Strata Movement Model of Filling Coal Mining Based on Two-Parameter Elastic Foundation

To avoid the discontinuity defect of the Winkler elastic foundation beam model, a two-parameter elastic foundation model of Pasternak reflecting the continuity of the waste foundation was applied in the regular analysis of strata movement in waste filling coal mining. A two-parameter elastic foundation beam strata movement mechanical model was established. The formulae to calculate the shear force, bending moment, deflection and foundation reaction force of roof strata were obtained using elastic foundation beam theory. The two-parameter elastic foundation beam model and the Winkler elastic foundation beam model were applied to an engineering example to analyze the influence of different waste foundation coefficient k and shear stiffness Gp on the force and deformation of roof strata respectively, and the results were compared accordingly. The results show that the shear stiffness has a certain influence on the force state and subsidence of the roof strata, when waste foundation coefficient is smaller, the difference between the two elastic foundation models is greater. Considering the continuity of the waste filling material, the subsidence of the roof beam obtained by the two-parameter foundation model is smaller than that by the Winkler model. The prediction of the development height of water flowing fractured zone and surface subsidence by the new model is more in line with the engineering practice.