Theses and Dissertations
Issuing Body
Mississippi State University
Advisor
Vahedifard, Farshid
Committee Member
Newman, Jr. James C.
Committee Member
Peters, John F.
Committee Member
Kim, Seongjai
Date of Degree
8-10-2018
Document Type
Dissertation - Open Access
Major
Civil Engineering
Degree Name
Doctor of Philosophy
College
James Worth Bagley College of Engineering
Department
Department of Civil and Environmental Engineering
Abstract
The main objective of this research is to present a robust numerical framework based upon Isogeometric analysis (IGA) for simulation of thermo-hydro-mechanical (THM) processes in variably saturated soils. The proposed platform employs the Bézier extraction operator to connect IGA to the conventional finite element analysis (FEA), allowing to take advantage of features offered by the two methods. In the first part, the formulation and numerical implementation for fully coupled numerical simulation of THM problems in saturated porous media are presented. The results are compared against analytical solutions and experimental tests available in the literature. In the second part, the proposed method is used to study the temperature effect on the hydro-mechanical response of sd supporting hydrocarbon pipelines, an aspect that has been overlooked in the majority of previous studies. The results highlight the need for considering nonisothermal behavior in different analysis and design stages of sd-buried pipelines. In the third part, the proposed IGA-FEA framework is extended to evaluate the nonisothermal elasto-plastic behavior of unsaturated soils. Drucker-Prager yield surface is used as criterion to limit the modified effective stress where the model follows small strain, quasi-static loading conditions. The framework is used to simulate strain localization of unsaturated dense sand subjected to undrained compression loading. In comparison with FEA, the present method smoothly distributes plastic strain over the adjacent elements. The parametric study highlights the importance of considering temperature effects in elasto-plastic analysis of unsaturated soils.
URI
https://hdl.handle.net/11668/19934
Recommended Citation
Shahrokhabadi, Shahriar, "Isogeometric Analysis of Thermo-Hydro-Mechanical Processes in Variably Saturated Soils" (2018). Theses and Dissertations. 2879.
https://scholarsjunction.msstate.edu/td/2879
Comments
Isogeometric analysis||Thermo-Hydro-Mechanical modeling||Variably saturated soils