1994 Fiscal Year Final Research Report Summary
Consolidation and strength characteristics of Ariake soft clay
| Project/Area Number |
04452296
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
農業土木
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| Research Institution | KYUSHU UNIVERSITY |
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Principal Investigator |
TAKAYAMA Masateru Kyushu Univ., Agriculture, Professor, 農学部, 教授 (60038312)
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| Co-Investigator(Kenkyū-buntansha) |
OKABE Tamenobu Kyushu Univ., Agriculture, Research Assistant, 農学部, 教務員 (60091378)
HIYAMA Hiroki Kyushu Univ., Agriculture, Assistant Professor, 農学部, 助手 (10208788)
HIGASHI Takahiro Kyushu Univ., Agriculture, Assistant Professor, 農学部, 助手 (00181066)
OHTUBO Masami Kyushu Univ., Agriculture, Associate Professor, 農学部, 助教授 (80112316)
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| Project Period (FY) |
1992 – 1994
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| Keywords | Ariake Clay / Flocculation / Self-Weight Consolidation / Zeta Potential / Secondary Consolidation / Deformation Analysis / Pyrite |
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| Research Abstract |
The present paper describes the settling and flocculation characteristics of clay particles and the self-weight consolidation characteristics of slurried clay associated with the development of tidal flat in Ariake Bay coastal area, and also the problems involved in the consolidation and slope failure of clays.
Flocculation of Ariake clay occurs under the salt concentrations above 0.1g/1, and the maximum zeta potential of the clays when the flocculation occurs is -20mv. The flocculative, interface, and compression settlings occur at the initial water content of above 5000%, 5000 to 1000%, and below 1000%, respectively. The self-weight consolidation tests in cylinders for different clay layr thickness, is also proposed.
The study of the consolidation of clays confirmed that the secondary consolidation started when the degree of consolidation reached to around 90%, and the degree of consolidation for secondary consolidation proportional to the time in logarithmic scale is above 98%.
The parameters required for the strength and deformation analysis are presented, and the bearing capacity analysis for normally consolidated clay ground was performed under a partially drained condition.
The investigation of the chemistry of Ariake clay indicated that the production of the sulfuric acid and iron oxide due to pyrite oxidation in the clays decreases pH below 4, which releases the adsorbed zinc on the clay surfaces, leading to the potential risk of groundwater contamination.
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