Date of Award
Master of Science
Civil, Construction, and Environmental Engineering
Civil Engineering (Geotechnical Engineering)
Cassandra J Rutherford
The purpose of this study was to investigate the influence of plastic and silty fines on the shear strength and the porewater pressure (PWP) response of Ottawa Sands. The sands have been mixed with both plastic and silty soils at different percentages. The fines were added ranging from 5% up to a threshold value by weight for constant dry unit weight and sheared in consolidated undrained triaxial compression (CU) test at a constant small strain rate. The advantages of using skeletal void ratio in cases where fines are present within pure sand samples are also discussed.
The properties of plastic fines such as the plasticity of the fines, the percentage of fines content, and the clay mineralogy are studied to understand the influence on the undrained behavior of sands. In order to have a better understanding of the generation and dissipation of PWP during undrained shearing in sandy and sandy soils with plastic and non-plastic fines, a novel PWP measurement system was designed to measure PWP at the center of a triaxial specimen. Factors influencing the development of PWP such as strain rates, the relative density of the sands and the percentage of fines content along with their plasticity index were investigated. Results from the study indicated that the effect the fines on the soil response varies on the amount and type of fines and also on the initial relative density of the host sand.
Padhye, Nikheel, "Effect of plastic and silty fines on the shear behavior and pore water pressure generation in sands" (2020). Graduate Theses and Dissertations. 17886.