Uniaxial compression tests of frozen clay with ice lenses were conducted to clarify the effects of ice lens contents on the strength. Specimens (5 cm in diameter, 8 cm or 10 cm in height) were prepared by using Fujinomori clay sampled from Kyoto and had ice contents (w_i) ranging from 50% to 4000%. The tests were carried out systematically with respect to the dependence of compressive strength on ice contents, temperature, direction of loading, strain rate and specimen height.
When the load is applied to the direction of freezing, the strength of frozen clay with ice lenses increases linearly as w_i increases, and then approaches gradually to the strength of the ice lens. When the load is applied perpendicular to the freezing direction, the strength of frozen clay with ice lenses is almost constant irrespective of ice lens contents under the same compressive condition. In comparison with frozen clay not including an ice lens, the strength of frozen clay with ice lenses does not always become small and can become large in some circumstances.

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River ice surveys at four observation stations in Kitami, located along the Tokoro River in Hokkaido, were conducted during the winter of 1981-82. The transverse ice concentration, which is defined as the ratio of the transverse length actually covered by ice to the total river width; was introduced to represent the ice coverage quantitatively. Some multiple regression equations were derived to estimate this concentration at four stations. The ice conditions at a station were classified from the maximum transverse ice concentration, the number of cycles, each having ice growth and decay, and the proportion of freezeover period to the total observation period.
Past studies on the thermal regime of river water have almost neglected the heat conduction through the stream bed and heat gain from viscous dissipation. On the basis of meteorological and hydrological observations during December 2-8 1981 at Wakamatsu Bridge, one of the stations, time variations in thermal balance of water mass were obtained including stream bed conduction and viscous dissipation. Discussions on several multiple regression models for estimating total heat loss led to the adoption of water temperature, air temperature, wind velocity, duration of sunshine and precipitation as predictor variables; all except water temperature being obtainable from AMeDAS (Automated Meteorological Data Acquisition System) of Japan Meteorological Agency.
It was revealed that for a given river section the growth or nongrowth of shore ice is determined by a linear relationship between the surface velocity of flow and daily accumulated heat loss.

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Vertical holes appear in an ice body of a perennial snow patch called “Kuranosuke Sekkei” located on the eastern side of Mt. Tateyama (3015 m) in the Northern, Japanese Alps in the end of the summer season of a particular year when the upper firn layer disappears. The size of the holes is 0.8 to 1.7 m in diameter along the longer axis and 1 to 20 m in depth. These holes appeared in 1977, 1979 and 1980 during the six years from 1977 to 1982 and the numbers of holes were 29 in 1977 and 23 in 1980. The features of vertical and surface shape and linear pattern of the distribution are similar to those of moulins which appear in an ablation area of a glacier. Since moulins are said to develop from vertical holes which are formed by melt water stream flows into crevasses or cracks, the existence of vertical holes in Kuranosuke Sekkei indicates the existence of a stage of the state of the perennial snow patch in the past when crevasses or cracks were formed and caused the formation of the present vertical holes.

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The frictional pressure loss of the snow-water mixture in circular straight pipes was investigated experimentally. The pressure losses both in a vertical and a horizontal pipe with an inner diameter of 40 mm, as well as the flow rate and the mixing ratio of snow in the discharge, were measured. The flow patterns were observed at the transparent parts of the pipe. The results were compared with those for the mixture of water and plastic beads, of which the size and the difference of density with water were nearly equal to those of snow used in this experiment.
Snow particles usually adhered to each other to make a large cluster whose dimension was nearly 50-80% of the pipe diameter, and the flow pattern did not change much with the flow rate or the mixing ratio of snow. The position of the pipe, that is whether it was horizontal or vertical, did not affect these flow patterns so evidently as it did in the case of the plastic beads mixture. At Reynolds numbers (Rm) below 5 × 10⁴ the coefficient of pipe friction was larger than that for water and increased with the mixing ratio of snow. At Rm above 5 × 10⁴ (or the velocity larger than 2 m/s) it was nearly equal to that for water independent of the mixing ratio of snow or the inclination of the pipe.

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