| Static installation methods
Under certain
conditions, where dynamic pile installation methods are not possible or
acceptable, piles can be installed by jacking. This method is usually
carried out hydraulically. Reaction for jacking can be either from an
existing building or adjacent piles. The method uses either short pile
elements or continuous pile sections. The method tends to be restricted
to micropiling, where the reaction loads are provided by the structure
being underpinned. Other, portable reaction systems or the weight or the
piling rig may be used to jack against in situations other than underpinning.
In the case of sheet pile installation, it is common to use adjacent piles
as reaction.
Jacking methods
are exceptionally quiet and vibration-free in use and by monitoring the
pressure in the hydraulic system an indication of the pile failure loads
can be obtained during installation. However, their use is limited to
soft and medium dense soils and to piles with a reduced tip resistance,
typically sheet piles.
|
