The deformations measured inside the Innsbruck-Ahrental exploratory gallery are used as a basis for reverse calculations and parameter determination. In order to show the expansion as close to reality as possible in the reverse calculation, the single expansion components will be subject to detailed analysis. Thereby, the shotcrete development within the first few days is of vital importance. In a second step, the deformation aliquot "in front of", "behind" and "at" the rock face will be analyzed accurately. The calculations are elaborated with the Convergence Confinement Method (CCM) for geologically homogeneous zones and with the FE programme Phase 2 by RocScience for geological complex zones. The resulting parameters are presented in bandwidths.