Near-Surface Geology and Dynamic Properties of Soil Layers in Bucharest

The importance of site effects due to soil condition in Bucharest was firstly observed during the 1977 Vrancea earthquake. A substantial understanding of the effect of near-surface geology on the characteristics of the ground motion came later, from the analysis of the frequency content of the 1986 Bucharest accelerograms and of corresponding soil profiles at recording sites. The paper focuses on the correlation of the frequency content of the recorded accelerograms in Bucharest with the properties of the near-surface geology (stratigraphy, dynamic characteristics of the soil layers, etc.).To a great extent, the near-surface geology study for the city of Bucharest is based on laboratory tests made by Metroul S.A., during Bucharest subway construction works. Soil layers in thousands of meters of boreholes were analysed.