For the love of our land.
South Africa must be better prepared for harsh storms and destructive floods
Global research shows that rising temperatures, caused by climate change, are altering our normal weather patterns, affecting coastlines, homes and infrastructure, as well as animals and plants, all over the world.
Global warming is increasing the frequency and intensity of storms, leading to disastrous flooding, which is intensified by rising sea levels. The effects of climate change on our environment will depend on how well we can adapt to ever-changing weather patterns and how much we can do to reduce global warming.
“We need to boost initiatives to protect our natural environment and keep coastal areas safe and attractive for everyone to enjoy for many years to come. The installation of well-engineered and durable coastal protection structures has never been more critical,” says Sefton Fripp, Managing Director, Fibertex SA, specialists in the manufacture and support of nonwovens and performance-based materials. “In addition to coastal rehabilitation, authorities need to look at ways to preserve the integrity of concrete structures that are affected by salt water, high temperatures and increased CO² levels and consider eco-friendly solutions that gently prevent soil erosion.
“South Africa needs to do all we can to prevent damage on our shorelines, to reinforce rivers and stop devastating flooding of populated areas.
“The Fibertex team, with decades of experience in coastal protection, works closely with authorities around the world designing advanced ecological solutions to protect shoreline areas and save buildings and infrastructure.
Coastal protection
Ageing seaside infrastructure, large waves and narrowing beach widths, all contribute to the urgent need for coastal rehabilitation, to ensure greater environmental protection.
Eco-friendly Fibertex products have been developed to withstand the effects of harsh wave action and are the perfect protection solution that allows beaches to retain their natural beauty.
The company manufactures FiberRock® Geosynthetic Sand Containers (GSC’s) which are used in the construction of efficient protection structures for coastal protection, erosion control, dune revetments and slope stabilisation, as well as for emergency protection in floods.
According to Fibertex specialists, using large sandbags as structural components of revetments is not a new trend in environmental protection, but the global Fibertex operation has made a substantial investment to design and manufacture the robust but soft FiberRock® GSC system, as an alternative to conventional rigid revetment structures.
The function of the lightweight and workable GSC system is to allow the free passage of water through the porous structure of the fabric and into the sand it carries, to absorb wave energy, while retaining the sand fill in the bag. This is unlike hard concrete structures, which predominantly protect by means of wave energy reflection, which could most likely have a negative long-term impact on adjacent structures.
FiberRock® GSC’s consist of a strong porous base fabric, which is mechanically needle-punched together with a coarse anti-abrasion and vandal resistant (AVL) cover layer. This durable fabric combination offers a flexible structure designed to retain a course fill medium – like sand – while allowing the free passage of water.
FiberRock® geotextile sand containers, which are manufactured from highly UV stabilised virgin Polypropylene (PP) fibres, can withstand the effects of repeated wave attacks in harsh coastal environments and are the perfect soft solution to beach rehabilitation and coastal protection.
The Fibertex team has given particular attention to critical factors in the development of this system, including abrasion, perforation, puncture and UV resistance, as well as tensile strength, elongation, permeability and drainage.
GSC material selection is critical to the long-term stability of the entire structure. In the case of coastal protection applications, where high energy bi-directional flow conditions are encountered, needle-punched staple fibre (SF) geotextiles are preferred. They have proven to be durable and the staple fibre geotextiles do not delaminate under the harsh flow conditions expected from wave action.
Fibertex has selected virgin Polypropylene fibre, with excellent frictional and low density characteristics, as the basis for manufacturing its GSC fabrics. Polypropylene has better performance to weight ratio than other more dense polymers, such as Polyester. Although Polyester is a strong, durable polymer, Polypropylene is preferred globally in the manufacture of heavy grade/voluminous GSC fabrics.
Other important properties for appropriate product selection include the design of the revetment structure, where environmental influences such as wave velocity, wave amplitude, wave period and wave direction need to be considered.
Size selection of GSC’s for each application is also critical. Smaller GSC’s might be sufficient for less harsh conditions, but direct wave attacks often require a larger, more stable FiberRock® GSC’s. The correct installation procedure and optimal filling and closure of GSC’s prevent free movement of the bag, to ensure the long-term stability of the structure.
Fibertex GSC’s, which are available in sizes between 200 kg and 4 000 kg, can be used in riverine, lagoon and coastal protection works, depending on specific environmental and engineering requirements of the designed structure.
The Fibertex team is currently working on a project in Umdloti, KwaZulu-Natal, to repair recent damage to the beach front embankment, which was damaged by tidal waves and heavy rain fall.
Most of the embankment eroded during the storm, leaving the main road above the bank vulnerable to collapse. The scope of the project is to rehabilitate the area and prevent tidal waves from creating further damage.
The solution is to install FiberRock® GSCs that will provide permanent retaining support to the embankment and barrier protection against tidal waves. In addition, this structure will create a coffer dam to prevent waves from causing further damage and protects the working area.
Fibertex SA has supplied FiberRock® GSC’s for many local projects, as well as large scale revetment structures in Africa, the Indian Ocean Islands, as well as in Europe and Australasia.
