Processes affecting the hydraulic stability of coastal revetments made of geotextile sand containers

Softer and flexible protection alternatives, such as structures made of geotextile sand containers (GSC) are often used instead of hard coastal structures made of concrete or rubble material.Although the effect of the deformations of the sand containers is significant, no stability formula is available to account for those deformations. To achieve a better understanding of the processes that affect the stability of GSC-structures several types of hydraulic model experiments and analyses were performed. The processes investigated were: (i) wave-induced loads on the sand containers, (ii) wave induced flow on GSC-structures, (iii) internal movement of sand in the containers, (iv) variation of contact areas among neighbouring GSCs during wave action, (v) types of displacement of GSCs within a coastal structure and finally (vi) the effect of the deformations on the stability of GSC-structures. In addition, a flow model and two structural dynamic models were further developed, validated and applied towards a better understanding of the processes involved in the wave structure interaction. Based on these results a better understanding of the processes that affect the stability of coastal structures made of sand containers has been achieved.