Influence of soil dynamic parameters on seismic response of a site at Fabriano, Italy

Dynamic parameters play an important role in evaluating the seismic response of soil deposits. However, they are affected by many uncertainties associated with the natural variability of soils, sampling techniques, laboratory testing procedures, sensing devices, instrumental biases, operators, etc. Therefore, choosing the ‘best values’ is generally a complex problem of decisionmaking. In this paper, the problem of the influence on seismic response of the uncertainties connected with laboratory testing equipment and procedures used in measurement of damping ratio is considered. Reference is made to the evaluation of site effects in a cohesive deposit in the town of Fabriano, Italy, which was damaged by the Umbro-Marchigian seismic sequence that initiated on September 26, 1997