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Volume 37 (1975)
- Issue 4 Pages 41-
- Issue 3 Pages 107-
- Issue 2 Pages 55-
- Issue 1 Pages 1-
Volume 37, Issue 1
Displaying 1-3 of 3 articles from this issue
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Masuyoshi MATSUDA1975 Volume 37 Issue 1 Pages 1-12
Published: March 31, 1975
Released on J-STAGE: January 20, 2010
JOURNAL FREE ACCESSServeral perennial snow patches of the order of 100 m in length are found in some valleys in Mt. Daisetsu, Hokkaido. Glaciological studies have been made for the past ten years on several snow patches located near the top of the slope curved on the east side of a plateau called “Takanegahara” (1730 m in altitude). On the basis of the observational results on the accumulation of snow in this area, calculations were made to obtain the climatic conditions in which small perennial snow patches on the slope grow to become a glacier.
Climatic conditions needed to form a glacier were estimated as functions of accumulation of snow and the average air temperature. The size, the thickness and the flow velocity of the “predicted glacier” were computed, taking Nye's theory of glacier flow into account. It was found, for example, that 3040% of the present snow accumulation was enough to form a glacier on this slope during the last Pleistocene Ice Age. At the equilibrium line of the “glacier”, flow velocity of 10 m/year and ice thickness of 3040 m were obtained in the present calculation.View full abstractDownload PDF (2173K) -
Tsutomu TAKASHI, Minoru MASUDA1975 Volume 37 Issue 1 Pages 13-20
Published: March 31, 1975
Released on J-STAGE: January 20, 2010
JOURNAL FREE ACCESSThis paper gives an exact solution of heat transfer equations in freezing soil with constant freezing speed accompanying uniform suction flow to the freezing front, as a boundary value problem. Temperatures in frozen and unfrozen soil, θ1 and θ2 respectively, are :
θ1=κ1/k1 (k2/κ2U+ν/U+υhθ∞+γwLwufU+υw/U+υh) {1-exp (-U+υh/κ1ζ)} for ζ<0 and
θ2=θ∞ {1-exp (-U+ν/κ2ζ)}, for ζ>0,
where, ζis variable of moving coordinate system with the same speed of the freezing front (at the freezing front ζ=0), U the constant advancing speed of freezing front, υwthe constant suction speed of water from unfrozen soil to the freezing front, υh the heaving speed of frozen soil,
υh = (1+Γ) (υw+nf1/1+ΓU),
where Γ is the ratio of volume increase of water when freezing (≅ 0.09), nf the volumetric content of freewater in the vicinity of the freezing front, κ1, κ2 the thermal diffusivity of frozen and unfrozen soil respectively, k1, k2 the thermal conductivity of frozen and unfrozen soil respectively; νthe parameter defined as
ν=Cwγw/Csγsυw
where γw the weight of unit volume of pore water, γs the weight of unit volume of unfrozen soil, Cw the specific heat of pore water, and Cs the specific heat of unfrozen soil; Lw the latent heat of pore water in freezing, and θ∞ the initial temperature of unfrozen soil.
In these equations the value of suction speed of pore water υw can be taken independently to the freezing speed U. However authors have shown previously (Takashi et al., 1974) that υw is a function of U;
υw=U/1+Γσ0/σ (1+√U0/U) -nfΓ/1+ΓU,
where, σ the effective stress in soil under freezing, σ0, U0 the characteristic constants of soil.
Therefore if the last equation is applicable to all kind of soils it would be said that the present problem was solved completely.View full abstractDownload PDF (1298K) -
With Special Reference to Characteristics of Tired WheelsMotomu YOKOMORI1975 Volume 37 Issue 1 Pages 21-31
Published: March 31, 1975
Released on J-STAGE: July 23, 2009
JOURNAL FREE ACCESSSeveral kinds of tired wheels of motorcycles were selected to test the stability and satety of driving on snow-covered roads. As a measure of stability felt by riders, the deflective angle of the handle was adopted. In the case of “snow tires”, the stability is much improved when the air pressure in the tire is lower than the specified pressure; if the lowering of pressure was done only for the rear tire the stability would be reduced. With wide tires, the stability is much improved when the weight, output and other mechanical characteristics of motorcycle are nearly the same. If a chain is used only on the rear tire, the stability becomes better, especially when the speed increases. The stability is improved by using a rope instead of a tire chain; the rope is more effective and also handy.View full abstractDownload PDF (5868K)
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