There is a considerable number of energy and soil-engineering problems associated with conventional snow-removal and snow-melting systems which utilize gasoline-mobile machinery and warm underground water.
To overcome these problems, snow-conveyance-gutter systems and snow-melting-gutter systems which utilize surface water have become the two principal means for effective and practical countermeasures. However, standard-design methods for these systems have not yet been established.
In this paper, the snow-disposal capacities of the snow-conveyance-gutter systems and the snow-melting gutter systems which use surface water are described, and standard-design methods for these systems are discussed.

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Meteorological data obtained from surface observations at the meteorological stations in Aomori Prefecture and upper air observations at Akita station have been analyzed statistically in order to study the characteristics of snowfall at Aomori City. The major findings are as follows. First, the snowfall at Aomori generally shows poor correlations with that at other stations, suggesting that the snowfall at Aomori is rather independent of that at other stations. Next, the snowfall at Aomori shows high correlations with the upper air conditions above Akita station : the heavy snowfall is associated with the advection of cold air and with the upward transport of water vapor by the convective mixing at lower layers. In addition, the snowfall at Aomori is also highly correlated with the surface meteorological conditions. Namely, the amount of snowfall increases with decreasing temperature and increasing wind speed. The snow is mostly carried by the southwesterly winds.
The high correlations with the upper and surface air conditions are peculiar to Aomori station and are not seen at other stations. The high correlation with the upper air conditions implies that the snow falling at Aomori is generated in the vicinity of a hgih mountainous region. The high correlation with the surface are conditions implies, on the other hand, that the air with a low temperature and strong wind is always associated with an upward flow at a windward area of Aomori, and the snowflakes generated at the high mountain area are transported by favorable winds to Aomori. Since the wind carrying the snowflakes is mostly southwesterly, the area which generates the snowflakes is considered to be above the western or northwestern flank of Hakkoda Mountains. In other words, the snow falling at Aomori is basically mountain snow which forms near the Hakkoda Mountains and is transported by the southwesterly winds toward Aomori.

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This paper describes an improvement of the system previously reported in Parts I and II. The improved system is designed for the same area, 16 km² in Nagaoka, and has the same rate of snow removal, 5000 t/h, while its snow storage capacity is reduced by 50 percent to 750000 t/y. The following technologies are newly incorporated in this design : improved snow feeders, dividing the area into an intensitive snow removal area and a second less intensive areas, introducing snow fraction measuring and controlling apparatus to the pipeline, moving the snow storage reservior to a lower elevation and closer to the city, introducing a fabric roof with floating foundations for insulating the reservior, and other improvements.
The technical and the economical performance of the improved system are evaluated with the following factors taken into account : stochastic analysis of snowfall, temperature and humidity in Nagaoka, the areal ratio of road and the number of residential families in the area where the system is to be placed, and so on.
It is concluded that this system has enough rate and capacity of snow removal and air conditioning to ensure comfortable city life. Its construction cost has been reduced to 58.9 billion yen from the previous value of 121.7 billion yen for the system reported in Parts I and II. This reduction reflects the incorporation of new technologies, and this value implies that the improved system is almost comparable to an existing system of snow removal. Moreover, the former is safer and more convenient to use than the latter. Its maintenance cost, however, which is estimated to be 868 million yen per year, is too high to balance with the income of 462 million yen per year received from the air conditioning service.

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This paper describes the results of frost heave experiments using specimens of consolidated and water-saturated clay. The specimens were frozen in an open system unidirectionally under various confining stresses. The frost heave ratio ξ, defined as the ratio of the volume increment to the initial volume of a specimen, attains its maximum for a given value of the over consolidation ratio, OCR. This tendency of ξ can be explained theoretically by resistance to the movement of soil-water through the unfrozen part of the specimen and by the consolidation of unfrozen soil during freezing. From the relation between ξ and OCR, it is shown that a correlation between ξ and physical properties (eg. water content, void ratio, unit weight of soil) can be obtained.

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