Beach nourishment with coarse sediments: An in-situ investigation on the issues of abrasion and chipping

Abstract

The use of coarse sediments for beach nourishment represents an alternative solution to structural interventions for the protection of coasts that are exposed to energetic waves. Predicting the mass loss of fill material due to abrasion and scouring is crucial for proper nourishment design, as it has implications for the littoral sediment budget and sediment stability under extreme wave conditions. The present study aims at characterising the typical abrasion and chipping of coarse sediments used for beach nourishments, providing insights into their correlation with the wave energy flux incident on the coast. Estimation of weight loss and roundness variability is obtained through RFID (Radio Frequency IDentification) sediment tracking technology, 3D scanning techniques, and Los Angeles tests. The 1 year and 7 months in-situ investigation was carried out at Marina di Pisa (Italy), an artificial beach where the size of supplied pebbles was significantly reduced after few months of typical wave climate, jeopardizing the sediment stability and the lifetime of the nourishment. The methodology could be applied to other beaches and lithologies to establish a database of weight loss useful for coastal managers and engineers.