Abstract

GONZALEZ, Jorge  and  SCHMITZ, Michael. Dynamic characterization of geotechnical profiles in Cariaco (eastern Venezuela), based on seismic refraction data. Rev. Fac. Ing. UCV [online]. 2008, vol.23, n.2, pp.83-93. ISSN 0798-4065.

The town of Cariaco in northeastern Venezuela, located close to the El Pilar Fault, suffered severe damage during the 1997 Cariaco earthquake. After the earthquake, geotechnical evaluations of the soil, and seismic refraction measurements were carried out. A total of 7 seismic lines with variable lengths between 360 and 1080 m were measured, obtaining the S-wave velocity structure of Cariaco with the velocity of the rock equivalent. Based on the geotechnical information obtained from 14 drillings in the area and the S-wave velocity profiles from the seismic profiling, two geotechnical type profiles were defined as input information for the dynamic modeling. The response spectra of both profile types were analyzed at the surface for near and distant earthquakes, comparing the derived response spectra with the normative elastic spectra S2 and S3. It is concluded from the modeling results that for near earthquakes and for distant earthquakes up to a fundamental period of 1.2 s, the town of Cariaco can be characterized globally as an S2 profile in accordance with the COVENIN 1756- 2001 seismic code. For high periods, the acceleration values of the response spectra are greater than the S2 profile.

Keywords : Cariaco; Seismic refraction; Seismic microzoning; Geotechnics; Dynamic analysis.