The system consists of dry stacking the interlocking blocks
one on top of each other and filling the hollows in the blocks
with compacted soil. The usual slope of the wall is 70 degrees
to the horizontal but this can be varied to suit prevailing
Cross-Section of a Honeycomb® Wall Structure
The top surface of each block is provided with a 10mm step which
gives the interlock action in the horizontal plane.
As with most retaining structures it is desirable that the material
used for backfill be a granular free draining soil in order to
prevent pore pressure build-up. If this is not practical some
form of drainage behind the wall will be necessary. However, in
normal conditions the vertical joints between the blocks provide
It has been found from experience with the many
walls already erected, that the single block wide structures containing
granular materials can be satisfactorily installed to between
3 to 4m in height. Walls higher than this can be erected using
a double block system or by a single wide block system incorporating
backfill reinforced with layers geofabric or geogrid clamped between
the horizontal joints in the wall.
Depending on the properties of the inclination
of the retained material, it has also been found from erected
walls that it is possible to design, single block wide walls,
without reinforced backfill, in excess of 3 to 4m. However, it
must be emphasized by the designer as the properties of both fill
and foundation materials will be the limiting factors and will
require special consideration.
During construction of the walls the compacting of the backfill
for 1m behind the wall should only be done by light compacting
equipment, such as hand stampers or small vibrating plates or
rollers, as heavy compaction rollers can displace the blocks or
damage the geofabric reinforcement.
Particular attention should be paid to the
proper compaction of the material within the blocks as this mass
is used in the stability calculations.