AbstractsEngineering

One of the primary factors that control the stability of earthen embankments is the shear strength of embankment fill soils. Karl von Terzaghi and U.S. Navy found empirical correlations between soil shear strength and lab or in-situ soil test results. Subsequently, the Navy proposed typical effective friction angle values for different soils types. However, it is not certain if these correlations and standard values are reliable for Ohio soils. The main objective of this thesis is to establish reliable correlations between shear strength and index properties/in-situ test measurements for embankment fill soils existing in Ohio. Relatively undisturbed soil samples were gathered from nine highway embankment sites spread throughout Ohio. Tri-axial compression tests were performed to determine the shear strength of these soil samples. During data analysis, statistical methods, such as regression analysis and T-tests, were utilized to assess the correlations. Through the statistical analysis, optimized correlations were identified between shear strength and other characteristics of soil have been found. Once the optimum correlations were established, soil shear strength properties were applied to sophisticated geotechnical software to perform a series of slope stability analysis for highway embankments. Lastly, results from the laboratory testing, field testing, statistical data analysis, and slope stability analysis were all combined to suggest technical guidelines for highway embankment design/constructions in Ohio.