Gabion history and Used
- Created on 12 January 2014
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A gabion (from Italian gabbione meaning "big cage"; from Italian gabbia and Latin cavea meaning "cage") is a cage, cylinder, or box filled with rocks, concrete, or sometimes sand and soil for use in civil engineering, road building, and military applications. For erosion control, caged riprap is used. For dams or in foundation construction, cylindrical metal structures are used. In a military context, earth- or sand-filled gabions are used to protect artillery crews from enemy fire.
The most common civil engineering use of gabions is to stabilize shorelines, streambanks or slopes against erosion. Other uses include retaining walls, temporary floodwalls, silt filtration from runoff, for small or temporary/permanent dams, river training, or channel lining. They may be used to direct the force of a flow of flood water around a vulnerable structure. Gabions are also used as fish barriers on small streams.
Reinforced earth with gabions,
Sveti Rok, Croatia.
A gabion wall is a retaining wall made of stacked stone-filled gabions tied together with wire. Gabion walls are usually battered (angled back towards the slope), or stepped back with the slope rather than stacked vertically.
Gabion baskets have some advantages over loose riprap because of their modularity and ability to be stacked in various shapes; they are also resistant to being washed away by moving water. Gabions also have advantages over more rigid structures because they can conform to ground movement, dissipate energy from flowing water, and drain freely. Their strength and effectiveness may increase with time in some cases, as silt and vegetation fill the interstitial voids and reinforce the structure. They are sometimes used to keep stones which may fall from a cutting or cliff from endangering traffic on a thoroughfare.
The life expectancy of gabions depends on the lifespan of the wire, not on the contents of the basket. The structure will fail when the wire fails. Galvanized steel wire is most common, but PVC-coated and stainless steel wire are also used. PVC-coated galvanized gabions have been estimated to survive for 60 years. Some gabion manufacturers guarantee a structural consistency of 50 years.
Variations in gabion design
Bridge abutment with gabions.
There are various special designs of gabions to meet particular functional requirements and some special terms for particular forms have come into use. For example:
• Bastion: a gabion lined internally with a membrane, typically of nonwoven geotextile to permit use of a granular soil fill instead of rock.
• Mattress: a form of gabion with relatively small height relative to the lateral dimensions; commonly very wide, for protecting surfaces from wave erosion and similar attack, rather than building or supporting high structures.
Reference to :https://en.wikipedia.org/wiki/Gabion
Last Updated on Tuesday, 04 June 2013 15:35