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Volume 42 (2001 - 200･･･
- Issue 6 Pages 335-
- Issue 5 Pages 264-
- Issue 4 Pages 208-
- Issue 3 Pages 140-
- Issue 2 Pages 74-
- Issue 1 Pages 2-
Volume 42, Issue 4
Displaying 1-7 of 7 articles from this issue
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Tomochika TOKUNAGA, Rika AOYAGI, Katsuro MOGI, Hiroshi KAMEYA, Hiroyuk ...2001 Volume 42 Issue 4 Pages 208-213
Published: October 10, 2001
Released on J-STAGE: February 23, 2010
JOURNAL FREE ACCESSA new method to determine hydraulic conductivity and storage coefficient was developed. Here, we tried to set the boundary conditions for the experiments as simple as possible, and to estimate both the hydraulic conductivity and the storage coefficient directly by measuring both the fluid pressure and strains of the porous medium.
This technique is very simple and straightforward to get two hydraulic properties for fluid flow process through a porous medium. Also, the comparison between measured and calculated strain behaviors during the dewatering process can be used to self-check the accuracy of the obtained parameters. Our method does not need to conduct complicate inversion calculations and can be used easily for parameter dentification.View full abstractDownload PDF (1822K) -
Toshifumi IGARASHI, Takahiro OYAMA, Noriyuki SAITO2001 Volume 42 Issue 4 Pages 214-221
Published: October 10, 2001
Released on J-STAGE: February 23, 2010
JOURNAL FREE ACCESSBatch leaching experiments were carried out to quantify the potential occurrence of acid leachate from sedimentary rocks, resulting from the oxidation of pyrite contained in rocks. Thirty sedimentary-rock samples were collected from several areas of Japan, and crushed rock samples were used for the experiments. The results showed that both pyrite content and calcite content in the rock played an important role in determining the pH of the leachate. Stoichiometrically, the pH of the leachate was proved to be weakly alkaline when the ratio of molar concentration between carbonate carbon and sulfide sulfur in the rock sample was greater than approximately 0.5 to 1. When the molar concentration ratio was smaller than 0.5, the pH of the leachate decreased with the depletion of the ratio. The decrease in the pH of the leachate with the leaching period was also observed due to a difference in the dissolution rate between calcite and pyrite.View full abstractDownload PDF (1510K) -
Development for Geo-engineering Application using Present Signal Transrnission MethodsMasaaki KOMAZAKI, Shigeru TSUKAZAWA, Kenji URATA, Fumito ITO, Masuyuki ...2001 Volume 42 Issue 4 Pages 222-230
Published: October 10, 2001
Released on J-STAGE: February 23, 2010
JOURNAL FREE ACCESSData transmission method through mobile phone and mobile multimedia network is the useful method to transmit measured data from field to a central monitoring office, when the measurement sites for disaster protection or geoengineering survery are located in mountainous or coastal areas where telephone lines are not equipped. It is difficult to find papers in which data transmission method through mobile multimedia network, and transmission time of dynamic data of large amount are discussed in detail. Because of this reason, three kinds of data transmission tests using PDC method, PHS method and Satellite Transmission method were carried out to examine the practical transmission times for the data capacity of 45 kbyte. This paper gives that measured transmissiontimes in 3 kinds of transmission methods were longer than calulated times. But the difference between measured and calculated times was only from several s to ten and several s. It was confirmed that practical transmission time was almost equal to calculated transmission time under the through put coefficient of 0.7.
Through the development of Information Technology Revolution, it will be possible to transmit data to anywhere in the world by new signal transmission method “IMT-2000” (International Mobile Telecommunication), which will start form October in 2001. Authors expect that this study including datatransmission technology using mobile multimedia network will surely develop several field on geo-engineering application and open the way for many researchers and engineers.View full abstractDownload PDF (2029K) -
Yoshiya INOUE, Kenji KAZARASHI, Takeshi YOSHIDA, Tatsuaki MIYOSHI2001 Volume 42 Issue 4 Pages 231-237
Published: October 10, 2001
Released on J-STAGE: February 23, 2010
JOURNAL FREE ACCESSWe were able to record the microtremor observation on the shallow submarine site (water depth within 10m) just like land-surface recording. Seismometers have been arranged like double triangls using 7 pieces of seismometers. The array's maximum radius is 50m.
1) Submarine seismometer needs waterproof container. The structure of container must resist sea-tide and wave.
2) This observation system is able to record at the water depth from 4m to 8m.
A further development is necessary to extend the maximum depth.
3) The normal frequency range is from 1Hz to 7Hz, for analysis of the surface-wave. The noise of sea-tide and wave be comes significant when the frequency of less than 1Hz is used.
4) In the case of a water depth within 10m and array's radius within 50m, we recommend the recording-system which connects submarine seismometers and degital-recorder on land or on ship with signal cables.
5) In the case of this observation system, it is desirable to fix the submarine-cable with weights to protect from cable noise.
We are going to research the submarine array microtremor observation and establish the method in the future.View full abstractDownload PDF (1746K) -
Taku KOMATSUBARA, Shiro WATANABE2001 Volume 42 Issue 4 Pages 238-241
Published: October 10, 2001
Released on J-STAGE: February 23, 2010
JOURNAL FREE ACCESSDownload PDF (2737K) -
Manabu TAKAHASHI, Takashi NARITA, Yasuo TOMISHIMA, Ruriko ARAI2001 Volume 42 Issue 4 Pages 242-247
Published: October 10, 2001
Released on J-STAGE: February 23, 2010
JOURNAL FREE ACCESSDownload PDF (1671K) -
2001 Volume 42 Issue 4 Pages 260
Published: 2001
Released on J-STAGE: February 23, 2010
JOURNAL FREE ACCESSDownload PDF (59K)
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