Date of Completion

Spring 5-10-2021

Degree Type


Degree Name

Master of Science in Construction Engineering


Construction Engineering


Structural and Geotechnical Engineering

Thesis Advisor

Dr. Jayhyun Kwon



California Bering Ratio (CBR) is used to evaluate the strength of the pavement materials by comparing bearing capacity of the material with that of a high-quality crushed stone. This test adopted by transportation agencies and widely used in the design and analysis of pavement. Several agencies developed design thickness chart based on the CBR values of the subgrade. However, CBR test is time consuming and expensive to perform compared to shear strength test and therefore several studies have been conducted to establish correlation between shear strength and CBR. The published correlation models between CBR and shear strength of soil are based on a limited number of soil test. As the required pavement thickness is directly related to the subgrade strength, misuse of correlation could lead to poor designs in practice. The aim of this study is to examine the published correlation models. Soil samples were collected from four regions in US. Various shear strength tests were conducted to investigate the factors affecting soil strength properties and the results from these tests are presented and discussed.