We determined the seismic model of the soil column within a residential project site in Istanbul, Turkey. Specifically, we conducted a refraction seismic survey at 20 locations using a receiver spread with 484.5-Hz ve...We determined the seismic model of the soil column within a residential project site in Istanbul, Turkey. Specifically, we conducted a refraction seismic survey at 20 locations using a receiver spread with 484.5-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 site-specific geotechnical earthquake engineering parameters for the site. Specifically, we computed the maximum soil amplification ratio, maximum surface-bedrock acceleration ratio, depth interval of significant acceleration, maximum soil-rock response ratio, and design spectrum periods TA-TB. We conducted reflection seismic surveys along five line traverses with lengths between 150 and 300 m and delineated landslide failure surfaces within the site. We recorded shot gathers at 2-m intervals along each of the seismic line traverses using a receiver spread with 4 840-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.展开更多
Seismic Hazard analysis requires geologic, seismologic and geophysical data to be applied in a certain area. There are several studies were established to estimate the seismic hazard of Syria. In this study, the autho...Seismic Hazard analysis requires geologic, seismologic and geophysical data to be applied in a certain area. There are several studies were established to estimate the seismic hazard of Syria. In this study, the authors integrated the historical, instrumental seismological data, the structural-geological data of Syria and the subsurface tectonic map of Syria to re-evaluate the seismic hazard of Syria. The current research introduces new seismic source models which were not used before. The source models were chosen according to the structural and tectonic setting of the study area. The recurrence relationship was applied for each source for obtaining the regression coefficients related to each seismic source. Finally, the seismic hazard maps were plotted for (50, 100, 200, 475, and 1000) return periods by using Poisson probabilistic method. Regarding with theses resulted maps, there is obvious increase of the seismicity from the eastern parts of Syria to the western parts which reaches to its maximum value in El-Ghab region.展开更多
文摘We determined the seismic model of the soil column within a residential project site in Istanbul, Turkey. Specifically, we conducted a refraction seismic survey at 20 locations using a receiver spread with 484.5-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 site-specific geotechnical earthquake engineering parameters for the site. Specifically, we computed the maximum soil amplification ratio, maximum surface-bedrock acceleration ratio, depth interval of significant acceleration, maximum soil-rock response ratio, and design spectrum periods TA-TB. We conducted reflection seismic surveys along five line traverses with lengths between 150 and 300 m and delineated landslide failure surfaces within the site. We recorded shot gathers at 2-m intervals along each of the seismic line traverses using a receiver spread with 4 840-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.
文摘Seismic Hazard analysis requires geologic, seismologic and geophysical data to be applied in a certain area. There are several studies were established to estimate the seismic hazard of Syria. In this study, the authors integrated the historical, instrumental seismological data, the structural-geological data of Syria and the subsurface tectonic map of Syria to re-evaluate the seismic hazard of Syria. The current research introduces new seismic source models which were not used before. The source models were chosen according to the structural and tectonic setting of the study area. The recurrence relationship was applied for each source for obtaining the regression coefficients related to each seismic source. Finally, the seismic hazard maps were plotted for (50, 100, 200, 475, and 1000) return periods by using Poisson probabilistic method. Regarding with theses resulted maps, there is obvious increase of the seismicity from the eastern parts of Syria to the western parts which reaches to its maximum value in El-Ghab region.
