Maccaferri managed to stop the erosion of a man-made lake in Lagos using Reno Mattress and Gabion products.
The client—Chevron made a request to protect the embankments of a man-made lake from erosion, in a residential estate in Lagos. The embankment consisted of imported fine sand that continuously eroded due to repetitive small wave action. The mild action from tidal and in and outflow of the lake also contributed to the erosion process.
As per the client’s request, the contractor designed a shoreline protection solution using gabion as an anchor and reno mattresses as a durable shoreline protection. The main design features of the solution circumscribed the inclusion of a gabion key made up of baskets used to form an anchor, buried below the ground line. Reno mattresses also featured prominently in the design as they were designed to be incorporated with the gabion anchors along the slope into the lake, below the lower water level.
Moreover, wires made of double-twisted mesh were chosen to feature in the as they are made of sturdy wire mattresses and 2.7 /3.2mm diameter wire (gabions). According to standard manufacturing procedures, the steel wire is heavily galvanized with Galfan a Zn-5% Aluminium alloy to ensure longevity and stability. Below the mattresses and gabion baskets, a geosynthetic filter cloth (a thermally bonded non-woven continuous filament geotextile) was placed to separate the soil from the stone basket and stone mattress. This prevents clogging of the mattresses and gabions, thereby maintaining a free flowing drainage system. The Gabions and Reno mattresses are filled with recommended stone sizes, minimum 75mm to maximum 150mm for best efficiency. The Gabion baskets and Reno mattresses are made up and connected to each other with specifically designed rings to ensure long term security.
After the envisioned design was implemented and completed in December 2011, Maccaferri received positive feedback from the client. Overall the aspect of the installation was said to be pleasing and respecting of the natural environmental features. The client was very pleased with how user-friendly the solution turned out to be, and also enjoyed Maccaferri’s periodical onsite assistance. Since the installation of Maccaferri’s solution the material used has proven to be durable. Until now it requires very limited maintenance, and when damaged it can easily be repaired. In this case study, Maccaferri was able to provide the client with all the requested solutions.
This project exemplifies how the combination of experience, professionalism, design software, technical support services and the aim of providing the best products in the market are indeed what sets Maccaferri apart from other engineering companies.
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For further technical information, please download the Case History.