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Volume 50 (2009 - 201･･･
- Issue 6 Pages 319-
- Issue 5 Pages 262-
- Issue 4 Pages 202-
- Issue 3 Pages 126-
- Issue 2 Pages 70-
- Issue 1 Pages 2-
Volume 50, Issue 3
Displaying 1-5 of 5 articles from this issue
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General Article
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Keiji KOJIMA, Yasunori OHTSUKA, Hiroyuki OHNO, Fumio KARUBE, Akiyoshi ...2009 Volume 50 Issue 3 Pages 126-139
Published: 2009
Released on J-STAGE: March 31, 2013
JOURNAL FREE ACCESSThe authors, first, reviewed past 50-year history of regional developments and artificially-changed natures in Tokyo Bay area. Then, they showed how engineering geology contributed to those artificial changes. They also showed how to create the logical system of engineering geology based on the basic earth-science and geotechnical theories and knowledge. The discussed case studies include; conversion of the logics for making geotechnical maps from ground surface maps; methodology for obtaining geotechnical properties by using natural analog theory; assigning geotechnical properties to geological strata and logical extension for degradation of geotechnical properties.
Based on the 50 years experiences, it is important that engineering geology should be developed by establishing logical extension of three basic logics (natural phenomenology, geotechnical properties theory, methodology) and their overlapping fields. In particular, it is important to extend logics and methods of sequence stratigraphy or natural analog and assigning geotechnical properties to geological strata. In other words, assigning geotechnical properties should be done on the basis of the natural ground properties obtained by wide and long-term observations. In order to sophisticate the prediction methods of natural responses due to artificial changes, it may be required to develop some advanced tools for observing natural phenomena widely and simultaneously.View full abstractDownload PDF (6581K)
Original Article
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Hironori KATO, Masahiro CHIGIRA2009 Volume 50 Issue 3 Pages 140-150
Published: 2009
Released on J-STAGE: March 31, 2013
JOURNAL FREE ACCESSGravitational slope deformation occurs in the Ho-oh Mountains that runs on the south of E-W trending Median Tectonic Line (MTL) in central Shikoku.
The deformation occurs intermittently along the main ridge as long as 20km, and deformational features, such as ridge-top depressions are made in some portions. It is found that the deformation was induced by the tectonic upheaval of the south side of the MTL and in turn it affected the near-surface morphology of the MTL fault. And it also affected gravitational slope deformation. The slopes along the MTL, which consist mainly of pelitic schist, form dip slopes along the MTL. And also it is that supposed ; it became unstable when they rise along the MTL and consequently gravitationally deformed by the downslope movement of the rock. The fault plane of the MTL, which is generally high-angle, is exceptionally and locally low-angle and dips to the south along the foot of the gravitationally deformed slopes. This could be attributable to that the fault, which is high-angle in the depth, occurs south-dipping thrust near the ground surface when the south side rose under the compressional force exerted by the southern slopes which are gravitationally deformed.
The examination of age and structures of lacustrine deposits in a ridge-top depression indicates that the gravitational deformation made a lake 50 thousand years ago, then, the lake breached 45-24 thousand years ago, and the current morphology of the mountains was formed.View full abstractDownload PDF (3435K)
Report
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—A Case Study on The 2005 West Off Fukuoka Earthquake—Takahito KUROKI, Nozomi ISO, Kensuke GOTO2009 Volume 50 Issue 3 Pages 151-159
Published: 2009
Released on J-STAGE: March 31, 2013
JOURNAL FREE ACCESSIn this study, we investigated the condition and the size of cracks caused by the 2005 West off Fukuoka Earthquake on various types of objects such as wooden house, concrete building, fence and floor and road in Fukuoka urban area and analyzed the data of cracks by GIS. We made a damage distribution map on the earthquake from the results of the analysis and discussed the relationships between that and geologic and geomorphologic conditions. We clarified the followings through this study.
1) We converted the points of condition and the size of cracks into 7 ranks of a unified standard based on these related setting between various types of objects in a small area, so we could make a damage distribution map with mostly objectivity.
2) The damages were large at the seaside area, the east area of Kego fault and the surface of the ground of buried valleys where the basement rock is deep. They were small at the surface of the ground over the underground convex landform of basement rock and near hills where the basement rock is shallow.
3) The damages were small at terrace, natural levee and alluvial plain. On the other hand, they were large at hills and the landforms near seaside such as reclaimed land since the World War II, coastal lowland and dune.
4) We referred to the concept of quantitative evaluation on a borehole wall and an outcrop in engineering geology for a unique compiling method on a damage distribution map.
We had better to study other cases for the map because the 7 ranks of a unified standard in this study are not sufficiently general.View full abstractDownload PDF (4102K)
Short Report
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Takato TAKEMURA, Namiko SAITO, Jyun-ichi IKENO, Manabu TAKAHASHI2009 Volume 50 Issue 3 Pages 160-164
Published: 2009
Released on J-STAGE: March 31, 2013
JOURNAL FREE ACCESSThe recent rapid advances in technology have resulted in an increased demand for the high-precision processing of the industrial materials such as silicon wafer. Against this backdrop, the wheel stone is one of the important tools for industrial technology and manufacturing industry. However, as for the finishing wheel stone, called “Awasedo”, it is assumed that the natural wheel stone may still more excellent than the artificial wheel stone. “Awasedo” is the most appreciated and most commonly used by craftsman whetting the edge of a Japanese sword.
In this paper, the objective is to innovate the excellent performance of “Awasedo” to the artificial wheel stone. With this objective in mind, we characterized the microstructure of “Awasedo” from the viewpoint of the engineering geology. As the results, we find out that the micropore of the high quality “Awasedo” is mainly composed of sub-micron pores.View full abstractDownload PDF (2755K)
General Article
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Hiroyuki OHNO2009 Volume 50 Issue 3 Pages 165-176
Published: 2009
Released on J-STAGE: March 31, 2013
JOURNAL FREE ACCESSTo solve environmental problem, we have to grasp the problem, being holoscopic. It is important that we grasp total flow of material/energy, to make the sustainable social environment. In this paper, I considered and examined what we can do about that.
Recently, according to environment changes such as the climate changes, environmental problems have been linking with disasters. Environmental destruction generates with disaster, and disaster would occur frequently because of environment changes. To solve these situations, it is necessary to improve the engineering. Thus we should carry out disaster/environment education in long-term view in several tens of years. And, it is shown what we should teach fundamentally.
In addition, the approach from practicing viewpoint is discussed based on logics of natural phenomena, geotechnical properties, and methodology. The author showed that it should take measure of the problem of regional environment for the maximum happiness of the greatest number. Therefore, we should introduce viewpoint of the applied ecology and the environment economics into engineering geology, and should apply the concept of complex systems on the viewpoint of four-dimension concept by time and space.View full abstractDownload PDF (5632K)
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