Seismic countermeasures on roof snow control method for timber houses in snowy areas were analyzed. Data for the analysis of roof snow control was obtained from the Japan Housing Finance Agency and from previous studies. Roof snow control methods used in prefectures from Hokkaido to Fukui were categorized into “keeping snow on flat roof”, “snow sliding” and “snow removal”. Seismic countermeasures on each roof snow control method were analyzed for each prefecture.
The results indicated that the “keeping snow on flat roof” and “snow sliding” methods were used for roof snow control in Hokkaido and Aomori Prefectures, while the “snow sliding” and “snow removal” methods were adopted in Niigata Prefecture. Regarding seismic countermeasures in the snowy season, considerations on “dynamic behavior of roof snow due to shaking”, “adfreeze between snow and roofing materials” and “increase in seismic load due to increase in snow load” are required for each roof snow control method. The necessity of further examinations on seismic countermeasures for each roof snow control method was clarified.

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In this study, we estimated basic response of timber structures in snowy areas, by conducting shaking table tests using one-story building model. Plywood (900 mm x 900 mm) was used to construct the test model and two kinds of coated steel sheets and float glass were used for roof surface materials. Natural snow was accumulated to 150 mm depth on the rooftop of the model. The slip condition of roof snow was categorized into four types; one slippery and three types of partially fixed conditions. Harmonic vibrations were used as input motions in the tests.
The results indicated that rupture of roof snow due to shaking depended on slipperiness of roof snow. The response acceleration of the model after rupture of roof snow was 0.5 to 0.9 times that before rupture, and the response acceleration increased with the number of fixed edges. Furthermore, the response acceleration of the model depended on the roof surface roughness; acceleration decreased with a decrease in surface roughness. Therefore, when we estimate seismic resistance of timber structures in snowy areas, it is necessary to consider the adfreeze condition of roof snow and the condition of roof surface materials.

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A heat and moisture transfer model for predicting the melting process of a snow/ice layer on a road is proposed in the present paper. Since the snow/ice layer is thin, 50mm or less, it is assumed to be uniform the model. The model is, therefore, called a ‘single layered model’.
It was found from the sensitivity analysis that (1) a calculation error becomes large for the thickness of the snow/ice layer more than 20mm, (2) the albedo and emissivity have stronger effect on the snow melting rate rather than the transmissivity and thermal contact resistance between the pavement and the snow/ice layer.

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Even though aggravation of global warming, snow hazards or frozen occurred inland area in northern part of Japan annually. Worsen catastrophic heat made it difficult to forecast of meso-scale under statistical deviation or coefficient of variation. From curtailed budget, it is required to reduce allocation of additional wage based on forensic treaty, in order to establish countermeasure for frost heave from road management or slope stability efficacy.
In this paper, the authors analyzed meteorological observation data Aomori, Nagano and Hokkaido including assimilated our data from Chino City Nagano, as to statistical period proximately two or three generation considering with deterioration of civil facilities. At first, we categorized each meteorological element on Dec., Jan., Feb. and Mar. adjust data of descriptive statistic for finding analogous characteristic results between Honshu and Hokkaido concern with cryogenic circumstances. Secondly, our research member scrutinized frozen ground with field survey, geo —morphological features and temperature focused on Nagano Pref. Finally, occurrence of frost heave and statistical analyzed climatic and hydrologic data, we concluded that several areas in Honshu Japan should be amended Hokkaido's maintenance of social infrastructure in order to alter or promote safety community swiftly.

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