This chapter describes the derivation of the necessary input parameters for the modelling work and aims to compare the recorded in situ deformations with those predicted by Universal Distinct Element Code-BB. It presents a numerical study considering the effects of excavation of the three smaller additional caverns in the vicinity of the ice hockey cavern. Based on core characterization in the existing caverns the following typical rock qualities were predicted, for the Olympic Ice Hockey cavern: typical best quality, typical poorest quality and weighted average. The engineering geological mapping in the existing caverns was from 50 to 100 m from the planned location, and the geotechnical logging of cores from four exploratory holes drilled at the cavern location, showed good correlation. The numbers in the cavern area refer to the excavation steps. The rock mass in the cavern arch and the walls were numerically reinforced by intentioned fully grouted rock bolts and anchors after each numerical excavation step.