07/1173 - Operational Works - Transport Type 6 - Refurbishment of Boathouse & Jetty [As Published] · 142007.1173

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11/08 '03 MON 06:50 Fax ‘o7 4936 1708 ROCLA POLES QLD @oi7

{Installation (cont) )

Potting
In hard ground conditions, it may be preferred to drill a hole and ‘pot’ the
pile into this hole.

The hole should givé adequate clearance around the pile so that the in-fill
material can adequately fill the gap to, eventually, achieve adequate
compaction. The in-fill material is usually sand or a similar granular material.
This in-fill must be able to transfer the reacticn loads between the pile and
the undisturbed foundation material under service leadings. The getting depth
may be limited by the strength of the in~fill material tather than the

foundation material.

Driving
Piles founding into clay soils are suited to being ‘driven’ into place.

Much care and experience is required to drive piles without creating
excessive pile stresses. Regardless of how the driving energy is delivered to a
pile, the driving energy produced should create pile stresses within the limits
given in the Table 5, at all times :

Compressive stress : no more than 40 MPa for all plies

Pile Type (dia/kNm) : 400/175 400/275 400/375 450/275 450/425 450/525

Tensile stress {MFa) : 4.0 8.0 6.0 5.0 2.0 @.0
Table 5

. The driving energy needs to be carefully controlled when there is @
likelihood that the pile :

- will psnetrate a hasd layer, particularly if this is close to ground level

+ will penetrate soft material (the penetration per blow should be limited)

or :
- reach a hard layer, particularly if it is impenetrable.

Pilea should not be over-driven. If the. pile has reached refusal before
_,achieving the desired set, the pile will need to be cut off at the head.

wot > ee ee =
: ee.

In general, the hammer mass should be comparable to the mass of the pile.
This best allows the appropriate driving energy to be delivered, without
excessive drop height of the hammer.

c.carter
16/6/99
pilehandle2.doc

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