Fundamental research for developing accurate logging system of S-wave Attenuation
| Project/Area Number |
59490007
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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 | Akita University |
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Principal Investigator |
KITSUNEZAKI Choro Mining College, Akita University., 鉱山学部, 教授 (90025338)
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| Project Period (FY) |
1984 – 1985
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| Project Status |
Completed (Fiscal Year 1985)
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| Budget Amount *help |
¥3,000,000 (Direct Cost: ¥3,000,000)
Fiscal Year 1985: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1984: ¥2,500,000 (Direct Cost: ¥2,500,000)
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| Keywords | S-wave / seismic wave / flexural wave / shaker source / logging / suspension type S-wave logging / attenuation / Q値 |
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| Research Abstract |
1. The two-source probe system of the suspension type S-wave logging was developed, which makes possible accurate measurement of attenuation and velocity of S-wave by compensating effects of erroneous transmission characteristics proper to every receiver position. The related researches on theories and data processings were carried out.
2. The system developed was tested in a 80m deep hole. Other systems were also examined for the comparison. The following results were obtained.
(1) The two-source system was surely effective to improve accuracy of the S-wave velocity measurement.
(2) High accuracy measurements of the attenuation are obtained for Q<less than or similar>20 also in this system. Sufficient accuracy was not obtained because Q<greater than or similaects of erroneous
(3) The present system has some problems as follows: diffeience of characteristics of the two sources; twist of the probe; insufficient strength of the cable.
3. At the experiments in shallow soils, abnormally low velocity and high attenuation in the sand layer below the ground water level were observed for P-wave. The S-wave properties, however, were normal. It was concluded based on White's model that these properties were due to small amount of gas phase in water contained in the sand layer.
4. The further improvements of the system are necessary. The system should be designed corresponding to the purposes. The above property related to gas inclusion may provide wide application to many fields.
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Report
(1 results)
Research Products
(6 results)
