With this article Edilsystem srlproposes a new possibility of use of the now tested Geosystem Minipalo Technology® (self-perforating hollow bars connected with valve sleeves).
Gabion structures are widely used in the construction of under-shoe retaining walls and counter-walls in the consolidation of road, railway, hydraulic, and architectural slopes.
The walls made with gabions act as gravity support structures or as protection of banks in the hydraulic field.
• Gabions are box-shaped structures made of metal mesh with galvanized wire filled on site with stones of suitable characteristics and sizes between 5 and 25 cm, split or river, but not freezing and not friable.
The gabion structure exploits the interaction between stones and wire mesh, acting as a monolithic whole.
The quality of the net, the stones and the quantity of internal ties that allow the system to correctly and effectively distribute the thrusts and loads, as well as a solid anchoring of the nails, are fundamental for a perfectly executed job.
Compared to the classic reinforced concrete walls gabions have the following advantages:
• They allow sensitive displacements and deformations without losing static functionality.
• They do not hinder groundwater circulation and perform an effective draining action, given the high porosity.
• They can be easily revived and therefore have a low visual and environmental impact, therefore ideal also for use in the urban context.
The growth of vegetation with consequent growth of the root system increases its resistance strength through the reinforcing action of the roots and contributes to the removal of part of the water circulating in the soil.
The flexible robustness of the gabions and the high draining power give the support walls thus created, as the best structure for the mitigation of landslides in silt-clay soils with high water content, up to a depth of 4-5 meters.
The combination of gabions with the nailing in the ground of the Geosystem® mini-piles represents an effective geotechnical tool that allows you to create mixed support-reinforcement works on any type of terrain.
The gravity support structure of the gabions is combined with the Geosystem® mini-piles (self-drilling hollow valved bars) with the function of being elements for the distribution and distribution of stress.
In order to make the gabion integral with the self-perforating bars, a galvanized (or non-galvanized) iron profile is used with a shape specially designed to work as a horizontal beam element.
The distribution element has a hole at the intersection of the diagonals where it is possible to insert the soil nailing element (Geosystem® mini-pole).
The minipalo Geosystem® (self-drilling bars with high resistance) after the insertion into the ground, which takes place with machinery equipped with a special rotary-hammer, we proceed with the injection into the bars of a specially formulated cement mixture, which comes out both from the tip to lose perforation and from the non-return type valves, placed in diametrically opposed pairs on each joint sleeve.
The latter are positioned along the length of the bar at a distance that can vary between 1 and 2 meters, in order to be able to control the perfect injection and the complete filling of the voids present within the ground.
Studded gabions as low impact support works
This technology creates a drained geotechnical device that has working characteristics such as a gravity wall and geotechnical improvement features of the soil through the shear and tensile strength offered by the nailing (Geosystem® minipiles), contrasting the mechanisms of breakage due to sliding and / or global break.
To conclude, we can summarize that the use of studded gabions are an optimal low impact solution for:
• Road under-shoe consolidation
• Upstream escarpment consolidation
• Road widening downstream
• Road widening upstream
The advantages of this technology are:
• Compact dimensions and excavations
• Reduction of excavation volumes
• High draining capacity
• Not affected by subsequent settlements
• It does not require aesthetic finishes
• Easily greened, therefore with low architectural impact
The advantages of using self-drilling bars of the Geosystem® mini-pole type can be summarized as:
• Rotation percussion drive, without pre-hole
• Ideal tie rods for temporary or permanent solutions
• Alternative to traditional anchoring techniques
• Extreme application versatility
• Quick and easy installation
• Use on any type of soil thanks to the subsequent injection with specific cement mixes