Driven RR micropile with effective splicing technology
RR piles are micropiles that offer quick and cost-effective splicing, minor displacement of soil, minor vibration disturbance and high installation strength. RR micropiles are installed by impact driving or jacking.
Pile pipes and elements
The RR piles are delivered either as pile pipes or as ready-made pile elements with an external sleeve splice at one end of the element.
Splicing of RR piles
The RR piles utilize friction-based splices that meet the requirements set for rigid splices in the Finnish national appendix to EN 1993-5.
- In RR75 - RR220 piles, the splice is an external double conical sleeve splice.
- Keeping the external splice in place during driving is ensured by welding, which is done at the factory as the splice is made. No welding of the splice is needed on site.
- RR140 - RR220 piles can be extended also with an internal splice if necessary.
- RR270 - RR320 piles are spliced by welding.
If splicing is done by welding, SSAB’s RR and RD pile design and installation manual provide recommendations concerning the creation of welded splices.
Usually a bearing plate is installed at the upper end of RR micropiles to transfer loads from the superstructure to the pile. The bearing plate is centred on the pile shaft by an internal sleeve, which
serves to keep the bearing plate in place.
The mechanically attached pile shoes of RR piles, bottom plates and rock shoes, meet the requirements of PO-2011. The rock shoe dowel is made of hardened special steel, which ensures good penetration into bedrock.