Improvement of design of storage cavity in rock salt by using the Hou/Lux constitutive model with consideration of creep rupture criterion and damage

The introduction of damage mechanics and a new material model including structural damages into design concepts for the construction of salt cavities reduces some deficits of previous knowledge and modeling. This seems to set out the scientific foundation for a more realistic and thus more economical cavity design while the same level of safety is kept.This paper introduces the major statements worked out by the authors about the further development of salt cavity dimensioning as well as its practical applications.As examples, the calculated load bearing behavior of the so called prototype cavity at the Asse mine and the minimum permissible internal cavern pressure for a storage cavern are examined, comparing the results of the Hou/Lux material model with those of the Lubby2 material model. The comparison shows the advantages of the Hou/Lux material model, such as stress rearrangements from the contour into the rock mass formation as well as the identification of dilatancy, damage, softening and spalling zones and last but not least increasing the profitability of storage cavities through reduction of the minimum pressure.