The Seismic Force Development Related to Romanian Designing Codes

Abstract

The seismic calculus researches in the past 50 years also based on experimental recordings are led to changes in the building design standards.
Major changes were made in estimating the dynamic amplification coefficient β which is established in relation to the spectral composition of the seismic movements generated by the Vrancea source and in relation with the reduction coefficient ψ, which accounts for the ductility of the structure.
This paper aims evolution of global seismic coefficient for 3 types of structures situated in Iasi and Bucharest.
By analyzing the results of the seismic force calculus according to the present standards one can notice the major increase of the seismic force value according to the P100-2006 Standard, in comparison with the former ones. Seismic force values representing 40-60% of the seismic force according to P100-2006 for various types of buildings designed in period 1963 - 1992 can be alarming if we think about the number of buildings are made in this time interval.