Slope erosion control

Reinforced soil is a technology that is revolutionising civil engineering and infrastructure construction. This innovative practice combines the use of geosynthetic materials with natural soils or granular materials to improve performance and stability. What are reinforced soils? Reinforced soils are engineered structures consisting of a combination of geosynthetic material, such as geotextiles or geogrids, and natural soil or granular material. These materials are used to improve the load, drainage and stability characteristics of the soil. Reinforced soil is often used in situations where unstable or poor-quality soil requires reinforcement. They originate from construction intuitions dating back to antiquity, into which materials such as ropes, cloths or strong cloths were inserted to increase their resistance, especially to traction. This practice stems from the recognition of the fact that some materials, such as the concrete used today, exhibit high compressive strength but lower tensile strength. For this reason, in the 1960s in France, the idea was developed to insert metal elements into the earth mass in order to increase strength (mechanically stabilized earth). Thus, the elements that characterise modern reinforced soils are the reinforcing elements represented by the geogrids and the covering of the surface by means of bio-mats and bio-textiles, applied to retain the small particles of soil that may become detached due to physical and atmospheric agents, with the task, in our case of the pre-seeded products, of greening the façade with a better environmental integration and a better aesthetic effect. The Viresco® Satorpre-seeded biotextile for example, is used for its ability to deal with critical situations while also enhancing them from an aesthetic point of view. The use of Viresco® Sator in reinforced soil Once the reinforced soil has been designed taking into account all the morphological, geological, hydrogeological and geotechnical variables of the situation in which it is to be worked on, we proceed to its construction by first creating the work plan. Subsequently, metal formwork of an established height and inclination is put into position. The geogrid is laid on top of these, fixing it at the bottom and at adjacent points between them. Practicality and ease of handling also make the Viresco® Sator biotextile advantageous during the construction phase, and once the arrangement of all other materials has been completed, the pre-seeded biotextile is laid in such a way as to create a 10-15 cm flap at the bottom and at the top of the formwork. The metal stiffening rods of the formwork are then installed by piercing the biotextile according to the planned inclination. Before backfilling, at least 20 cm of fertile plant soil is laid close to the structure that is in contact with the bio-textile fabric, compacting it slightly. The remaining backfill soil can be recovered at the site or retrieved from external sources. The backfill soil must therefore be placed in layers and compacted in a manner appropriate to its constituent characteristics and the degree of humidity in which it is to be used, in order to avoid significant settlements at a later date after construction. In the case of reinforced soil over several levels, the operations described above are repeated until the top level of the work is reached. Once the construction phases have been completed, and depending on temperature and sunshine, it is recommended to water the turf frequently until it is fully settled. Viresco® Sator effectively retains the finer parts of the soil and ensures its greening while achieving truly aesthetic results. Advantages of using Viresco® Sator The possibility of customising the essences contained in the pre-seeded biotextile allows for the best vegetative performance in the most diverse environmental and climatic conditions. Furthermore, variations are also possible according to the customer's needs, up to and including floral arrangements and colour requirements. Given the difficulty in greening these surfaces (due to slope, substrate quality, water shortage, etc.), having such a refined and perfected technical solution such as Viresco® Sator is a non-negligible and much appreciated advantage. Reinforced soils, once they have been planted, have a well-ordered appearance, with healthy plants that fully fulfil their function from a physical, aesthetic and environmental point of view in terms of mitigating dust, noise and providing all the environmental health benefits that greenery can provide. Applied in all latitudes and geographical contexts, Viresco® now boasts 30 years of experience in geotechnics and reinforced soils, establishing itself as the best and most environmentally friendly solution for greening these types of soils.

Land preparation and maintenance before the autumn rains The sharp variations in climate that we have witnessed in recent months and the unpredictability associated with rainfall remind us with increasing urgency of the need and importance of maintaining our land in the best possible condition, in order to be ready to face not only extreme weather events of short duration, but also prolonged periods of bad weather. Despite the fact that nowadays it is more and more complex to predict these sudden climatic changes, autumn remains a period characterised by a large amount of precipitation; this is why it is essential to take preventive measures to ensure effective land preparation and maintenance. What are the main actions that should be taken to ensure successful soil preparation through preventing erosion? First of all, a regular flow in the watercourses must be ensured to protect their banks and embankments; It is necessary to carry out regular cleaning and maintenance; Areas that have been stripped of their original vegetation must be consolidated and greened; As well as reducing the use of concrete and land consumption. Different types of products for different types of situations As part of these activities to protect the land and prevent hydrogeological and erosion risk, various types of techniques and materials are generally used, including bio-mesh, geo-mesh, bio-mats, bio-textiles, geo-grids, geo-cells and geo-composites. Among this wide range, Virens' products are the only pre-seeded materials to be available both in a biodegradable version, i.e. temporary, and in a permanent version, i.e. with synthetic or metallic components. Having both the technical and vegetative solution for protecting, consolidating and greening surfaces in a single product is a considerable advantage in terms of the final result and operability of the intervention. Moreover, Virens products are customised in terms of seeds, fertiliser, etc., offering the possibility to cope with different situations with the best possible greening tools, such as bio-textiles, geo-textiles and geo-composites, all pre-seeded and designed to grass and vegetate any type of soil surface. Virens bio-textiles Our Viresco® Sator belongs to the biotextiles/biofelts category. Composed entirely of cellulose-derived fibres, it completely biodegrades in about 4-5 months, and being very thin (approx. 4mm) it adheres perfectly to the ground, preventing underlying seepage and offering excellent surface erosion protection. Our Viresco® Sator biotextile firmly retains seeds and fertiliser in the mesh, even under extreme conditions and inclinations, ensuring uniform greening and ideal ecological and landscape results. It is widely used for lining and protecting natural and artificial earthen slopes or embankments, including watercourses, for erosion control and the protection of seeds from runoff, as well as to ensure more favourable conditions for them to take root and grow. But that's not all, it is in fact recommended for all critical situations in construction, in landscaping, in the greening of landfills, reclaimed land, quarries, in geotechnics, as a fine particle retentor and as a matrix for grassing façades of strengthened and reinforced soil.   Virens Geomats Virmat belongs to the category of geo-mats, available in a heavier structured version (Virmat) and a lighter, more manageable version (Virmat L). These are three-dimensional, anti-erosive gripping geo-mats, which again are the only ones of this type of product that are pre-seeded. They consist of the combination of a high-tenacity, three-dimensional geo-mat with the Viresco pre-seeded biotextile, and provide robust slope protection on the one hand, and quick grassing and reinforced root anchorage to the soil and three-dimensional structure on the other. The result is a single, vigorous block capable of resisting the strongest erosive forces. Virmats can also be applied at very steep angles, up to 70°, and are able to perform an effective protective and vegetative action. A solution particularly suitable in all the situations and contexts listed above and in particular characterised by: slopes of significant height very steep slopes watercourses banks and beds very loose slopes poor soils poorly irrigated escarpments.  The RecsViresco geo-composite Also belonging to the category of geo-composites is RecsViresco, the latest addition to Virens' range of erosion control pre-seeded products. The result of combining a double-twist wire mesh with the pre-seeded Viresco® Sator biotextile, it is designed for erosion control and vegetative covering of steeply sloping soils or soils that are exposed to erosion and surface instability. The metal reinforcing element has a permanent function of containing and absorbing the deformational stresses that develop on the surface of the soil mass, but on its own it does not offer the necessary protection against erosion of the medium-to-fine fraction of the soil. To achieve this, the combination of pre-seeded biotextile with high greening capacity well anchored to the soil by the wire mesh itself is very useful. RecsViresco is used for: immediate erosion control of the slope surface and fine soil parts;  regular and uniform plant establishment and growth;  erosion protection and soil seeding in a single step without the need for sowing before or after laying;  greater speed of execution of the work; excellent environmental compatibility from a physical-chemical point of view;  landscape improvement associated with the securing of critical slopes. The choice of Virens products may vary depending on the slope of the terrain, as it is necessary to diversify the proposal as the slope increases: Viresco® Sator works well on slopes up to 45 degrees. Virmat L works well on slopes up to 45-55 degrees. Virmat works well on slopes up to 55-70 degrees. RecsViresco works well on slopes up to 60-70 degrees.

What are Geomats? Three-dimensional geomats were developed in the 1960s and consist of synthetic filaments woven together and fused at the contact points with a thickness of approx. 2 cm, making them a very flexible, lightweight and easy-to-use material. They are used to control the erosion of slope surfaces caused mainly by atmospheric phenomena, such as water runoff and wind, and perform this function from the moment they are laid, thanks to the strength of the materials they are made of. They are highly durable and fall into the category of Turf/Earth Reinforcement Mats (TRMs). The role of geomats Three-dimensional geomats consist of an open structure with a high void ratio that allows vegetation to grow and establish itself without creating any obstacles. It is important to remember that a well-vegetated geomembrane slows down the flow velocity of water, but also of wind, and is capable of doubling resistance to water flows. For this reason, they are mainly used on earthen slopes, and prior to installation, adequate preparation of the intervention site is required by means of reprofiling the slopes and establishing a slope profile that is compatible with the geological characteristics of the site and the requirements of stability, safety and landscaping. Application of geomats  The geomats are usually applied after digging anchor trenches approx. 50 cm beyond the top of the slope, which can differ depending on the type of soil, the slope inclination, or the presence of watercourse banks, etc. Subsequently, the trenches, once the geomat has been laid and anchored, must be filled with soil and compacted. The geomats are then unrolled, taking care to maintain contact with the ground, anchoring and overlapping the rolls according to possible water flows. Geomats can be applied to: slopes of significant height very steep slopes watercourses banks and beds loose slopes poor soils poorly irrigated escarpments. Geomats are easy to lay and do not require specialised labour or technical equipment, and they do not suffer from corrosion the way metal products do. Virmat pre-seeded geomats They Virmat geomats are an evolution of traditional geomats: combined with pre-seeded biotextile Viresco® Sator fabric assembled in the lower part of the product, they are designed to offer the best performance on the market. This combination produces an effective protective action and an excellent vegetative result by permanently fixing seeds and fertilisers. The ability of pre-seeded three-dimensional geomats to retain a layer of vegetable soil at the top of the mat provides moisture and thermal protection to the seed contained in the underlying bio-textile, which in turn, prevents the loss of fine soil in all weather conditions and ensures perfect cover for vegetation.  Thus, on the one hand it provides robust slope protection from the outset, and on the other hand, it provides rapid grassing and reinforced anchoring of the roots to the soil and the three-dimensional structure, which is rendered invisible by the vegetation. The result is a single vigorous block that is resistant to erosive forces. In the case of traditional unseeded three-dimensional geomats, it is necessary to spread the seed underneath, before laying, or on top, after laying. With Virmat on the other hand, erosion control and seeding are achieved in one single solution, with lower costs and increased effectiveness.