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Volume 8 (1967)
- Issue 4 Pages 171-
- Issue 3 Pages 95-
- Issue 2 Pages 55-
- Issue 1 Pages 1-
Volume 8, Issue 2
Displaying 1-3 of 3 articles from this issue
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Takaaki Ando, Teruo Aihara, Takao Kanai, Keiichi Kodai, Akira Unosawa1967 Volume 8 Issue 2 Pages 55-70
Published: June 01, 1967
Released on J-STAGE: June 04, 2010
JOURNAL FREE ACCESSThe authors di d a field experiment by way of the neutron moisture meter (Hitachi PB-1 style)&γ-ray density meter (Hitachi PG-3 style) in the visinity of Lake konoike, Kamisu Village, Ibaraki Prefecture, in order to put the instruments to practical use. The experiment using and γ-ray proved effective in measuring water content in soil through the following three procedures which were deviced by authors.
At first they dug bore holes (7m deep with the diameter of 85mm) and inserted an iron pipe (diameter 57mm) into the holes, then let the neutron probe hang down to the bottom. To exclude water which interevened between a pipe and the wall of the hole, they tried several technical devices so that natural status of stratum may reflect directly to the neutron apparatus.
1) Driving method. The end of an iron pipe was sharpened and the pipe was allowed to be driven with a hammer under the bottom of holes as deep as 60cm. This is the most correct measuring method, because stratum approaches to the probe nearer, but it is a defect that a pipe is difficult to be driven, as stratum becomes harder.
2) C Cl4 method. It is a method which eliminates watar intervened between a pipe and the wall of a bore hole on account of the larger density of C Cl4 (1.49), but it is a weak point that C CI 4 penetratesinto sandy bed and is difficult to revise.
3) Packer method. A gum tube is put over an iron pipe which is inserted bore-holes to the botom, then compressed air is sent through the pipe, making the gum tube swell towards the wall of a bore-hole. Afterwards the apparatus is hung down to measure. This is capable to use in a harder ground as well, but it has the defect of destroying a bore-hole.
Calibration was carried out in June. A drum was field with dried sand, and water being poured step by step, and probe was inserted into the sand for measuring; at the same time moisture content in the sand was estimated at 105°C in an oven of the laboratory. Thus calibration curves of practical use were obtained.View full abstractDownload PDF (2207K) -
Hidetoshi Inoma1967 Volume 8 Issue 2 Pages 71-76
Published: June 01, 1967
Released on J-STAGE: June 04, 2010
JOURNAL FREE ACCESSGeotechnical surveys in the area of the Ena Tunnel have being carried out by Japan Highway Public Corporation from 1965. In the area of Nakatsugawa, the west side of the Ena Tunnel, 5 boring works were completed, and several physical characters of boring cores and bore holes were tested and measured.
From their resul ts, the geotechnical section of the west side of this tunnel is drawn. Considering difficulty of boring works and observation of boring cores, it seemed that geotechnical conditions in this area is not desirable for tunnel work beyond expectionView full abstractDownload PDF (537K) -
GOJI YAMADA1967 Volume 8 Issue 2 Pages 77-87
Published: June 01, 1967
Released on J-STAGE: June 04, 2010
JOURNAL FREE ACCESSThe landslide has occurred between ASAMUSHI ST. and NONAI ST. of TOHOKU main line. in the 27th, july, 1966.
The sliding earthmass burried the railroad over the length of 80 meters and the total sliding mass amounted to 100, 000 cubic meters. This site is situated at the ver tical crossing of highway route no 4.
Before the landslide, the small slope failure occurred under the influence of the rainfall of typhoon No.4 in the 29th, June, and this means the sign of the landslide.
This slope is composed of liparitic tuff affected by the hydro-thermal alteration and the weathered zone having some 10 or 15 meters depth contains the soft clay along joints.
The behavior of the landslide on the basis of data obtained by the contineous measurement of the displacement of the landslide and the point of the repaired construction are mentioned.
The difficulty of construction involves in the cutting of the toe of slope in the ac tive landslide as maintaining the stabil ity of slope.View full abstractDownload PDF (1434K)
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