Spurs and dykes
To enhance the strength of the gabion cross wires
are incorporated into the overall structure. This
transverse wire can be finer than the main wire
used (Figure 11).
Overall dimensions of gabions can vary. 3m x1m x
1m and 2m x1m x 1m rectangular structures have
been commonly used in Nepal.
Once the gabions cages are made they are placed
in their correct position and stones can then be
loaded into them by the local community.
Practical Action
Figure 10: Steel pin jig design for
hexagonal gabion construction in Sri
Lanka. Illustration: Practical Action / Neil
Noble.
Evenly graded stones can be used so that the
gabions are well packed. The largest stones
should not be more than 2/3 of the minimum
dimension of the gabion.
Figure 11: Cross links with wire
Illustration: Practical Action / Neil Noble
Any stones that tends to crumble or are soft and
disintegrate with abrasion are not suitable.
Stones from the river that have already been
worn smooth are most suitable.
When correctly positioned the gabions are then
fixed together with wire.
Life of gabions depends on the type of wire used.
Galvanised wire protects against rust as long as
the surface coating is not damaged.
The amount of water exposure will also affect the
life of the gabion and if saltwater is present then
corrosion will be more extreme. 20 years is
regarded as a safe minimum.
Figure 12: Loading rocks into the
gabion cages, a community activity.
Photo: Practical Action Nepal.
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