Geodeco has developed an automated seismic hazard software for computing probabilistic seismic hazard maps at the soil surface via multiple analyses over a grid of pre-defined locations. The novelty of this tool hinges on the way that site amplification effects are accounted for. Given the imperfect knowledge of local soil conditions, one or more alternative amplification functions, AF, can be derived, and this epistemic uncertainty is appropriately propagated to obtain the final estimates of the surface hazard via a logic tree approach. At each location the hazard at the ground surface is determined by convolving the seismic hazard at the bedrock with the amplification functions. The AF functions are obtained using a response surface technique. The response surface, which uses the initial elastic fundamental frequency of the soil column as predictor of the AF, is obtained prior to the hazard map computations from a set of non-linear site amplification analyses performed for a large variety of soil formations. In this paper most emphasis is placed on the site amplification module which represents the most original feature of the system.

Hazard maps can be produced on the basis of geotechnical information produced by a geotechnical investigation in the interested local area.

Hazard maps can also be produced on the basis of solely geological information as that contained in a geological map at wider area (regional or national scale).







For more information on Geodeco's seismic risk services please contact Paolo Bazzurro, Ph.D.