The Platipus Anchoring
System is well proven in the field of Civil Engineering, Utility
Services, Tree Anchoring and tie-downs as a lightweight, cost
effective alternative to traditional techniques. Hundreds of
thousands of Platipus Anchoring Systems have been installed
worldwide in an increasing range of applications.
Platipus produces
lightweight, high capacity anchoring systems, in a wide range of
materials and sizes. They are quick and easy to install using
simple tools and plant. The anchors are driven into the ground and
proof loaded to precisely the load required using powered or
manual jacks. They are then ready to use immediately with no
waiting time, e.g., for concrete to cure. Thus, significant
savings can be made in comparison to traditional methods, in terms
of time and money.
APPLICATIONS
- Soil Nailing
- Retaining Wall Support
- Gabion Support
- Sheet Pile Retention
- Pipeline Buoyancy
- Rock Stabilisation
- Temporary Shelter Tie Down
- Bridge Repair
- Guyed Structure Tie Down
- Tree Support (Root Ball Kits
and Guy systems)
- Caravan, Portable Building and
Scaffolding Security/Tie Down
- Park benches, rubbish bins,
light aeroplanes, boats, equipment, Security/Tie Down
- Marine Buoyancy Control
INSTALLATION
There are three main stages to the installation of an anchor
system. These same principles apply to all sizes of installation
light, medium or heavy. The hand installation of a lightweight
system (say from 2 kN to 20 kN) is illustrated below.
LOADLOCKING
Due to the design and shape of the anchor and the position of the
tendon, when a load is applied the anchor will rotate in the
ground by up to 90° and loadlock.
In dry granular material, the anchor will normally loadlock within
its own body length. In a saturated clay material, this loadlock
distance can be expected to increase by up to three times. The
distance an anchor system travels through the ground during
loadlocking and proof loading is known as extension and is
normally measured in mm.
As additional load is applied to the anchor system, the body of
soil ahead of the anchor is compressed and tends to bond along the
shear angle of the soil. This provides resistance to any further
anchor movement. The size and spread of this body of soil can be
visualized as being a truncated cone or frustum. This soil is
referred to as the Frustum Cone.
THE FRUSTUM CONE
A typical granular material consists of different particles that
interlock, bond and compact when subjected to a load. Coarse sands
(ranging from 0.6mm to 2mm) and gravels (coarser than 2mm) are
generally of this composition. Typical shear angles for
non-cohesive granular soils range from 30° to 50°.
The Platipus anchor system performs exceptionally well in granular
material as the interlocking, bonding and compaction serves to
create a frustum cone of large size and volume.
The actual size and volume of a frustum cone will largely be
determined by:
- The type of soil in which the
anchor system is installed;
- The condition of the soil in
terms of water content, voids, mechanical strength and shear
angle;
- The size of the anchor used;
- The load applied; and
- The depth of installation.
In free
draining, non-cohesive granular soil (good soil), as indicated
above and illustrated in the diagram on the right. The
larger shear angle increases the volume of the frustum cone
created, the load achieved and its resistance to being pulled out.
In cohesive, saturated clay (poor soil with a typical shear angle
of between 0° and 20°), the volume of the frustum cone created,
the load achieved and its overall resistance to being pulled out
will be reduced (as illustrated on the left). Nevertheless, even
with a shear angle of 15° to 20°, it is still possible to achieve
satisfactory loads with the Platipus system.
Thus the frustum cone might be envisaged as the “dead weight” that
holds the anchor in place and the load carried by that anchor must
be greater than that “dead weight” before that anchor can be
pulled out of place.
Caravan and Portable Building Security
Example
Protect your assets through an outlay of only a very small
fraction of their value
Demountable buildings and caravans can be ruined if they are not
anchored down, particularly in open, windy spaces. Platipus
Demountable Building and Caravan Systems are a complete tie-down
system that provides maximum security against movement (be it
through environmental forces or attempted theft). They can be
installed in most instances by unskilled labour in a matter of
minutes, using basic installation tools and providing maximum
stability to the building structure.
