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Volume 11 (1970)
- Issue 4 Pages 127-
- Issue 3 Pages 91-
- Issue 2 Pages 35-
- Issue 1 Pages 1-
Volume 11, Issue 4
Displaying 1-4 of 4 articles from this issue
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Yoshiro Hayashida1970 Volume 11 Issue 4 Pages 127-131
Published: December 01, 1970
Released on J-STAGE: February 23, 2010
JOURNAL FREE ACCESS -
M. Inoue, M. Omi, T. Kikuta1970 Volume 11 Issue 4 Pages 132-138
Published: December 01, 1970
Released on J-STAGE: February 23, 2010
JOURNAL FREE ACCESSIt is important for the non-destructive testing carried out the measurement of wave propagation velocities to know the extent of variation of the propagation velocity of elastic waves in porous rocks by changing water content. We had been made an investigation of this problems.
In this paper, we showed experimental results of the propagation velocity of elastic waves in rock specimens cured at the four circumstances which are the most easy curing method. They are (1) cooling in a desicator contained silicagel silicagel at room temparature after heating in the drying oven at 100-110°C above 24 hours, (2) drying in desicator contained silicagel to become a constant weight, (3) room dry, and (4) immersing in water during about a month to become a constant weight.
On the experiment, the velocity dilatational wave Vpl and the velocity of shear wave Vps were measured by ultrasonic pulse method, and the velocity of longitudinal vibration VRl and the velocity of torsional vibration VRS were measured by resonant frequency method.
Summary of this experiment are;
(1) The propagation velocity of dilatational waves in racks cured at desicator with silicagel or at room dry measured by pulse method became the minimum, and the velocity increased when rock specimens were more saturated.
(2) Velocities of the longitudinal vibration measured by resonant frequency method gradually decreased when rock specimens were saturated from dry state.
(3) Both shear wave velocities measured by pulse method and resonant frequency method show a similar tendency of variation of the wave velocity with saturation of rocks.View full abstractDownload PDF (1138K) -
on the relation between stratigraphical succession and hardness of Kwanto “loam”, represented by N-valueA. Unozawa, S. Oka, K. Kuroda1970 Volume 11 Issue 4 Pages 139-148
Published: December 01, 1970
Released on J-STAGE: February 23, 2010
JOURNAL FREE ACCESSA study on the relation between stratigraphical succession of Kwanto “loam” (volcanic ash beds) and its hardness, especially consolidated dark blue part of the volcanic ash, are made at Oba district, western part of Fujisawa city. The Kwanto “loam” are divided into Shimosueyoshi loam and Younger loams (Musashino loam and Tachikawa loam are put together in this paper), and the following five terraces are distinguished in the area studied; namely, Kaza, Golf-jo, Hiko-ja, Matano and Hikiji-gawa terraces. Many pumice or scoria seams, which are of for stratigraphic correlation of Kwanta “loam” at each outcrops and bore-holes, are summarized throughout the area, among them, Tokyo pumice, Miura pumice, An-shin pumice, Fujisawa pumice, etc. are remarkable. Results of standard penetration test (N-value diagram) are compeared with the bore-hole stratigraphical succession at each boring sites, by observation of core-samples with naked eyes.
As results, the followings are concluded;
1) From the results of standard penetration test, the Kwanta “loam” is subdivided into four groups:
Group I: N≅ 3-4
Group II: N≅ 7-8
Group III: N≅ 11-16
Group IV: N≅ 20 or more
Among the groups, III and IV are consolidated volcanic ash under visual observation, which is dark bluish in color.
2) Distinct difference of N-value are found between Shimosueyoshi loam and Younger loams. Shimosueyoshi loam is more solidified throughout all bore-hole successions.
3) Younger loams, covering the higher terrace, is more solidified than that of the lower terrace.
4) Consolidated dark blue part of Kwanto “loam” are, in most cases, found upwards or around the pumice seams. On the contrary, pumice or scoria seams are less solidified than the surrounding volcanic ash beds.
5) Solidification of volcanic ash is presumably caused by geochemical reaction between volcanic ash and ground water which are contained or permiate into the pore space of the loam beds.View full abstractDownload PDF (1210K) -
Yotaro Seki1970 Volume 11 Issue 4 Pages 149-151
Published: December 01, 1970
Released on J-STAGE: February 23, 2010
JOURNAL FREE ACCESS
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