Variation law and influencing mechanism of surface movement parameters in Shendong Mining Area

The mining areas in western China generally have the characteristics of large reserves, shallow depth and simple overlying rock structure, and mining activities in such areas have a significant impact on the surface. In order to study the variation law of surface deformation and rock movement parameters in Shendong Mining Area, the dynamic deformation of the surface was studied based on the measured data of working face 22201 of Daliuta Coal Mine. Then the relationship between surface movement parameters and geological mining conditions were obtained from the measured data of 18 working faces in Shendong Mining Area, and the influence mechanism of geological and mining conditions on surface movement parameters was analyzed. The results show that mining in Shendong Mining Area has a fast surface subsidence rate and a short recession period, with the maximum subsidence rate of 643.3 mm/d, and the subsidence in the active period accounts for 99.05% of the total subsidence. The subsidence coefficient has a quadratic function relation with the ratio of loose bed thickness to mining depth that first increases and then decreases; the horizontal movement coefficient and the main influence angle tangent have a quadratic function relation with mining height times mining rate(width to depth ratio times bedrock thickness) and bedrock thickness times mining rate(mining depth times mining height) that first decreases and then increases, respectively. The boundary angle and crack angle have a positive linear relationship with the ratio of loose bed thickness to mining depth, and the displacement angle is directly proportional to the ratio of bedrock thickness to mining depth and inversely proportional to the mining thickness and the mining rate. The changes in bedrock bearing loose layer load and loose layer arching effect are the root causes of changes in ground movement parameters. The research could provide engineering practical value for the control and treatment of surface damage, and mine production safety and ecological environment restoration in western mining areas.