Working works commencing. The certificate highlights the specific

Working
platform are geotechnical structures which support the forces of heavy track
plants such as piling rigs and cranes providing a stable working platform over soft
subsoils, this preventing failure or over-turning of the tracked plants. It is
a foundation for large plants weighting in the region of 5 – 150 tonnes which
most soils are unable to bare the weight.

 

The
platform needs to be of a certain thickness in order for the usage of heavy
track plant to be used and resist failure soil failure and overturning of the
plants. It is constructed for the reduction of the ground pressure imposed on
the underlying soils, the material used are stronger than the formation.

 

Inadequate
design of working platform can result in dangerous accidents, delays in the
programmes and damaging the reputation of the company. Hence, the working
platform should be monitored and maintained throughout the duration of the use
of heavy tracked plants to ensure failure doesn’t occur, the main contractor is
responsible for all of this.

 

A
certificate has to be in place to confirm the platform has been adequately
designed and constructed in accordance with the design, and to ensure it will
be maintained throughout. The main contractor must sign it and hand it to the
piling contractor prior to any piling or foundation works commencing. The
certificate highlights the specific responsibilities, increases safety
awareness and the importance of maintaining the platform in good condition. The
use of working platform certificated is to ensure correct measures have been
followed, the ground is sufficient to support the piling rig, there are no
irregularities that could result in subsidence or toppling. A daily check is
required using checklist form to review the general condition of the platform.

 

Consequently,
a working platform is designed, constructed and maintained with use of the BRE-470.
However, some users have reported that the thickness size given is unnecessary
and uneconomical which leads to additional expense.

 

Ground
surface can deteriorate over time, trenches and excavations must be
appropriately backfilled to avoid forming soft spots that will give away when
piling rigs are on tracks.

 

There
are two types of working platforms which needs to be considered;

·       Permanent working
platforms which are designed and built to be permanently integrated with the
design of the structure which will be constructed.

 

·       Temporary working
platforms which are designed and built as long as the work commence after the
construction of the heavy tracked plants are completed the working platforms
are dismantled.

 

There
have been numerous incidents which have occurred of piling rigs toppling, and
research has indicated it is due to the isolated areas of weakness or the
ground collapsing beneath the platform due to exceeding the bearing capacity of
the soil.

However,
when constructing any type of working platform, a foundation is a necessity to
transmit the load on a large area of soil. The foundation should be designed
and constructed so the soil beneath does not fail in excessive settlement or
shear.

 

Bearing
capacity is the maximum load per unit area which the soil can take without
yielding or displacing. The resistance to deformation of the soil depends on
factor such as the water content, angle of friction, bulk density and the
techniques in which loads are applied on the soil.