Dismantling hall for nuclear waste, Lubmin
Lubmin, Germany / 12.2018 - 12.2019
The federally owned nuclear power plant disposal company Entsorgungswerk für Nuklearanlagen (EWN) GmbH is planning a new hall for dismantling large low to medium-level radioactive power plant parts, where they will be broken up and prepared for disposal or final storage.
PORR Spezialtiefbau was awarded the contract for the foundation works in a bidding consortium with STRABAG AG – Direktion Nord-Ost after a public call for tenders.
Bored piles transfer loads
The team was responsible for the production of 336 large-diameter bored piles to transfer the loads of both the future hall and a water basin located inside the hall into the subsoil. A secant bored pile wall with 86 piles was constructed for this purpose alongside 250 foundation piles.
Challenging subsoil
The subsoil in Lubmin consists mainly of medium-dense sands connecting to cohesive stratified drift. The piles were set down in the underlying dense to very dense sand.
Facts & Figures
Company
PORR Spezialtiefbau GmbH
Type
Foundations
Runtime
12.2018 - 12.2019
Secure foundation with bored piles
All the boreholes had to be drilled under hydrostatic pressure, while taking into account the high level of fines in the soil.
Limited space
The site logistics were challenging, as both employees and suppliers had to register in advance before being permitted to pass through the security gates and enter the plant premises. EWN was also engaged in dismantling a contaminated track while the drilling work was being carried out. This meant that the track section running diagonally across the construction site had to be extensively cordoned off, resulting in very cramped conditions for the Stump-Franki team.
The first test piles were produced in December 2018, and the remaining piles were produced by December 2019 using a Bauer BG 28 H drilling rig. The plant went into operation in late 2021.
Stump-Franki services
- 336 bored piles, d = 88cm, l up to 26.5m