Theses and Dissertations

Issuing Body

Mississippi State University


Vahedifard, Farshid

Committee Member

Peters, John F.

Committee Member

Yarahmadian, Shantia

Date of Degree


Document Type

Graduate Thesis - Open Access


Civil Engineering

Degree Name

Master of Science (M.S.)


James Worth Bagley College of Engineering


Department of Civil and Environmental Engineering


The main objective of this research is to use IGA as an efficient and robust alternative for numerical simulation of unsaturated seepage problems. Moreover, this research develops an IGA-based probabilistic framework that can properly account for the variability of soil hydraulic properties in the simulations. In the first part, IGA is used in a deterministic framework to solve a head-based form of Richards’ equation. It is shown that IGA is able to properly simulate changes in pore pressure at the soils interface. In the second part of this research, a new probabilistic framework, named random IGA (RIGA), is developed. A joint lognormal distribution function is used with IGA to perform Monte Carlo simulations. The results depict the statistical outputs relating to seepage quantities and pore water pressure. It is shown that pore water pressure, flow rate, etc. change considerably with respect to standard deviation and correlation of the model parameters.