Coastal protection and restoration

Rising sea levels combined with more frequent major climatic events such as tropical storms or hurricanes have been a constant threat for many years now.

Highly concerning, the impact of this phenomenon in many parts of the world is extremely critical, eroding land away and putting populations and infrastructure at risk.

Preventive solutions protecting populations and infrastructures

Terre Armée companies offer solutions to public authorities and land owners for the protection and restoration of shorelines, and developed land. At an early stage, our engineers will work with you in assessing the local situation and proposing preventive solutions to mitigate both current and future risks.

Common preventive solutions include constructing sea walls, bulkheads, dykes, groynes and breakwaters, complemented by revetment systems.

Sea walls

Sea walls are efficient structures to prevent coastal erosion and other damages caused by waves and storm surges. They are particularly well adapted when land use is at a premium such as exposed city fronts or when supporting vital transportation links.

Reinforced Earth® waterfront structures are designed and built to resist the combined forces of water and water borne debris which can be highly destructive during and after storms. Geosynthetic soil reinforcements are a logical choice of soil reinforcement exposed to sea water environment as well as to the possibly brackish water of estuaries.

Reinforced Earth® panels combined with proper backfill materials ensure adequate drainage, especially when the structures are subjected to rapid variations of sea levels due to high tidal amplitudes. Wave deflectors can be integrated into the panels.

T-Wall® and TechWall™ precast retaining walls can also be used for the construction of sea walls, allowing for construction under water in some siutuations.

Bulkheads

Bulkhead structures have two functions: retaining or preventing land slidings and protecting coastlines against damagees caused by wave action. They provide a well-defined separation between land and sea along protected shorelines, including in estuaries or marina basins.

Reinforced Earth®, T-Wall® and TechWall™ retaining walls solutions are well adapted to the construction of bulkheads.

Dykes

Dykes are sea defense structures used for the protection of low coast and coastal lands against floods as a result of tides, wave run-up or storm surges. The TerraDyke™ concept developed by Terre Armée is a customized engineered solution particularly well adapted to the construction of dykes.

This state-of-the-art technique is based on the use of geotextile tubes which constitute the core of the dykes. It is a soft solution offering the advantages of geosynthetic materials and locally available fill materials.

In addition to geotextile tubes, TerraDyke™ structures are composed of other geosynthetic components such as geotextiles, antiscour aprons and anchor tubes. Site specific primary and secondary armor layers will complement the design to provide the adequate surface protection against erosion caused by waves and currents.

In specific situations for which the footprint has to be minimized or for high structures, Reinforced Earth® dykes, either with vertical or steep faces, are the solution allowing for proper adaptation to site conditions.

Combined with deep in-situ waterproofing techniques, Reinforced Earth® embankments become efficient geo-barriers. This applies to new built structures and also to the raising or existing structures which may be required due to the raising level of seas.

Groynes and breakwaters

Groynes and breakwaters are commonly built structures for shoreline management. They serve different but complementary purposes as far as littoral transport is concerned. As for dykes, the TerraDyke™ is well adapted to such structures, specialized design allowing them to be adapted to site specificities and constraints.

Revetments and articulated concrete blocks

In areas that are exposed to strong and damaging hydraulic flows, “hard” revetments can be put in place that will allow for long term protection. Articulated Concrete Block (ACB) mattresses can also be installed to cover and protect shorelines as well as man-made structures such as dykes.

Under proper conditions, TechRevetment™ fabric formed concrete mattresses will provide for wave and scour protection. They can be installed in under water conditions.

Due to the severe hydraulic constraints met in coastal projects, our TerraTextile™ geotextiles are essential components of our solutions to cope with filtration and separation issues.

Reconstruction and rehabilitation of shorelines

When not anticipated and acted upon, sea movements can completely reshape landscapes and erode shorelines.

In such cases, solutions allowing for the reconstruction and rehabilitation of shorelines do exist. Our TerraDyke™ geotextile tubes and geotextile bags can be used to re-build shorelines.

Geosynthetic containers have proven to be an efficient way to build gravity standing structures that retain and stabilize granular materials such as sand. Once buried, these structures provide for a natural rendering while protecting the shoreline from erosion.