Stratification transfer method of the mining subsidence based on the characteristics of layered structure in coal overburden

Layered structure of overburden is a remarkable and important geological characteristic of coal occurrence.It not only affects the development of mining subsidence, and also determines the final shape of surface subsidence.Based on the geological characteristic of 2^-2 coal seam and the representative drilling in the Yushen Coal Mining Area and under the conditions of the same depth and bedrock thickness, 18 simplified models with different types of layered structure of overburden strata were constructed by taking the number of sandstone layers, their average thickness and the sand-shale ratio as variables.Study was made on the influence rule of three characteristics upon the subsidence coefficient through the numerical simulation test, and the corresponding quantitative relationships were constituted.The basic principle and assumed conditions of the stratification transfer method of the mining subsidence based on the characteristics of coal overburden were proposed from the view of transfer and superposition of deformation. The stratification transfer prediction models, including subsidence, horizontal movement and horizontal deformation in the trend main section of subsidence basin were constructed.Engineering example verified that this new method has a higher predic-tion accuracy than the probability integral method, so that it could provide a better technological support for the prevention of mining subsidence in Chinese western coal mining area.