// Long-term Safety Studies

ProSiD

Process simulation for the design of support and sealing elements for shaft closures

An essential component in closure concepts for shafts is a gravel column, which serves as a support element for overlying sealing elements due to its settlement stability. An alternative to this would be a column filled with salt gravel. The advantage of using native material is the fact that not only would one have a supporting column, but one could also rely on the long-term sealing effect of this column. Due to the convergence of the rock mass, the salt gravel is further compacted and its permeability reduced. Achieving this requires the best possible compactability of the native material as well as suitable compaction methods. In the context of this project, model calculations will be used to investigate, firstly, at which particle size distribution the best possible in-situ compactability can be achieved and, secondly, which process engineering measures within in-situ compaction processes can lead to the best possible compaction.

For this purpose, a particle model will be developed, which can generate different particle size distributions and simulate a compaction process. It will be examined which particle size distribution ensures the best possible compactability and what influence different compaction methods have on the compaction result. The methods include vibratory compaction and impulse compaction. Both methods involve compacting the material in a short period. Rheological material behavior such as creep is not relevant in these methods.