Research on the Relationship between the Surface Dynamic Subsidence and Overburden Separated Strata of Coal Mine and Its Model

Abstract

In this paper, the relationship between the dynamic surface subsidence and overburden separated strata has been studied under the condition of sedimentary coal measure strata. When the underground coal seam is mined, the ground surface subsidence will be caused. The surface subsidence is caused by the goaf clearance passing along the overlying strata up to the surface. During the course, the bed-separation space would be generated and its size directly affected the value of mining goaf passing up to the ground - the surface subsidence. It shows that the surface subsidence is closely related with overburden separated strata. Therefore, the research on the dynamic development law of overburden separated strata contributes to recognition and prediction of surface dynamic subsidence, which is the important basis for the control of mining subsidence damage. In this paper, the whole processes form cracking, propagation, to closure of the mining overburden separated strata are analyzed in the first chapter. The various steps of surface dynamic subsidence, from the initial step, the active step, and then to the recession are researched. And then the corresponding relationship between the surface dynamic subsidence and overburden separated strata is studied and its model is established for analyzing factors of geological and mining that influenced this relationship. At last, a similar material model for coal measure strata in sandy shale is established and carried on the excavation experiment of coal seam. Then by use of the test, the development law of mining overburden separated strata is studied, and the space-time corresponding rule of the surface subsidence and overburden separated strata is analyzed. And on this basis, we find the relationship between the surface subsidence and overburden separated strata. Based on allometric growth of mining overburden separated strata, which would provide a new research and analysis method for control and prevention of mining subsidence damage, we establish the model of mining subsidence.