Abstract
In long-term consolidation process, bentonite shows secondary and tertial stages. Bentonite is a microinhomogeneous material consisting of mainly nanometer scale of smectite clay minerals, micron scale of macro-grains, water, and air. One smectite mineral is a platelet or lamella. Several minerals are piled up and form a stack. In saturated bentonite, water exists both in the interlayer space of stacks and in external pores. The interlayer water is chemically active. Here, we first present experimental results of an in situ X-ray diffraction (XRD) analysis during consolidation process. The data suggest that at the first stage of consolidation, water is drained from external pores, and at the secondary stage, the interlayer water is drained. Second, molecular dynamics (MD) analyses are applied to specify local properties of hydrated smectite. We also show that by MD the secondary consolidation is not caused by visco-elastic characteristics of clay skeleton. Third, we present a multiscale homogenization analysis (HA) method applied to the seepage behavior of bentonite. Here, the local property of water viscosity calculated by MD is used. Fourth, the results of permeability change are introduced in a 1-D finite strain consolidation analysis, which can represent the secondary consolidation behavior. And if multicharged anions are infiltrated, the chemical properties of bentonite are drastically changed. This causes a change of permeability. This is a major factor of the tertial consolidation. We discuss an analysis method of tertial consolidation because of this permeability change.
| Original language | English |
|---|---|
| Pages (from-to) | 487-513 |
| Number of pages | 27 |
| Journal | Mechanics of Materials |
| Volume | 36 |
| Issue number | 5-6 |
| DOIs | |
| Publication status | Published - May 2004 |
| Externally published | Yes |
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Keywords
- Bentonite
- Diffusion
- In situ X-ray diffraction
- Molecular dynamics simulation
- Multiscale homogenization analysis
- Permeability
- Secondary and tertial consolidation
ASJC Scopus subject areas
- Mechanics of Materials
Cite this
Secondary and tertial consolidation of bentonite clay : Consolidation test, molecular dynamics simulation and multiscale homogenization analysis. / Ichikawa, Yasuaki; Kawamura, Katsuyuki; Theramast, Nattavut; Kitayama, Kazumi.
In: Mechanics of Materials, Vol. 36, No. 5-6, 05.2004, p. 487-513.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Secondary and tertial consolidation of bentonite clay
T2 - Consolidation test, molecular dynamics simulation and multiscale homogenization analysis
AU - Ichikawa, Yasuaki
AU - Kawamura, Katsuyuki
AU - Theramast, Nattavut
AU - Kitayama, Kazumi
PY - 2004/5
Y1 - 2004/5
N2 - In long-term consolidation process, bentonite shows secondary and tertial stages. Bentonite is a microinhomogeneous material consisting of mainly nanometer scale of smectite clay minerals, micron scale of macro-grains, water, and air. One smectite mineral is a platelet or lamella. Several minerals are piled up and form a stack. In saturated bentonite, water exists both in the interlayer space of stacks and in external pores. The interlayer water is chemically active. Here, we first present experimental results of an in situ X-ray diffraction (XRD) analysis during consolidation process. The data suggest that at the first stage of consolidation, water is drained from external pores, and at the secondary stage, the interlayer water is drained. Second, molecular dynamics (MD) analyses are applied to specify local properties of hydrated smectite. We also show that by MD the secondary consolidation is not caused by visco-elastic characteristics of clay skeleton. Third, we present a multiscale homogenization analysis (HA) method applied to the seepage behavior of bentonite. Here, the local property of water viscosity calculated by MD is used. Fourth, the results of permeability change are introduced in a 1-D finite strain consolidation analysis, which can represent the secondary consolidation behavior. And if multicharged anions are infiltrated, the chemical properties of bentonite are drastically changed. This causes a change of permeability. This is a major factor of the tertial consolidation. We discuss an analysis method of tertial consolidation because of this permeability change.
AB - In long-term consolidation process, bentonite shows secondary and tertial stages. Bentonite is a microinhomogeneous material consisting of mainly nanometer scale of smectite clay minerals, micron scale of macro-grains, water, and air. One smectite mineral is a platelet or lamella. Several minerals are piled up and form a stack. In saturated bentonite, water exists both in the interlayer space of stacks and in external pores. The interlayer water is chemically active. Here, we first present experimental results of an in situ X-ray diffraction (XRD) analysis during consolidation process. The data suggest that at the first stage of consolidation, water is drained from external pores, and at the secondary stage, the interlayer water is drained. Second, molecular dynamics (MD) analyses are applied to specify local properties of hydrated smectite. We also show that by MD the secondary consolidation is not caused by visco-elastic characteristics of clay skeleton. Third, we present a multiscale homogenization analysis (HA) method applied to the seepage behavior of bentonite. Here, the local property of water viscosity calculated by MD is used. Fourth, the results of permeability change are introduced in a 1-D finite strain consolidation analysis, which can represent the secondary consolidation behavior. And if multicharged anions are infiltrated, the chemical properties of bentonite are drastically changed. This causes a change of permeability. This is a major factor of the tertial consolidation. We discuss an analysis method of tertial consolidation because of this permeability change.
KW - Bentonite
KW - Diffusion
KW - In situ X-ray diffraction
KW - Molecular dynamics simulation
KW - Multiscale homogenization analysis
KW - Permeability
KW - Secondary and tertial consolidation
UR - http://www.scopus.com/inward/record.url?scp=0346279917&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0346279917&partnerID=8YFLogxK
U2 - 10.1016/S0167-6636(03)00073-5
DO - 10.1016/S0167-6636(03)00073-5
M3 - Article
VL - 36
SP - 487
EP - 513
JO - Mechanics of Materials
JF - Mechanics of Materials
SN - 0167-6636
IS - 5-6
ER -