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Volume 46, Issue 1
Displaying 1-4 of 4 articles from this issue
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Effect of Specimen Size and Rock Properties on the Uniaxial Compressive Strength of Ryukyu LimestoneTetsuya KOGURE, Hisashi AOKI, Akira MAEKADO, Yukinori MATSUKURA2005 Volume 46 Issue 1 Pages 2-8
Published: April 10, 2005
Released on J-STAGE: February 23, 2010
JOURNAL FREE ACCESSA uniaxial compressive strength (UCS) test was performed to clarify the effect of specimen size and rock properties on UCS of Ryukyu Limestone. Specimens were square pillars of similar shape but different size, having side d (1cm, 2.5cm, 5cm, 7.5cm, and 10cm) and height of 2d. We found that (1) the UCS has a clear scale effect, decreasing with increasing size of the specimen; (2) the UCS increases with increasing density of the specimen; and (3) the UCS increases with increasing secant Young's modulus. The UCS of Ryukyu Limestone is strongly influenced by specimen size and rock properties.View full abstractDownload PDF (1264K) -
Keisuke KOJIMA, Daisuke SUZUKI2005 Volume 46 Issue 1 Pages 9-19
Published: April 10, 2005
Released on J-STAGE: February 23, 2010
JOURNAL FREE ACCESSThe accurate evaluations of Quaternary structure of the region are indispensable in order to accurately predict the seismic damage. However, deep borehole, PS logging and elastic wave exploration have been executed only on limited points around the Fukui Plain. The problems analyzed in this study are statistical estimations of the 3D Quaternary configuration of the Fukui Plain using data from 197 microtremor observations. The 3-components single-site microtremor observations were carried out in every mesh of the 1 minute interval which covers the Fukui Plain. The 3D configuration models of Quaternary have been evaluated by using kriging and cokriging procedure in which the correlations of the estimated depths of quaternary with the altitudes of the sites were taken into account. By comparing with kinds of inversion analysis results and boring data, the validity of the estimated structure was examined.View full abstractDownload PDF (4211K) -
Yoshikazu YAMAGUCHI, Yosuke NAKAMURA, Makoto NAKAMURA, Noriaki HAKOISH ...2005 Volume 46 Issue 1 Pages 20-27
Published: April 10, 2005
Released on J-STAGE: February 23, 2010
JOURNAL FREE ACCESSFoundations for embankment dams are often composed of soft rocks and/or strongly weathered rocks. Rocks of these kinds usually have low strength and are very susceptible to slaking. Therefore, foundation surface of such rocks should often be covered with shotcrete before an embankment to be prevented from slaking. For the excavationmanagement of rock foundation of this kind, in addition to the conventionalmethods, such as visual observation and hammer blow, the development of a quick and accurate excavationmanagementmethod is strongly required. In this study, we have investigated the applicability of needle penetration test to verify design strength of soft rock foundations for embankment dams. We firstmade needle penetration tests at a dam site, and estimated unconfined compressive strength. Secondly, we performed the triaxial compression tests of the undisturbed samples collected from the dam site. From these results, we finally concluded that a needle penetration test could be used as a quick and accurate verificationmethod of design strength of dam foundations composed of soft rocks.View full abstractDownload PDF (2741K) -
Guoyun ZHOU, Tetsuro ESAKI, Mowen XIE, Yasuhito SASAKI2005 Volume 46 Issue 1 Pages 28-37
Published: April 10, 2005
Released on J-STAGE: February 23, 2010
JOURNAL FREE ACCESSA GIS-based thee dimensional landslide prediction systems is proposed. Firstly, all single slopes (Slope unit) are identified by proposed GIS terrain analysis. Secondly, 3D slip surface is modeled by using an interface between ground and an ellipse. The spatial posture of this ellipse is determined based on the digital data of terrain elevation, aspect and slope angle. A modified HOVLAND's three dimensional slope stability safety factor equation is used. By using Monte Carlo simulation technique, the spatial posture of the ellipse and the ellipse curvature can be randomly changed, and by calculating the safety factor for all the cases the critical slide surface, which gives minimum safety factor for slope failure, can be found and corresponding critical spatial slide volume can be determined for every slope in entire area.View full abstractDownload PDF (2247K)
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