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Volume 20 (1979)
- Issue 4 Pages 139-
- Issue 3 Pages 87-
- Issue 2 Pages 47-
- Issue 1 Pages 1-
Volume 20, Issue 2
Displaying 1-4 of 4 articles from this issue
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Kenji KASUYA1979 Volume 20 Issue 2 Pages 47-57
Published: June 30, 1979
Released on J-STAGE: February 23, 2010
JOURNAL FREE ACCESSThe slope stability of soft to semi-hard rocks has a close relation with the weathering of composing rocks. Auther surveyed the weathering of aged stone buildings such as ancient tombstones, and have been studying on the weathering mechanism and weathering speed of various kind of rocks. As the first step, obtaind results are as follows.
1. The rate of surface weathering on stone buildings differs with each direction of their face, and then it is evidently larger on the south face or the west. It seem that this weathering rate depent on the deger of temperature difference on their surface.
2. The defect by weathering on the surface of stone buildings is the maximum in depth at the place of 20-30 cm above their bacement. This defect is estimated to be related with reflection of heat, Jumping of rain water, etc. from basement stone or road surface.
3. The rate of weathering depends on property of rocks. The weathering defect extendery to 0.5 cm in depth from the surface requires a period of about 20 years on the rock having 100 kg/cm2 of uniaxial compressive strength (dry), and a period of about 900 years on the rock of 2, 000 kg/cm2.View full abstractDownload PDF (1797K) -
Kunio WATANABE1979 Volume 20 Issue 2 Pages 58-68
Published: June 30, 1979
Released on J-STAGE: February 23, 2010
JOURNAL FREE ACCESSMicro-crack system in granitic rock was observed by means of scanning electron microscope, liquid penetrant test, soft X-ray photograph and polarized microscope with the following results;
(1) The liquid penetrant test is useful to observe the micro-crack system.
(2) The surface of micro-crack has generally irregular form probably due to the secondary mineral growth or corrision by the infiltration of ground water.
The evaluated results of the micro-crack system by statistical methods are as follows;
(1) The width distribution of micro-crack can be represented by N (t) Δt= K. t-mΔt, where, K, m are the constants, t is the width and N (t) Δt is the number of micro-cracks in the distance between t and t+ Δt
(2) The m-value in the above equation tends to decrease with the increase of rock porosity.
(3) Only slight variations of the area of crack surface in a unit volume and the length of crack in a unit area are recognized in granitic rocks on the porosity of which ranges from 0.76% to 2.79%.View full abstractDownload PDF (4726K) -
A Case Study at Uminokuchi Stock Farm Located on the Eastern Foot of Mt. YatsugatakeItsuro KAWASAKI1979 Volume 20 Issue 2 Pages 69-77
Published: June 30, 1979
Released on J-STAGE: March 25, 2010
JOURNAL FREE ACCESSMost studies on forst hummocks are concerned with the areas of high latitudes or the cold districts, and no report has ever been provided on frost hummocks occurring in the area of moderate latitude. The present article reports on the investigation dealt with the frost hummocks occcurring on the eastern volcanic slope of Mt. Yatsugatake located on latitude 36°N. It has been established, the characteristics of the volcanic ash bed structure, aside from the cold climate, does play an important role in the formation of the frost hummocks.View full abstractDownload PDF (2324K) -
[in Japanese]1979 Volume 20 Issue 2 Pages 78-81
Published: June 30, 1979
Released on J-STAGE: February 23, 2010
JOURNAL FREE ACCESSDownload PDF (1528K)
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