Comparison of Measured and Proxy-Based VS30 Values in California

摘要

This study was prompted by the recent availability of a significant amount of openly accessible measured V-S30 values and the desire to investigate the trend of using proxy-based models to predict V-S30 in the absence of measurements. Comparisons between measured and model-based values were performed. The measured data included 503 V-S30 values collected from various projects for 482 seismographic station sites in California. Six proxy-based models-employing geologic mapping, topographic slope, and terrain classification-were also considered. Included was a new terrain class model based on the Yong et al. (2012) approach but recalibrated with updated measured V-S30 values. Using the measured V-S30 data as the metric for performance, the predictive capabilities of the six models were determined to be statistically indistinguishable. This study also found three models that tend to underpredict V-S30 at lower velocities (NEHRP Site Classes D-E) and overpredict at higher velocities (Site Classes B-C).