Micropiles offer an effective and convenient way to implement the piling
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.
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.
RR® and RD® piles design and installation manual
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.
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® 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.
Read moreThe micropiles may be drilled through all natural soil layers all the way into bedrock, with small deviations in position and inclination.
Read moreShaft-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.
Read moreAvailability of micropiles: section lengths and micropile pipe lengths.For project specific dimensions, please contact our sales.
Mill dimensions of RR (S460MH) and RRs (S550J2H) pile sections and pile pipes
X = stock size O = project-specific size – = not in production
RR75
RR90
RR115/6.3
RR115/8
RR140/8
RR140/10
RR170/10
RR170/12.5
RR220/10
RR220/12.5
RR245/10
RR245/12.5
RR270/10
RR270/12.5
RRs115/8
RRs140/8
RRs140/10
RRs170/10
RRs170/12.5
RRs220/10
RRs220/12.5
RRs245/10
RRs245/12.5
RRS270/10
RRS270/12.5
Mill dimensions of RD (S460MH) and RDs (S550J2H) pile sections and pile pipes
X = stock size O = project-specific size – = not in production
RDT90
RDT115/6.3
RDT115/8
RDT140/8
RDT140/10
RDT170/10
RDT170/12.5
RDT220/10
RDT220/12.5
RDT270/10
RDT270/12.5
RDT320/10
RDT320/12.5
RDTs115/8
RDTs140/8
RDTs140/10
RDTs170/10
RDTs170/12.5
RDTs220/10
RDTs220/12.5
RDTs270/10
RDTs270/12.5
RDTs320/10
RDTs320/12.5
RD90
RD115/6.3
RD115/8
RD140-RD320
RDs90
RDs115/6.3
RDs115/8
RDs140-RDs320
Standard steel grades of SSAB’s micro piles
S440J2H
S460MH
S550J2H
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.
Software for fast and easy design
PileCalc 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 moreSSAB 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