Civil Engineering Reference
In-Depth Information
This method of pile installation lacks thorough investigation. It is potentially very
effective, but there is a tendency for the driving equipment to suffer from the damaging
effect of the severe vibration associated with the large energy inputs required to drive
bearing piles and the results are to some extent unpredictable. Noise and vibration
propagation can be high, leading to settlement in nearby structures. The method can
be used to good effect for pile extraction.
3.3.4 Jacking methods of pile installation
By jacking (usually hydraulically) against a reaction, lengths of pile, either in short
units or in continuous lengths, may be forced into the ground. The method is well
suited to micro-piling (see section 3.6), as the reaction loads can then provided by the
structure being underpinned. Other, portable reaction systems may be used in situ-
ations other than underpinning. An early application was the 'Taywood Pilemaster'
system, in which sheet piles were forced into the ground against the reaction provided
by adjacent piles. The Taywood Pilemaster is no longer available but is superseded
by more modern systems typified by the Giken (Arcelor) (Figure 3.14) and the 'Still
Worker' (Stent Piling). The system can in certain circumstances be extended to install
tubular piles by using adjacent sheet piling which is likely be present within a cof-
ferdam for reaction. Jacking methods are exceptionally quiet and vibration-free in
use and by monitoring the pressure in the hydraulic system an indication of the
UPLIFT FORCE
SHEET PILE
HYDRAULIC RAMS
PRESS-IN FORCE
CHUCKING POINT
CLAMPING POINT
PILE RESISTANCE
REACTION PILES
Figure 3.14
Giken pile driver.
