All issues
Volume 39 (1998 - 199･･･
- Issue 6 Pages 486-
- Issue 5 Pages 414-
- Issue 4 Pages 346-
- Issue 3 Pages 244-
- Issue 2 Pages 174-
- Issue 1 Pages 4-
Volume 39, Issue 5
Displaying 1-7 of 7 articles from this issue
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The Case of Ao Granite, Ryoke Belt, Mie Prefecture, SW JapanMakoto OHKOUCHI, Yutaka MORITA, Eiji OKUDA1998 Volume 39 Issue 5 Pages 414-422
Published: December 10, 1998
Released on J-STAGE: February 23, 2010
JOURNAL FREE ACCESSWhen several joint systems are developed in rock masses, different deterioration conditions along those joints are often observed. This shows that those rock masses are different in stages of deterioration. As for the deterioration along joint surface, the following process is recognized in general; from fresh part to weathering part, “fresh joint surface→brown pollution of joint surface→progresses of rock mass weathering”. From such phenomenon, brown pollution along joint surface may be regarded as a phenomenon of initial stage of weathering in fractured rock. In this paper, it is tried to grasp the deterioration tendency of joint by describing the brown pollution conditions on each joint surface. As a result, it was confirmed that the following joint deteriorated, “the joint that was displaced again by most late geological age tectonics”, “low angle joint that is distributed groundwater surface neighborhood”. Since there are limited informations obtainable in the study of engineering geology, we consider that it is very useful to grasp such a tendency.View full abstractDownload PDF (1770K) -
Masuyuki UJIHIRA, Shingo SUZUKI, Shougo HOSOYA, Hiroshi SAEKI, Minoru ...1998 Volume 39 Issue 5 Pages 423-432
Published: December 10, 1998
Released on J-STAGE: February 23, 2010
JOURNAL FREE ACCESSA study on the cable sensor which has the possibility for wide area monitoring of the noises caused by rock fall impact and rock failure was carried out, stretching cable sensors of 19 strings in grid pattern on the internal surface of a model tunnel of which diameter and length were 135cm and 16m respectively. Impact caused by a steel ball dropping was measured by the cable sensors and recorded by a simple system consist of a data logger and a personal computer. Following points were clarified from the study ; 1) Distance between each cable sensor can be extended to 10 m at least because of high sensitivity of the sensor, when the sensors are stretched in a grid pattern on the surface of a concrete spreading of a tunnel or a rock shed. 2) Output voltage of the cable sensor can be converted easily to the value of acceleration from the experimental equation which is obtained from an impact test using a cable sensor and an accelerometer. 3) Signal-to-noise ratio of the cable sensor is almost equal to those of accelerometers or velocity pickups usually used for geological surveys. 4) Impact source caused by a steel ball dropping could be judged clearly, both from rise time and amplitude of wave forms of cable sensors, when the cable sensors were stretched on the internal surface of a model tunnel. 5) A topography which was drawn using peak values of wave forms of cable sensors of 19 strings could display the impact source of a steel ball dropping to the roof of the model tunnel. 6) Impact signal caused by the weight dropping could be distinguished clearly, even when the vibration which corresponded to traffic noise was given to the tunnel.View full abstractDownload PDF (2786K) -
The Structure and Origin of Conical Hills on Nirasaki Mudflow, Japan (2)Hideo KASAI1998 Volume 39 Issue 5 Pages 433-442
Published: December 10, 1998
Released on J-STAGE: February 23, 2010
JOURNAL FREE ACCESSThe author carried out the VLF-MT survey to investigate the details of the geological structure of the Yato Castle Hill, which is located on the Nirasaki mud flow at the southern foot of Mt. Yatsugatake, Yamanashi Prefecture. Apparent resistivity, phase angle, electric field strength and magnetic field strength are measured along the lines using 50meters station intervals, and we interpreted the obtained VLF-MT data on the assumption of the two-layer earth model, according to the model based upon the distributions of the observed phase angle and resistivity. Yato Castle Hill consists of four layers; a layer of 27-94hm meters, a layer of 100-250ohm meters, a layer of 470-900ohm meters, and a layer of 1, 000-2, 240ohm meters. A layer of 100-250ohm meters is the same as that of the plateau around the hill, and a high resistivity layer more than 1, 000ohm meters rests on the plateau. This high resistivity layer is thought to be an alternating layers of tuff breccia and lava. These results indicate that the Yato Castle Hill is a small volcano.View full abstractDownload PDF (2210K) -
Shigehiko KIMURA1998 Volume 39 Issue 5 Pages 443-455
Published: December 10, 1998
Released on J-STAGE: February 23, 2010
JOURNAL FREE ACCESSWe present a new method to detect the position of buried faults under the Quaternary deposits using the Gamma-ray measurements. This method enables us to evaluate the grade of fracturing or opening of the buried faults quantitatively. It may be useful for detection of groundwater and/or hot spring, and for prediction of sudden water outflow caving-in and so on. Furthermore, we developed the measurement systems for the land-surface and the water-bottom (for a sea/lake bottom), and done the in-situ tests. In results, the fault traces which were detected using our method agree with the faultes pointed out by previous literatures.View full abstractDownload PDF (2513K) -
Kohkichi KIKUCHI, Yoshitada MITO1998 Volume 39 Issue 5 Pages 456-470
Published: December 10, 1998
Released on J-STAGE: February 23, 2010
JOURNAL FREE ACCESSThe large rock block failure had been occurred on the rock slope above the west side entrance of Toyohama Tunnel, Route 229, located in the west coast of Hokkaido, Japan, at about 8 : 10 a. m. on 10 February 1995. The mechanism of the rock block failure is discussed with several facts concerning geotechnical characteristics of the field and natural conditions around the field, especially the seasonal change of groundwater behavior, based on the results of field observations, field tests, laboratory tests and field measurements. In conclusion, the main factor of the rock block failure is considered as what the hydro-mechanical pressure, occurred by the phenomenon that groundwater had been sealed by the ice lens on the slope under extreme low temperature condition, has been applied to the discontinuity behind the rock block.View full abstractDownload PDF (7640K) -
Katsunobu SHOJI, Tetsuo AMAYA, Mitsuru TOKUDA, Yasuhiro KAWAGUCHI, Shu ...1998 Volume 39 Issue 5 Pages 471-474
Published: December 10, 1998
Released on J-STAGE: February 23, 2010
JOURNAL FREE ACCESSDownload PDF (672K) -
Tomochika TOKUNAGA1998 Volume 39 Issue 5 Pages 475-479
Published: December 10, 1998
Released on J-STAGE: February 23, 2010
JOURNAL FREE ACCESSDownload PDF (825K)
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