Innovative Solutions in Dike Construction and Rehabilitation

The field of dike construction and rehabilitation is shaped by complex challenges, ranging from flood defence to geological and biological influences. This page provides detailed insights into modern and proven methods for ensuring the stability and safety of dikes.

The focus is on the latest techniques for combating seepage, regressive erosion, damage caused by burrowing animals and decayed roots, as well as preventing suffusion and erosion on dike slopes. By using geosynthetic materials such as Bentofix® geosynthetic clay liners and Secutex® filter nonwovens, combined with structural reinforcements through geogrid-geotextile composites, solutions are presented that are based on years of experience and scientific research.

The goal is to tackle the current challenges in dike construction and to promote future-proof, sustainable methods that effectively protect dikes from a wide range of threats.

The Solution Against Seepage and Regressive Erosion in Dikes

Three-Zone Dike with Geosynthetic Clay Liners and Geotextile Filter Nonwovens

During prolonged flooding, water can seep through the dike body and emerge on the landside. This leads to the loss of fine-grained material and results in regressive erosion.

Seepage in dikes is minimised by using geosynthetic clay liners (Bentofix®). The Secutex® H geotextile filter nonwoven prevents fine-grained material from migrating from the dike core into the landside drainage layer, ensuring a pressure-free discharge. These materials are particularly suitable for dike rehabilitation, helping to reduce seepage water and enhance stability.

Advantages of the Solution with Sealing Liner and Hydraulic Engineering Nonwoven:

  • Effective Sealing: Bentofix® geosynthetic clay liners provide long-term seepage reduction, making them ideal for sandy-gravelly soils in existing dikes.

  • Reduction of Seepage Water Volumes: Minimises the risk of piping effects and instability caused by water saturation.

  • Increased Stability: The drainage layer supports dike dewatering, promotes soil consolidation, and reduces erosion.

  • Long-Term Safety: The use of Secutex® H filter nonwoven prevents fine particles from penetrating the drainage layer, maintains the dewatering function, and contributes to the longevity of the dike.

  • Availability: Suitable for dike rehabilitation, especially when traditional sealing materials are not available.

The Solution Against Seepage Caused by Burrowing Animal Damage and Decayed Roots in Dikes

Rehabilitation of Waterside Cavities in River Dikes

Prolonged flooding and damage caused by burrowing animals can create weak points in river dikes. Animals such as beavers dig tunnels, which, when saturated with water, can lead to structural weaknesses, dike breaches, or undercutting. Similar problems arise from decayed roots.

The rehabilitation involves filling cavities with earth materials and covering and sealing them with a geosynthetic clay liner (Bentofix®). Additionally, for damage caused by burrowing animals, the installation of a beaver protection mesh is recommended.

Advantages of the Solution with Bentonite Mats and Protective Mesh:

  • Effective Sealing: Use of Bentofix® geosynthetic clay liners to regulate water flow and prevent erosion.

  • Flexible Repair: Filling cavities with earth materials restores the dike’s original strength.

  • Protection Against Burrowing Animals: A beaver protection mesh prevents animals from penetrating the dike and minimises risks associated with burrowing activity.

  • Optimal Placement: The protection mesh is strategically installed below the crest and above the high-water level to ensure maximum effectiveness

  • Long-Term Safety: These measures contribute to the durability and stability of the dike by preventing internal erosion and the formation of seepage paths.

The Solution for Undermining (“Piping”) Caused by Suffusion (Internal Erosion) in Dikes

Preventive Measures Against Suffusion (“Piping”) in Dikes

During prolonged flooding, suffusion or “piping” can weaken the dike body. As water infiltrates, fine-grained materials are washed out, creating voids beneath the dike foundation, which can lead to dike breaches. This process seriously destabilises the dike’s internal structure.

The conversion of a single-zone dike into a three-zone dike with a waterside sealing apron and a landside drainage trench provides protection against suffusion. On the waterside, Bentofix® geosynthetic clay liners are used, while on the landside, a drainage trench wrapped in Secutex® filter nonwoven is implemented. Additionally, the load-bearing capacity can be enhanced with a Secugrid®/Combigrid® geogrid-reinforced base layer.

Advantages of Using Geosynthetic Materials

  • Reliable Sealing: Bentofix® geosynthetic clay liner at the dike toe regulates infiltrating water and prevents fine-grained material from being transported.

  • Effective Drainage: A landside drainage trench wrapped in Secutex® filter nonwoven prevents fine-grained material migration and stabilises the dike.
  • Improved Load-Bearing Capacity: The use of Secugrid®/Combigrid® geogrids enhances the dike’s stability and ensures safe accessibility even during flooding events.
  • Adaptable Design: The choice of the appropriate solution is based on careful planning, tailored to the specific conditions of the dike.
  • Long-Term Stability: The combined measures ensure the durable reinforcement of the dike and, together with Secugrid®/Combigrid® geogrids, prevent uneven settlements.

The Solution Against Erosion on the Waterside Dike Slope

Waterside Erosion Protection in Dike Rehabilitation

Erosion on the waterside slopes of river dikes during floods is caused by increased water pressure, flow velocity, and wave action. This leads to the detachment and displacement of soil material, resulting in settlements, washouts, and potentially dike breaches, which threaten the structural integrity of the dike.

To protect against this type of erosion, vegetation planting and revetments are used. An effective erosion protection system consists of a cover layer of riprap combined with a Secutex® H geotextile nonwoven, which provides both filtration and soil retention capabilities.

Advantages of the Solution with Hydraulic Engineering Nonwoven and Robust Cover Layer

  • Robust Cover Layer: The Naue Secutex® H hydraulic engineering nonwoven, combined with a ballast cover layer, withstands hydraulic forces and effectively protects against erosion.
  • Geotextile Filter: Secutex® H nonwoven provides excellent filtration, retaining soil material while allowing water to pass through. This layer ensures the erosion protection of a cover structure.
  • Effective Protection Measure: The combination of Secutex® H, stone reinforcements, and cover layers offers outstanding erosion protection.
  • Slope Stabilisation: This solution reduces external erosion and stabilises the dike slope.
  • Long-Term Integrity: The applied geotextiles contribute to the durability and structural stability of the dike.

The Solution for Dike Overtopping

Near-Surface Overtopping Protection for Dikes

When a river dike is overtopped, damage occurs due to water pressure and flow forces. These forces erode the dike crest, wash away material from the landside slope, and can scour the foundation at the landside dike toe. This leads to structural weaknesses and an increased risk of dike failure. Additionally, overtopping water can reach the landside, causing further erosion and flooding.

The solution is a near-surface overtopping protection system using Combigrid® (2-dimensional), a high-strength geogrid-geotextile composite. It is installed across the landside dike slope and fixed with ground anchors. In case of grass cover loss and topsoil erosion, a stable overtopping bed remains, ensuring high protection effectiveness against erosion of the dike core material.

Advantages of the Geogrid-Geotextile Composite Solution

  • Effective Erosion Control: The Naue Combigrid® geogrid-geotextile composite provides strong protection against erosion, even if the grass cover is lost.
  • Stable Overtopping Bed: Maintains structural integrity and protection even when the topsoil layer is eroded.
  • Low Implementation Effort: Easy and efficient installation with minimal effort while delivering high effectiveness.
  • Adaptability: Suitable for various dike designs and environments.
  • Long-Term Safety: Provides sustainable protection and minimises the risk of dike breaches and severe flooding.

The Erosion-Resistant Dike

The erosion-resistant dike features an integrated overtopping protection system that provides a high level of security. By using layered, encapsulated soil with Secutex® H nonwovens or Combigrid® geogrid-geotextile composites in an envelope method, failure due to overtopping—as seen in conventional unreinforced dikes—is prevented. This construction allows dikes to withstand hydraulic overload scenarios, even with steep slope inclinations.

Advantages of the Erosion-Resistant Dike Construction

  • Maximum Protection Level: The integrated overtopping protection system ensures optimal erosion resistance, maintaining a high level of security.

  • Prevention of Structural Failure: Unlike conventional unreinforced dikes, this system effectively prevents failure due to overtopping.
  • Optimised Material Utilisation: The use of Secutex® H nonwovens and Combigrid® geogrid-geotextile composites enhances stability and durability.
  • Adaptability to Challenging Conditions: Even in steep slopes and hydraulic overload situations, the dike remains stable.
  • Long-Term Security: Ensures lasting protection, reducing maintenance efforts and repair risks.

Advanced Dike Construction and Rehabilitation Techniques

Modern dike construction and rehabilitation techniques, incorporating geosynthetic materials and structural reinforcements, provide essential solutions for the challenges of flood protection. By using innovative Naue products such as Bentofix® geosynthetic clay liners, Secutex® H filter nonwovens, and Secugrid® and Combigrid® geogrids, the durability and stability of dikes are significantly enhanced.

These approaches play a crucial role in ensuring safety and protecting surrounding ecosystems and communities.