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Atrium Furniture Store
Technical data of the project This project contains the static of a 750 t heavy steel structure (S235) and a 750 t heavy concrete construction (B30 and B40) for the Commercial and Business Building "ATRIUM - House of the Furniture" in Bratislava - Slovakia, where the steel structure was mounted from January to September 2003. The total length of this structure is 102,90 m, the width between 8,25 to 20,50 m, the area 1550 m² and the volume more than 40.000 m³. The building costs have been 4.000.000 Euro.
Description of the Steel Structure The static system is a space frame in both directions. The steel structure consists of two main dilatation structures and 13 modules (6 + 7) with a length of 7,50 m. The steel structure consists of 41 main columns, connected to one another with horizontal beams on levels of relevant floors and minimum cross bracings - due to architectural de-sign. The steel structure is designed as a self-supporting static system, which is able to transfer horizontal and vertical forces into the foundations and into the two steel-concrete boxes for both of the main dilatation structures, which create a stable unit due to its rigid walls. The access to relevant floors is enabled in these steelconcrete boxes via sideways concrete stairways and lifts. The steel structure is open at the ground floor, here garages for cars are foreseen. On the following floors the walls are clad with ALU glass- and thermo- panels. The constructional height of every floor is 4,20 m. Wall cladding is stiffened by auxiliary columns and cross- bracings between elevations +3,00 and +13,70 m.
Description of the Parts of the Steel Structure The main columns are designed of broadflanged beams HE600A (0. to 3-th floor) and HE300A (4-th to 5-th floor). There are erection joints on two elevations of the structure. Transversal beams are made of open-section rolled steel beams. The connection of col-umns and beams is made by means of steel sheet flanges and bolts. The floor beams are made of open-section rolled steel beams. The various parts are connected with bolts in the erection phase. The beams are secured against yawing with profiled sheets with a thickness of 1 mm under the steel concrete floors.
Why is this Project so Important? The individual floors serve as exhibition and sales areas for luxurious furniture goods. The lower area is an enormous parking space for cars, by means of a lift the client has direct access to the exhibition and sales areas without having to leave the building. The main en-trance is accessible from the street through a bilateral platform, one of which serves as an entrance for the disabled. All the floors are connected, both by lifts and inclining planes, all visible from the outside through the glass façade. The highest two stories serve for the management and offices. The building is filled with highlevel furniture, a new market seg-ment in Slovakia. With its architecture, significance and supply of goods, this sales space is therefore meeting the requirements of even the most demanding clients.
Why is this Project so Special? Frame cross beams in the main modulus axes are positioned in transverse direction, they are so-called cellular beams of an overall height of 900 mm with circular apertures of diame-ter 600 mm. Cellular beams are manufactured with a specific technology on special produc-tion lines, on order, from IPEprofiles 500 mm. After long negotiations with the investor and the architect, the steel structure was designed from steel, fully revealing, without any hiding structures. Severe aesthetic demands were imposed with regard to connections, surface, dressings, etc. The cellular beams serve for concealing air ducts and other cabling, the visi-bility of which is however ingeniously suppressed by impressive illumination. The investor expressed the demand for additional sales areas outside the basic ground plan area of the building. This was realized by means of bracket plates which are suspended on the steel structure by oblique tense steel profiles. These "drawers" are arranged absolutely irregularly on the rear façade of the object above the railway, it is architectonically very impressive.
Foundations Four anchoring bolts with T- heads anchor the structure into the foundations. Steel concrete feet are positioned on concrete pilots (each one with bearing capacity of 500 kN). The foundation of the building on site was very difficult (pilots). The seismicity is of 7o MSK-64, category "A".
Material and Loading Data The horizontal bearing structures of the top of the building are concrete plates of thickness 100 mm (concrete B30). The foundation and bearing structures were designed acc. to ENV 1993-1-1:1992 Euro code 3. The design of the construction consists of the calculation and the evaluation of a number of load cases and their complex combination effect: the dead load (own weight) was considered as well as the live load - on each floor 4,00 kN/m², on the stairways 3,00 kN/m², snow loading so = 0,70 kN/m² and wind loading wo = 0,55 kN/m² (during erection and on final building). After that was considered the seismicity of 7o MSK-64, category "A" and temperature loading (shell structure contains a higher tem-peratures as column support during operation, which leads to thermal stresses).
Description of the Method of Static Calculation The static calculation is prepared with software NEXIS rel. 3.40. Not less than 164 of the most dangerous combinations, acc. to ENV 1993-1- 1:1992 Euro code 3 with coefficient 1,35 in two basic combinations (bearing capacity and deformations), have been calculated. The model contains 1715 nodes, 3177 bars and 1786 macros 1D. The final file was 22,5 MB. The model contains 130 different profile sections of both basic materials - steel and concrete. The linear base modulus (3D frame) had to solve 10290 equations. The program for the calculation of cellular beams acc. to procedure by F. Faltus was done with software MC rel. 7.
