Study on fracture and movement of overlying Bedrock in shallow seam Under Thick sand

摘要

Based on the field observation results of ground pressure in shallow seam, the move- ment characteristics of overlying strata in front and behind and the subsidence of the earth's sur- face are studied. Also, the paper analyzes the stability of overlying bedrock according to the the- ory of voussoir beam's "S-R" stability and the hypothesis of step subsidence. It points out that silide instability is the fundamental form of overlying bedrock movement.