Hydromechanical modeling framework for multiscale porous materials
Abstract/Contents
- Abstract
- Hydromechanical interactions between fluid flow and deformation in porous geomaterials give rise to a wide range of societally important problems such as landslides, ground subsidence, and injection-induced earthquakes. Many geomaterials in these problems possess two-scale porous structures due to fractures, particle aggregation, or other reasons. However, coupled hydromechanical processes in these multiscale porous materials, such as ground deformation caused by preferential flow, are beyond the modeling capabilities of classical frameworks. This thesis develops theoretical and computational frameworks for fully coupled hydromechanical modeling of geomaterials with two-scale porous structures. Adopting the concept of double porosity, we treat these materials as a multiscale continuum in which two pore regions of different scales interact within the same continuum. Three major developments are presented. First, we build a mathematical framework for thermodynamically consistent modeling of unsaturated porous media with double porosity. Conservation laws are formulated incorporating an effective stress tensor that is energy-conjugate to the rate of deformation tensor of the solid matrix. Based on energy-conjugate pairs identified in the first law of thermodynamics, we develop a constitutive framework for hydrological and mechanical processes coupled at two scales. Second, we introduce a novel constitutive framework for elastoplastic materials with evolving internal structures. By partitioning the thermodynamically consistent effective stress into two individual, single-scale effective stresses, this framework uniquely distinguishes proportional volume changes in the two pore regions under finite deformations. This framework accommodates the impact of pore pressure difference between the two scales on the solid deformation, which was predicted by thermodynamic principles. We show that the proposed framework not only improves the prediction of deformation of two-scale geomaterials, but also simulates secondary compression effects due to delayed pressure dissipation in the less permeable pore region. Third, we develop a finite element framework that enables the use of computationally efficient equal-order elements for solving coupled fluid flow and deformation problems in double-porosity media. At the core of the finite element formulation is a new method that stabilizes twofold saddle point problems arising in the undrained condition. The stabilized finite elements allow for equal-order linear interpolations of three primary variables—the displacement field and two pore pressure variables—throughout the entire range of drainage conditions.
Description
| Type of resource | text |
|---|---|
| Form | electronic; electronic resource; remote |
| Extent | 1 online resource. |
| Publication date | 2016 |
| Issuance | monographic |
| Language | English |
Creators/Contributors
| Associated with | Choo, Jinhyun |
|---|---|
| Associated with | Stanford University, Department of Civil and Environmental Engineering. |
| Primary advisor | Borja, Ronaldo Israel |
| Thesis advisor | Borja, Ronaldo Israel |
| Thesis advisor | Kitanidis, P. K. (Peter K.) |
| Thesis advisor | Linder, Christian, 1949- |
| Thesis advisor | Regueiro, Richard |
| Advisor | Kitanidis, P. K. (Peter K.) |
| Advisor | Linder, Christian, 1949- |
| Advisor | Regueiro, Richard |
Subjects
| Genre | Theses |
|---|
Bibliographic information
| Statement of responsibility | Jinhyun Choo. |
|---|---|
| Note | Submitted to the Department of Civil and Environmental Engineering. |
| Thesis | Thesis (Ph.D.)--Stanford University, 2016. |
| Location | electronic resource |
Access conditions
- Copyright
- © 2016 by Jinhyun Choo
- License
- This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).
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