1990 Fiscal Year Final Research Report Summary
Study of Oceanic Wave and Submarine Mass Movement
| Project/Area Number |
63490019
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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 |
広領域
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| Research Institution | Niigata University |
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Principal Investigator |
TATEISHI Masaaki Niigata University, Faculty of Science, Associate Professor, 理学部 (00126426)
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| Co-Investigator(Kenkyū-buntansha) |
FUKUE Masaharu Tokai University, Department of Marine Civil Engineering, Associate Professor, 海洋学部, 助教授 (40119699)
MARUI Hideaki Niigata University, Research Institute for Hazard in Snowy Area, Associate Profe, 積雪地域災害研究センタ, 助教授 (10219545)
IZUMIYA Tatsutoshi Niigata University, Faculty of Technology, Lecture, 工学部, 講師 (60151429)
OHKAWA Hideo Niigata University, Faculty of Technology, Associate Professor, 工学部, 助教授 (50018826)
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| Project Period (FY) |
1988 – 1990
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| Keywords | Submarine mass-movement / Wave / Storm wave / Submarine soil layer / Liquefaction / Grain-size distribution / Pore pressure / Efficient of compaction |
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| Research Abstract |
The purpose of this project is to make clear the phenomena and the process of liquefaction and mass-movement of submarine soil layers, and of the transportation of sand body, which are caused by the interaction between submarine soil layer and wave, especially storm wave. The results are summarized as follows :
1) The investigation of characteristics of the submarine soil profile in Sagami Bay, Suruga Bay and Seto Inner Sea reveals that sediment profiles can be well expressed by the simplified equations deduced assuming grains. Using the equations, sediment profiles can be predicted in terms of water content, void ration, undrained shear strength, unconfined compressive strength and effective overburdened pressure.
2) The mass-movement sediments caused by storm waves in the geologic and historical ages are fine- to very fine-grained, well sorted sands which don't include the smaller grains more than silt-sized. They show characteristic hummocky stratification. The sheet sands by storm-ge
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nerated turbidity currents are deposited in the deeper environment than storm wave base.
3) The general relationship between wave condition and outbreak of liquefaction of soil layer was deduced. The examination of the relationship indicated that the outbreak of liquefaction is affected more by coefficient of pore pressure than by the efficient of compaction.
4) To research the liquefaction and effusive sand in the soil layer intercalated with clay layer, the model experiment vibrated forcely was made. The result showed dynamic water pressure with vibration, which indicates the dynamic flow of the soil as liquid, is observed at the liquefied stage, and that the resistance of clay layer accelerates the liquefaction.
5) The movement of sands under the condition coexisting wave and turbidity is examined in terms of probability using the Fokker - Planck equation. The result indicated that the distribution of transportation distance is the Gauss distribution in which the distance is increased as time. Less
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