Determination method of maximum subsidence value for surface based on remaining free space height of overburden

In view of the problem that it is difficult to accurately determine the maximum subsidence value of the surface of the fully mechanized caving face, according to the characteristics of movement, deformation and damage of overburden in goaf and the law of mine pressure appearance, it is proposed that the height of the remaining free space of the overburden is equal to the maximum subsidence of the surface. Through the analysis of the spatial transformation relationship between the residual free space height of overburden and the mining height, the height of caving zone and the residual swelling height of caving rock mass, the calculation model of the maximum subsidence value of the working face to be mined is established. Taking the S2S2 working face of Daping Mine as an example, the maximum subsidence value of the surface obtained by the calculation model is 11.17 m, and the maximum subsidence value obtained by the actual measurement is 11.07 m. The relative error between the calculation result and the actual measurement result is 0.10 m, and the error rate is only 0.90%.