Study on the Law of Earth’s Surface Movement on Ultra-Long Working Face

High-intensity mining effect induced by long working face mining causes dynamic disasters to safe and efficient coal mining. For the purpose of in-depth study of the movement law of earth’s surface on ultra-long working face, this paperused to build a numerical model, analyzes the law of roof-to-floor strata behaviors in coal bed during mining, and studies the weakening of roof-to-floor parameters in coal bed, bearing pressure and the law of roof caving and rock strata movement. Analyzes the face length effect resulted from the difference in face lengths. It has been recognized that the sphere of influence of bearing pressure changes from small to large and then to small, and changes in distribution of arch bottom and arch height at the plastic failure zone are further intensified over advancing of the working face, moreover, the movement of rock strata is subject to the cumulative influence of the advancing direction of the working face and the face length effect. The above-mentioned research results can serve as a theoretical basis for practical engineering.