Akademik Veri Yönetim Sistemi
6th International Conference on Earthquake Engineering and Seismology, Kocaeli, Türkiye, 13 - 15 Ekim 2021, cilt.1, ss.559-567
Natural period equation in earthquake codes of many countries is mostly given depending on the number of stories
or the height of the building. However, the calculation of the period considering only the height of the building,
or the number of stories may lead to faulty designs. It is well known that the period is related to mass and stiffness.
Mass can be considered equivalent to building weight. But the stiffness varies depending on the building
dimensions, dimensions and quantity of the vertical reinforced concrete elements, concrete material properties,
floor height, infill wall quantity and properties. In this study, natural vibration period equation including the factors
affecting the stiffness and mass of framed and/or shear walled buildings is developed. In the proposed equation,
height of the building, total vertical load carrying members including infill walls in the direction considered,
principal plan dimensions of the building and concrete compressive strength are taken into account. Predicted
natural vibration periods was firstly compared with the periods of the 23 buildings obtained from microtremor
measurements and RMS error was calculated as 0.045. Some of the microtremor measurements were recorded
from the strengthened buildings. It was found from the microtremor measurements that infill walls should be
considered in the dynamic analysis of the 3d models of the buildings. From this finding, additional 35 buildings
were considered and 3d modeled. Natural vibration periods were found after dynamic analysis, and they were
compared with the periods calculated from the proposed equations. The RMS error was found as 0.033. It was
realized that the proposed equation predicts natural vibration periods better than the available equations. Besides
it can predict periods of both principal directions of a typical building. As the equation considers the concrete
strength and the amount of the load carrying members in direction considered it can be utilized from frame
buildings to shear wall buildings.