Dikes on Peat
‘Dikes on Peat’ is an innovative research project that Deltares is carrying out in collaboration with the Hoogheemraadschap Hollands Noorderkwartier water authority and Rijkswaterstaat. The aim is to develop a new calculation method specifically for the dikes around the Markermeer lake. There are many dikes on peat in the province of North Holland and little was known about these structures until now.
It was thought that dikes on peat might be stronger than previously assumed. That hypothesis has now been confirmed by concrete trial results. This innovative research project was organised in the run-up to the upgrading of the Markermeer dikes. Deltares coordinated five unique field trials, during which the strength of the subsurface was measured and recorded. A range of model tests were also conducted in the GeoCentrifuge. The findings from the field trials, analyses with DAM, numerical models, centrifuge and laboratory tests were brought together. The conclusion: peat is tough. On the basis of the results, it was concluded that the Markermeer dikes need less extensive upgrading in some places than had been assumed on the basis of previously available knowledge and computer models. In follow-up studies, the three parties involved worked on the development and application of the results from the Dikes on Peat project. The amended calculation method for the upgrading of the Markermeer dikes was delivered in late 2014.