supports and concrete base were simulated. The stiffness of the supports was designed by the rule that the results of horizontal force had to be less than 10 % of the vertical force. From separated load cases, design combinations were created. All members are checked according to STN 73 1401 for ULS. In shell elements stresses are also checked. Structural model The structural model of the tunnel shuttering, as mentioned above, was created by the FEM method. For modelling the shell of the shuttering (a part of which is directly contact with the concrete), the reinforced ribs of the shell, the struts, fixed shell elements were used. With regard to the poured concrete, hydrostatic pressure free loads were used. Each segments of the shuttering is a model (two webs on each part, very close to each other). Between the two ribs, short beams with a node in the middle were created. Working with such a huge model without the use of macro elements and without the possibility to make some parts invisible is practically impossible. ESA-Prima Win/NEXIS made the computational model creation possible. Codes and standards Loads are calculated according to STN 73 0035 (86) Members are checked according to STN 73 1401 (98) Computer programs Internal forces (forces and stresses) calculation is perform by FEM with NEXIS-ESA-Prima Win 32.50.10 For rest of calculations, MC 2001 (by MathSoft USA) was used. 159
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