Thesis Defense Announcement

The Herff College of Engineering announces the final Thesis of

Sudip Khadka 

for the Degree of Master of Science
on March 2, 2018 at 9:00 AM in Engineering Science Building, Room 111

Advisor: David Arellano

A Study on the Influence of Degree of Saturation and Dry Unit Weight on the Shear Strength of Unsaturated Fulton Loess.

ABSTRACT:  Loess is a windblown deposit comprised primarily of silt particles that have a metastable structure characterized by randomly open and loose particle packing with high porosity. It has an ability to stand in near vertical slope in its unsaturated state but resulting in collapse with the increase in the degree of saturation apparently due to the loss in the effective cohesion and matric suction. The higher degree of saturation decreases the shear strength of the soil that makes the structure on loess vulnerable to collapse or excessive settlement and instability. The overall objective of this research is to find the effect of degree of saturation and dry unit weight on the shear strength of loess. To obtain the overall objective of this research, disturbed and intact soil samples will be collected from the field and then, remolded soil specimens will be prepared in the laboratory. The shear strength parameters, cohesion (c') and internal friction angle (φ'), will be determined using direct shear test equipment per ASTM D3080 on both remolded and intact soil specimens under application of various normal stresses and different saturation levels. In addition, matric suction under targeted saturation levels will be measured by determining soil-water characteristic curves (SWCC) using Fredlund device under various application of vertical stresses. Results of these tests will be analyzed to observe the effects of degree of saturation and unit weight on the shear strength of loess.