FABRICATION OF GABIONS:
Step 1. Stretching: The gabions shall be unfolded on the ground and stretched to the
maximum extent possible while ensuring that all creases are in the correct positions
for forming the box.
Step 2. Cutting: Any cutting required shall be carried out so that the cut ends of
wire are a minimum of 50 millimetres from the twisted joins. After stretching and
cutting as required the side and end panels shall be lifted so that the tops of all
sides are level. Any loose ends of wire protruding above a level plane at the top or
from the corners shall be bent down into the gabion box.
Step 3. Fastening and Lacing: Corners shall be fastened securely and the box shaped
prior to commencing any binding. The binding wire shall be securely fastened to the
top of a corner by lacing between two meshes at the corner and twisting the binding
wire through three half turns. The wire shall then be laced around the two vertical
selvedges, when applicable, and through each mesh in turn in a continuous lacing
action and shall be pulled tight before securing to the bottom corner by the three
half turns to an adjacent wire.
Step 4. Positioning of gabion boxes before filling: The diaphragm panels shall then
be placed in position and secured to the gabion sides in the same manner as the
corners. The empty box shall then be firmly seated on a prepared area in its final
position and laced to the adjoining corners or sides of gabions previously placed
along all adjoining corners and tops. If additional binding of the gabions is
required this shall be shown on the Drawings or specified.
Placement of the Gabion Boxes:
The placement of the gabion boxes shall be carried out in an orderly manner so that
a face of uncompleted work is maintained. At least two rows of empty boxes shall be
wired together at the face of uncompleted work prior to filling the box closest to
the completed work.
Prior to filling any box one end or side of the box shall be secured to completed
works or to stakes driven into the ground at the corners or in any other approved
manner and the opposite end, side or corner shall be stretched with crowbars and
secured top and bottom in an approved manner.
Filling Boxes
When boxes used are one (1) metre high or more they shall be cross tensioned in each
compartment at third points in the height by wires of the same diameter as the
binding wire securely tied by two turns around the mesh or selvedge wire and three
half turns around itself.
The gabions wire boxes shall be filled to between 25 and 50 millimetres above their
tops. The lids shall be stretched tight over the filling with a crow-bar or similar
and wired down in a continuous lacing process in the same manner as that specified
for corners. Each edge may be laced with a separate length of binding.
Measurement of Gabion Works
The Gabions shall include for all work specified including excavation, filling,
compaction and trimming necessary to construct the gabions to the lines and levels
specified. Measurement of the quantity in cubic metres will be made shall be based
on the nominal external dimensions of the gabion baskets which have been constructed
in accordance with the Contract. The unit of measurement for Reno mattresses shall
be the cubic metre (m3).