Wall design using Standard Gabions 39

Gabion walls - filling materials

The design of a gabion retaining wall is based on the mass of the contained stone or rock being able to resist the disturbing forces due to soil and external loadings. The design does not consider that the gabion mesh provides improvement to stability. The design code applicable to gabions is BS 8002 - The Code of Conduct for Earth Retaining Structures.

In the design of the retaining structure, the principles are the same for both woven and welded mesh gabions. Where walls are subject to possible settlement, woven mesh gabions have more flexibility and therefore may be best suited in these situations. Where a high quality of appearance is needed, a welded gabion is superior providing that the
correct selection of mesh wire combinations are chosen. The selection of rock or stone fill is very important, as the performance of a gabion wall structure is dependant upon the mass. Although the mass is the criteria for design, other
factors to be considered are:-

Grading of fill

Gabion fill is normally a graded fill of between 100 to 200mm in diameter with a nominal 6% smaller or larger.
The grading can be tightened to 80 to 150mm providing the control of the grading is tight. Stones smaller than the mesh will not be contained by it. The grading is important to ensure that voids within the unit are minimised
otherwise settlements can occur.

Angularity of fill

The more angular the fill, the better interlock and the less deformation of the face occurs.
Rounded stone
has little interlock and results in greater deformation of the face. To overcome the deformation, a heavier mesh wire should be used. Welded mesh gabions are manufactured from 3, 4, or 5mm wire diameters and
Woven gabions from a wire diameter of 2.7mm. Therefore for a rounded stone fill, welded wire mesh gabions should be specified, 4mm for gabion 27 system and 5mm for standard gabion 39 system.
Crushed concrete or gritstone,
although angular, tend to become rounded. They do have greater interlock than rounded stones and therefore 4mm welded wire mesh should be specified
Quarried stone
which is normally angular, is the preferable fill as the interlock is very good. some quarries
Blocky stone or flat stone
when machined filled can result in large voids being present which can result in settlements. Care should be taken when machine filling to minimise large voids.

Ideally, all gabions should be fair faced (hand packed on the exposed faces). Where the cost of quarried rock fill is high, the gabions can be filled with 2 types of fill, a quarried rock or block stone for the exposed face with a cheaper stone fill behind. To assist in placing of differing fills, an additional cell can be incorporated normally set back 300mm from the
face during gabion manufacture to assist in the construction.


UK manufactured Gabions large range of gabion sizes