Geotextile sand elements are used in various hydraulic structures. These sand elements consist of a closed geotextile, which is usually filled with locally mined sand. CUR reports 214 and 174 provide insight into these sand elements.
The geotextile used is a nonwoven, woven synthetic fabric or a combination of both, also known as (geo)composite. Geotextile sand elements are used as an alternative to loose sand in the core of hydraulic structures such as dams, dykes and groynes, or as an alternative to quarry stone. They can also be used as soil and bank protection.
Geotextile sand elements have the advantage that local material can be used and no quarry stone needs to be extracted and transported. Using locally mined sand saves on transport costs and reduces environmental impact. Using geotextile sand elements can be more financially favourable than using traditional construction methods. They can also provide technical advantages in execution. When applying these elements, the type of contract concluded with the contractor is also very important (allocation of responsibilities).
Geotextile sand elements exist in different types with different dimensions and functions:
- Geobags: Sandbags with a size of about 0.3 to 2 m3. They can be used to fill erosion pits, as flood barriers and as emergency dykes.
- Geomats: Flat sand elements divided into several cells/lanes that are filled separately. Geomats can serve as soil protection against erosion and, if necessary anchored at the top, as slope protection.
- Geotextile tubes: Long round geotextile sand elements. They can be used as core material for quays and dams (in shallow water) and as reinforcement of a dune base.
- Geotextile containers: Elements of approximately between 100 and 600 cubic metres. These elements are applicable as core material for embankments and dams (in deep water). They are placed with a splitting bucket.
Sandbags with a size between 2 and 100 cubic metres are not applied. There are currently no acceptable placement methods for these sizes.
CUR reports
CUR report 214 on geotextile sand elements was published in 2004: 'Geotextile sand elements'. In 2009, CUR published a revised edition of CUR Report 174: 'Geosynthetics in hydraulic engineering'. Geotextile sand elements are also emphatically covered in that report.