Spatial Variability of Shear Stiffness in Quaternary Alluvium

Session: Data Fusion and Uncertainty Quantification in Near-Surface Site Characterization [Poster]
Type: Poster
Date: 4/30/2020
Time: 08:00 AM
Room: Ballroom
Description: 

The spatial variability of shear stiffness of near surface materials is important to consider when evaluating the seismic performance of continuous civil infrastructure or lifelines. In this study, spatial autocorrelation (SPAC) was used to find Rayleigh wave velocity profiles every 5 meters along a 300 meter transect of Quaternary younger alluvium (Qya). The dispersion curves from the SPAC measurements were then used to invert shear wave velocity profiles along the transect. The spatial correlation/variability of shear stiffness was calculated using semi-variograms, giving the distance where this spatial correlation is at a minimum. This study found the distance (the range of the semi-variogram) to be roughly 100 meters for soil at a depth of 10 to 15 meters and 90 meters for soil at a depth of 30 meters. This semi-variogram range is then used to evaluate the probability of failure of an idealized lifeline system.

Presenting Author: Robb Moss

Authors