Author ORCID Identifier

Date Available


Year of Publication


Degree Name

Master of Science in Civil Engineering (MSCE)

Document Type

Master's Thesis




Civil Engineering

First Advisor

Dr. L. Sebastian Bryson


The small-strain shear modulus and shear strength are two crucial mechanical behaviors used in the design of geotechnical structures and in the analyses of earth materials subjected to static and dynamic loadings. Traditional testing methods for these parameters are expensive and time-consuming. This research aimed to address these challenges by developing a model based on the inverse relationship between mechanical behavior of unsaturated soils and the soil-water characteristic curve (SWCC). The proposed model integrates a scaling function to align the SWCC with the mechanical property curve. Empirical relationships were established for the scaling function, specifically aligning with the air-entry value of the SWCC. Recognizing that empirical relationships derived from small laboratory samples may not fully represent field conditions, this study calibrated the proposed relationships using data from large scale tests in a box. To achieve this, two soils were compacted within a large-scale test box with sensors positioned to measure matric suction, volumetric water content, and electrical conductivity at varying densities. Accelerometers were also placed to capture seismic data within the box. By correlating the small-strain shear modulus determined from shear wave velocity measurements with the proposed model, calibrations were made to better reflect large-scale test conditions. Subsequently, the modified model was applied to a field site, demonstrating satisfactory agreement with the measured data.

Digital Object Identifier (DOI)

Funding Information

The material presented in this thesis is based upon work supported by the University of Dayton Research Institute under Subcontract # RSC19048, in support of the US Air Force under Prime Contract # FA8650- 18-C-2808