For the purpose of solving statically the deformation of the river or lake ice-plate which is loaded by vehicles or other loading, it is possible to derive the elastic equation of ice-plate by considering the ice-plate as the plate on elastic foundation ; on this case, the buoyancy of water affects as the reaction to the plate. Namely, the deflection, the bending moment and the shear of the ice-plate may be indicated by the Neumann's or Hankel's cylindrical functions by solving the elastic equation of the plate.
For the practical purpose, it may be considered that the Young's modulus, the Poisson's ratio and the allowable strength fo the ice have the values of limited range, therefore, applying the numerical calculation to the above-mentioned theoretical equations, those equations, simplified to approximate equations, and then, the practical equations as to the deflection and the loading capacity of the ice-plate are derived.

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The author researched a method to measure the shearing strength of fallen snow by means of pulling out a cooling box which is frozen to the snow sample.
At first, we take out two bocks from a snow layer, and between them hold a flat box which is called “cooling box” by the author. When we next put a freezing mixture (composed of salt and snow) in the box, the both outer surfaces of the box freeze to the snow brocks. Next, keeping down the snow brocks by a plate in which a hole of a suitable size is made, we pull out the box through the hole. Then the snow brocks break down in such a state that the fractions of the snow brocks are fixed with a homogeneous thickness on the both outer surfaces of the cooling box. Then the pulling force divided by the area of the sections cut off from the snow brocks is the shearing strength of the snow sample. In the measurement as above mentioned there is no such a compression as arises in the measurement by the usual shearing apparatus which is composed of three strata. The results measured by this method for the various layers in a deeply deposited snow were shown. The effects of the size of the hole in the plate which is used for keeping down the snow brocks on the force required to pull out the cooling box, the effects of cooling on the mechanical properties of the snow surface to be broken and the stress distribution in the snow sample under the pulling force were respectively researched both theoretically and experimentally, and it was made sure that our new method as above mentioned give ous satisfactory results as a method to measure the shearing strength of snow.

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The experiment of taking off the cornice, the main cause of avalanche by an explosion was made and found out that for the fixed amount of powder the method of charging many dynamites with small amount of powder is more effective than that of a few large ones. The experiment has also proved out that the possibility of putting this method into practice. It is believed this is very useful method from the economical point of view, too.

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[in Japanese]

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