Projects
Freeze shafts in a salt deposit, Gorleben shafts Nos. 1 and 2, Germany
Design and construction of exploratory shafts for the investigation of the potential as a final disposal facility for nuclear waste using the deep ground freezing technique. Shaft sinking was by drilling and blasting, a shaft cutter being deployed in the freeze shaft part. The ground is water-bearing and unstable down to a depth of 250 m below which the salt dome is located.
The Gorleben shafts were designed to investigate the salt dome for its suitability as a final disposal for nuclear waste. The history underlying the sinking of the shafts is characterised by extensive approval procedures and high safety requirements. The Gorleben Shaft No. 1 was sunk using the final headframe. Various other underground excavations, such as the workshop, were constructed in the vicinity of the shafts. The inner waterproof lining in the freeze shaft part consisted of a composite lining with asphalt backfill. The outer lining was a steel ring liner. The salt dome area was lined with mesh and rockbolts.
