Some Examples of 1D Fully Stochastic Site Response Analyses of Soil Deposits

It is well known that the seismic amplification characteristics of ground motion are strongly influenced by the geotechnical properties of soil deposits and the associated uncertainties. Also the variability of the seismic input significantly affects the results of the ground response analyses. A single deterministic site response analysis, using the mean values of mechanical and physical properties of soil layers and a single recorded time history, does not allow assessing the uncertainty associated to the computed ground motion, due to the aleatory nature of model parameters and the variability of seismic input. Even a series of parametric analyses may not be sufficient, since some critical combinations of geotechnical parameters and seismic input may induce significant ground amplification that is completely overlooked by such an analyses. The uncertainty and reliability of results obtained from ground response analysis may only be achieved via fully stochastic-based procedures. This work aims at illustrating the results of 1D linear equivalent, fully stochastic site response analysis at two sites, one in Southern India, the other in Northern Italy, that have been recently carried out using Monte Carlo simulations associated with the Latino Hypercube sampling technique.