ENGINEERING SEISMOLOGY IN GEOTECHNICAL PROJECTS APPLICATION EXAMPLES (In turkish)


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Yılmaz Ö., Eser M., Şenay G., Berilgen M. M.

Sixth National Earthquake Engineering Conference, İstanbul, Turkey, 16 - 20 October 2007, pp.1-11

  • Publication Type: Conference Paper / Full Text
  • City: İstanbul
  • Country: Turkey
  • Page Numbers: pp.1-11

Abstract

We determined the seismic model of the soil column within a residential project site in

Istanbul, Turkey. Specifically, we conducted refraction seismic survey at 20 locations using a

receiver spread with 48 4.5-Hz vertical geophones at 2-m intervals. We applied nonlinear

tomography to first-arrival times to estimate the P-wave velocity-depth profiles and performed

Rayleigh-wave inversion to estimate the S-wave velocity-depth profiles down to a depth of 30

m at each of the locations. We then combined the seismic velocities with the geotechnical

borehole information regarding the lithology of the soil column and determined the sitespecific

geotechnical earthquake engineering parameters for the site. Specifically, we

computed the maximum soil amplification ratio, natural period of the soil column, maximum

surface-bedrock acceleration ratio, depth interval of significant acceleration, spectral

acceleration ratio, and design spectrum periods TA-TB. We conducted reflection seismic survey

along five line traverses with lengths between 150-300 m and delineated landslide failure

surfaces within the site. We recorded shot gathers at 2-m intervals along each of the the

seismic line traverses using a receiver spread with 48 40-Hz vertical geophones at 2-m

intervals. We applied nonlinear tomography to first-arrival times to estimate a P-wave

velocity-depth model and analyzed the reflected waves to obtain a seismic image of the deep

near-surface along each of the line traverses.