Civil and Environmental Engineering


First Advisor

Jongwan Eun

Second Advisor

Seunghee Kim

Date of this Version



Robertson, D.W. (2022). "Experimental and Numerical Analysis of Soil-Geosynthetic Composite for a Geosynthetic-Reinforced Roadway System." NTRC No. MPMC-11, Nebraska Department of Transportation.


A THESIS Presented to the Faculty of The Graduate College at the University of Nebraska In Partial Fulfillment of Requirements For the Degree of Master of Science, Major: Civil Engineering, Under the Supervision of Professors Jongwan Eun and Seunghee Kim. Lincoln, Nebraska: May, 2022

Copyright © 2022 Daniel W. Robertson


The present research conducted tests to evaluate the reinforcing performance of geosynthetics including three geogrids (GG1, GG2, and GG3) and one geotextile (GT) for three different soil types – sand, clay, and red shale. All geosynthetics showed great improvement under the lowest confining pressure. The report concluded that between the Large-Scale Direct Shear test, the Large-Scale Pullout Box, and the FLAC simulation, the three geogrids showed the greatest improvement when conducted with sand. The sand could withstand a much greater normal pressure than either clay or red shale. The biaxial geogrids, GG1 and GG3, had ideal results for lower stress application. The clay showed that while not one geosynthetic was clearly better than another, the geotextile produced the best results at low pressure. The red shale showed that generally the three geogrids worked better, specifically GG2 and GG3 with their smaller aperture size.

Advisors: Jongwan Eun and Seunghee Kim