Geotechnical safety for a cavity field will be assessed on the basis of model computations. The statistical uncertainty of rock salt parameters as well as possible variations in the dimensions of a cavity field under design result in the necessity to carry out a parametric study. The purpose of the paper is to explain probabilistic modeling with respect to structural response computations, using sensitivity and uncertainty analysis. Probabilistic finite element computations have been carried out for a hexagonal cavity configuration. The results are discussed with respect to the variability of the following parameters and their interrelation: diameter, spacing, depth and height of the cavities, creep of the salt rock, and stiffness of the overburden.