Date of Award:


Document Type:


Degree Name:

Master of Science (MS)


Civil and Environmental Engineering

Committee Chair(s)

Brady R. Cox


Brady R. Cox


James A. Bay


Mohsen Z. Esteghamati


In order to design structures that can withstand anticipated earthquake loads, it is first necessary to understand the behavior of the subsurface when subjected to ground motions. To achieve this, different models and approaches have been proposed in recent decades, each with the aim of estimating how site-specific stratigraphy can amplify and/or scatter seismic waves. All of these methods require, to varying extents, information about the types of soil layers, their thickness, their stiffnesses (represented by a shear wave velocity profile), and lateral variability across the site. This last characteristic is often both difficult and costly to determine. Past research has shown that excluding lateral variability within a model leads to predictions that differ greatly from actual recordings when applying one-dimensional ground response analysis.

The purpose of this paper is to analyze a cost-effective approach to incorporate spatial variability in soil stratigraphy by using only one invasively-measured shear wave velocity profile and recordings of ambient noise from numerous receivers distributed on the surface. These receivers aid in the identification of soil column heterogeneity by indicating changes in the fundamental frequency (i.e., the lowest resonant frequency) of a given area with only a few minutes of three-component (two horizontal, one vertical) ambient noise recorded. Once a pseudo-3D shear wave velocity model has been composed, future numerical wave propagation studies can apply the model to better correlate and correct theoretical results to empirical ground motion recordings.