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Volume 43, Issue 1
Displaying 1-6 of 6 articles from this issue
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Masuyuki UJIHIRA, Takehiko IIZUKA, Youhei KAWAMURA, Minoru KAWAKITA2002 Volume 43 Issue 1 Pages 2-13
Published: April 10, 2002
Released on J-STAGE: February 23, 2010
JOURNAL FREE ACCESSPhotograph is often used in geological survey to measure the length or width of a snapped object, placing some scales such as scale itself, a hammer or a cigarette box nearby the object. However, it is difficult to place a scale nearby the object when the object is too far and high from the taking point or too dangerous to get to the object. In this study, practical applicability of magnification equation of lens for indirect calculation of the length of an object was examined. From this study, following points were made clear (1) Upper limit of applicable distance of magnification equation of lens is more than 300m when the lens whose focal length is longer than 100mm is used. (2) Distortion of a snapped image is within 1.0-2.0%, when the lens whose focal length is longer than 100mm is used. (3) Distortion of a snapped image can be revised using the relationship between the displacement from the correct point and radius from the optical axis. (4) Indirect scale measurement method of a long distant object using a camera and a non-prism razor telemeter is useful. However, accurate measurement of the distance, use of a lens of accurate focal length and accurate measurement of the snapped image on a film are absolutely necessary.View full abstractDownload PDF (2699K) -
The Relation between Acoustic Emission Activity and Growth of Crack in the Fracture Process of RocksTadao IMAI, Fumio SUGIMOTO, Naoto KAMOSHIDA, Shigeru YAMASITA, Mitsuma ...2002 Volume 43 Issue 1 Pages 14-23
Published: April 10, 2002
Released on J-STAGE: February 23, 2010
JOURNAL FREE ACCESSAE amplitude frequency distribution shows a power law by AE activities in the fracture process of rocks. This law is critical for the prediction of the rock fracture. Thefefbre, in the rock fracture brocess, if the relationship between the slope of AE amplitude frequency distribution and crack growth was made clear, then the prediction of rock fracture can be made possible by the analysis of the real time of AE amplitude frequency distribution.
In this study, we investigats the slope (|b| value) of the AE amplitude frequency distribution in the compaction fracture process of rock specimen and the observation of the crack growth in rock specimen after test with the microscope.
In the result of the AE measurement, the |b| value for granite and sandstone decreases before the failure, but that for marble and tuff hardly decreases. Therefore, the observation of the cracks with the microscope, for granite and sandstone revealing that the |b| value decreases, the large under ihtercrystalline cracks grow. For marble revealing that |b| value hardly decreases, the intracrystalline cracks grow closely, but, for tuff, the cracks hardly grows except for along the shear plane.View full abstractDownload PDF (4667K) -
Hidekazu YOSHIDA, Haruo SATO, Takeshi SEMBA2002 Volume 43 Issue 1 Pages 24-34
Published: April 10, 2002
Released on J-STAGE: February 23, 2010
JOURNAL FREE ACCESSMatrix diffusion is one of the key processes to be considered by safety assessments concerned with varied waste disposal in geological host rocks, but especially disposal of radioactive waste. An appropriate method is proposed for evaluating nuclide retardation by matrix diffusion along flow-paths in crystalline rock, using in-situ geological information. The usefulness of the method is evaluated and the results are summarized as follows:
(1) Detailed in-situ characterization of flow-path structures shows that a flow-path can be classified into three types by its structural features. The structural information is important for supporting reliable qualitative analysis of matrix diffusion by laboratory experiments, e. g. to ensure that porosity measurements and diffusion experiments investigate relevant parts of the rock mass.
(2) Information from natural analogues, such as studies of the migration of natural uranium-series isotopes along flow-paths, is useful to build confidence in short-term laboratory experiments for evaluating the long-term diffusional processes.
(3) Mineralogical studies, microscopic observations and dating of the fracture-fillings would be valuable for estimating the long-term stability of fractures and are important for evaluating the usefulness of the methodology for evaluating matrix diffusion in the host rock.View full abstractDownload PDF (3472K) -
Takeshi KAMEI, Hirokazu ISHIHARA, Hideaki KONDO2002 Volume 43 Issue 1 Pages 35-42
Published: April 10, 2002
Released on J-STAGE: February 23, 2010
JOURNAL FREE ACCESSThis paper describes an integrated study of the sedimentary environment of Holocene deposits in the Takaoka Plains (Kochi prefecture), southwest Japan. The geological history and geochemistry (total sulfur, total nitrogen and total organic carbon concentration) of Holocene deposits in the Takaoka Plain form the basis of the study. Total sulfur, total nitrogen and total organic carbon relationships in Holocene sediments have been used to characterize depositional environments, namely normal marine, brackish water and freshwater sediments. The weight ratio of organic carbon to pyrite sulfur (C/S ratio) and total sulfur (TS) are useful for evaluating sedimentary environments. To this end, CNS elemental analysis has led to a better understanding of sedimentary environments. The geological processes of Takaoka Plain with respect to sea level change during the Holocene is also presented.View full abstractDownload PDF (2041K) -
Manabu TAKAHASHI, Xiaochun LI, Weiren LIN, Takashi NARITA, Yasuo TOMIS ...2002 Volume 43 Issue 1 Pages 43-48
Published: April 10, 2002
Released on J-STAGE: February 23, 2010
JOURNAL FREE ACCESSDownload PDF (1536K) -
2002 Volume 43 Issue 1 Pages 57
Published: 2002
Released on J-STAGE: February 23, 2010
JOURNAL FREE ACCESSDownload PDF (79K)
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