Study of soil properties using seismic noise for different regions of Georgia

Author: Tamar Shubladze
Keywords: soil properties, HVSR Method
Annotation:

Georgia, like the whole South Caucasus, is a tectonically and structurally complex region. It is one of the most active segments of the Alpine-Himalayan belt, therefore it is important to assess the seismic hazard for Georgia. At the regional scale, this assessment is evaluated by applying probabilistic seismic hazard analysis that identifies the annual probability of exceedance of various ground – motion levels defined in terms of selected ground motion intensity measures, such as PGA or accelerations corresponding to various return periods related to pissible future earthquake scenarios for a site represented by soil classes A according to EC8, Eurocode 8-EN 1998-1 (1998). At the local scale, seismic hazard assessment is made by analyzing the geological, geomorphological, geotechnical and geophysical charasteristics of the site, as it is well established that the incoming seismic motion can change in amplitude, frequency, and duration due the site-specific local charasteristics. That is the subject of microzonation investigation. Site – specific local charasteristics are presented by the following parameters: Dominant frequency, V_(s,30) (averaged shear-wave velocity to a depth of 30 meters) and amplification factor. In this work, we presented results of geophysical surve assessing local seismic conditions by dominant frequency and V_(s,30) for designing and construction of seismically resistant critical infrastructure like hydro power plant in west Georgia and high-riseebuilding in Tbilisi. For this purpose, seismic records have been used first time in Georgia.