Geotechnical in situ investigation used for seismic design of buildings

The present process of harmonization of Romanian seismic codes with European standards requires that the effect of local site conditions be included through the soil factor, S, which must be included in the National Annex of Eurocode 8. The modern codes for earthquake resistant design, including Eurocode 8, classify the soils based on qualitative indicators (description of stratigraphy, soil type, layer thickness etc.) and quantitative indicators (average shear wave velocity, Standard Penetration Test results, etc.). Eurocode 8 specifies that the influence of local ground conditions on the seismic action shall generally be accounted for by considering the five ground types A, B, C, D and E, described by the stratigraphic profiles and parameters. The results of the SPT, down-hole prospecting, surface-wave method and CPT tests from the only one available Romanian site (Bucharest Tei) will be presented. The borehole data and the experimental research performed in the last years revealed a new series of elements regarding the stratification and soil characteristics in Bucharest. The evaluation of the soils liquefaction resistance based on in situ tests and the use of the earthquake records will be presented. (authors)