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Volume 43 (2002 - 200･･･
- Issue 6 Pages 345-
- Issue 5 Pages 270-
- Issue 4 Pages 208-
- Issue 3 Pages 124-
- Issue 2 Pages 66-
- Issue 1 Pages 2-
Volume 43, Issue 2
Displaying 1-5 of 5 articles from this issue
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Gen FURUYA, Atsuo TAKEUCHI, Z. SHOAEI, J. GHAYOUMIAN, Hideyuki TANAKA2002 Volume 43 Issue 2 Pages 66-74
Published: June 10, 2002
Released on J-STAGE: March 25, 2010
JOURNAL FREE ACCESSGroundwater behavior has been considered as one of the main factors that have been causing many landslides in Iran. However, investigation and study for groundwater flow in landslide has not been enough. We investigated temperature of groundwater flow and underground temperature in every one-meter depth at some landslides in semi-arid area, northwestern Iran in 1997 and 1998. Ground water vein-streams have been especially tried to presume by the result of onemeter depth underground temperature survey at the Barikan landslide. In addition, water quality investigation (water temperature, electric conductivity, chemical analysis) has been carried out at springs, irrigation channel and river in and around this landslide to evaluate these vein-streams. The conclusions of this study have been made as follows : From the measured temperature of one-meter depth underground and ground water at some landslides around the Alborz mountains, it is understood that the one-meter depth underground temperature survey is applicable in northwestern Iran. However the determination about inappropriate period for this survey is necessary in future because this period is different from the case of Japan. There are five low temperature zones at the Barikan landslide, which is first serious case of this survey in Iran. From the results of water quality test and location of springs, it is estimated that groundwater veinstreams in the landslide mass form these low temperature zones. In addition, the groundwater that is supplied fromthe terrace behind the active landslide block has an effect on landslide movement at the Barikan.View full abstractDownload PDF (3272K) -
A Cace Study of an Application to Landslides of Colluvial Deposits with a Gentle and Long Slope in the Yuya Peninsula, Northwestern Yamaguchi PrefectureKiyoshi HISANAGA, Motoyuki SUZUKI, Tetsuro YAMAMOTO2002 Volume 43 Issue 2 Pages 75-82
Published: June 10, 2002
Released on J-STAGE: February 23, 2010
JOURNAL FREE ACCESSLandslide strength is the most important value among parameters that influence the cost of landslide prevention works. However, it is difficult to determine the precise value of the landslide strength. The landslide strength can be generally calculated by the back analysis, assuming that a stability factor of an objective slope is approximately equal to 1.00. In the case of an inactive landslide, the landslide strength may be underestimated by the assumption that the stability factor is equal to 1.00. This underestimation results in an over design of the prevention work. Therefore, it is necessary to determine a reliable value of the landslide strength for inactive landslides individually.
In this paper, the authors proposed a new simple method to determine the landslide strength for landslides of colluvial deposits having a gentle and long slope in the Yuya Peninsula, northwestern Yamaguchi Prefecture. The landslide strength obtained by the back analysis has previously been used to estimate the stability factor of a landslide block that occurs in landslide protection regions in the peninsula. It is pointed out that the landslide strength is related to the slope angle and thickness of landslide deposits. Residual strength of each colluvial deposit that constitutes the landslide blocks is also measured by ring shear tests. Accordingly, the validity of the method is approved in order to determine strength parameters of an inactive landslide of colluvial deposits having a gentle and long slope.View full abstractDownload PDF (1212K) -
Ming ZHANG, Manabu TAKAHASHI, Tetsuro ESAKI, Hidenori ENDO2002 Volume 43 Issue 2 Pages 83-91
Published: June 10, 2002
Released on J-STAGE: February 23, 2010
JOURNAL FREE ACCESSThe accurate hydraulic characterization of low permeability geologic environments has important practical implications. In the present study, we clarified some major problems in using conventional laboratory methods for testing low permeability geological materials. A new and versatile laboratory system is devised that can implement any of the three test methods, the constant-head, flow-pump and transient-pulse tests, while subjecting a specimen to high confining pressures and pore pressures, thereby simulating in situ conditions at great depths. To exam the capabilities of this new laboratory system, a series of cross-check permeability tests is also performed on Shirahama sandstone and Inada granite that are two rock types widely encountered in Japan. The results showed that the permeabilities derived from the three complementary laboratory methods are in general agreement with variations in the same order. The consistency of these results illustrates the versatility and effectiveness of the new laboratory system for testing low-permeability geological materials.View full abstractDownload PDF (1961K) -
Takeshi KAMEI, Hirokazu ISHIHARA2002 Volume 43 Issue 2 Pages 92-100
Published: June 10, 2002
Released on J-STAGE: February 23, 2010
JOURNAL FREE ACCESSDrammen is located 40km southwest of Oslo, in the valley of the Drammen river. The landscape consists of terraces of post-glacial marine clay. CNS elemental analysis was performed on Drammen clay to investigate the relationship between total sulfur (TS), total organic carbon (TOC) and total nitrogen (TN) in the post-glacial sediments from Drammen, near Oslosfjord. A simplified method for distinguishing freshwater sediments from marine sediments based on TOC and TS has already been proposed. The method was defined as the weight ratio of organic carbon to pyrite sulfur (C/S). Variations in TS, TOC and TN with depth were determined. The principle of this method is also useful for evaluating sedimentary environments, namely normal post-glacial marine sediments and fresh water sediments poor in organic matter.
In addition, an attempt was made to determine calcium carbonate contents of the actual specimens used for assessing engineering characteristics. The variation of calcite (CaCO3) content within natural soils with respect to depth and its effect on strength-deformation characteristics is also investigated. The results show thatstrength-deformation characteristics generally increase with increasing CaCO3 content of the soils.
Use of the CNS elemental analysis makes such determinations relatively quick and inexpensive and is recommended.View full abstractDownload PDF (1902K) -
Noriyuki FUJII2002 Volume 43 Issue 2 Pages 101-109
Published: June 10, 2002
Released on J-STAGE: February 23, 2010
JOURNAL FREE ACCESSDownload PDF (3181K)
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