- History of technology
- Purpose of gabions
- Design features
- DIY decorative gabions
- Manufacturing and application of technical gabions
Quite often, technologies originally intended for military needs take root in civilian everyday life. Today we will talk about gabions, developed for the rapid construction of fortifications, but which have also found application in landscape design..
History of technology
Gabion is a lightweight spatial mesh structure filled with knocked down soil or stones. It would seem that the story can be ended at this, but such structures are so diverse and specific that they should be considered in all details..
What materials have not been used as mesh fencing of gabions. Initially, these were nets woven from vines, veneers, vines, in fact, baskets made of plant materials. When the technology was first tried to modernize in the XX century, the metal mesh with an anti-corrosion coating began to be used. Today this trend has continued, although military engineers increasingly prefer polymer materials – composite rods and reinforced polyethylene sacking.
A bomb shelter built from gabions and turf
Gabions were intended to create shelters from bullets and shrapnel, so they could be filled with both soil and stones. Backfilling with a viscous material contributed to more efficient absorption, but large cobblestones were beneficial in another aspect: the mesh in such cases could have a larger cell, which means it was lighter. The same approach is used in modern construction: stones are more massive and easier to work with, moreover, they have more pronounced aesthetic qualities..
Although the primitive appearance of gabions hints at handicraft, this technology is subject to strict standardization in accordance with GOST R 52132-2003. The most interesting provision of this regulatory document is the use of a grid in accordance with GOST R 51285–99, which has a hexagonal cell. Also noteworthy is the classification by the shape of the gabion. In our review, we will consider box structures, they are most often used in civil engineering..
Purpose of gabions
In the garden, gabions find two main uses. The first is as reinforcing structures used in geodetic planning. Gabion structures are a quick and easy way to create retaining walls for earth dumps and steep terracing slopes. However, the use of such structures is strongly limited by two factors: if the hydrogeological situation is unfavorable and increased requirements for stability and supporting capacity are imposed on the objects of geodetic planning, gabion structures must be erected according to a special project. In such cases, the support of the soil with reinforced concrete structures is considered much more reliable..
The second function is purely decorative: gabions are well suited for territorial zoning or the creation of small architectural forms, for example, flower beds on a hill or halos in places where trees are planted. Gabion structures of small cross-section and elongated shape are best used to create fences for paths or objects of domestic infrastructure. The most important advantages of gabions in this context are excellent decorative qualities, durability and minimum effort to maintain the appearance..
To ensure the stability of the gabion and the preservation of its geometric shape for a long time, a number of technical solutions are provided for the mesh structure. First of all, you need to distinguish between decorative and supporting structures. To ensure increased stability, the latter are equipped with a reinforcing panel – a solid mesh fabric located in the plane of the support. The task of this element is to prevent the pushing of the soil under the gabion, to provide a strong connection between the individual blocks of the structure and to exclude their vertical displacement relative to each other.
According to the standard, the reinforcing panel is used for retaining walls from three meters high. However, its presence may be advisable in other structures experiencing increased loads, for example, from soil heaving or lateral pressure, or when the angle of repose is significantly exceeded..
Decorative and small technical gabion structures have no bottom and this is their only difference. For their manufacture, a grid is used, the width of which is selected in accordance with the height of the block, and the length of the cut – with its perimeter on the horizontal plan. To give the mesh structure rigidity inside it, transverse diaphragms are installed every meter – mesh partitions, tightening the front and rear walls.
The configuration of the gabion does not allow making it seamless, but there are no restrictions on the presence of joints in the vertical walls and the lid. They are valid only for the reinforcing panel, which must be solid, or made with an overlap of at least one block length. The connection between the parts of the mesh, as well as between the walls and the diaphragm, is made by ligation with low-carbon wire, the thickness of which is less than in the main fence.
The last design feature concerns the material of the fence – the mesh, or rather its protective coating. Any gabion structure is arranged taking into account its service life, which directly depends on the resistance of the mesh to corrosion. Galvanizing provides durability from 7 to 10 years, polymer coating – 15-20 years, but if the gabion has to stand for more than 50 years, you should choose combined coatings made of mischmetal in a polymer sheath.
DIY decorative gabions
It is quite difficult for a private developer to arrange a gabion according to all technological rules, mainly due to the insufficient prevalence of a grid with a hexagonal cell. However, for decorative structures, it is quite acceptable to use a conventional mesh for reinforcing plaster, which has a rectangular cell. You just need to meet two conditions:
- The diagonal of the rectangular cell must be equal to the width of the hexagonal one, set by the standard.
- The thickness of the wire in the mesh should be increased by 25%.
The assembly of a gabion structure from a square mesh is somewhat easier than from a hexagonal one. The canvases must be cut in such a way that protruding wires remain at the edges, with which the dressing is then performed. The basket is assembled according to the standard scheme: one long sheet forms horizontal walls, transverse partitions are inserted inside, then a lid is tied from above.
Filling the gabion with stones will also not cause difficulties. It is only important to alternate the fraction of boulders so that the masonry is as dense and stable as possible. The stones are laid flush with the top rim, and then a lid is tied on top of the basket. If desired, the gabion can be covered with small stones on top, which can wake up into the mesh cells.
Manufacturing and application of technical gabions
If the gabion structure is to have load-bearing properties, its manufacture should be carried out in full compliance with technical standards. It is necessary to use a mesh of the appropriate type and size, choose the right filler and assemble the cage according to a certain pattern.
As mentioned, load-bearing gabions are constructed on a reinforcing panel. It is advisable to remove the sod layer of soil over the entire area of the support and tamp the surface. After that, a mesh is rolled out along the line of installation of the structure, the edges of which are bent to a height of 1.5 cells along the common line of the vertices of the hexagon. After that, vertical walls are tied to the flanging so that the cells coincide with their faces, each pair of which is connected by a clamp of 3-4 turns of low-carbon wire.
At the corners and reference lines of the membranes, the connection is made in the same way. When a stable cell is formed, stones of different sizes are laid inside, achieving the highest possible packing density. The filling is carried out to such a height that the edges can be folded in and the lid can be tied.
How can such gabions be used for household needs? This is primarily a good foundation for fences or livestock pens. Also, as the cage is filled, it is possible to install pillars with thrust bearings that support the canopy of a parking space or an open gazebo.
Sometimes gabions are used as fences for artificial reservoirs: they form a closed loop, inside which a waterproof bowl is inserted. If, in the construction of the cage, thin (6-8 mm) reinforcement on welded joints is used, the gabion turns into a full-fledged fence or a series of pillars, between which filling panels are inserted from a picket fence, forged gratings or profiled sheet.