Estimation of the Period of Vibration of Existing Egypt RC Building Based on Experimental Data and Numerical Results Under the Effect of Soil-Structure Interaction

Abstract

Most seismic design codes generally provide formulas to be used for the estimation of the base shear and lateral loads. For the determination of the lateral loads, it is required to estimate first the fundamental vibration period of the building theoretically or experimentally. This fundamental period and its length are relevant to earthquake engineering applications on existing buildings, and must be treated very carefully. In various current codes and in the recommendations of many researches, empirical formulas relate the building fundamental period of vibration (T) to the building overall height (H) or the number of stories (N) without consideration of the soil structure interaction (SSI). In the present study, a data set acquired of about 150 reinforced concrete building in Egypt using ambient vibration measurements (AVM) has been analyzed in order to investigate the fundamental period. Improved formulas for estimating the fundamental period of vibration (T) of reinforced concrete moment-resisting frame buildings using regression analysis are developed by taking the effect (SSI). The results indicate that the value of coefficient (T) in the current international and Egyptian building codes’ formulas should be modified to be function of the effect of (SSI). Comparisons between the periods determined using the proposed formula and the measured values show good agreement.