Soil Influence in Seismic Design of Bridges in Cuba

Soil geological conditions affect directly the seismic structural behavior of bridges. This work shows the importance of determining the site coefficient, a parameter used by Cuban seismic code for considering the influence of soil in the structural response. The research is based in the results obtained from the application of geophysical seismic refraction method. It is presented as an example a bridge located on Granma highway in Santiago de Cuba city, showing variations in lithology present in the area, character-ized by poor soils conformed by saturated sands, and clays. The analysis of these changes in surface lithology demonstrates the relevance of using the weighting of the characteristics of each stratum, be-cause of its influence in the elastic response spectrum and therefore in the shear used for seismic design.