Micropiles

RR® and RD® micropiles

Micropiles offer an effective and convenient way to implement the piling

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    The easy-to-use and cost-efficient splicing method allows quick installation of RR® and RD® micropiles with minimal material waste.

    Micropiles consist of a longitudinally welded steel pipe, mechanical splices, a tip and a bearing plate.

    The selection of a suitable micropile type should be based primarily on soil conditions, but superstructures and ambient structures also play a major role.

     

    Applications:

    • Office and business buildings
    • Industrial buildings
    • Residential buildings
    • Public buildings
    • Road and railway structures and bridges
    Micropiles

    Micropile installation

    RR® micropiles can be installed using light basic equipment (<20 to 25 t) up to a size of about RR170. They can be installed by impact driving or jacking. A heavy hammer may be advantageous when driving RR® micropiles into dense soil, but it also increases the risk of bending. Pile cushions are usually not needed. If a micropile cushion is not used, a dolly made of a thick steel plate is used between the hammer and the pile. The head of the micropile is adjusted inside the lower part of the helmet to ensure that the impact is transmitted centrically.

    RD® micropile installation can be done in all soil conditions. They may be drilled through all natural soil layers all the way into bedrock, with small deviations in position and inclination. In very exacting conditions, such as those involving thick fill layers containing large boulders, the smallest diameter micropiles may pose a slightly higher risk of bending in comparison to large diameter micropiles.

    For more information regarding RR® and RD® micropile installation, see SSAB’s RR® and RD® piles design and installation manual.

    pdf 2,24 Mb
    RR® and RD® piles design and installation manual

    Micropile design

    Micropile design requires that micropile foundations are always designed together withthe structures to be supported on it, which allows selecting the most suitable shape, dimensionsand stiffness for the entire structure.

    The RR® micropiles are delivered either as pipes or as ready-made elements with an external sleeve splice at one end of the element. They are designed to offer quick and cost-effective splicing, minor displacement of soil, minor vibration disturbance and high installation strength.

    The RD® micropiles are delivered as pipes when splicing is done by welding. Another option is threaded RDT splices in which case the piles are delivered as ready-made elements with both ends threaded and with external threaded sleeves.

    An RDT micropile comprises:

    • A bearing plate installed on the upper end of the micropile
    • An external threaded sleeve
    • Extension pipe (both ends are threaded)
    • Starter micropile (one end is threaded)
    • A casing shoe and reamer bit (in concentric drilling) at the lower end of the micropile

    For the standard lengths of the micropile elements, the sectional properties and the steel grades, see SSAB’s RR® and RD® piles design and installation manual.

    RRPileCalc is a design program for SSAB's steel micropiles. Eurocodes as well as National codes and instructions are applied in the end-bearing micropile design. See the Design Tools section below for more information.

    RR® micropile

    Driven RR® micropile with effective splicing technology

    RR® micropiles offer quick and cost-effective splicing, minor displacement of soil, minor vibration disturbance and high installation strength. They are installed by impact driving or jacking.

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    RD® micropiles

    Drilled micropiles for drilling in difficult ground conditions

    The micropiles may be drilled through all natural soil layers all the way into bedrock, with small deviations in position and inclination.

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    Shaft-grouted RR® micropile

    Shaft-grouted RR® micropile and fitted equipment

    These micropiles are mainly shaft-bearing piles where the geotechnical bearing resistance of the shaft is improved through continuous shaft grouting. These are suitable for frictional soils where the high shaft resistance of grouted micropiles allows using essentially shorter piles.

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    Availability

    Availability of micropiles: section lengths and micropile pipe lengths.For project specific dimensions, please contact our sales.

    RR® pile

    Mill dimensions of RR (S460MH) and RRs (S550J2H) pile sections and pile pipes

    X = stock size O = project-specific size – = not in production

    Length of pile section (incl. splice)
    Length of pile pipe (excl. splice)
    Pile
    12 m
    6 m
    4 m
    3 m
    2 m
    1.5 m
    1.2 m
    1.0 m
    6 m
    12 m
    16 m
    RR75 -
    X
    O
    O
    O
    O
    O
    O
         		-
    X
    O
         		-
    RR90 -
    X
    O
    O
    O
    O
    O
    O
         		-
    X
    O
         		-
    RR115/6.3
    O
    X
    O
    O
    O
    O
    O
    O
         		-
    X
    O
    O
    RR115/8
    O
    X
    O
    O
    O
    O
    O
    O
         		-
    O
    X
    O
    RR140/8
    X
    X
    O
    O
    O
    O
    O
    O
         		-
    O
    X
    O
    RR140/10
    X
    X
    O
    O
    O
    O
    O
    O
         		-
    O
    X
    O
    RR170/10
    X
    X
    O
    O
    O
    O
    O
    O
         		-
    O
    X
    O
    RR170/12.5
    X
    O
    O
    O
    O
    O
    O
    O
         		-
    O
    X
    O
    RR220/10
    X
    O
    O
    O
         		- - - - -
    O
    X
    O
    RR220/12.5
    X
    O
    O
    O
         		- - - - -
    O
    X
    O
    RR245/10
    O
    O
    O
         		- - - - - -
    O
    O
    O
    RR245/12.5
    X
    O
    O
         		- - - - - -
    O
    X
    O
    RR270/10
    O
    O
    O
         		- - - - - -
    O
    O
    O
    RR270/12.5
    X
    O
    O
         		- - - - - -
    O
    X
    O
    RRs115/8
    O
    X
    O
    O
    O
    O
    O
    O
         		-
    O
    X
    O
    RRs125/6.3
    X
    X
    O
    O
         		- - - - -
    O
    X
         		-
    RRs140/8
    X
    X
    O
    O
    O
    O
    O
    O
         		-
    O
    X
    O
    RRs140/10
    X
    O
    O
    O
    O
    O
    O
    O
         		-
    O
    X
    O
    RRs170/10
    X
    O
    O
    O
    O
    O
    O
    O
         		-
    O
    X
    O
    RRs170/12.5
    X
    O
    O
    O
    O
    O
    O
    O
         		-
    O
    X
    O
    RRs220/10
    X
    O
    O
    O
         		- - - - -
    O
    X
    O
    RRs220/12.5
    X
    O
    O
    O
         		- - - - -
    O
    X
    O
    RRs245/10
    O
    O
    O
         		- - - - - -
    O
    O
    O
    RRs245/12.5
    O
    O
    O
         		- - - - - -
    O
    O
    O
    RRS270/10
    O
    O
    O
         		- - - - - -
    O
    O
    O
    RRS270/12.5
    O
    O
    O
         		- - - - - -
    O
    O
    O

    RD® pile

    Mill dimensions of RD (S460MH) and RDs (S550J2H) pile sections and pile pipes

    X = stock size O = project-specific size – = not in production

    Length of pile section with threaded ends
    Pile
    1 m
    1.2 m
    1.5 m
    2 m
    3 m
    4 m
    6 m
    12 m
    RDT90
    O
    O
    O
    O
    O
    O
    O
         		-
    RDT115/6.3
    O
    O
    O
    O
    O
    O
    O
    O
    RDT115/8
    O
    O
    O
    O
    X
    O
    O
    O
    RDT140/8
    O
    O
    O
    O
    O
    O
    O
    O
    RDT140/10
    O
    O
    O
    O
    O
    O
    X
    O
    RDT170/10
    O
    O
    O
    O
    O
    O
    X
    O
    RDT170/12.5
    O
    O
    O
    O
    O
    O
    X
    O
    RDT220/10
    O
    O
    O
    O
    O
    O
    O
    O
    RDT220/12.5
    O
    O
    O
    O
    O
    O
    X
    O
    RDT270/10
    O
    O
    O
    O
    O
    O
    O
    O
    RDT270/12.5
    O
    O
    O
    O
    O
    O
    O
    O
    RDT320/10
    O
    O
    O
    O
    O
    O
    O
    O
    RDT320/12.5
    O
    O
    O
    O
    O
    O
    O
    O
    RDTs115/8
    O
    O
    O
    O
    O
    O
    O
    O
    RDTs140/8
    O
    O
    O
    O
    O
    O
    O
    O
    RDTs140/10
    O
    O
    O
    O
    O
    O
    O
    O
    RDTs170/10
    O
    O
    O
    O
    O
    O
    O
    O
    RDTs170/12.5
    O
    O
    O
    O
    O
    O
    X
    O
    RDTs220/10
    O
    O
    O
    O
    O
    O
    O
    O
    RDTs220/12.5
    O
    O
    O
    O
    O
    O
    X
    O
    RDTs270/10
    O
    O
    O
    O
    O
    O
    O
    O
    RDTs270/12.5
    O
    O
    O
    O
    O
    O
    O
    O
    RDTs320/10
    O
    O
    O
    O
    O
    O
    O
    O
    RDTs320/12.5
    O
    O
    O
    O
    O
    O
    O
    O
    Length of pile pipe without threads
    Pile
    1 m
    1.2 m
    1.5 m
    2 m
    3 m
    4 m
    6 m
    12 m
    12 - 16 m
    16 - 34 m
    RD90
    O
    O
    O
    O
    O
    O
    X
         		- - -
    RD115/6.3
    O
    O
    O
    O
    O
    O
    X
    O
         		- -
    RD115/8
    O
    O
    O
    O
    O
    O
    O
    X
    O
         		-
    RD140-RD320
    O
    O
    O
    O
    O
    O
    O
    X
    O
    O
    RDs90
    O
    O
    O
    O
    O
    O
    O
         		- - -
    RDs100
    O
    O
    O
    O
    O
    O
    O
         		- - -
    RDs115/6.3
    O
    O
    O
    O
    O
    O
    O
    O
         		- -
    RDs115/8
    O
    O
    O
    O
    O
    O
    O
    X
    O
         		-
    RDs125/6.3
    O
    O
    O
    O
    O
    O
    O
    X
         		- -
    RDs140-RDs320
    O
    O
    O
    O
    O
    O
    O
    X
    O
         		-

    Steel grades

    Standard steel grades of SSAB’s micro piles

    Steel grade
    Carbon equivalent
    Chemical composition, max.
    Mechanical properties
    Impact strength
    CEV max.
    C
    Mn
    P
    S
    fymin
    fu
    A5min
    T
    KV min
    [%]
    [%]
    [%]
    [%]
    [%]
    [MPa]
    [MPa]
    [%]
    [°C]
    [J]
    S440J2H
    0.45
    0.16
    1.6
    0.02
    0.02
    440
    490-630
    17
    -20
    27
    S460MH
    0.46
    0.16
    1.7
    0.035
    0.03
    460
    530-720
    17
    -20
    40
    S550J2H
    0.47
    0.12
    1.9
    0.02
    0.02
    550
    605-760
    14
    -20
    27

    Order & delivery

    Contact our sales to order steel micropiles from SSAB's stock or straight from the mill.

    SSAB applies the General Conditions, ALBIF 2000, for deliveries with the addition that the parties will comply with applicable legislative and regulatory requirements and refrain from participating in any corrupt business practices.

    The technical terms of delivery for steel micropiles manufactured by SSAB are in accordance with the EN 10219-1 and ETA-12/0526. The dimensions and tolerances are as defined in EN 10219-2 and ETA-12/0526. Engineering work, as applicable, is in accordance with standard EN 1090-2.

    Steel micropiles are delivered with bundle tags and SSAB's micropile markings to enable full traceability and identification.

    Type 3.1 material certificate will be provided according to the standard EN 10204.

    Build stronger with high performance RRs and RDs steel micropiles

    Our high-strength RR® and RD® micropiles, in combination with efficient designing, easy and quick installation, lower environmental impact than traditional piling create a solution that is now stronger than ever.

    By using the higher steel grade S550J2H, the micropiles load-bearing capacity can be added by up to 20% over that of steel grade S460MH. The increased load-bearing capacity of the pile can be maximized by using smaller micropiles or decreasing the number of micropiles. For the customer, this means a significant improvement in the overall economy of the project.

    micropiles

    Design tools

    Software for fast and easy design

    RRPileCalc is a design program for SSAB's steel piles. Eurocodes as well as National codes and instructions are applied in the end-bearing pile design.

    PileWallCalc design tool enables easy calculation of cross section properties and bending resistances of the pile walls. The program calculates the bending resistances and normal force resistances of RD® pile wall, Combi wall and Zig-Zag Combi wall.

    Read more

    Environmental responsibility and sustainability

    SSAB develops new products and services in order to improve our customers’ performance in sustainability and overall efficiency.

    Life cycle assessment data for SSAB’s products are available in the form of Environmental product declarations (EPDs). Manufacturing chain from raw material to finished product is carefully managed.

    SSAB has introduced CE marking for infrastructure products. Declarations of Performance (DoP) indicate the technical characteristics of CE-marked products.

     

    Read more

    Customer cases

    • Ecovillage at Parainen

      New ecovillage in Parainen, Finland to be carbon negative

      Construction company Godai Oy is building a carbon-negative small house ecovillage to Parainen, Finland. Godai is concerned about the environmental aspects of climate change in the construction industry and this construction project has high goals, as the plan is to build Finland’s first carbon-negative small houses. According to the Ministry of the Environment, construction and buildings account for about one third of Finland’s greenhouse gas emissions.

    • Metsä Fibre Kemi Bio product plant

      SSAB steel piles to Finland’s largest piling site

      Metsä Fibre, part of Metsä Group, is building a new bioproduct mill in Kemi next to existing pulp mill. The new mill will consume 7.6 million m3 of wood in a year and produce 1.5 million tons of pulp of which 70 % will be exported. Metsä Fibre’s investment to Kemi bioproduct mill is worth 1.85 billion euros and it will increase Finland’s export revenue with 0.5 billion euros annually. SSAB supplied displacement piles and micropiles for this new bioproduct mill, which Metsä Fibre is currently building in Kemi, Finland.

    • Underpinning of As Oy Matti in Turku

      Underpinning of As Oy Matti in Turku, Finland

      Residential building of As Oy Matti was originally built on end bearing timber piles in the end of 1960s. The level of the building has been followed for some years and the first leveling data is from 2012. During the first years of leveling, the building was in practice non-settling. Since 2016 there has been clear settlement on one area of the building. The settlement rate accelerated during years 2018 and 2019, which emerged the need for underpinning of the building.

    See all customer cases