Bank reinforcement using geogrid systems is a well-proven way of constructing a durable shoreline. Geogrid systems protect the coastal area against erosion and deformation.
Geogrid application cases
Geogrid is a geocell structure of polymeric strips bonded among each other by strong weld joints in a chess order.
Geogrid helps:
- increase a coastal area functionality and reliability;
- maintain the required shoreline borders over a long period of time without any strengthening;
- protect banks against erosion;
- protect a shoreline against flooding.
Material selection
Various materials and techniques are used for strengthening natural and artificial water basin shorelines. Such applications may contain either natural or man-made materials. The natural ones include leaf wood beams and cocoa matting, and the man-made ones include metal and concrete piles.
Geogrids can be successfully used either jointly with natural and artificial materials, or separately. Bank reinforcement material selection is defined by the type of structure installed. Geogrid type, brand and other parameters are finalized based on a would-be system characteristics specified by the project design documentation.
The value of using geogrids:
- The service life of structures installed increases;
- Inter-repair spans increase;
- Construction time and cost reduce;
- Allows strengthening of the weak soil of the subgrade upper part.
Laying techniques
The installation area soil should be prepared before doing the job. First, the fertile soil layer and all protruding plant roots should be removed, along with rocks and stones that can damage a geogrid. If required, a certain part of soil can be cut to modify the slope angle. Then the slope should be compacted.
A drainage system may be required for swamp material areas and banks exposed to underflooding. Design of such systems often includes nonwoven materials that have high water permeability.
Installation
With prep completed, geogrids should be placed over the slope, then fixed and interlocked into one structure, thus forming a reinforcement system. Steel L-splash anchors are used to attach the structure to the soil. Their length and shape are selected depending on the area geological profile. 70 to 100 cm is the most common length.
The structure elements are connected by a pneumatic stapler thus making it a single piece. Once bound together, make sure the sides of all the modules are parallel and the body is firmly attached to the ground.
Then all the geogrid cells should be filled with soil or other material. If necessary, the coastal area may be landscaped, which would require sowing the soil with perennial plant seeds. Post filling, the material should be compacted.
Conclusions
Geogrid-assisted bank reinforcement is an effective way of constructing a reliable and durable coastal area strengthening structure. Geogrid installation does not require any special equipment. It effectively protects the shoreline from erosion and maintains its shape.
