Comparative Dynamic Analysis of Existing Construction and Construction with Superstructure

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.