Abstract:
Many countries throughout the world have accepted the concept for design of RC buildings
based on the “capacity design” methology.This has been proved also by the Eurocode-8 that is
largerly based on this method.The main idea of this method is to predetermine places at which
the occurrence of nonlinear deformations shall be dictated.This critical parts,the so called
plastic hinges,are designed and processed separately to enable those places dissipate the total
energy.It is desirable that all the inelastic deformations be due to bending,which with the
provided previous and necessary conditions,corresponds to ductile behavior of the structure.
This paper presents the application of the “capacity design” in a structure consisting of RC
frames in both orthogonal directions.In such structures this method is reduced to elimination of
the possibility of formation of plastic hinges in the columns in order to fulfill the basic
principle of(weak beams-strong columns) which is included in almost all seismic
regulations,this method requires a considerably higher bearing capacity of columns.Such a
conservative approach leads to the requirement of larger proportions of columns and a greater
amount of longitudinal reinforcement.
As an example, the proposed methodology is applied to an actual reinforced concrete building
frame structure.Beams,supporting floors,and columns are continuous and meet at nodes,called
rigid joints.Such frames can readily carry gravity loads while providing adequate resistance to
horizontal forces ,acting in any direction.We will make the elastic and plastic analysis by the
program,according Eurocode 8. The analysis will be performed until the response of the
building will reach three conditions. After the final model is reached we will propose the next
step to design the structural elements.The final design of elements will be given in the % of
required reinforced steel.And finally ,we will make the time-history analysis for an actual
earthquake.
