Geotextile sand filled containers as coastal defence: South African experience

Geotextile sand filled containers (GSC) have rapidly become the preferred coastal defence on the east coast of South Africa. Their growth can be attributed to political, social and environmental factors. This paper details South African experiences and the observed performance of GSCs. The main failure mechanism of geotextile sand bag seawalls is identified to be the movement of sand within the bags. This movement is observed to be a result of insufficient filling, bag elongation and sand leaking. Through a review of local and international manufacturing and construction techniques we identify methods of reducing the internal movements of sediment. The observed performance of local bags provide a practical full scale validation of the physical model findings of Hornsey et al. (2011); Recio and Oumeraci (2007).