Coastal protection in hydraulic engineering describes the construction of structures that defend shorelines, dunes, beaches and coastal infrastructure against wave attack, erosion and sea level rise. Without effective protection, sandy coasts can lose several metres of shoreline per year under storm conditions. Secutex® H, Secutex® HB and Secutex® Soft Rock deliver proven filter, separation and structural solutions for revetments, dune reinforcement and breakwaters.
Naue geosynthetic products are used wherever shoreline stability, long-term filter performance and economic efficiency are required.
Filter and separation layer below armour stone to prevent scour and soil particle loss
Engineered dunes with sand container core resistant to storm surge overtopping
Dyke core protection against wave erosion and overtopping damage
Filter layer beneath the underwater rock fill installed from a vessel
Coastal protection structures face demanding conditions from the first day of installation. Products must withstand heavy stone fill, tidal currents and wave impact during and after placement. Secutex H nonwoven geotextiles and Secutex HB sand mats are engineered for high mechanical resistance during installation and long-term service in saline, dynamic environments.
The dimensioning of geosynthetic coastal protection systems is based on recognised standards. Key design parameters include wave height, wave period, water depth, slope angle, subsoil grain size distribution and required filter stability coefficients. Our software tools as well as our engineering team support specifiers in selecting the correct product type and verifying compliance.
Jetty foundations, pier connections and scour protection
Practical advantages:
In coastal revetment systems, the subsoil loses fine particles under repeated wave action unless a filter layer retains them. Loss of fines causes progressive settlement, scour and structural failure of the armour layer. Secutex® H geotextiles act as the critical interface between the subsoil and the armour layer.
Key principle: A filter retains fine particles while allowing free water movement in both directions. Without a filter, armourstones settle progressively into the subsoil and the slope fails.
The correct product choice depends on application type, water depth, wave exposure and whether a structural function is required. The table below provides a clear eight-criterion selection guide for specifiers and site managers.
| Criterion | Secutex® H geotextile | Secutex® HB sand mat | Secutex® Soft Rock |
|---|---|---|---|
| Installation environment | On-land or shallow water revetments | Deep underwater (over 6 m) from a vessel | On-land, beach and shallow marine |
| Primary function | Filtration, separation, drainage | Filtration, separation, ballasted sinking | Structural element plus filter stability |
| Load-bearing/structural | No - filter layer only | No - filter layer only | Yes - replaces armourstone |
| Subsoil type | Sandy, gravelly or cohesive | Soft seabed, sandy or mixed | Sandy or granular fill inside container |
| Wave/current exposure | Moderate - beneath armourstone | High - stable in tidal currents during installation | High - stable against wave overtopping |
| Typical applications | Revetments, dike slopes, beach fills | Breakwaters, groynes, harbours | Dune reinforcement, emergency protection |
| Local material use | Not applicable | Not applicable | Yes - local sand fill reduces transport |
| Applicable standard | BAW TLG 2018, EN 13253 | BAW TLG 2018, EAG-GTD | EAK, BS 6349, EN ISO 10318 |
Long-term shoreline stability
Secutex® products prevent progressive erosion by retaining fine particles and maintaining revetment integrity under repeated wave action. Structures protected with Naue geosynthetics have demonstrated service lives exceeding 25 years.
Faster installation, local material use
Secutex® HB sand mat rolls are deployed from a work vessel using a long-arm excavator. This decouples filter layer installation from breakwater construction, shortening the required weather window.
Secutex® Soft Rock containers are filled with locally available sand on site, which reduces the need for expensive imported quarried rock.
Engineering confidence
All Naue coastal geosynthetics are tested and certified in accordance with applicable standards including BAW TLG 2018, EN 13253 and EAG-GTD. The Federal Institute for Hydraulic Engineering (BAW, Karlsruhe) has contributed to stability calculations for Naue-based coastal structures.
Coastal protection in hydraulic engineering refers to the design and construction of structures that defend shorelines, beaches, dunes and coastal infrastructure against wave erosion, storm surge and sea level rise. Geosynthetics such as Secutex® H act as filter, separation and structural elements within revetments, dune systems and breakwaters. They replace or supplement natural armourstone where availability or cost is prohibitive.
Product selection depends on the application. For standard revetments and dike slopes, Secutex® H nonwoven geotextile provides filter and separation below armourstones. For underwater installation, Secutex® HB sand mat sinks reliably and provides stable filtration. Where armourstone is unavailable or costly, Secutex® Soft Rock containers filled with local sand form a robust structural and filter layer. You can get digital product selection support in the Naue SolutionFinder.
Naue products comply with EAK (Empfehlungen fuer die Ausfuehrung von Kuestenschutzbauwerken), EAG-GTD (Empfehlungen fuer den Einsatz von Geokunststoffen im Damm- und Deichbau), BAW TLG 2018, EN 13253 (geotextiles for erosion control) and EN ISO 10318. Secutex® HB fulfils BAW TLG 2018 Type A and B2 sand mat requirements. For UK projects, BS 6349 applies.
Where Secutex® Soft Rock containers are filled with locally sourced sand, the need for quarried armourstone is reduced or eliminated. Armourstone is often the largest cost item in remote or island locations. Faster installation also reduces the required weather window and plant hire costs.
Secutex® HB sand mats are supplied in roll format and deployed from a work vessel using a long-arm excavator and crossbeam. The quartz sand ballast allows the mat to sink to the seabed rapidly, even in current conditions. Installation is feasible at depths exceeding 6 m. Fender piles can be rammed through the mat after installation. Rock fill can be placed directly onto the mat without impairing the filter function.
Secutex® H and Secutex® HB are tested for filter efficiency, positional stability, erosion stability, robustness and flexibility in line with BAW TLG 2018 requirements. Pore water pressure and tensile strain under wave loading are analysed in stability calculations. The Federal Institute for Hydraulic Engineering (BAW, Karlsruhe) has provided specialist input on stability calculations for Naue-based coastal structures.
Yes. Reference projects include the Medmerry managed realignment in West Sussex, UK (24,300 m² of Secutex® HB), North Berwick West Links dune restoration in Scotland (850 Secutex® Soft Rock containers), Blyth South Beach dune reinforcement in Northumberland, and the Prerow Replacement Harbour on the Baltic Sea coast, Germany. Case studies are available on this page.
Filter stability is verified using grain size distribution data from the subsoil. The characteristic opening size (O90) of the geotextile must be compatible with the d90 and d50 values of the subsoil according to EAG-GTD and BAW TLG 2018 criteria. Naue’s engineering team can assist with filter stability calculations and product selection based on project-specific soil data.
Naue Secutex® products are manufactured from polypropylene or polyester fibres, which are chemically resistant to salt water, UV exposure and biological degradation. Field performance data and accelerated ageing studies indicate service lives exceeding 25 years in saline, tidal and wave-exposed environments. Specific durability data and material certificates are available on request via this contact form.
Naue Secutex® Soft Rock is a geotextile sand container for coastal protection, scour protection and riverbank stabilisation — supplied for the Asia-Pacific region with UV-stabilised nonwoven, double-seam construction and pre-manufactured filling ports.
Naue Secutex® H is a geotextile for separation and filtration in hydraulic engineering, coastal protection and waterway construction.