Geophysics and Geophysical Exploration ISSN:1229-1064(Print) 2384-051X(Online) 지구물리와 물리탐사

To reveal shear-wave velocities (vs) and site characterization of Wonju, Korea, Rayleigh waves were recordedat 78 sites of lower altitude using 12 to 24 4.5-Hz vertical geophones for 20 days during the period of February toSeptember 2013. Dispersion curves of the Rayleigh waves obtained by the extended spatial autocorrelation method wereinverted using the damped least-squares method to derive vs models. From these 1-D models, the average vs to a depthof 30 m (vs30), vs of weathered rocks, depths to these basement rocks, and average vs of the overburden layer werederived to be 16.3 ± 0.7 m, 576 ± 8 m/s, 290 ± 7 m/s, and 418 ± 13 m/s, respectively, in the 95% confidence range. Todetermine adequate proxies for vs30, we computed correlation coefficients of vs30 with topographic slope (r = 0.46) andelevation (r = 0.43). An empirical linear relationship is presented as a combination of individually estimated vs30 withweighting factors of 0.45, 0.45, and 0.1 for topographic slope, elevation, and mapped lithology, respectively. Due to aweak correlation between vs30 obtained from inversion of dispersion curves and the proxy-based estimation (r = 0.50),however, the relatively large error range should be considered for applications of this relationship.