| | The subject of this paper is the basis of structural design according to the proposal EN 1998-1: 2004, in seismically active areas. The static linear-elastic method, the method of equivalent lateral forces and the nonlinear ("pushover") method for estimating the nonlinear behavior of reinforced concrete load-bearing structures during seismic actions are presented. The paper presents the requirements for the adoption of dimensions and reinforcement of sections in accordance with the regulations of Eurocode 8, which should, in addition to the required load-bearing capacity, meet the requirements of local ductility, which prevents the formation of a plastic mechanism in the form of a flexible floor. By the method of equivalent lateral forces, the seismic action is represented over the acceleration spectrum. Linear elastic analysis of the structure was done using the program "Tower", where the cross sections were adopted and sizing was done strictly taking into account the recommendations from EC 8. In the Tower, two-dimensional elements were used in the analysis of the structure. A nonlinear analysis of the frame with the same adopted dimensions, reinforcement and authoritative load combination was done in the “Abaqus” program, the result of which is the push curve. For modeling columns and beams in Abaqus, three-dimensional hexahedral elements C3D8R were used, which have six degrees of freedom at each node, three translational degrees of freedom (1,2,3) and three rotational degrees of freedom (4,5,6). During the reinforcement modeling, the elements of the B21 linear beam were used, which have two translational degrees of freedom (1,2) and one rotational degree of freedom (6). |
