layer; ICCE, Lisbon, 2004
Grondmechanica Delft 1993: PLUTO: Toepassing van het eindige elementeprogramma PLUTO in de geotechniek. Grondmechanica Delft rapport SE-57043
Hamer et al; Strength and loading of flood defences; Deltares publication 2011; SBW@Deltares.nl.
Klein Breteler, M., R. 't Hart and T. Stoutjesdijk; Influence of wave steepness on stability of placed block revetments; Proceedings of 30th ICCE conference, San Diego USA, 2006
PMid:16699078
Kruse G.A.M.; Build up and erosion of grass sods on dikes. GeoDelft report CO-307282/18 for Rijkswaterstaat DWW, Delft, 74 pp (in Dutch), 1993.
Kruse, G.A.M., J.D. Nieuwenhuis; Impact of weathering on erosion resistance of cohesive soil. Proc. 8th Congress IAEG Congress, Balkema, Rotterdam, pp.4299-4306, 1998.
Kruse G.A.M.; Study for guidelines for clay on dike slopes in the river areas. (in Dutch) Deltares rapport 1202512-000-GEO-0002, 110 pp (in Dutch), 2010.
Lefebre, G., K. Rohan; On the principal factors controlling erosivity of undisturbed clay. In: Proc. Symp. on Cohesive Shores, Natl. Res. Council Canada, pp 170-195, 1986.
Roelvink, D., A. Reiniers, A. van Dongeren, J. van Thiel de Vries, R. McCall, J. Lescinski; Modelling hurricane impact on beaches, dunes and barrier islands. Coastal engineering 2009.http://dx.doi.org/10.1016/j.coastaleng.2009.08.006
Steetzel, H.J.; Cross shore transport during storm surges, Ph.D. thesis Delft University of Technology 1993
Van Thiel de Vries, J.S.M.; Dune erosion during storm surges, Ph.D. thesis Delft University of technology 2009
Wellens, Borsboom and Van Gent. 3D simulation of wave interaction with permeable structures. ICCE 2010.
Wellens, P. and M.R.A. van Gent; wave induced setup in permeable structures; ICCE 2012.
Wenneker, Wellens and Gervelas (2010). Volume-of-Fluid model ComFLOW simulations of wave impacts on a dike. ICCE 2010.
Wolters et al; Dike erosion strength after initial damage; Coastal Structures Conference 2011, Yokohama, Japan
Wolters et al; Delta Flume tests to measure the strength of bolder clay of Wieringermeer dike (in Dutch); Deltares, report H4739, 2007.
Wouters, Residual strength of block revetment on clay (in Dutch), Delft Hydraulics, report H195, 1993
Verhey, H. and S. Giri; Reststerkte van een kleidijk met gras (rivierdijken); deel 4 in Reststerkte van dijken na initiƫle schade; SBW-reststerkte fase 1: inventarisatie, Deltares, report 1200393 / 1202122, 2010
Osman, A.O. and Thorne, C.R., Riverbank stability analysis. I: Theory. Journal of Hydraulic Engineering, ASCE, Vol. 114, No. 2, pp. 134-150, 1988.http://dx.doi.org/10.1061/(ASCE)0733-9429(1988)114:2(134)
Partheniades, E., 1965. Erosion and deposition of cohesive soils. Journal of Hydraulic division, 91(1), 105-138.