抄録
To protect from the damages caused by the avalanche, the Japan National Railway forests the defence forest and builds the defence pile on the slope where an avalanche is threatened.
To find out the bending strength of the defence forest tree and the defence pile agains the pressure of the snow cover on the slope, the trees were classified according to the size of diameter while the defence pile was classified according to the material, and then each of them was pulled by a wire rope in parallel with the slope and the maximum bending strength just before its break was observed.
