For embankments or bridge abutments to be effective, stability and longevity are key.
To provide support and be resistant to soil erosion from water run-off and adverse weather, they must be carefully planned and executed during construction works then maintained on completion.
A number of methods are available to deliver stable, long-lasting solutions, including: soil nailing – driving rods into the soil; rock reinforcements – placing large rocks on embankments to dissipate the weather’s impact by slowing water run off; and, most commonly, pile foundations – driving a series of columns into the ground.
Each of these methods makes hard engineering less visible, allowing structures to better blend into the natural environment. However, there can be significant cost and environmental implications to each.
An alternative, often simpler and more effective, method is to use geotextiles, geocell, or geogrids.
Layering these can reinforce and strengthen ground, supporting the stability and improving the longevity of an installation, while saving on costs, time and space and delivering environmental benefits.
Geotechnical solutions – such as geogrids, geocell, geotextile fabrics or geotextile membranes – are a cost-effective method both in terms of direct material costs and associated installation and labour costs. The products are budget-friendly to purchase and transport to site. They can then be layered to build strength, with backfill material of soil or stone placed and compacted, requiring limited labour and equipment.
As they do not require specialist trades or equipment, this also offers programme sequencing benefits, with less time required for installation. Additionally, as they do not require heavy plant or machinery, they are ideal for use in smaller or tighter spaces, or more remote locations which it would be challenging to bring equipment to.
These solutions offer environmental benefits too. By negating the need to purchase and transport heavy rock to site or use specialist plant to drill or drive piles on-site, they reduce carbon emissions. And like all geogrid, geocell or geotextile solutions, they can be seeded or planted to deliver an attractive green finish, blending into the surrounding area and creating a habitat for flora. Established vegetation can then further strengthen the ground, reducing erosion and reinforcing embankment stabilization.
Geogrids, geocell or geotextiles made from polyester, polypropylene or polyethylene are most common, and are recommended for steep slopes in particular, offering resistance to heat, light, soil conditions or attack by bacteria or fungi.
All types can be used on new developments or retrospectively in maintenance or repairs on existing sites.
As with any abutment or embankment stabilization technique, comprehensive prior planning and ground testing is vital. Investigations will need to be clear on ground strength, weather conditions, drainage requirements and the load-bearing capacity needed. Where drainage is required, non-woven geotextiles are optimal, offering permeability, while woven solutions are ideal for softer ground, offering greater load-bearing capacity. Ongoing checks and maintenance will then be necessary after construction is complete.
Combining geogrids and geotextiles is a high-quality, cost effective solution, delivering stable and long-lasting reinforcement to embankments and bridge abutments.
Stratec are experts in geotechnical products and solutions. Get in touch for more information or advice on how to optimise your projects.