Literature review Achilles-grant work relevancy for Dutch levees : SITO PS B&O Waterkeren

A review of the U.K. Achilles publications led to insights in clay deterioration process which are also relevant to Dutch clay slopes, including levees. These insights include deterioration in soil water retention curves, shear strength and an increase in hydraulic conductivity, which are all because of dry-wet cycles and subsequent cracking and micro-cracking. The influence on erosion of the slope surface was not covered by the Achilles program. Instabilities during severe precipitation events as experienced in the UK with railroad and road embankments and cuttings are not expected for Dutch levees, because they were built differently. The process described by the Achilles publications are however relevant for Dutch levee circumstances because clay deterioration can reduce the safety margin in geotechnical stability which might be necessary for flood protection. The negative effects on clay strength will increase if more severe drought occur in the future. The topic of clay deterioration will be addressed in the upcoming EU Bonsai project. This review is intended to provide input for the Bonsai program.