Seismic soil characterization of Tashkent using Vs30 mapping techniques

This study analysed the distribution of average shear wave velocities in the upper 30-m strata across Tashkent city using the multichannel analysis of surface waves (MASW) method. Shear wave velocities were obtained at more than 600 locations throughout the city. Subsequently, V s maps were constructed and analysed at depths of 5, 10, 15, 20, 25, and 30 m. This study primarily aimed to map the distribution of V S30 (average shear wave velocity in the top 30-m) in Tashkent using data on the given engineering and geological conditions and to categorize the soil based on its seismic properties. This is the first study to assess soil classification using both V S30 values and engineering geological parameters. The results indicated that the V S30 within the study area ranged from 236 to 757 m/s, classifying the soils into categories D, C, and E according to Eurocode 8. The analysis is crucial for engineering design and addressing seismological challenges. Herein, we present a map that categorizes the soils based on their seismic properties and integrated the engineering geological zoning map of the city with the MASW data. This map provides a foundation for assessing seismic hazard and risk of an area as well as for seismic microzoning. • Near surface seismic investigations in Tashkent, Uzbekistan revealed that V S30 = 236–757 m/s. • Based on Eurocode 8 classification, V S30 values correspond to classes D, C, and E. • The territory of Tashkent was divided into several engineering geological zones. • The area proportions were A: 3.4 %; B: 34.8 %; C: 11.4 %; D: 50.4 %.