How to strengthen slopes to combat erosion and landslides. Strengthening an area on a slope The soil is sliding, how to strengthen it

Planting on the terrace

Owners of plots with uneven terrain often face the problem of how to strengthen the slopes. The issue is solved in a variety of ways, including planting. At the same time, it is important not only to stop the destructive process, but also to integrate the slope into the overall design of the garden.

Methods of strengthening

In relatively flat areas there are ravines and hills, heterogeneity of micro- and mesorelief. In such areas, problems often arise associated with landslides and soil washout from slopes. Both linear and planar water erosion can cause great damage to the soil cover. A particular danger threatens unturfed slopes, which lack not only trees and shrubs, but also herbaceous vegetation.

There are quite a few ways to counteract erosion phenomena.

• On steep slopes, a system of flat terraces with retaining walls is installed.
• One of the effective methods of strengthening slopes can be the creation of a rock garden or rocky hill, while terracing the slope is complemented by planting soil-fixing ornamental plants.
• At large angles of inclination, metal gabion meshes filled with stone, as well as geogrids, cellular geogrids and geomats, into which mixtures of lawn grasses are sown, help.

But still, one of the most environmentally friendly ways to combat erosion processes is to stabilize the slopes by planting trees and shrubs that form a well-developed root system. This method is most effective when the slope is less than 25–30%. However, even on steeper slopes it is possible to plant using geogrid or geogrid, which helps to further strengthen the soil.

The mentioned method is used for afforestation of large areas in rugged terrain, for strengthening slopes during road construction, and for landscaping park areas and personal plots.

An example of the use of phytoplasty

Strengthening slopes by planting trees and shrubs- This is an area of ​​activity in which knowledge in the field of engineering biology and ecology, landscape design and dendrology may be necessary.

So, what plants will help stabilize the soil on slopes?

Volumetric root system

First of all, these are woody species with a branched, fairly voluminous root system, such as

• mountain ash,
• intermediate rowan,
• small-leaved linden,
• tall ash.

Strong fibrous roots that bind the soil well form:

• common bird cherry,
• Norway maple,
• field maple,
• ash maple,
• red maple and some others,
• most elms and beech trees.

Under certain conditions, a fibrous root system is also laid horse chestnut, silver birch And fluffy birch And some coniferous species: common larch, Scots pine, some firs, Although It should be noted that the nature of the root system of these breeds varies significantly.

A site with even a slight difference in relief can be transformed by a retaining wall decorated with perennials

To a lesser extent, plants with a taproot system, which, although going deep into the soil, are poorly branched, can solve this problem. These include:

• English oak and some other types of oak,
• black alder,
• Amur velvet,
• nuts,
• many hawthorns,
• pseudotuga Menzies,
• on soils with a light granulometric composition – apple, pear and plum trees.

Superficial root system

Species with shallow, underdeveloped roots effectively fix only the upper soil horizons on slopes, reducing the threat of erosion, but doing little to reduce the risk of landslides. This group of trees and shrubs includes:

• many ate
• poplars,
• aspen,
• red oak,
• white acacia,
• different types of serviceberry.

Shallow roots are also noted:

• at the Japanese scarlet,
• silver maple,
• maple Ginnala,
• cypress trees,
• thuja occidentalis,
• hemlock,
• at the goat willow,
• brittle willow,
• white willow and many others, but this “disadvantage” is more than compensated for by their high growth activity.

It is important to know

Plants with flat, shallow root systems are usually more susceptible to wind damage and may also suffer from lack of soil moisture, which is often observed on slopes. All this somewhat limits their use for soil consolidation.

Organizing a trail system on slopes can replace terracing

Shrubs

Many shrubs have a fairly powerful and branched root system:

• honeysuckle,
• suckers,
• and you,
• spirea,
• privet,
• barberries.

They are also successfully used to fix slopes:

• caragana tree,
• aralia,
• bladderworts,
• dereny,
• rose hips.

The slope is decorated and strengthened with wild roses

To strengthen and decorate steep slopes and retaining walls, planting creeping and creeping shrubs, as well as thicket-type perennials, which help create a dense or even continuous ground cover, are widely used.

Among the shrubs that will look most natural and decorative in such an environment, you should choose forms with a crown spread out or pressed to the ground, such as creeping willow And rock willow, horizontal cotoneaster And tiny cotoneaster, barberry Thunberg ‘Green Carpet’ or stephanandra incisifolia.

Important Details

The greatest anti-erosion effect is usually achieved by row planting across the slope, however, for decorative purposes, trees and shrubs can be planted in separate picturesque groups.

It is important to know

It should be taken into account that the nature of the root system of the same species varies significantly depending on the type of soil and ground on which they grow. Thus, many plants on soils with light mechanical composition develop a deeper, tap root system, and on highly compacted, as well as heavy, damp soils, a superficial root system.

There are quite a few tree and shrub species that form rooting shoots or root suckers. Thanks to this, they can relatively quickly fix the soil surface over a large area around the mother plant. This ability is possessed by:

• white derain,
• shoot sod,
• sea ​​buckthorn,
• gray alder,
• aspen,
• other poplars,
• common bird cherry,
• blackthorn.

The tendency of plants to form offspring increases significantly with mechanical damage to the root system, therefore, by loosening the tree trunk circle, this process can be enhanced.

In addition to the above plants, this feature is also distinguished by:

• staghorn sumac,
• white acacia,
• common raspberry,
• fragrant raspberries,
• cut blackberries and
• garden blackberry,
• silver goof,
• Eleven angustifolia,
• some rose hips,
• mountain ash,
• buckthorn laxative.

A number of species of trees and shrubs easily take root when propagated by green and woody stem cuttings, as well as root cuttings. By planting them in rows or staggered patterns in the soil on hillsides, steep river banks, road slopes and dams, you can quickly create plantings that effectively delay the development of erosion. Such plants include:

• gray alder,
• many types of willows and poplars,
• common barberry,
• Thunberg barberry,
• less – Forsythia intermediate, mountain ash, common hazel, mock orange, some dogwoods, lilacs and spirea.

Using mock orange ‘Aurea’ to decorate a slope

Lianas

To design and fix slopes, relief changes and retaining walls, you can use some vines, such as:

• lemongrass,
• parthenocissus,
• wood pliers,
• princes,
• ivy (in the southern regions of the country),
• climbing roses.

When grown on the ground, without high supports, they will act as ground cover crops.

Many people use them not only as soil-protective plantings, but also as effective decoration of slopes. varieties of climbing roses, cultivated as creeping, as well as ground cover roses with arched, drooping or whip-like shoots. They are, as a rule, characterized by abundant and rather long flowering, and in addition, they are very unpretentious and frost-resistant.

Coniferous ground cover

Quite unpretentious plants play a significant role in securing and decorating embankments and slopes. ground cover coniferous plants. Nurseries now offer a large selection of species and varieties creeping junipers, pines, spruces and other conifers, extremely diverse in bush shape, texture and shades of needles.

These can be widespread:

• Cossack juniper,
• m. horizontal
• m.scaly,
• m. ordinary, for example variety ‘Repanda’,
• mountain pine cultivars pressed to the ground, or
• openwork microbiota cross-paired.

By combining plants according to the color of their needles, you can create an original variegated carpet based on contrasts of green, bluish-blue and golden-yellow tones.

And all the rest

In addition to tree and shrub species, they are also planted on slopes.creeping and hanging perennials and subshrubs, such as:

• coin loosestrife,
• periwinkle,
• lamiastrum zelenchukova,
• creeping tenacious,
• ivy-shaped budra,
• wallsteinia trifoliate,
• pachysandra apex.

Herbaceous plants, of course, have less of a fixing effect on the soil, but can be used as a useful addition to planted woody species. In addition, many perennials perfectly decorate slopes.

For example, creeping types of phlox are very impressive:

• phlox subulate,
• phlox Douglas,
• star phlox,
• soddy phlox,
• snow phlox,
• dwarf phlox,
• their varieties that form dense turf.

Silvery spots diversify the appearance of slopes stachys woolly, tomentosa and Biberstein's jasmine, speckled jasmine, colored clumps of creeping tenacious, thymes, aubriet, arabis, sedum and other prostrate and carpet perennials.

These plants, planted taking into account their environmental characteristics, are well suited for securing, camouflaging and decorating small embankments and slopes in garden and cottage areas.

Choosing a style

It is well known that there are only two main garden styles: formal And free , and within each of them separate artistic movements are formed. Therefore, in relation to the tasks of designing slopes, we can talk about two stylistic settings. We have no choice but to choose between regular and landscape directions or try to combine them within one project.

The formal approach was widely used during the Renaissance, when terrace gardens became widespread in Italy. In most cases, they were a system of terraces, retaining walls, flights of stairs and ramps, organizing the slope into a decorative architectural, sculptural and plant composition, often using flowing water and numerous water devices. Modern options for terracing slopes, in fact, differ little fundamentally from those that have been tested for a long time.

The framework of the landscape style is perhaps more spacious. They allow the designer to work in a wide range from organizing simple group plantings of tree and shrub species or ground cover crops on slopes to constructing a slope landscape using modern geoplastic methods.

_________________________________________________

Often a construction site or vegetable garden is located on uneven terrain. This applies to ravines, slopes, and banks of reservoirs. Often such an area is subject to landslides. And areas on the banks of reservoirs are often mobile, which is explained by the nearby groundwater. That’s why it’s worth thinking about strengthening the slopes and slopes on your site.

Features of strengthening slopes of varying steepness

Various methods are used to strengthen slopes and slopes. When choosing them, the slope of the site, groundwater level, and geological features of the soil are taken into account. Don’t discount the risk of the area being washed away, which happens when water bodies overflow.

First, pay attention to the slope of your site. If the slope is small and medium (up to 8%), then the slope can be strengthened by planting shrubs and trees of vertical and horizontal action. Sometimes situations arise when it is impossible to sow the slopes of a site with plants. Then you can go the route of digging blocks of concrete, stones and logs into the ground. Such stone structures will also be an excellent decoration for the site.

If the size of the slopes is large (8-15%), it is worth thinking about the advisability of internal soil reinforcement and the use of artificial structures. These are geogrids, lawn gratings, gabion structures, geomats, geotextiles. Combining several options will allow you to increase the ability of the slope to withstand the load. It is advisable to fill geogrids and gabions with any material of your choice - concrete, pebbles or stones.

Plants for strengthening slopes

To strengthen inclined surfaces, choose plants that have a well-developed root system. It is recommended to plant them in special cellular reinforcement structures. The principle of strengthening a slope with plants is as follows. The roots will intertwine with the reinforcement structure, preventing soil erosion.

The leaders among plants used to strengthen the slopes of summer cottages are ground cover species. This particularly applies to junipers. In addition, perennials such as cedar, pine, snowberry, hawthorn, chaenomeles, lilac, rose hips, blackberries, fieldfare, quince, sea buckthorn, vinegar tree, deutzia, and tree peony are suitable.

Fences as a retaining wall

Slopes and slopes on a personal plot can be strengthened by installing a fence made of brick, concrete slabs, sandstone and limestone. Such structures have many advantages. Firstly, they are durable, secondly, they perfectly resist natural destructive factors without interfering with the growth of plants and garden crops, and thirdly, they require minimal care. In addition, you can decorate them by setting up a flower bed, adding a decorative staircase and arranging a composition with lanterns.

When building a fence to strengthen the dacha area, take into account some requirements: the presence of a solid foundation, the minimum height of the fence is one meter, the thickness of the structure is close to 1/3 of the height, the presence of a drainage system for draining rainwater from the slope, if possible, constructing a fortifying fence in several rows .

Strengthening the slope with stone

To strengthen the slopes at the dacha, they are dug into the ground with stones, strictly adhering to the direction - across the slope. When choosing the location of stones, take into account the type of soil and its condition. Select stones taking into account the appearance of the garden, because they should fit harmoniously into the overall picture of the area. For drainage, you can dig a tray to direct the flowing water down.

The method of strengthening with stones can be used on slopes with different levels of slope, including those with a large angle. Not only stones, but also logs and boards dug across the slope will help hold the soil. Wooden dies will also work.

Geotextiles for strengthening slopes

To protect the slope from landslides and destruction, you can use geotextiles - a non-woven material that is sold in rolls. It is made from polyester and polypropylene fibers by needlepunching.

Geotextiles have the following high qualities:

• Frost resistance;
• Resistance to aggressive environments;
• Ability to withstand large stretches, up to 120%;
• Not susceptible to fungi and mold;
• Does not rot;
• Does not tear or puncture;
• Water resistance;
• Easy to install and cut with a hand saw.

The shear strength of this material is quite high, and this helps the soil to withstand heavy loads that it itself cannot bear, that is, the soil receives increased bearing capacity. In addition, when strengthening the slopes on the site with geotextiles, mixing of soil layers when water drains is prevented. Geotextile material is suitable for strengthening slopes whose inclination reaches up to 60 degrees.

The procedure for laying geotextiles is as follows:

1. Level the surface to be strengthened.
2. If you fill the site flush with the surface, then remove the soil to a depth of 20-50 cm. Cover the excavation with geotextiles, pour gravel or crushed stone on top. Lay geotextiles on top again and fill with sand. Lay tiles or paving stones on it. For this you can use cement mortar.
3. When arranging a site that will be higher than the ground, lay geotextiles, maintaining an overlap of 20 cm. Make formwork around the perimeter. As in the first case, pour stone or sand onto the geotextile, then lay more geotextile material, then sand again and finally tiles.
4. Secure the parts of the geotextile that overlap with staples. You can also lay some bulk material along the seam.

Geomats for slopes and slopes

To prevent soil erosion, it is recommended to use geomats. This polymer material is similar in structure to a washcloth, which has many voids. It is made from layers of polypropylene gratings, they are superimposed on each other and connected thermally.

Geomats are resistant to ultraviolet radiation, water and aggressive environments, are environmentally friendly, non-toxic (can be laid near drinking water sources). This material does not lose its properties over a wide temperature range.

Geomat is suitable for strengthening steep slopes - about 70°. The roots of plants that grow on the site are intertwined with geomat fibers. The result is a strong system that protects against erosion. In addition, this way you can forget about weathering.

When laying geomats, adhere to the following instructions:

1. Level the site by first removing debris. When constructing a fill slope, compact the surface using a hand roller.
2. Dig a trench at the top and along the lower edge of the slope, which is about 30 cm deep. Do not forget to arrange drainage using trays and ditches to drain water down.
3. Roll out the roll and then cut if necessary.
4. Stretch the roll to avoid any unevenness or wrinkles. The material should fit tightly to the surface, repeating the profile of the slope.
5. Lay geomats with the smooth side down. The overlap in the longitudinal direction should be about 15 cm, and in the transverse direction - 20 cm.
6. Secure the upper edge of the geomat in the trench. Use anchor bolts or dowels. In addition, it will be possible to attach the material with wooden spikes driven into the ground. The number of anchors on an average slope reaches 2 anchors per 1 square meter of surface.
7. Secure the lower edges of the canvas to the bottom of the anchor trench, use the same fasteners as for fastening the upper edge of the geomats.
8. Fill the anchor trenches with soil, maintaining a layer of 2-5 cm. After this, it must be compacted.
9. If there is a risk of water drainage, backfill with crushed stone. It should have a fraction of 2-6 mm.
10. After this, sow the soil with seeds, using approximately 40 g of seeds per 1 square meter.

Geogrid for soil reinforcement

To reinforce soil on steep slopes (up to 70°), it is recommended to use geogrid - a grid with square cells. It is designed for the construction of buildings on soft soil. With small deformations, geogrids can withstand significant loads and are resistant to aggressive influences.

Features of the geogrid are as follows:

• The material is permeable over the entire surface;
• Environmentally safe;
• Able to follow the terrain of the site;
• Acts as a natural habitat for plants;
• Possibilities for increasing soil stability and strengthening;
• Ease of installation.

The procedure for laying mesh to strengthen slopes is as follows:

1. Level and compact the surface of the slope. Use hand rollers for this or you can do it manually.
2. Distribute the rolls along the length of the area. The height of the geogrid is usually determined during design, choosing depending on the load. Rolling out rolls can be done manually, as well as installing sheets. The geogrid is laid out end to end.
3. In addition, for rigid fixation of the structure, you can connect the canvases to each other using anchors with diameters of 3-5 mm. The fastening step is 1-1.5 m. If high wind loads prevail in the region, then use anchors in the form of U-shaped brackets.
4. Align the sheets with slight tension lengthwise. Make sure that the material adheres to the surface as tightly as possible.
5. After this, the geogrid is covered with heaps of crushed stone, then with stone, then with soil. The thickness of the backfilled layer must be at least 20 cm.
6. If the area covered with geogrid is large, then level the filled soil with a bulldozer. In the case of a small area, work manually.
7. If you have laid sod over geogrid and sowed grass for your lawn, water the area. In about a month, the root system will bind the soil and geogrid together.

Geogrid for soil stabilization

In order to combat slope deformation, a geogrid is most often used, which strengthens the soil and its downward movement and is more stable than a geogrid. Low load capacity soil is replaced with high load capacity soil. When stretched, the material forms a stable frame. It is fixed on the ground with filler - concrete, sand, crushed stone, soil.

Features of geogrid for strengthening slopes:

• Non-toxic material;
• Resistance to ultraviolet radiation and aggressive environments;
• Ability to pass water;
• The geogrid does not decompose and does not silt;
• Ability to follow the contour of the site's relief;
• Resistance to soil displacement during freezing, washing, thawing;
• Allows plants to germinate.

The process of strengthening slopes with geogrid looks like this:

1. Level the surface of the area, as in the previous options, mark the boundaries.
2. Install the anchor marks, which are 600-900 mm long, made of durable plastic or steel. Wooden pegs can be used as load-bearing anchors.
3. The anchor installation scheme is developed taking into account the steepness of the slopes and the hydrological conditions of the site. But in any case, the anchors are installed along the contour of the geogrid modules. The anchor fastening step is 1-2 meters.
4. Stretch the geogrid over the installed anchors. Lay the material from top to bottom.
5. It is necessary to place water-permeable geotextiles in the base for additional arrangement of the reinforcing layer. It is preferable to use non-woven geotextiles, which have a density of about 200-400 g/m.
6. To fill the cells of geogrids, it is customary to use crushed stone, concrete or plant soil. In the latter case, you can grow various plants or arrange a lawn.
7. All geogrid cells, except the outer ones, must be filled with an excess of at least 5 cm. This will protect the material from exposure to ultraviolet radiation.
8. At the last stage, the “pie” is compacted. For this purpose, rollers with pneumatic tires or vibratory rollers are used. The equipment should have sufficient weight, but do not overdo it so that a wave does not form on the surface of the geogrid. However, on slopes that are too steep, proceed manually.

Gabion structures for slopes

Gabions are an ecological modular system in the form of a mesh box with hexagonal cells for soil reinforcement. It is often used in conjunction with geogrids, geogrids and geotextiles. The material used is double twisted steel wire, which ensures high structural strength.

The qualities of gabion structures are:

• The metal mesh is able to withstand any load, tearing is excluded;
• High level of strength, since the design is very similar to a monolithic one;
• High water permeability;
• Over the years, the efficiency of gabions and soil compaction increase;
• Gabions allow plants to grow while restraining any soil movement.

Installing a gabion structure is not too difficult to do it yourself:

1. First, level the surface and fill it with sand. You can also use crushed stone.
2. Strengthen the lower gabions to the soil with rods 16-19 mm in diameter, driven into the corners.
3. Connect the gabions together. To do this, use a wire with a diameter of at least 3 mm. You can connect manually or automatically, similar to a stapler.
4. Fill the gabion frame with backfill. It is recommended to use a hard, heavy, water-resistant stone. The stones must be of high density and frost resistance. Thus, you should give preference to igneous rocks.
5. Place larger stones at the edge of the structure. Fill the basket itself with small ones. To ensure that the material fits tightly together, compact the top layer of stone before installing the lid.
6. If desired, you can make a homemade gabion structure. Such products are welded panels made in the form of a box made of stretched metal mesh.
7. Place homemade gabions on the slope, after removing the turf. Tie them together, fill the voids with backfill. Both crushed stone and cobblestones, as well as vegetable soil, are suitable. If soil was used, compact it and reseed it with grass. The result is a steel frame, which will support the slope.

Thus, the problem of slopes and steep slopes on your site should be addressed immediately. Fortunately, the modern market offers a lot of materials for strengthening the soil - geogrids, geogrids, geomats, geotextiles. But, in addition, do not forget about the good old techniques that our grandparents used - plant plants with a strong root system, use logs and stone blocks.

It is rare to find a garden plot with a perfectly flat surface. Somewhere there’s a stump, somewhere there’s a hole, and somewhere there’s even a slope, so what should you do, reconcile and adapt, get upset every time, or still try to level the land with your own hands? We offer options on how to make the ground surface flat, without the use of heavy “artillery”. If there are stumps on the site, then immediately determine for yourself whether they are bothering you. Stumps can be used as stumps, or they can be removed using a tractor or burned with saltpeter.

If you are concerned about voids in the ground, holes and a slight slope, then it will be enough to remove the top layer of soil and turf with a shovel, fill the voids with earth taken from elevated areas with a pitchfork, level the surface with a rake, throw the turf back and after 1-2 weeks walk along the surface again land with a rake.

If the slope is very small, but which does not allow, for example, to make a beautiful lawn, then it will be faster and less labor-intensive to use a steam cultivator. Walk it several times, first in one direction, then in the other, thus fluffing up the soil. Use a rake to level the surface and begin sowing lawn grass seeds. If you plan to make a flower bed in such an area, you can create an illusion. Level the surface with a rake and sow flowers of different heights, where tall beauties will grow at a lower level.

If you are leveling a small area with a large slope, then prepare pegs of the required length and install them along the perimeter of the area that needs to be leveled. Using a building level, make marks on the stakes to what height you need to pour or remove the soil, pull the thread, securing it to the marks. Remove the sod, transfer the soil with a shovel, return the sod to its place and level it.

If a large area is in poor condition with a slope, then most likely you will still have to use a bulldozer. However, before work, collect all debris, stones and remove the turf (fertile layer of soil). After leveling the area, return the turf and spread it over the surface with a rake.

You may have to start new soil if the soil under the turf is very clayey.

If the plot is on a steep slope, then even a bulldozer will not help make the surface level. Terracing is a great way to improve the landscape, hide the disadvantage of a slope and, if desired, make a garden bed. On a steep slope it is quite difficult not only to build something, but also to grow crops, because... from watering and rain, the soil will be washed away, exposing the root system of plants, and fertilizers will not be able to stay on the hill. You definitely need to make a drain.

Clear the area of ​​debris, remove the top layer of soil and install stakes horizontally every 1.5 m. Install vertical stakes according to the shape of the relief. Do not make the width of the terrace more than 1.5 m, for the convenience of cultivating the beds, and so as not to create large soil pressure on the support. Create easy steps between decks using retaining walls at high points.

It is better to strengthen the soil on a slope, especially if it contains sand. If the slope of the site is no more than 10º, then planting lawn grass, trees or shrubs with a strong root system (ivy, spirea, broom, etc.) will be sufficient to reinforce the soil. But on a steeper slope, it is necessary to strengthen the soil from erosion using special reinforcing structures - geogrid, geogrid or anti-erosion mat, log. Here are the main materials:

Geogrid is a convenient flexible reinforcing structure that can be used to strengthen soil on slopes in both vertical and horizontal positions. First you need to delimit the area, level and compact the soil on the slope. Lay (preferably, but not necessarily) geotextiles, lay geogrid from top to bottom and secure with anchors or drive in pegs. Fill the grid cells with crushed stone, cover with soil and sow lawn grass seeds.

Geomat or anti-erosion mat perfectly strengthens the soil on a slope if the angle of inclination is 50-70º, and also secures the root system of young shoots. This material is easy to work with because... it fits any slope topography. The geomat is laid with its smooth side to the ground, giving an overlap of 15-20 cm. The edges of the mat are fixed with anchors every 50-70 cm to a depth of 30 cm. Make sure that the material lies tightly and evenly on the ground, without waves. Next, fill the geomat with soil and sow lawn grass.

To strengthen the soil on a slope (slope angle up to 60º), you can use large and small stones or logs (boards). To do this, depressions are made in the soil and stones are placed in them very closely to each other, large ones at the base of the slope, smaller ones at the edge. If logs or boards are used, they are laid deep and across the slope.

It often happens that the site for construction and planting is located on uneven terrain: these can be slopes of varying steepness, ravines, and the banks of reservoirs. Particular difficulties arise on slopes that may be subject to landslides; areas on the banks of reservoirs and slopes of ravines are often mobile due to the clay underlying the top layer of soil. In order to strengthen the slopes, various methods are used, which are selected taking into account the slope, the proximity of groundwater, the likelihood of the area being washed away due to a flood of reservoirs, soil characteristics and other unfavorable natural factors.

First of all, the magnitude of the slope is taken into account. For small and medium slopes - up to 8% - you can strengthen the slope with vertical and horizontal plants, as well as trees. In many ways, the strengthening of inclined surfaces of a site is facilitated by plants with a developed root system, which can be specially planted in the cells of reinforcing structures. The root system of plants, intertwined with fasteners and reinforcement structures, strengthens the soil and prevents erosion and landslide processes.

Depending on the purpose of the slope, various strengthening systems are used.

For slopes above average - that is, from 8% to 15% - artificial structures in the form of biomats, lawn gratings, and geogrids are usually used. A greater slope involves the use of geogrids and gabion structures. But it is also possible to use the previous systems if the slope has a decorative function. Their connection increases the slope's ability to withstand loads.

But in some cases, the slopes cannot be sown with plants, and then they are strengthened with the help of logs, stones, ceramic and concrete blocks dug into the ground. Geogrids and gabions can also be used in the case of clay and rocky slopes when filled with concrete, stones, and pebbles.

All these methods help to stabilize the slopes through internal reinforcement, that is, “implanting” the frame of the reinforcing structure into the soil layer. The process of reinforcing slopes occurs either through reinforcing metal bolts - anchors, or by deepening the surface (like gabions), or by logs and buried stones driven into the slope.

All strengthening structures, in addition to fulfilling their direct purpose, also serve as decoration. With their help, you can create a variety of compositions from stones and plants that will make the slope not only strong, but also pleasing to the eye with its beauty.

Methods for strengthening slopes of varying steepness

To strengthen slopes of different slopes, the construction industry offers a variety of materials and structures. (Note: Slope is the fall of a surface, which is calculated by the ratio of the difference in height between two points on the ground to the distance between these points projected onto the horizontal (Fig.) or the tangent of the angle of inclination of the line terrain to the horizontal plane at a given point. For example, a rise of 15 m per 100 m of horizontal movement corresponds to a slope of 0.15 (15%).

Designing the strengthening of steep slopes can be divided into stages:

1. Calculation of total soil pressure: carried out visually or with the help of design engineers.
2. Selection of reinforcing material: made taking into account the slope and general properties of the soil; in cases of complex terrain with talus soils, it is better to consult with design engineers and builders.
3. Determination of the strengthening zone and choice of anchorage: made depending on the chosen reinforcement (see below), if there is a likelihood of landslides or other unfavorable factors: water discharge, erosion of the slope, etc., you can use combined fasteners, which is better to decide on after examining the soil by engineers.

(note: Anchor- this is a fastener that resembles an anchor in shape, for example, anchor bolts, etc.)

Ceramic blocks, stones

For various slopes, even quite large ones, including on slopes with the possibility of a landslide, a method is used to strengthen the surface with stones and logs dug deep into the mountain. If water flows down the slope, you should use a special tray to direct it into a certain channel so that it does not destroy the soil (Fig.)

Rice. An example of strengthening a collapsing slope using ceramic blocks: 1 - foundation soil; 2 - sand and gravel base; 3 - lying stone; 4 - turf layer; 5 - curb stone-bed; 6 - direction of mini-debris slide; 7 - direction of water flow; 8 - draining excess mudflow water; 9 - water flow into the drainage tray; 10 - tray; 11 - side stone; 12 -plants.

In some cases, the slope can be strengthened with stones dug into the ground (Fig.) To strengthen it, concrete blocks dug deep into the ground are used (Fig.)

Boards and logs dug across the slope, wooden dies dug into the ground, and so on will also help to hold the soil on the slope. The choice of a specific solution depends both on the style of the garden and on the condition of the surface and soil of the slope.

Geotextiles

Geotextiles are often used to protect slopes from landslides and destruction. The shear strength of geotextiles is much higher than that of soil. Due to this property, the combination of soil and geotextile can withstand a load much greater than that which the soil itself can withstand.

This material is very technologically advanced when carrying out work, which reduces time and costs.

Geotextiles are non-woven material in rolls made from polypropylene and polyester fibers using the needle-punched method. It has high strength and water permeability, increases the bearing capacity of soil foundations, protects soils from frost, prevents mixing of layers when water drains, and protects against erosion.

Basic properties of geotextiles:

• Not susceptible to aggressive environments, frost-resistant.
• Does not form by-products.
• Not susceptible to fungi and mold.
• Does not rot, does not decompose
• Accepts heavy loads due to elasticity and performs the function of reinforcement (note: Reinforcement is strengthening due to the introduction of the frame into the soil layer)
• Withstands large stretches - up to 120%
• Due to the filtering ability, soil does not get into the pores of the fabric
• High resistance to mechanical stress, tearing and puncture.
• Lightweight and compact, it reduces labor costs, transportation and storage costs.
• Does not absorb water.
• Easy to cut with hand and chain saw.
• Maintains permeability in the soil even under pressure and vibration.

Non-woven geotextile materials are used to strengthen slopes with an inclination angle of up to 60 degrees. The length of the anchoring zone is determined depending on the length of the slope and its height.

Laying geotextiles:

1. Before laying geotextiles, the surface of the slope must be leveled. The alignment process is worth monitoring.
2. If the site is filled flush with the surface, then the soil should be removed. Recess depth: 20-50 cm - determined during design. The excavation - both the bottom and the walls - are covered with geotextiles. A layer of crushed stone or gravel is poured on top. Geotextiles are laid on it again. Then sand is poured in and paving stones, decorative stones or tiles are laid on it. You can lay the tiles on cement mortar laid on top of sand.
3. If a site is planned above ground level (this decision is made by designers and civil engineers depending on the condition of the surface and the slope), then after leveling the surface, geotextiles are laid on the ground with an overlap of 20 cm. Formwork is installed along the perimeter of the surface to be strengthened. Sand or crushed stone is poured onto the geotextile, and the next layer of fabric is placed on top of it, on which sand is again poured. You need to lay cement mortar on the sand and lay tiles on it. You can do without cement mortar if the builders believe that the slope allows this. In this case, stone, tiles, paving stones, etc. are laid on top of the sand. The technology for laying geotextiles must be strictly observed.
4. Ensure that overlapping geotextile pieces are secured with spikes, staples, or by placing a small amount of fill material along the seams. Crutches and braces can be wooden or metal and have a length of about 20 cm.
5. Make sure that the geotextile is laid immediately before filling it with aggregate, especially during strong winds. Standard geotextile rolls range in width from 2 to 6 meters.

Geotextiles are used to reinforce the surface, preventing soil erosion and draining water from slopes.

Geomats

Geomats are used to combat soil erosion and landslides. Geomats support vegetation cover on slopes and slopes.

Geomat is a polymer material with a water-permeable structure. It is created by layers of polypropylene gratings, superimposed on each other and connected to each other by thermal means. In its structure, the geomat resembles a kind of washcloth with a large number of voids.

The structure of the geomat protects the top layer of soil and secures the roots of plants growing through it. The roots of sprouted plants intertwine with the fibers of the material and together with them form a strong system that strengthens the top layer of soil on slopes and slopes, protects against hydroerosion, weathering and landslides. There is a wide range of possibilities associated with the use of geomats: sowing with grasses, as well as filling structures with crushed stone and bitumen.

Geomat is used even on steep slopes. The use of this material allows for landscaping slopes and slopes with an inclination angle of up to 70°. In combination with geotextiles, geomats are used to strengthen and increase the bearing capacity of slopes.

Basic properties of geomats:

• UV resistant
• Resistant to aggressive environments and water
• Retain properties at temperatures - from -30°C to 100°C
• Have low flammability and low smoke levels
• Non-toxic, can be used in contact with drinking water - on slopes near a spring, for example.
• Allows you to maintain the natural appearance of the landscape
• Reduce construction time and cost due to ease of installation and installation, which does not require special skills

Laying geomats:

For anti-erosion protection of slopes, geomats are considered one of the most effective materials in terms of manufacturability and cost of construction.

A combined method of strengthening a slope with stones,

bonded with adhesive geotextiles.

If you want to strengthen the slope using a combined method, you should make masonry along the slope containing two layers of stones. Stones are scattered across the surface of the slope in rows - from bottom to top. The shape and origin of the stones can be different: granite blocks, boulders, unprocessed stones of various sizes: for example, granites, sandstones, slates, gabrs, etc.

It is important to select stone types that are suitable in their properties for use in a certain climatic zone, for example, frost resistance. Before use, stones must be washed, cleared of clay, etc. and dried. After this, they can be laid on the geomat. To attach the mat to the surface of the slope, metal anchors are used - pin nails measuring up to 30 cm in length.

The stones are connected with a porous geotextile fabric impregnated with glue, for example, Dornit fabric. Geotextile fabric is cut into strips and impregnated with glue. The use of fabric impregnated with glue as a binder when constructing masonry is technologically advanced and convenient. Its free placement between layers of stones will provide a large contact surface and ensure a reliable adhesive connection. The glue must provide a flexible connection of layers of stones, therefore polyurethane adhesive compositions are used.

Slope strengthening scheme:

1 - stones, 2 - layer of fabric soaked in glue.

Geogrid

Geogrid is often used to reinforce soil on steep slopes and slopes. Geogrid is a square cell grid designed for construction on soft soils. Glass geogrids

(from glass threads) and polyester are used as reinforcing elements to strengthen slopes.

Possessing high rigidity, geogrid can withstand significant loads with very low deformations. Special impregnation ensures the resistance of geogrids to aggressive influences.

Geogrids to control erosion and strengthen soil on the surface are laid on steep slopes - at an inclination angle of up to 70°.

Geogrid Features:

• Water permeable over the entire surface.
• Does not decompose, environmentally friendly.
• It follows the contour of the relief and creates a beautiful landscape due to the germination of plants.
• Creates a natural habitat for plants and insects.
• Increases soil stability and protects against corrosion.
• Allows the germination of plants, the root system of which, together with the lattice, strengthens the soil.
• It is transported folded and takes up a small volume.
• Easy to install.
• Not affected by aggressive environments.

Laying geogrids

If you do not remove the protective material from the created lawn for a month, the root system will form and bind the geogrid and soil into a single whole, which will serve to reinforce the slope. The geogrid under the layer of crushed stone and soil does not allow the layers above it to move, so the surface of the slope will not “sag” under loads. When the height of the grass cover reaches more than 3 cm, the geogrid is no longer visually visible. This is also important for protecting the geogrid from exposure to UV rays. The geogrid allows water and air to pass through, the rest of the grass rots under it, but mold and rot do not form under the structure. This technique is also used when improving a children's playground.

Geogrid

The most popular means of combating landslides and slope deformation at present is geogrid. It ensures the strength and stability of the slope and protects the soil from erosion. A geogrid installed on slopes strengthens and stabilizes the soil and prevents downward movement of the soil. Soil strengthening occurs by replacing the soil cover: instead of soil with a low load-bearing capacity, soil with a higher load-bearing capacity is used.

Geogrid is a frame structure consisting of strips of non-woven permeable material - geotextile, created on the basis of polyester fibers. A geogrid is used to protect construction soils and soil from erosive deformations in gully areas. When stretched, the geogrid forms a stable frame, which is fixed to the surface of the earth with filler. Sand, concrete, crushed stone and other materials are used as filler. Filling the grid with permeable materials increases the stability of the slopes, and the moisture in the cells promotes plant germination. One way to strengthen slopes is to use a geogrid filled with earth. The use of geogrid makes it possible to green slopes, protecting them from sliding. Compared to geogrid, geogrid is a stronger structure.

The geogrid is created from polyethylene tapes 1.5 mm thick, which are fastened in a checkerboard pattern with strong welds. The geogrid material is non-toxic, resistant to ultraviolet radiation, resistant to aggressive environments, including water of any composition, this allows it to maintain its characteristics for many years. The choice of geogrid height depends on the load on the slope and filler materials, and is taken during engineering design.

Features of geogrid:

• Passes water over the entire surface
• Not subject to decomposition
• Environmentally friendly
• Follows the contour of the relief
• Not subject to siltation
• Increases soil stability
• The resistance between the fill materials and the perforated cell wall provides resistance to upward movement when the filler freezes, thaws, and washes out of the cells.
• Allows the germination of plants, the root system of which, together with the lattice, stabilizes the soil. Creates a natural habitat for plants and insects.
• Transported folded and takes up small volume
• Reinforces the slope surface

Laying geogrids:

1. Make sure that the slope surface is level before installing geogrids.
2. According to the project, boundaries are marked.
3. According to the marks, anchors with a length of 600 - 900 mm made of high-strength plastic materials, metal or wood are installed. (The installation scheme of anchors, their material, and length are determined by engineering calculations depending on soil geological, hydrological conditions and slope steepness).
4. The geogrid is stretched over the installed anchors.
5. Water-permeable geotextiles can be laid in the base - it will serve as an additional reinforcing layer. A layer of non-woven geotextile with a density of 200-400 g/m should be laid between the geogrid and the surface of the slope. Soil, crushed stone and concrete with frost resistance of at least M200 are used as filler for geogrid cells.

   If the soil consists of gravel, compacted sand, or crushed stone, the geogrid can be laid directly on the ground immediately after leveling. Geogrids should be laid from top to bottom.

6. Check that the geogrids are secured to the ground and to each other using L-shaped mounting anchors with a diameter of 10-14 mm and a length of 50-120 cm, made of steel or high-strength plastic. Mounting anchors are used to fix the geogrid in an extended working position and connect the modules to each other. Anchors are installed along the contour of each module to ensure its correct tension in the form of a rectangle. Load-bearing anchors have a design similar to mounting ones and are used for fastening geogrids to the ground surface. Load-bearing anchors are installed evenly over the area in increments of 1-2 m. When protecting slopes from erosion, wooden pegs can also be used as load-bearing anchors.
7. After fixing the geogrid modules, the cells are filled (the filler can be crushed stone, stone, plant soil, etc.) Filling the geogrid cells is done in 2 stages:

   First stage: the outermost cells of each section are filled manually, after which the mounting anchors can be removed.

   Second stage: make sure that the remaining cells of the geogrid are filled in excess - at least 5 cm above them - this will also be needed to protect the grid from exposure to ultraviolet radiation.

8. The last stage is compaction. The size of compaction equipment depends on the capabilities of the soil and the angle of the slope. Make sure that the equipment used is of sufficient weight, as using equipment that is heavier than necessary will cause waves on the surface of the geogrid. If the soil is moistened, this will ensure maximum adhesion of the geogrid to the surface. Check how tightly the geogrid adheres to the slope.

Scheme for installing geogrid on a slope:

1. Geogrid
2. Geotextile fabric (for example, dornite)
3. Vegetable soil
4. Mounting anchors
5. Gutter

Compaction of the aggregate can be done with vibratory rollers, rollers on pneumatic tires, or manually, depending on the aggregate.

The big advantage is that the geogrid segments can be moved manually. They unfold quickly. Compaction does not always require technique. In cases of steep slopes, the last stage of installation, like the previous ones, can be done manually. The main thing is to check compliance with the installation technology.

Gabion structures

Under the influence of load, most soils are subject to displacement and disruption of the internal structure. The use of gabions will reinforce and strengthen the soil, increasing the stability of slopes of almost any slope.

Gabions are an ecological modular soil reinforcement system used to secure soil, slopes and slopes, and combat rockfalls. Often used in combination with geogrids, geotextiles, and geogrids.

Gabion (from Latin “wire basket”) is a module that is a mesh box, which is made of double-twisted steel wire, with hexagonal cells, divided into sections using diaphragms installed inside the gabions every meter along the length (Instead of a zinc coating, steel mesh wire can be coated with galfan, which is an alloy of zinc and aluminum).

Double twisted wire mesh ensures strength and uniformity

load distribution, prevents unwinding in case of mesh rupture. If gabions are used in an aggressive environment, galvanized wire with a sheath of polyvinyl chloride - PVC is used for the meshes. The PVC coating protects the wire and provides greater resistance to chemical, mechanical and corrosion damage. For greater structural strength, partitions can be made of mesh inside the cube, which gives the gabion additional rigidity.

Gabions are made not only in the form of a box, but also as a cylinder, mattress, etc. Gabion mattresses come in three sizes: 3x1x0.5 m, 4x2x0.5 m and 2x1x0.25 m. They are used to strengthen slopes. The covering of slopes made of gabion mattresses must have a reliable support made of gabion boxes or continue in the flat part of the slope (Fig.)

Cylindrical gabions are used on coastal slopes.

Gabions are used for the construction of retaining walls, landscaping, and protection against soil erosion. PVC-coated gabions are used to protect slopes from landslides and coastal collapse. Gabion structures made of natural stone in mesh containers strengthen unstable soils.

Features of gabion structures:

• Flexibility. Double torsion metal mesh with a breaking load of 3500-5000 kg/m resists any load without breaking. Structures made from gabions absorb soil settlement without destruction.
• The high strength of gabion structures is achieved due to the double torsion mesh and the strong connection of each gabion module with its neighbors. This combination makes the structures look like monolithic structures.
• High water permeability.
• Durability. Over the years, the effectiveness of gabion structures increases, since over time, plants grow through the gabions, their root system is strengthened, and the soil is compacted.
• Economical. Gabion structures are cheaper than other reinforcing systems. Savings when using gabion structures reach 50%.
• Environmental friendliness. Gabions do not interfere with the growth of plants that grow through the structure.
• Gabion structures retain any movement of the soil. Over time, the gabions are overgrown with grass and shrubs, which further strengthens the slopes.

Laying gabions

1. Make sure to level the surface and fill it with sand or crushed stone.
2. Check that the lower gabions are secured to the ground with rods with a diameter of 16 -19 mm driven into the corners.
3. Gabions are connected to each other with wire with a diameter of at least 3 mm. Gabions can be connected manually or using automatic staplers (Fig.)
4. Gabion frames are filled with hard, heavy stone of water-resistant rocks: pebbles, boulders, stone from quarries with dimensions that should exceed the size of the mesh cell by 1.5-2 times. The stones must have high density, strength, and frost resistance. Igneous rocks are most preferred. When filling box gabion frames, larger stones should be located at the edge of the mesh, and smaller ones should be inside the basket. Face stones should protrude from the cells. Mattress frames on slopes are filled with one-dimensional stone. To ensure that the stones fit tightly together, before installing the cover, the top layer of the stone is compacted using manual or mechanical tampers.

The slope can also be strengthened using homemade gabions. They may look like welded panels in the form of a box made of metal mesh stretched over frames. Gabions are laid on a slope with the turf removed, connected to each other, and the voids are filled with crushed stone, cobblestones or soil. If soil is used as backfill, it is compacted and seeded with grass. This creates a steel frame that supports the slope.

When erecting gabions on weak unstable soils and large surfaces, qualified engineering calculations of structures for shear, overturning, deformation, internal stresses and overall stability are required. Design decisions can take into account the possibility of stimulating plant growth.

Lawn grates

For small (up to 3%) and medium (up to 8%) slopes, lawn gratings can be used. Lawn gratings made of plastic give the grass surface high resistance to mechanical stress and are used to strengthen small slopes, terraces, etc.

The lawn grate consists of 400x600 mm modules, which can be assembled directly at the installation site using locks located on the edges of the modules. The assembled modules form a fabric that strengthens the grass cover, which, in turn, protects the soil from erosion.

Features of the lawn grate:

• Easy to install
• Ease of transportation and loading
• Withstand high loads
• Weather resistance
• Possibility of grass germination
• Maximum speed and ease of installation with a top connection.
• Anti-slip upper profile.
• UV resistant
• Identical hexagons allow uniform grass growth.
• The space between the connection of modules gives stability to the system in the presence of temperature differences.
• The holes between the cells allow free growth of roots and provide drainage in case of heavy rainfall.
• The top connection system allows for quick installation of the grating.

Laying the lawn grate:

1. Make sure: before installing lawn gratings, a layer of a mixture of sand and gravel 2-3 cm thick should be poured onto the surface, after which the surface should be leveled.
2. Make sure that large areas are marked, placing pegs approximately every 30 square meters.
3. Lawn grates are installed in rows or in a checkerboard pattern. Laying in a checkerboard pattern increases the stability of lawn gratings. Individual cells are connected to each other. The modules have a special connection at the top.
4. After installation, the cells are filled with turf for planting grass. Before planting, the turf needs to be watered. The level of the turf should be the same height as the top edge of the grates.
5. Filling the cells with substrate or turf is carried out in two stages - before sifting and after sifting. Before sifting, the area is thoroughly watered. After the herbs have been planted, the level of the turf should coincide with the top edge of the trellis in height.

Biomats

Slopes up to 45% slope can be strengthened with grasses vertically and horizontally. Some types of grass, thanks to their developed root system - up to 1.5-2 m in depth - strengthen vertical slopes. Other types of grasses, thanks to the rapid development of vegetative shoots, strengthen the slopes horizontally, creating a surface tightly intertwined with their roots. Third types of grasses add decorative properties.

When strengthening slopes with plants, it will take a certain time for the development of the root system, therefore, in combination with grasses, mechanical strengthening of slopes is used, which is done with biomats. On a slope whose inclination angle is 30% or more, it is recommended to strengthen the biomats with gabion mats, which are attached to the surface with special pins, at least 40-50 cm long.

Biomats are a multilayer fabric consisting of natural fibers superimposed on a thin layer of cellulose and reinforced with two layers of polypropylene photosensitive mesh or two layers of jute mesh. This fabric is stitched on both sides with polypropylene or jute thread. Based on the composition of the fibers, biomats are divided into three main types: biomats made from straw, from coconut fibers, mixed type from straw and coconut fibers.

Features of biomats:

• Eco-friendly. The decomposition of fibers helps fertilize the soil.
• A good means of protecting slopes from rain and wind.
• Create optimal conditions for rapid seed germination.
• Protect seeds from sun exposure, air temperature fluctuations, washout, etc.

Laying biomats:

1. Make sure to remove stones and level the surface.
2. Then the slope is covered with plant soil in a layer of no more than 10 cm.
3. Compact the plant soil with a hand roller.
4. Check that the upper part of the biomat is fixed to the surface of the slope using staples or stakes. The size of the staple is approximately 30 cm in length and 5 cm in width. The number and location of staples and stakes depends on the magnitude of the slope and the nature of the soil. After this, the roll is unwound and laid so that the cellulose layer touches the surface of the slope.
5. Make sure that the canvas adheres well to the ground and is secured to the surface. The edges of the biomat sheets are placed one on top of the other by approximately 0.1 m.
6. Please note: if the slope is more than 30%, gabion mats are fixed on top of the biomats, attaching them to the surface with pins 40-50 cm long. It is recommended to place the mats 1.5-2 meters beyond the upper edge of the slope.
7. After laying the canvas, if it is not sown, you need to sow grass to strengthen the soil vertically and horizontally. The choice of herbs is made taking into account specific conditions: soil, slope steepness, winds, gas pollution and their aesthetic qualities of plants.
8. If the biomats are laid out already with seeds, then they are watered.
9. After sowing the grasses and fixing the mats, fine-drip irrigation of the slope is carried out during the first 25 days. At air temperatures above 25 degrees, water 3 times a day. After the appearance of dense grass, fine-drip watering is not necessary, but water from 1 to 5 times depending on the air and soil temperature.
10. Approximately on the 16th - 20th day, the grass stand is mowed for the first time at a height of 5 cm and then cut every 12 days.

One of the varieties of biomaterials for surface strengthening is biomesh. Due to its high strength characteristics, it can quite effectively solve the problems of reinforcing the surface layer of soil on slopes. For strengthening and landscaping slopes, terraces, slopes, etc. Bio-fabric can also be used.

Bio-canvas- non-woven needle-punched or thread-stitched material made of organic fibers or straw. By rotting, it creates favorable conditions for the growth of herbaceous vegetation, which strengthens the slopes, and throughout the entire period of its existence, the bio-canvas supports the plants until they receive an extensive root system. Bioengineering technologies that create such natural structures help strengthen the stability of soil on slopes and protect it from erosion.

All of the above structures work to strengthen and reinforce slopes. Their application depends on various factors discussed above. But, unfortunately, such structures cannot always strengthen a steep, more than 40% slope, area, especially if the soil does not allow it, or the slope is long. In these cases, terracing with installation is carried out. But this is a topic for another article.

After acquiring land for development, it often turns out that the terrain and geology of the area are not entirely suitable for long-term use and agricultural activities. We will talk about raising and leveling the soil, from marking to protective landscaping.

When does it make sense to raise a site?

One of the worst geomorphological conditions is considered to be a rise in groundwater level above the depth of soil freezing. In such areas, heaving is especially pronounced, which is why there is a need for complex types of foundations, for example, pile-grillage. Shallow foundations do not work in such conditions, and full deepening requires support on a layer of soil 2.5-3 meters from the surface; above that, the foundation remains unstable and can be subject to precipitation due to high soil moisture.

It cannot be said that geodetic site planning is a cheap method to get rid of soil problems. However, the usefulness of such a solution can be expressed economically in favor of the developer, if raising the soil eliminates problems with waterproofing, insulation and stabilization of the foundation and the associated costs. This is usually true: planning allows you to solve the problem of poor geomorphology cheaper and, most importantly, faster, ultimately significantly reducing the period of foundation shrinkage. This solution is especially indicated when building a log house or installing prefabricated foundations.

But raising the level on the site does not always solve the problem. With a large slope (more than 5-7%), terracing should be done rather than raising the soil, and this is a completely different technology. On such slopes, even using special equipment to pour bored piles costs less money, but among foundations this is one of the most complex. There may also simply not be a dense enough layer of soil in the area to support the construction of the required mass. Raising the site in such a situation will not give anything at all; in any case, you will have to make the foundation floating.

Is drainage needed?

Drainage systems are indicated for artificially leveled areas with significant elevation differences, where, as we know, conventional elevation cannot solve the problem. However, the phenomena of erosion and washout can be expressed even on small slopes, so minimal backfilling and surface drainage will have to be done.

Along both boundaries of the site, located along the slope, you need to dig rain trenches, one of which (the lower one) receives water from a cross-section arranged along the upper border of the site. The bottom of the trenches is filled with crushed stone, and shrubs are planted along the slopes. Periodically, the trenches will have to be cleaned; usually the owner of the site will have to clean the one that is higher in level. The depth of the trench should reach the upper aquitard and cut it slightly - about 20-30 cm. In order to disturb the terrain less, the depth of the trenches can be adjusted with hygroscopic material - the same crushed stone or construction waste.

If the direction of the slope and the trenches diverge by more than 15º, you should be prepared for increased water flow. The bottom of the upper trench should be paved with bricks, or even better - with trays. In such areas, it makes sense to level the soil locally exclusively for buildings. In this case, the plot for the garden is simply protected from erosion by a trench across the slope, along the upper slope of which willow or several birch trees are planted. It is recommended to fill the bottom of the trench and its upper slope with crushed stone to prevent siltation.

There is no point in covering the entire layer of the embankment with black soil, just as there is no point in throwing clay on top of the fertile layer. The top layer will have to be removed to clean clay, and then returned to its place. If only part of the site is to be leveled, the excess soil is simply thrown onto the adjacent territory. If the site is planned completely, the work is carried out in two stages.

Soil excavation is carried out in order to eliminate the plastic washable layer between two dense layers, since there is a high probability of the embankment sliding under its own weight. The only exception is when the site is located simply in a lowland without a slope 20-30 cm below the adjacent territory. Here it is reasonable to limit ourselves to increasing the thickness of the fertile layer.

After the dense formation is exposed, a series of geodetic measurements are carried out. Knowing the configuration of the upper aquifer, you can determine the required volume of soil and begin its delivery. At the same time, they calculate the volume of crushed stone for backfilling and plan the installation of a drainage system.

How to fill the hill

To create an embankment, hard-plastic clay in a swollen state, loam or sandy loam is used. The ability of the bedding to pass water is determined by geomorphology: if, when there is an abundance of water, it is not possible to fill a tightly compacted terrace or the bedding is carried out on top of a porous layer, the embankment should have limited water permeability. It is optimal if the load-bearing capacity of the clay matches the underlying layer, so don’t be lazy to take samples.

In places where the site plan rises above the adjacent areas by more than 30-40 cm, it is necessary to backfill with road crushed stone of a fraction of 70-90 cm. It is also used in surface drainage. Crushed stone is dumped immediately after excavation under the formed edge. The width of the fill in the lower part must be at least half the height of the crushed stone shaft. On the sides of the site along the slope, crushed stone can be used to immediately form the bottom of drainage trenches.

Supports more than a meter high are covered with geotextiles, which are immediately pressed down with a small layer of clay. After this, imported soil is brought in and distributed throughout the site. The simplest route for laying is starting from the shaft, laid from the point of entry of the equipment to the opposite point, and then into the dump in both directions.

It is not recommended to pour more than 0.7-0.8 meters of clay embankment at a time. If it is necessary to raise more, you should wait for heavy rain or give the embankment time to overwinter. But with the use of compaction and excavator equipment, you can quickly create more impressive dumps.

Is compacting or rolling necessary?

It is optimal if the imported clay is sequentially unloaded completely at the upper level of the dump, and then pushed into unfilled areas with a bucket. This is how high-quality compaction occurs, in which the final shrinkage takes place in one or two wettings.

Tamping is used when there is a need for high speed of work, for example, when the optimal time for filling an embankment is limited by season or weather. With alternate tamping, you can pour 0.6-1.0 layers of pure clay one after another without prior wetting. Let us note once again that only swollen clay is suitable for compaction; dry clay will not acquire water-resistant properties until swelling and subsequent compaction.

Layers of 30-40 cm can be compacted by rolling, but wheeled vehicles are not suitable for these purposes. A crawler excavator is indispensable if the site is being raised to a height of more than a meter; in other cases, it is wiser to resort to manual transportation and leveling, and to entrust compaction to precipitation.

Please note that it is often not necessary to manually grade the site. Due to the movement of surface water, the fresh embankment will eventually take on a natural slope. If there is an abundant supply of water, sometimes it is even necessary to slightly raise the embankment at the bottom of the slope in advance.

If you rush and bring in chernozem before the final compaction of the clay, erosion will quickly have a detrimental effect and the area will greatly lose its fertility. Unfortunately, only plowing the soil in spring and autumn can save you from this phenomenon, and even then only partially.

It is better to pour the chernozem or fertile layer dry and not roll it, preferably manual distribution and leveling of the soil. The equipment must import chernozem in the reverse order from the order in which the clay was poured. The area from the edges to the center is filled. At the end of the backfill, it is also filled.

This is the most labor-intensive stage of raising the site: in addition to the fact that it is necessary to level the soil not only in one plane, but also with uniform compaction, the top bulk layer may not be uniform. Usually, before unloading chernozem, formwork is installed, the foundation is cast and waterproofed, and then covered with crushed stone. Surface support mounds are also installed before the fertile layer is formed.

Protection against erosion, strengthening the embankment on the slope

In addition to backfills and drainage, there are other ways to prevent soil erosion. Of these, the most famous and quite effective is planting plants with a developed root system along the upper and lower boundaries of the planned area, and in the upper part - actively absorbing water.

Shrubs are planted along the slopes of drainage trenches to strengthen their walls. Plants from blackberries and rose hips to reeds are suitable here: they do not create much shade and at the same time pump water out of the soil well. From the highest tier, in addition to birch and willow, you can use low-growing elderberry and sea buckthorn. On steep slopes, it is recommended to strengthen the embankment with geogrids and an underground drainage network.

But with a small difference in soil level, backfilling and protective landscaping will be quite sufficient.