18 kilometers of steel piles are being driven and drilled in Jätkäsaari, Helsinki, to build the foundation for the Atlantinsilta bridge and its surrounding structures. Costs and environmental impacts were reduced by optimizing the amount of steel used in the project. SSAB’s versatile range of steel pile dimensions and steel grades allowed optmization of design. At the working site you can see at the same time large diameter and micro piles both drilled (RD® piles) and driven (RR® piles). The works include also an extensive RD pile wall with pre-welded interlocks. There are steel piles from diameter of 169.3 mm to 1016 mm used in the project design. Total amount of steel delivered by SSAB is approximately 2 500 tons.

“This project included a wide variety of SSAB’s steel pile products and piling solutions. By utilizing different pile types, pile dimensions, steel grades and also possibilities for customer specific pile lengths our customer can optimize their piling work and the amount of steel used. Also in this project we could respond to our customer needs both from product range and delivery schedule point of view.” tells Jari Mara, Business Area Manager, SSAB Europe Oy.

Foundation work of the Atlantinsilta bridge in Jätkäsaari, Helsinki, has begun in late 2019 by the contractor YIT. New bridge in Jätkäsaari will serve both local residents and passengers arriving at the West Terminal. Project owner the City of Helsinki expects the project to be completed in May 2021. Project has very tight schedule and challenging circumstances in an urban environment. There is continuous passenger traffic of West Harbour and several building construction projects around the Jätkäsaari area, which is still in the building phase. Project includes a bridge over a waterway and also the construction of shore and quay structures, streets and municipal engineering.

SSAB has been steel piles supplier and co-operation partner with YIT in several major projects in the Helsinki region during the past years like Veturitie street and Pasila Tripla. Project requires trusted suppliers and good co-operation. In this project steel pile foundations are needed for the temporary working bridge (RR270), intermediate supports and abutments (RR600 and RD1000). Piling work is also done for the other structures which belong to the contract. This includes surrounding structures of the bridge; the pile slab (RD170 and RD400) and shoreline retaining wall (RD400, RR220 and RR320). Underneath the pile slab will be RD pile wall working as a lateral support structure to eliminate soil moving and at the same time working as a foundation for the slab. RD pile wall consists of RD500 piles.

The ground conditions overall in this project are challenging; below the ground surface there are fill layers with boulders which are mixed with soft clay layer below. SSAB has designed special lightweight rock shoe for the temporary bridge piles. Challenging conditions also means that there are long pile lengths up to 33 meters being installed to create reliable foundations.