1977 年 93 巻 1071 号 p. 359-363
A series of model experiments on the mechanism of floor lift in coal mines were carried out in our laboratory, and some effects of several factors (depth of roadway etc.) to the floor lift were examined. Refering to the experimental results and todays Japanese coal mines conditions, we applied the floor bolting as one of the useful method of combating floor lift and the effect was demonstrated experimentally. As the material of floor bolting, wood dowels or vinyl pipes are suitable. The relations between length of bolt and effect of bolting were shown and discussed.