| Project/Area Number |
16360233
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Geotechnical engineering
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| Research Institution | Saitama University |
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Principal Investigator |
ODA Masanobu Saitama University, Graduate School of Science and Engineering, Professor, 大学院理工学研究科, 教授 (90008855)
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| Co-Investigator(Kenkyū-buntansha) |
IWASHITA Kazuyoshi Saitama University, Graduate School of Science and Engineering, Associate Professor, 大学院理工学研究科, 助教授 (40203377)
KISHINO Yuji Tohoku University, Graduate School of Science and Engineering, Professor, 大学院工学研究科, 教授 (00005448)
SUZUKI Kiichi Saitama University, Graduate School of Science and Engineering, Associate Professor, 大学院理工学研究科, 助教授 (70282423)
KAZAMA Hidehiko Saitama University, Geosphere Research Institute, Professor, 地圏科学研究センター, 教授 (40008868)
川本 健 埼玉大学, 工学部, 助手 (50292644)
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| Project Period (FY) |
2004 – 2006
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| Project Status |
Completed (Fiscal Year 2006)
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| Budget Amount *help |
¥11,500,000 (Direct Cost: ¥11,500,000)
Fiscal Year 2006: ¥1,200,000 (Direct Cost: ¥1,200,000)
Fiscal Year 2005: ¥3,200,000 (Direct Cost: ¥3,200,000)
Fiscal Year 2004: ¥7,100,000 (Direct Cost: ¥7,100,000)
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| Keywords | Granular materials / Mechanism of granular flow / Shear zone / Image analysis / Numerical simulation / 実験 |
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| Research Abstract |
Soil-related structures such as embankments and retaining walls are usually designed on stability analysis. To analyze the stability, soil engineers need a failure criterion of soils, and have done a lot of research works for it. However, failure of soil-related structures is repeated every year, and flowing soil debris causes a huge damage to the civil engineering structures and human lives. This fact implies that not only the failure criterions but also the flowing behavior after failure are very important to reduce such damage. Soil movement starts as quasi-static flow along a shear band, and the speed increases, as called rapid flow, if a certain condition (not understood yet) is satisfied. In order to understand the transition behavior from quasi-static to rapid flow, laboratory tests and numerical simulation tests are carried out, with special interest in the microscopic aspect of flow mechanism during quasi-static and rapid flow. The conclusion are summarized as follows:
1)Two-di
… More
mensional flow of particle assembly is generated in a rotary shear cell, and individual particles are chased by means of high-speed camera and image analysis. Micro-behaviors of granular flow such as particle rotation, granular temperature, collision angle and velocity gradient profile are investigated to obtain a criterion distinguishing between quasi-static and rapid flow from a microscopic point of view.
2)Three-dimensional micro-structure in a quasi-static flow domain is observed by means of micro-focus X-ray computed tomography. Based on the results, a new dilatancy model in a shear zone is proposed under strong support from numerical simulation of Distinct Element Method (DEM). A new methodology for quantitative representation of micro-structure is also proposed.
3)DEM is applied to simulate numerically transition from quasi-static to rapid flow, and the results are compared with the ones of laboratory tests. It is found that DEM provides a reliable tool to simulate of whole range from quasi-static to rapid granular flow of granular materials. DEM is expanded, with success, so that the effect of water on granular flow can be taken into account. Less
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