Assessment of Soil Conditions with Rayleigh Ellipticity Analysis and Microtremor Methods at Strong Motion Stations in Diyarbakır (Türkiye)

This article presents the results of single-station microtremor measurements conducted in Diyarbak & imath;r Province. To develop shear wave velocity profiles and determine dynamic soil parameters for the region, measurements were carried out at eight strong-motion accelerometer stations located within the provincial boundaries and operated by the Disaster and Emergency Management Authority (AFAD). Data were recorded in three components over a 30 min period. For analysis, the Rayleigh wave ellipticity method was employed in combination with inversion techniques, along with the Horizontal-to-Vertical (H/V) Spectral Ratio method. These analyses yielded shear wave velocity profiles for each station, from which Vs values, predominant ground frequency, and amplification factors were obtained. Based on the average shear wave velocity in the upper 30 m (Vs30), ground classifications were made. In the final stage, earthquake acceleration records were analyzed and compared with the microtremor results. The findings indicate that the predominant frequency values range from 3.64 to 16.61 Hz, while ground amplification values vary between 1.20 and 2.85. The lowest Vs30 value was 555 m/s, and the highest damage vulnerability index (Kg), calculated from the H/V analysis, was 1.90.