Project/Area Number |
16360238
|
Research Category |
Grant-in-Aid for Scientific Research (B)
|
Allocation Type | Single-year Grants |
Section | 一般 |
Research Field |
Geotechnical engineering
|
Research Institution | Kyoto University |
Principal Investigator |
OKA Fusao Kyoto University, Graduate school of Engineering, Professor, 工学系研究科, 教授 (10111923)
|
Co-Investigator(Kenkyū-buntansha) |
KIMOTO Sayuri Kyoto University, Graduate school of Engineering, Associate Professor, 工学系研究科, 助教授 (70362457)
KODAKA Takeshi Meijo University, Faculty of Science and Technology, Associate Professor, 理工学部, 助教授 (00252271)
YASHIMA Atsushi Gifu University, Faculty of Engineering, Professor, 工学部, 教授 (90144394)
OTANI Jun Kumamoto University, Faculty of Engineering, Professor, 工学部, 教授 (30203821)
|
Project Period (FY) |
2004 – 2006
|
Project Status |
Completed (Fiscal Year 2006)
|
Budget Amount *help |
¥14,800,000 (Direct Cost: ¥14,800,000)
Fiscal Year 2006: ¥1,600,000 (Direct Cost: ¥1,600,000)
Fiscal Year 2005: ¥2,000,000 (Direct Cost: ¥2,000,000)
Fiscal Year 2004: ¥11,200,000 (Direct Cost: ¥11,200,000)
|
Keywords | compaction bands / strain localization / X-ray CT / diatomaceous mudstone / elasto-viscoplastic model / shear bands / sensitive clay / triaxial test / ひずみの局所化 / 三軸圧縮試験 / 構成式 / 数値解析 / 砂 / 軟岩 / 三軸試験 / 有限要素法 |
Research Abstract |
ABSTRACT: Strain localization problems such as shear bands and slip surfaces are very important because those are precursor of failure. Hence many researchers have been studying for the last 30 years. On the other hand, compaction bands have been studied in recent years for the analysis of large settlement of off shore structures. In fact, experimental work on porous geomaterials has been done from 90s. A series of triaxial compression tests under the drained conditions was performed on diatomaceous porous rocks. A rectangular-shaped prismatic specimen was used to easily measure the strain distributions on the specimen surface. The distributions of local strain, i.e., shear strain, axial strain, and volumetric strain, were measured on the surface of the specimen by using an image analysis technique newly developed for this experiment. After the shear testing, the changes in density of the specimen were measured by an X-ray CT scanner. Some high density regions were found to correspond to the compaction bands observed in the image analysis in the cases of relatively high confining pressure levels. Then, we have carried out a numerical simulation of sensitive clay using an elasto-viscoplastic model with structural degradation based on the finite deformation theory, and we have found the compressive strain localization during the consolidation process. In addition, using the same model, numerical simulations of consolidation of soft clay and drained triaxial tests of diatomaceous mud stone have been carried out to study the compressive localization, namely, compaction bands and strain localization of geomaterials was discussed.
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