1976 年 92 巻 1065 号 p. 707-711
Researches to find suitable methods to combating floor lift require investigations of floor lift mechanism. The authors carried out a series of model experiments on floor lift in roadways. The floor lift is caused by many factors. In this report the authors describe the effect of two factors, i. e. a distance from roadway to upper coal seam and the thickness of weak floor to floor lift. For example whe a roadway has a depth of 600m from the surface, and the weak floor has a thickness of 8m, the roadway must be located at a distance of more than 30m from the upper coal seam in order to depress the floor lift. In our experiments the movements of weak floor were investigated also and the data to determine floor bolting parameters to combating floor lift were obtained.