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Site Trial Before Permanent Installation of Gabions Works

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 Prior to commencing placing of gabions, it is important to carry out a site trial using the materials, equipment and working procedures using for the permanent gabions installed works.

The trial shall be located off the permanent works in a position to be agreed with the Engineer. The trial shall include a minimum of two rows of gabions baskets, each ten baskets long with associated reinforcement.

The working methods shall cover the following:
 - placing and wiring baskets
 - tensioning course of baskets
 - filling with stone, installing bracing
 - wiring down lids
 - placing and connecting gabion mesh reinforcement
 - placing asphalt
 - quality control of materials
 - removing spilt asphalt.

Before commencing the site trial, the Contractor shall submit in writing his proposals for carrying out the trials for the approval of the Engineer. On completion of the trial the Contractor shall submit a report on the trial to the Engineer.

The construction of the permanent works shall not commence until the trial has been completed to the satisfaction of the Engineer.
Gabions Box Type

Gabions Box Type are galvanized double twisted hexagonal woven mesh with a rectangular box shape. The compartments or cells are of equal size and dimension and are formed by internal diaphragms being placed within the basket. The compartments or cells are filled with natural stone and the diaphragms minimize stone migration within the basket providing even distribution of the stone fill throughout the basket even after structural movement. The gabion box strength comes from a double twisted hexagonal mesh of steel wire which is reinforced by selvedge of heavier gauge wire running along the edges and by transverse internal diaphragms at 1m centers.

Materials: low carbon steel wire, galvanized wire and PVC coated wire
Installation of Gabions Boxes
Gabion box shall be assembled individually and placed on the surface to the lines, with the position of all creases and that the tops of all sides are boxes shall be properly staggered horizontally and vertically according to the construction requirement. Finished gabion products shall have no gaps along the perimeter of the contact surfaces between adjoining units. All adjoining empty gabion units shall be connected along the perimeter of their contact surfaces in order to obtain a monolithic structure. All lacing wire terminals shall be securely fastened. All joining shall be made through selvedge-selvedge or selvedge-edge wire connection; mesh-mesh wire connection is prohibited except in the case where baskets are offset or stacked and selvedge-mesh or mesh-mesh wire connection would be necessary. As a minimum, a fastener shall be installed at each mesh opening at the location where mesh wire meets selvedge or edge wire.

Gabion boxes offered by Qiaoshi Gaviones Manufacture Co. are made in standard sizes. Custom designs available upon request. Welcome to contact us with your specific requirements.
Two types of gabions are required for the Works:

-Gabion boxes (the tenns baskets and crates are synonymous);

-Gabion mattresses.

Gabions and mattresses are available .in a wide range of standard sizes.

The size and type of wire mesh, diaphragms binding wires, and selvedge wire are specified in the following paragraphs. The fabric of the gabions shall be triple twisted hexagonal woven steel wire mesh. The wire shall be galvanized before weaving. All wire used in the manufacture and tying of gabion shall comply with the BS.1052: 1980 “Mild steel wire for general engineering purposes” and shall be galvanized in accordance with BS 443: 1982 “Specifications for testing zinc coatings on steel wire and for quality requirements.”


Gabions Specifications

a) Mesh
The gabion boxes shall have hexagonal woven mesh with a maximum size of 10 cm x 12 cm, with the joints fonned by twisting each pair of wires through three half turns. Wire used for the fonnation of the mesh panel will have a diameter of 3.0mm.

b) Wire

The diameter of the wire used in the fabrication of the mesh shall be 3.0 mm. Sufficient binding and tie wires, horizontal and vertical bracers, and other accessories needed for the assembly and erection of the gabion works shall be supplied, at no additional cost, by the Contractor. The quantity of such wire shall be not less than 10% by weight of the gabions supplied under this Contract. The diameter of the binding and connection wires shall be 2.4 mm.

c) Galvanizing

All wire used in the manufacture of gabion boxes and in the wiring operations during construction shall be heavily coated with zinc. The minimum weight of zinc coating shall be as follows:
The adhesion of the zinc coating to the wire shall be strong enough of an extent that when the wire is wrapped six turns around a mandrel of four times the diameter of the wire, it does not flake or crack to such an extent that any zinc can be easily removed by rubbing with the bare fingers.
d) Selvedges
All edges of the gabion boxes including end-panel and diaphragms shall be mechanically selvedged in such a way to prevent unraveling of the mesh. The selvedge shall be of a wire having a diameter of 3.9 mm.

 Diaphragms shall be supplied to divide each gabion unit into cells to control movement of fill material within the gabion. The diaphragm to be provided shall be equally spaced at a distance of 1 m along the length of the gabion. The diaphragms shall be selvedge to a diameter of 3.9 mm.


Gabions Mattresses specification
 a) Mesh

The gabion mattresses shall be triple twisted hexagonal woven steel wire mesh of size 6cm x 8cm. The mattresses shall be divided by internal diaphragms into compartments of 1 m width.
Installing of the gabion and gabion mattresses

a) Foundations
 The ground on which the gabions are to be founded shall be trimmed by hand to form  a plane surface before placing the baskets, Where shown on the drawing or ordered  by the Project Manager the gabions mattresses shall be laid on a graded filter or an approved geotextile, Filtered  material  shall consist of graded  rock of a dense, sound quality free from weathering or mechanical weakness, The size and grading shall be such that the filter will be retained by the  rock in the gabion and will itself retain the finer particles of the adjacent general filling,
 If necessary the filter shall be placed in successive  layers of different grading, reducing in particle size from the gabions to the general filing, The completed filter layer shall be such that it shall represent a dense mass well consolidated and not subject to settlement

b) Fixing
  After placing in position and before filling, the gabions shall be stretched to their full size and shall be stretched to their full size and shall be wired to the adjoining row at the top and bottom edges and at the corners.
c) Stone Fill
   Stone for filling gabions shall be between 120 mm and 250 mm dia stone, It shall be hard and resistant to abrasion, uniform in texture and sound, without cracks or other imperfections likely to impair resistance to weathering,

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