Geo-data modelling an engineering tool as guidelines for estimating near-surface seismice effects

Significant damages of built environment recorded during past seismic events have led to consideration of Romania's capital city as one of the major earthquake-prone urban area worldwide. Strong historical ground motions have outlined that variability and specific parameters of layered unconsolidated sedimentary young deposits represents one of key component in site-response analysis. To predict seismic effects of near-surface soils, comprehensive surveys are needed for the estimation of dynamic behavior and site characterization. A large number of shallow and deep boreholes, standard penetration tests and non-invasive field techniques as down-hole and MASW have been carried out in Bucharest sites by CNRRS (now https://ccers.utcb.ro) and UTCB. Shear wave velocities (VS) and penetration resistance (N-SPT) have been set as main indicators in quantifying seismic properties. Empirical correlations to predict VS from N-SPT test values were developed by using statistical methods. The accuracy analysis of proposed correlations is compared with regression equations suggested in technical literature for assessing parameters performance with previous studies and to set out a good fit correlation for analyzed soil conditions. A comparative method between basic soil dynamic indexes determined by in situ investigation and the ones predicted by applying existing numerical models have been performed. The end-results can be considered as efficient guidelines to predict the potential effect of site conditions on similar soil types, layer sequences and properties, and might be useful for evaluation of buildings safety and optimization of seismic risk management strategies.