Journal of the Japanese Society of Snow and Ice

Fluid Dynamical Analysis of Powder Snow Avalanches at Maseguchi in Niigata

Yusuke FUKUSHIMA

1987 Volume 49 Issue 1 Pages 1-8
Published: March 30, 1987
Released on J-STAGE: September 04, 2009

DOIhttps://doi.org/10.5331/seppyo.49.1

JOURNAL FREE ACCESS

Show abstractHide abstract

The large scale powder snow avalanche which occurred at Maseguchi, Niigata, is simulated by a fluid dynamical model, which uses the conservation equations of air, snow particles, momentum of avalanches, and kinetic energy of turbulence. The powder snow avalanche was generated on the steep slope of Mt. Gongendake located near Maseguchi, where thirteen people were killed at 11 : 00 pm on 26th January 1986. Horizontal distance between Maseguchi and the summit of Mt. Gongendake is about 1800 m and the steepest angle of the slope of Mt. Gongendake is about 50°.
The depth of the newly fallen snow layer is considered in the model as an important parameter. As the depth of the newly fallen snow layer grows, the concentration of snow particles in the avalanches increases and the speed of the avalanches rises. It is concluded that a depth of newly fallen snow layer of over 2 m, which value is almost the same value as was observed at Maseguchi just after the avalanche, is needed to form the storng powder snow avalanche which was able to reach Maseguchi.

View full abstract

Download PDF (1334K)
Attempts at prevention of snow, frost and ice damage in railways by means of a novel ice repellent coating system using new polymeric materials

Fujio OHISHI, Heihachi MURASE, Atushi YOKOTA, Kiyoshi NANISHI

1987 Volume 49 Issue 1 Pages 9-17
Published: March 30, 1987
Released on J-STAGE: September 04, 2009

DOIhttps://doi.org/10.5331/seppyo.49.9

JOURNAL FREE ACCESS

Show abstractHide abstract

Various means have been tried to prevent snow, frost and ice damage. In this study, a novel ice repellent coating system is developed for application in the field of railways. As coating materials the following polymeric substances have been created : a modified silicone polymer in which the bond angle of water molecule is restricted by added metal ions, and modified fluoropolymer which has the highest degree of water repellency. The results of application in railways proved the coating system to be effective in reducing snow and ice damage in pantographs and trolley wires.

View full abstract

Download PDF (7391K)
[title in Japanese]

[in Japanese]

1987 Volume 49 Issue 1 Pages 19-26
Published: March 30, 1987
Released on J-STAGE: September 04, 2009

DOIhttps://doi.org/10.5331/seppyo.49.19

JOURNAL FREE ACCESS

Download PDF (2997K)

Register with J-STAGE for free!