Mirage Shopping Centre - Zilina, Slovakia
The building is designed as a reinforced concrete monolithic skeleton structure with bracing walls. It consists of two main parts – four-floor bodywork of the existing park house and the new building with eight floors (four underground floors).
The foundation slab of the new building has a thickness of 800 mm and is laid on the clay stone layer 1.5 m under the underground water level. The foundation slab and the peripheral underground walls are made of watertight reinforced concrete.
The vertical load-bearing elements are reinforced concrete monolithic columns and walls. The walls of the vertical communication cores ensure the stability of the building. The spans in the main elliptic axis are 10.5 m. There is a primary continuous beam placed on these columns as well as on the secondary conic beams anchored to it and taking the cantilever of 4.2 m.
The cantilever circles around the whole interior space. In the third floor there is a main elliptic beam placed on the end of the cantilever performing as a support for the great glass dome skylight. The span of the skylight is 32 m. Horizontal load-bearing elements are beamless solid slabs with reinforced concrete mushroom heads.
The thickness of the slabs is 220 mm and the mushroom heads ensure that the allowed deflections and shear forces are not exceeded. The existing park house was executed with the possibility of the bodywork for four uniform floors. New architectural design requested different modulus axis. That is why the new massive reinforced concrete grid was designed at that spot, taking the columns of the upper part. Some vertical load-bearing elements of the existing park house had to be strengthened. Here were added the micro piles working together with the existing foundation slab at positions where the pressure in the foundation base was too high. The software Scia Engineer R2008 was used for the static and dynamic analysis.
The Slovak standards were used for the calculation. Two complete models of the structure were made and all load-bearing elements were designed.
The Scia software allowed for doing the model of the complicated building very easily. It allowed for preparation of several alternatives of the structure as well. There were more designs in the process of the work according to client and architect’s demands and Scia software made it possible to change the structure very easily. The real deflections of the structure were measured on site, and the results are very near to the calculated deflections.