PHYSICAL AND DYNAMIC PROPERTIES OF THE QUATERNARY SEDIMENTARY LAYERS IN AND AROUND BUCHAREST CITY

New seismic measurements are performed in Bucharest area with the purpose of defining better physical and dynamic properties of the shallow sedimentary rocks. Downhole seismic measurements were performed in 10 cased boreholes drilled in the Bucharest Metropolitan area. Processing and interpretation of the data lead to the conclusion that shallow sedimentary rocks can be considered weak in the area, down to 150-200 m depth. Seismic wave velocity values and bulk density values presented in the paper associated with local geology are useful primary data in the seismic microzonation of Bucharest City. They are used as 1D models to derive transfer functions and response spectra for the stack of sedimentary rocks in several parts of Bucharest area, leading to a better knowledge of the local site amplification and associated frequency spectra. This paper was presented in the symposium "Thirty Years from Romania Earthquake of March 4, 1977", 1-3 March 2007, Bucharest, Romania.