Controlling surface erosion with biomats and geomats
Soil erosion is an almost inevitable natural phenomenon that has become a greater concern in recent years due to the worsening climate situation – in Italy, for example, 132 extreme weather events were recorded between January and July 2022, a higher number than the annual average over the last decade – combined with long periods of drought.
Strong winds, heavy rain, hail and runoff tend to remove the surface layer of exposed soils, which often include organic matter and seeds. Climate change facilitates erosion, making it not only inevitable but also hazardous if left uncontrolled.
It’s essential to counter or mitigate the phenomenon: soil provides us with food, biomass and raw materials; human activities take place on it and it’s part of the landscape and our cultural heritage.
Which structures are more subject to surface erosion?
The areas of application most affected by the erosive action of the climate are:
- slopes and the sides of landfills and contaminated sites, and those that have been grassed for appreciable aesthetic improvement;
- reinforced earth structures, more specifically terracing in vineyards and the embankments of canals or rivers;
- ascending/descending ramps from flyovers, tunnel entrances and noise barriers on roads and railways;
- dry, rocky slopes, of all angles, that shape the terrain of Italy.
The effects of surface erosion
The uncontrolled removal of the surface topsoil and the failure of vegetation to take root results in ‘thinning’ of the soil and a risk to the stability of sloping areas.
What can be done to prevent surface erosion?
We should begin by pointing out that a case-by-case assessment is required that considers many variables, such as the nature and uniformity of the soil, the slope gradient, the type of slope (dry or rocky) and the weather conditions in the area where intervention work is to be carried out.
In general, vegetation, whatever type it is, has a natural ability to protect soils from erosion. So the best course of action is to quickly encourage grassing and then apply biodegradable mats made of jute, straw, coconut and cellulose fibre, which can also be pre-seeded.
TeMa Geo Solutions recommends biomats such as Ecovermat, Ecovermat P and PC, and Ecovernet.
Alternatively, or combined with these, synthetic geomats, mainly made of polymer monofilaments, can be used.
Once laid, they are covered with another layer of soil: in this way, the roots of growing vegetation will become entangled with the geomat, creating an almost permanent erosion protection system.
Once again, TeMa Geo Solutions offers a wide range of geomats to choose from.
Uncertain about what to choose? We can help you. CONTACT US!
- Published in Erosion mats, GEO, Landfills, Reinforced earth structures, Reinforced earth structures - Erosion control, Roads
Reinforced earth structures as noise barriers
Hearing the noise of traffic outside your window all day long is irritating and distracting and, in the long term, also harmful to your health.
This is why the WHO and a number of laws govern the use of noise remediation systems in cities: the Framework Law no. 447 of 1995 for Italy and the European Directive on Environmental Noise no. 49/2022. If the cause of the noise cannot be addressed, the solution is to install protective barriers. Various kinds can be used, but in this case we focus on reinforced earth structures that require specific measures, which we discuss here.
For example, the Pedemontana Veneta is a new toll motorway in Italy: nearly 100 km long. Almost entirely in operation in the north-east of the Veneto region, the main route of this motorway runs through a deep trench in order to minimise the ‘territorial’ and environmental impact on the surrounding area. This means that long sloping areas of reinforced earth can be found along the sides of the motorway, with rows of trees and hedges for 58.61 km and green areas covering 1,333,410 square metres of hedgerows, groves, grassy slopes and tree-lined meadows.
A focus on noise with much regard for the landscape.
What do reinforced earth noise barriers consist of?
For this type of embankment with its typical trapezoidal shape, earth is used that will be covered by vegetation over time. Geosynthetic reinforcements and geogrids are added to support the earth, which already has good compressive strength. These are inserted horizontally into the ground and develop friction and tension that stabilise the structure, increasing its resistance to stress.
The TeMa Geo Solutions offer includes the X-Grid Pet PVC range of geogrids, with different resistance values, which are ideal for all kinds of contexts.
Another aspect to bear in mind is surface erosion of the soil: to counteract this, synthetic geomats are applied, also with a mulching function to encourage the growth of grass cover, or natural fibre bionets.
Also in this case, TeMa Geo Solutions offers a wide choice ranging from Ecovermat F Grass and Ecovernet FJ to the K-Mat range.
Why use a vegetation barrier as a protective noise barrier?
A vegetation barrier has an unquestionable ability to limit the spread of sound waves: some of them are absorbed, some reflected and some deflected. As a result, the amount of sound waves reaching the receiver is greatly reduced and noise can be dampened by several decibels.
The advantages of a reinforced earth sound-deadening barriera
Creating reinforced earth structures brings considerable advantages:
- it costs less because you can often use earth available on-site
- no special maintenance is required other than regular trimming.
- it helps the environment and integrates with it: the use of vegetation also reduces vehicle emissions by absorbing CO 2 and purifying the air.
Tunnels: the problem of groundwater inflows and water seepage
We are heading towards summer and finally, after two years of the pandemic, people will be making a mass exodus to tourist resorts again. Those who choose the mountains (or the sea, for example, the Ligurian Riviera) will find themselves passing through more than one tunnel.
Italy is one of the countries in Europe with the largest number of road tunnels. As for the TERN (TRANS-EUROPEAN ROAD NETWORK), there are currently about 610 road tunnels in operation covering a total length of about 710 km. The total number of tunnels in operation on ANAS (National Autonomous Roads Corporation) roads is 1,235 km, covering a total length of approximately 755 km.
Especially in older tunnels, you may notice large damp patches running high up the inside walls, or dangerous water stagnation on the ground. So, let’s see what exactly happens and how to prevent the problem.
When building tunnels today, tried and tested systems and materials exist. However, the problem that still needs to be addressed is the hydro-geological aspect, which highlights two main problems: groundwater inflows and water seepage.
By groundwater inflows, we mean the sudden flow of water from walls, coming from an aquifer that finds a new outlet. So, after detecting it, it becomes a priority to plan adequate drainage methods.
Water seepage, instead, refers to the passage of water due to its inherent capillary action or to the force of gravity.
The consequences of groundwater inflows and water seepage can be seen if problems are not tackled, or rather prevented, correctly.
Water is a major threat to structures such as tunnels, since it reduces the life of concrete cladding, causing structural deterioration, endangering systems and posing a hazard to road safety.
What can be done about water?
The ideal solution is to design with suitable drainage systems, with studded membranes and drainage geocomposites.
Maxistud and HDD by TeMa Geo Solutions are HDPE studded membranes with high compressive strength: the former is a 20 mm thermoformed membrane, whereas the latter is a 10 mm membrane bonded to a non-woven geotextile, available in different weights and increasing compressive strengths.
Drainage geocomposites such as Q-Drain ZW5 60 20P TG, 5mm thick with a monofilament core, and a nonwoven fabric can also be used.
The choice of product and the thickness depends on conditions regarding groundwater inflow and the relative risk of water seepage.
Controlled landfills and the importance of isolating them
Landfills for inert, non-hazardous and hazardous waste are governed by specific laws in each country, which set out precise regulations on the construction and maintenance of these sites.
As they are virtually in the ground and designed for certain types of waste, they must meet environmental and safety standards.
Let’s take a look at everything in detail.
The risks of not isolating them
Assuming that proper disposal is essential, many types of waste can take years, even decades, to disintegrate and complete natural decomposition processes. At this stage, they produce a large amount of slurry, such as leachate, which is extremely contaminating for the soil and for groundwater.
Moreover, biogases are also produced, mainly methane and carbon dioxide, due to the breakdown of organic material, which must be controlled and could be used to produce renewable energy.
How to isolate them
Controlled landfills need to be isolated from the ground that hosts them, but to be safe they need to fulfil different functions.
Surface erosion control
Vegetation naturally protects the ground from erosion by weather conditions such as wind and rain, which would cause subsidence. While waiting for grassing to protect the sides and surface of the landfill, anti-erosion geomats, in a biodegradable and synthetic version, can be chosen according to needs.
TeMa Geo Solutions offers a wide range to choose from, which can be browsed here.
Reinforcement
A landfill site is sometimes designed and built on more or less steep slopes. If a slope is steep and the ground is unable to support itself, retaining grids need to be installed in order to prevent slippage, which would expose and damage lower layers. View all our solutions.
Drainage
Specific products, drainage geocomposites, can be used for the drainage of rainwater and leachate, which inevitably builds up and must be kept away from the ground.
Barrier
Bentonite-based products, such as Barrier Bento, allow the area to be waterproofed, including walls with high slopes and the bottom.
Capping
Landfills also have a final cover that must meet precise criteria. These include isolating waste from the ground and surface erosion control. However, minimising water seepage and blending into the landscape are equally important.
New solutions in road construction and/or repairs
The safety of road infrastructures is the main goal, and maintenance work – whether preventive or supplementary – is systematic.
Road surfaces withstand heavy traffic loads and atmospheric changes with significant variations in temperature. Constant maintenance is therefore required in order to ensure even surfaces and the stability of structural elements.
Let’s look at the main factors involved in building new roads or maintaining roads.
Controlling surface erosion
Erosion is largely due to freeze/thaw cycles, which make asphalt less elastic and therefore more prone to internal voids. Such voids allow water to penetrate into underlying layers, gradually eroding the structure.
In addition, heavy traffic loads, especially heavy vehicles, cause deformation of the surface layers: this results in water penetration, which “softens” the structure and makes it less resistant.
Anti-capillary drainage
The water capillarity, i.e. the ability of liquids to move in micro-spaces even against the force of gravity, is a rather complex concept closely monitored in the construction industry. With the help of pressures exerted on lower layers, water rises upwards, dragging the finer components of materials with it and causing deformation.
It is therefore necessary to provide a drainage geocomposite, a three-dimensional membrane obtained by bonding two or more synthetic components in order to convey fluids to the exterior and prevent them from rising.
You can discover all our solutions here.
Reinforcement
It may sometimes be necessary to install reinforcement grids, especially if there is a more or less pronounced slope that would cause a road shoulder to slide downwards.
The choice of the most suitable type of reinforcement, and therefore also of the position of the geogrid in the layering, clearly depends on the problems to be faced i.e. reinforcing the surface area to limit the spread of cracks to underlying layers, improving the load-bearing capacity and reducing the stresses transmitted to lower layers, or providing a separation (and anti-contamination) function.
Discover all our solutions here.
Stabilisation
During intervention works, softer soils may be encountered, which may be subject to instability or even collapse in the early stages of intervention works. Even if this should not jeopardise the feasibility of the works, there is still the risk that the minimum legal safety requirements will be compromised.
Also in this case, geosynthetic products are the solution to the problem, as they absorb tensions at least until the intervention work achieves structural stability.
Discover the solutions in the X-Grid line here.
- Published in Drainage geocomposites and membranes, Erosion mats, GEO, Geogrids, Roads
Why don’t puddles form on soccer fields?
Let’s take a step back: nowadays, synthetic turf fields are the most cost-effective solution for football clubs, for both the first team and the youth sector. So, the construction of a synthetic system is an opportunity not to be missed. It is therefore important to construct a synthetic field that is ideal for the type of use and level of play.
TeMa staff can assist in the construction – especially in the design phase – to define the characteristics of the synthetic turf field. We are very familiar with the different layers it is made of (sub-base, turf and sand, rubber or natural infill) and its various features recommended by experience depending on different climatic conditions. The initial step is also important for determining the procedure that any club – in almost all cases through the municipality, the owner – needs to follow in order to construct the most suitable synthetic field in terms of type and frequency of use.
The secret is…
…drainage. Having a quality sub-base is even more important than the surface turf. This is where the experience of TeMa steps in with the company’s drainage solutions, developed on 4 continents. They guarantee the timely disposal of water in the quickest possible time and the use of the field even in severe weather conditions.
Drainage of a synthetic turf field
On synthetic turf fields water drainage is horizontal: after stabilising and levelling the surface, an impermeable membrane is applied that prevents liquids from penetrating into the ground below, conveying them to the channels on the long sides of the field.
This prevents water from stagnating on the surface of the field, avoiding puddles and the removal of surface material.
Natural or synthetic turf for the field?
A natural grass surface requires more maintenance and higher costs: it needs to be cut at regular intervals, treated, fertilised and watered. Moreover, weather conditions may affect the use of the field.
By contrast, synthetic turf is more resistant to weather conditions. It can also be used intensively all the time, regardless of the season and requires much less maintenance: it only needs to be “combed” regularly to revitalise the turf.
In addition to the (much) shorter construction time, a factor that tends to make synthetic turf preferable to natural turf is its permeable capacity: the control over water filtration is clearly superior and the sub-base is designed to drain excess water during heavy rainfall and/or store it. This makes it easier to maintain favourable conditions for both the game and the durability of the field, while also protecting the health of the players.
What makes the field so even and linear?
Drainage geocomposites provide maximum performance.
Q-Drain ZW8 Football consists of a monofilament core bonded with two non-woven fabrics, to which a PE membrane can be added if required.
Q-Drain ZW8 WP Football, ideal for horizontal drainage applications, consists of a monofilament core bonded with a non-woven fabric and a waterproofing film.
To support these products, we recommend T-Kanal Football, a cement channel for perimeter drainage that contains a special drainage membrane. The system is made complete with a grid, fixings and T-Tape, for joining the rolls during installation.
- Published in GEO, Synthetic turf soccer fields - Accessories
The importance of geogrids in reinforced earth structures
In recent years, reinforced earth structures have been particularly popular in projects due to their excellent functional and aesthetic importance in the residential building and public building industries.
Such intervention works achieve the best results by allowing the soil and geosynthetics to “work in synergy”, each one with its own features of ensuring the stability of the work as a whole.
It’s easy to see the high environmental value of such solutions, but let’s take a closer look at the two major factors in reinforced soil works. In this way, we can understand how and why, working together, they lead to amazing results, also in aesthetic terms.
What are reinforced earth structures?
They are structural intervention works in various gradients and dimensions aimed at retention and/or stabilisation. We can identify a few main areas of application:
- Road and railway embankments.
- Restoration and consolidation of collapsed soil on a road.
- Construction of ramps for ascending and descending flyovers.
- Canal or river bank elevations.
- Rockfall barriers.
- Noise barriers along roads or railways.
- Widening of elevated car parks.
- Construction of terracing systems in vineyards.
- Soil consolidation at tunnel entrances.
What are geogrids and why are they often the best solution?
Soil has the intrinsic features of friction and compressive strength, but practically no tensile strength. This is not enough to ensure the stability of a structure.
Major slopes, weather conditions, proximity to embankments, etc. can erode soil, causing landslides and subsidence. For reinforced earth structures, it’s therefore necessary to use geogrids, two-dimensional structures horizontally inserted into soil, which integrate with it without deforming. Their open-mesh structure develops “passive” resistance, thereby increasing the stabilising effect.
This bonding exploits the abilities of the two construction elements, making the entire structure more efficient.
Naturally, the feasibility of retaining works needs to consider:
- the intrinsic characteristics of the soil, such as grain size, the degree of thickening and shear strength, as well as the dilatancy phenomenon;
- the characteristics of the geogrids, such as tensile strength and stiffness, the use of raw materials (polymers) that can also withstand harsh chemical and physical conditions (attacks by chemical agents, soil pH, etc.), and the appropriate geometric structure.
Greening
Eventually, grass will grow and none of the intervention work will be visible: a really attractive and natural reinforced structure. In addition to its aesthetic function, greening also plays an important role in helping the natural friction of soil.
Find out more about our products here.
Embankments in home gardens: small colourful islands
Made of masonry alone, embellished with different types and colours of plants and flowers, and of varying heights, embankments are often part of public buildings in parks and squares, but also a distinctive feature of private gardens. In the urban construction context, embankments can be borders for roadside verges, steps and flowerbeds, reaching a relatively low height, almost always less than 1 metre.
The provide a very attractive and organised visual effect and can be customised with the colours and types of plants you prefer. However, in order to achieve adequate stability for such intervention work, regulations require certain specifications to bear in mind for their construction.
A short and simple recap: let’s start by understanding what they are and how they are built.
What are embankments?
Embankments are accumulations of earth that form more or less evident differences in the level of the ground and can be natural or artificial. Natural embankments are caused and possibly accentuated by landslides, whereas artificial ones are man-made and consist of an earth fill supported by a wall, often in order to highlight the difference in level.
The risk of landslides
As mounds of earth, especially if they are of a certain height, embankments can be severely tested by atmospheric events, resulting in erosion and runoff due to rainwater.
Various characteristic elements can therefore be recognised:
- drainage and runoff systems in the underlying area where all rainwater accumulates;
- support and reinforcement of slopes, the part most susceptible to erosion;
- substrates and erosion control systems to allow plants to grow in the best conditions by sheltering the topsoil from the effects of the wind, sun and rain until the plants have become strong and well-rooted.
Block retaining walls and reinforcement grids
In order to prevent soil erosion or irrigation, embankments are reinforced with retaining walls in a combination of concrete blocks and geogrids, which meet geotechnical, building and architectural requirements.
TeMa Geo Solutions has the right products to create this type of construction.
For soil reinforcement we suggest X-Grid, reinforcement geogrids, which are knitted uniaxial geogrids made of high tenacity polyester yarns covered with a protective PVC layer.
For retaining walls, the range includes T-Block, a single concrete block for building reinforced walls.
The special feature of this product is the male/female joint, shaped directly on the block. This ensures maximum connection between the blocks, thus avoiding the use of mechanical fasteners, glue or mortar and making the wall stronger and more resistant to damage.
Find here all the specifications of the products mentioned.
Protecting the vineyard landscape: tried-and-tested technologies… sitting lightly in the field.
The photo conjures up a lofty tale: “Autumn arrives and with it, the first rains, days draw in, the temperature starts to drop and, above all… it’s harvest time!”
We’re in the eastern corner of the Veneto region, the Prosecco hills have outdone themselves once again this year and a steady stream of grape-laden trailers continue to roll past on their way to the wineries. But this year’s harvest has had to contend with rather uncertain weather patterns: frosts in late spring, persistent rain interspersed with dry spells, with violent storms and hail over summer.
These conditions certainly don’t help the soil, putting it at risk of slips, subsidence and erosion. But if we apply TeMa Geo Solutions’ modern technologies and materials designed for this very purpose, we can protect the land from damage and, what’s more, do it in a sustainable way.
Not far from here, just a few kilometres from our headquarters, the Prosecco hills fall largely within the UNESCO World Heritage Site, meaning any measures must be strictly reconstructive, designed to protect the status quo and absolutely non-invasive: “gentle” on the environment.
TeMa Geo Solutions has come up with high-performance solutions to control the natural erosion of the soil, reinforce slopes, and drain water with:
- biodegradable fibre matting made from 100% natural jute such as Ecovernet® J500 XL and Ecovermat P Grass, which provide protection to stop soil being blown or washed away by the elements, and encourage vegetation;
- the K-Mat F erosion control synthetic geomat;
- reinforcement geogrids such as X-Grid PET PVC, which can withstand considerable stress levels;
- the Speedrain drainage geocomposite, which drains away water from the surrounding soil, stabilizing any surface slips.
Products
If you wish to receive more information, CONTACT US or take a look and download our “Vineyards” catalogue.
The new TeMa catalogues for environmental intervention works
TeMa Geo Solutions has presented two important publications summarising the products and technologies used in the field of major environmental works, which have enabled the Vittorio Veneto-based company to convince designers on all continents.
In addition to novelties, in the new catalogue we present solutions for intervention works in the environmental field that respect a new awareness towards protecting our natural heritage, which includes much hilly terrain and cultivated slopes. In recent years, these have been increasingly affected by climate changes that, in turn, have intensified some weather conditions.
We have included TeMa products for the major environmental works sector in the new Geosynthetic Products catalogue by TeMa Geo Solutions. In 48 pages, we present 29 products separated according to categories: drainage geocomposites, studded membranes, geonets, geogrids, geomats, biomats and geocomposites. They are all the result of research into new materials aimed at solving critical issues related to drainage, erosion control, filtration, separation, reinforcement, waterproofing and protection using dozens of applications (geotechnical and environmental) that the soil requires in certain hydrogeological and morphological situations.
Vineyards Catalogue
The same effective solutions with low environmental impact are offered in the Vineyards catalogue, specifically dedicated to safeguarding the vineyard heritage. It is, indeed, a centuries-old culture that has been a typical part of our lives for generations. We have only to consider the steps built by hand by farmers in the past. In the catalogue, we present various sustainable solutions, specifically for setting up vineyards and for their maintenance. The technological content of TeMa solutions goes hand-in-hand with its spirit of eco-compatibility, which has led to considerable savings, over the years, in terms of raw materials and CO₂ emissions into the air. TeMa has eliminated the use of millions of cubic metres of cement and inert materials with its “reinforced earth” technique, thus avoiding spreading thousands of tonnes of carbon dioxide and particulates that heavy vehicles would emit into the atmosphere in order to transport them.
The environmental choice of TeMa Geo
All this is accompanied by researching equally eco-compatible products that can be used in a natural context without spoiling it or changing its appearance. These are often 100% natural solutions which, despite being degradable over time, achieve their objective of settling the soil in a more than natural way.
Relying on TeMa Geo means making an environmental choice: you will discover that we have built four post-consumer plastic recycling plants to obtain, according to our own specifications, quality recycled raw materials to be used in specific percentages in our products.
To download the new catalogues and get an idea of our work philosophy, go to our Geosynthetics Catalogue and go to our Vineyards catalogue.
- Published in GEO
