Abstract:According to the fierce underground press and bench convergence in shallow seam mining

taking Shendong mining area as an research object，the roof strata moving law in shallow thin bedrock was studied with 3D simulation experiment. The dimension of the simulation model was 1050mm×2000mm×1130mm; the model tests were conducted with a geometrical scale of 1∶100

a gravimetric scale of 1:1.67

a temporal scale of 1:10

and a stress scale of 1:1.67. The monitoring was conducted on the surface displacement and roof strata move. The results showed that: there were only caving zone and fractured zone in the roof strata during mining; the immediate roof kept caving as long as mining; the first weighting interval was 40m

the periodic weighting distance was 20m; there were procreant crannies reaching the earth's surface

clearly side stepped subsidence

sand bursting in the area of cut and terminal mining line

and collapse pits in the the surface; the roof strata move was mainly vertical displacement

and increased along with the mining; the bridge leaded to the roof strata move smaller near the coal pillar than far away the coal pillar; there were notable positive correlation between roof strata move and surface displacement

but the surface displacement was smaller and hysteretic to the roof strata move

and was affected by the sand bursting.