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3. DESIGN STANDARDS AND
IMPLEMENTATION CONTROL
The Eurocode standards are followed in building
construction projects according to the decrees of the
Ministry of the Environment. In civil engineering projects,
the Eurocode standards are applied according to the
instructions of the Finnish Transport Agency. Instructions
of other authorities (such as municipalities/cities) are
observed where necessary.
The geotechnical class (GL1, GL2, GL3) of the site is
selected according to PO-2016 and RIL 207 (Application
Eurocode 7). The foundation engineer responsible for the
site determines the geotechnical class.
GL1 sites do not normally require piling. Most soil
conditions and sites belong to geotechnical class GL2.
Owing to the good and versatile properties of steel piles,
they have many applications at geotechnical class GL3
sites.
Piling class (PTL1, PTL2 or PTL3) is determined on the ba-
sis of consequence class (CC1 to CC3, cf. EN 1990 National
Annex) and geotechnical class.
4. RECOMMENDATIONS FOR THE
SELECTION AND DESIGN OF PILE TYPE,
PILE SIZE AND PILING CLASS FOR
DIFFERENT APPLICATIONS
Various applications and advantages of different SSAB's
steel pile types are presented in brochures on RR and RRs
piles, RD and RDs piles and RD pile walls.
The selection of a suitable pile type should be based
primarily on soil conditions, but superstructures and
ambient structures also play a major role. Some
instructions and recommendations for the selection of
pile type, pile size and piling class are given below.
Pile loads
SSAB's steel piles can be divided according to pile sizes
and applications based on pile loads, for example, as
follows:
RR75–RR/RD140/8
1 & 2 family houses and other struc-
tures subject to relatively light loads
RR/RD140/8–RR/RD270
multi-storey buildings of about 3 to
8 storeys
RR/RD220–RR/RD500
heavy multi-storey buildings
(>5 storeys) or industrial building
projects
RR/RD140–RR/RD270
pile slab projects
RR/RD220–RR/RD400
noise barrier piles
(single pile foundations)
RR/RD500–RR/RD1200
bridge and harbour construction and
buildings of more than 10 to 15 storeys
When selecting between RR and RD pile sizes, it should be
noted that the design strength of RD piles bearing on solid
bedrock is typically clearly higher (about 1.2 to 2.0 times)
than that of an RR pile of corresponding size. Owing to
the comprehensive pile size range, foundation structures
can always be optimised by using several (typically two or
three) pile sizes at a site.
Installability of piles
RD piles can be installed in all soil conditions. In very
exacting conditions, such as those involving thick fill
layers containing large boulders, the smallest RD piles
(pile sizes around RD90 to RD140) may pose the risk
of slightly higher pile bending in comparison to large
diameter RD piles. If the bedrock surface is particularly
inclined, close to ground level (<3 to 5 m), and in
conditions where there are no supporting friction soil
layers on top of the bedrock surface, an RD pile is a risk-
free solution in terms of support for the lower end of the
pile.
The penetrability of driven RR and RRs piles increases
with increasing pile size. When the amount/size of
stones and boulders in soil and fill layers
–
or the density
or thickness of the soil layer – increases, the risk of
deviations in the positions and verticality of driven piles
increases. The risk that piles bend or fail to reach a load-
bearing soil layer also increases. RR large diameter piles
have successfully penetrated rock fills several metres
thick, even ones over 20 metres thick. An RR170 or
RR220 pile is often rigid enough to penetrate relatively
thick layers of rocky fill and moraine all the way to a
bearing basal formation, provided that the size and
amount of stones and boulders is not exceptionally
large. A rock shoe improves the penetrability of a pile.
When building 1 & 2 family houses on thick moraine soils
containing stones it is recommended to use at least pile
size RR115/6.3.
Positional and verticality tolerances of piles
When a structure is set strict positional and verticality
tolerances, like, for instance, railway bridges built using
the bridge-moving technique, where a large diameter
pile is attached to the deck and also acts as a column,
the RD pile is the least risky alternative. It is also the
most recommendable alternative for corresponding
building construction projects where the pile also acts
as a column. Strict tolerances may also be required in
foundation underpinning or industrial building projects.
Environmental impacts of piling and nearby
structures
The environmental impacts of piling and issues related
to the selection of pile type are discussed in Sec. 6.7 of
these instructions.