Seismic hazard of the Bayamo region (eastern Cuba) considering local soil typologies

Probabilistic seismic hazard for the Bayamo region (eastern Cuba) is computed taking into account the local soil characteristics, moving away from a broader regional seismic hazard assessment performed over the last few years. A detailed subdivision of local conditions, in terms of soil type categories, is proposed using the available geological map for the region. Two approaches for site-dependent hazard computation follow: the first implies the use of soil-related attenuation relations, the second applies soil amplification factors to the bedrock estimates. For both approaches European and American standards are considered and composed into a logic-tree structure. More precisely, a PGA attenuation relation calibrated on European data and another one calibrated on data from central America are used; PGA amplification factors for soil response are taken from the European and the U.S. building codes. Similarly, macroseismic intensity maps are computed using amplification increments from European and American literature. The final PGA map is, then, converted into a hazard map in terms of macroseismic intensity and compared with the map obtained using intensity data and soil-dependent amplification increments for intensity. A good agreement is obtained following the different approaches. For Bayamo, PGA values ranging from 0.17 to 0.23 g , corresponding to an intensity which goes from VIII to VIII-IX MSK, are expected for a 475-year return period. These values are fairly similar to those obtained using only macroseismic data, that range from VII-VIII to VIII-IX MSK. A local PGA hazard map like the one presented can be used for urban planning and detailed risk estimates, while the map in terms of macroseismic intensity gives an immediate rough estimate of the possible damage and can be used, then, for retrofitting policies.