Shear-wave velocity model of reference site conditions in South Carolina for site response analysis and probabilistic seismic hazard mapping.

This paper presents the development of a shear-wave velocity (V S) model of reference site conditions in South Carolina for site response analysis and seismic hazard mapping. Model development involves creating contour maps of two geologic surfaces in the Coastal Plain with high contrasts in V S and combining the results with median V S profiles that extend to hard rock (V S ≥ 3000 m/s). Uncertainties associated with the contour maps of depth are captured in maps of the standard prediction error. Values of time-averaged V S in the top 30 m (V S,30) ranging from 1183 to 1538 m/s and 354 to 385 m/s characterize the reference site conditions in the Blue Ridge and Piedmont regions and the Coastal Plain region, respectively. The model is divided into 14 zones to facilitate site response analysis and to avoid over-smoothing resonances due to the impedance contrasts. This study is part of a larger effort to develop statewide probabilistic seismic hazard maps for the South Carolina Department of Transportation. • A geology-based, shear-wave velocity (V S) model of reference site conditions in South Carolina is developed. • Two depth contour maps are created: 1) Top of the Jurassic and older basement; and 2) Bottom of the Santee Limestone. • V S30 for reference outcrop site conditions are between 354 m/s and 385 m/s in Coastal Plain of South Carolina. • In the South Carolina Blue Ridge and Piedmont, V S30 for reference outcrop site conditions range from 1183 to 1518 m/s. • South Carolina is divided into 14 zones for the purposes of site response analysis. [ABSTRACT FROM AUTHOR]