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In the case of Combi-wall and RD pile wall structures
it is often practical to aim at tolerances considerably
stricter than the above general positional and verticality
tolerances. Used tolerances must be determined case
by case and at least a preliminary plan of measures to
be taken to attain the tight tolerances must be made
already at the design stage. Recommended tolerances for
these structures are presented in design and installation
manual for RD pile wall.
Combi-wall structures are usually equipped with
sufficiently sturdy templates made of steel beams or the
like, which allow accurate positioning of the piles. In RD
pile wall structures, the starting pile of the wall structure
in practice determines the direction and inclination of
the entire wall, which means that the installation of the
starting pile(s) and used tolerances must be planned
with great care. Procedures and important things during
installation of these structures are presented in design
and installation manual for RD pile wall.
Positional and angular deviations of piles due to
installation are taken into account in the design of the
pile foundation. After installation, the actual positions and
inclinations of the piles are measured. If the positional
tolerances allowed by the design are exceeded, the
possible overloading of each structural members must be
determined and necessary measures taken.
6.7 Impact of piling on previously installed piles,
other foundation structures and immediate
surroundings
The geotechnical works of the building site, piling
included, are designed and executed so that they do not
decrease the resistance of previously installed piles or
cause damage or nuisance to the immediate surroundings
of the site. If there are structures susceptible to damage
in the immediate surroundings of the site, they must
be charted to a sufficient extent in connection with
geotechnical investigations, or in any case before piling.
If necessary, the condition of nearby structures must be
established through inspections.
The environmental impacts of driven and drilled piles
can be estimated as described in PO-2016, Part 2,
Sec. 4.7. The selection of pile type, piling method and
piling equipment can have a significant effect on the
environmental impacts.
Small-diameter driven RR piles displace very little soil
in relation to their bearing capacity. Therefore, the
increase in pore water pressure and lateral displacements
and heave of soil usually remain very small. Owing to
their small cross-sectional diameter, the piles can be
driven below ground water level in loose silty and sandy
soils with low impact energy, whereby the compaction
of compacting soil layers due to piling remains minor.
Correspondingly, penetration of dense soil layers that
cause vibration can be achieved with relatively low
impact energy, so that the vibration from piling is minor.
Especially when using light piling equipment and pile
drivers, RR piles can usually be installed safely very close
to existing structures. The environmental impacts of pile
driving may also be minimised by selecting piling class
PTL3 and RRs piles.
If installed according to the installation instructions, RD piles,
especially small diameter RD piles, do not displace soil or
remove extra soil, which keeps the environmental impacts of
piling, such as soil displacement and compaction, vibration,
and increase in pore water pressure, very low. With large RD
piles (
≥
RD400), due to the higher consumption of flushing
agent (usually compressed air) and larger DTH hammer
equipment, piling can have minor environmental impacts,
which must be considered in design and implementation
when RD piles are installed in the immediate vicinity of
existing structures.
The jacked RR piles used in underpinning usually cause
the least environmental impacts, whose installation also
causes very little noise.
In soft subsoils, the movement of heavy (>40 to 60 t)
piling equipment may cause more vibration than the pile
installation itself.
7. PILING
7.1 Material needed for piling: working plan and
quality plan
The material needed for piling, the working plan and
quality plan, are presented in PO-2016, Ch. 2, Sec. 5.1.
7.2 Storage, handling, inspection and erection of
steel piles
The storage and handling of piles on site are covered
by a separate manual ”Piles and pile accessories,
recommendations for safe handling for the customer"
(www.ssab.com/infra).
Inspection of delivered piles and their accessories takes
place immediately after the delivery arrives on site.
A visual inspection is made to ensure that the shipment
corresponds to the order and consignment note. The steel
grade and dimensions of piles are verified from product
descriptions and markings on the pile pipes. Pile sections
and accessories must correspond to the products specified
in designs. A faulty or wrong product must not be installed.
More detailed instructions for the handling of threaded
RD pile sections and threaded RD sleeves are presented
in Sec. 7.4.4.