Hydraulic climbing circular wall formwork

The tank is made as a caisson, it is sunk by its own weight and continuous excavation inside the tank

The tank drops systematically as the soil is removed and the wall is poured. Due to repetition and future similar works it was decided to use customised round formwork of which the inside can retract and climb hydraulically. This automatic climbing avoids the need to use a crane and thus keep the opening of the tank free for the removal of soil from inside.

• Inner diameter 20m, wall thickness 800mm, height 26,5m
• Full circumference inside and outside formwork, poured in one go, height 2m
• Partition wall between dry and wet part of the tank is poured afterwards
• A 1m starter is cast on both ends of the partition wall in phase 1