Abstract:
The impossibility to provide building land in central urban areas imposes the need for new housing. The
subject of this paper is to make a comparative dynamic analysis of different reinforced concrete structural
systems, the existing and newly designed construction with superstructure of real residential building
which is located in Skopje.
The analysis of the structures is executed with the software package SAP2000 in 3D mathematical
models. In the models are applied static loads, wind loads according to applicable technical regulations,
seismic loads according to Macedonian regulations with the method of equivalent static loads (simplified
modal spectral analysis) and linear time history of earthquake record. Afterwards it is executed dynamic
analysis of the existing construction, construction with superstructure with the same structural members
as the existing construction and the strengthened construction with superstructure (since the dimensioning
is executed). Strengthening of structural members is designed with increasing of cross sections by
addition of new layer.
By the executed dynamic analysis of the reinforced concrete structural systems is made a comparison of
bearing capacity and stress - deformation state of characteristic structural members by comparing:
periods, base reactions, maximal horizontal displacements, M-Φ and M-N diagrams for characteristic
structural members and maximal normal concrete stress in columns.
By the analysis it’s been concluded that the cross sections of strengthened construction had increased
their strength, stiffness, deformation and ductility characteristics, and the construction as a whole
possesses the required level of security for acceptance of the loads.
