In April 2015, construction of Finland's largest urban project started: the REDI Complex in Kalasatama, Helsinki's eastern inner city area. This project consists of six new high-rise buildings with 1,200 apartments, an office and a hotel tower as well as a 60,000 m² shopping centre.
In the first step, the excavation pit for the towers and the shopping centre including the planned parking decks was excavated and the needed foundations were built.
Majakka Tower: Finland's tallest apartment building
At a height of 132 m and with 35 floors, Majakka Tower, the first building, will be Finland's tallest apartment building after its completion, which is scheduled for 2018. The complete project is scheduled for completion between 2022 and 2024.
In total, the large construction site required approx. 200 temporary, 7-12 strand, 25 m long strand anchors. Furthermore, about 100 permanent, 7-15 strand and 20 m long rock anchors were installed to stabilize the excavation.
The TH concrete walls needed for the different buildings were anchored in the soil and rock using permanent WR single bar anchors. The TH walls were then individually post-tensioned in sections using post-tensioning bars, and the individual tendons were extended to the required lengths using couplers. About 500 bar anchors with double corrosion protection in lengths of 12-15 m were used for this purpose.
The installation, stressing and tendon grouting was carried out by DSI Construction's licensee Tensicon. The bar anchors were stressed using a portable hollow-piston CFRP cylinder.