Gabion Baskets for Retaining
Walls Toe and Footing Design Guidelines
Typical Gabion Retaining Wall Sections
900mm High Gabion Retaining Wall
1.35m High Gabion Retaining Wall
1.8m High Gabion Retaining Wall
2.25m High Gabion Retaining Wall
2.7m High Gabion Retaining Wall
NOTES:
No liability is accepted where a
typical section is used as a the basis for the final design. The details provided are guidelines only.
It is recommended that a soil investigation
is undertaken and that the wall is designed by a geotechnical engineer.
Stability is improved by backfilling behind the wall with a free draining granular material and
building the wall with a slope of 5-10 degress
The retaining wall toe prevents the gabion wall
sliding forwards, the depth of the toe needs to increase the wall gets bigger.
When building gabions on softer soils, both the depth of the toe and the size of
the base needs to be increased to spread the load over a wider area. Your engineer's design will
consider the design limit
states and specify the dimensions
of the toe and base for your wall.
When the gabion retaining wall is subject to a
additional surcharges, from a driveway or other loads, the engineer's design
will most likely increase the size of the gabions, to take the higher expected
loads.
The gabions are normally machine filled in layers with the
contractor picking the stone over by hand to reduce excessive voids. The exposed faces are
also systematically hand packed to provide an appearance of a dry stone wall.
Angular rock is the best the fill, as it
provides a good interlock and therefore less
deformation of the face occurs. When using rounded river rock as gabion fill, it
is recommended that you use the heavier 4.5mm gabion baskets.
Where the cost of quarried rock fill is high, the gabions can be filled
with 2 types of fill, a quarried rock for the exposed face with a cheaper stone fill
behind.
Gabion fill is normally a graded between 100 to 200mm in
diameter with a nominal 6% smaller or larger. The grading is important to ensure that voids within the unit
are minimised otherwise settlements can occur.
Welded mesh gabions can be readily modified on site by cutting the mesh back to the next transverse mesh
wire.
When constructing gabion retaining walls in
strongly acidic soils(PH over 5.5), the soil and the corrosive groundwater must
be separated from the gabion structure by using geotextile fabrics and a
properly designed drainage system.
For advice or assistance with the design of an economical gabion
wall, please email engineer@gabion1.com.au
