Yan Weitao / Henan Polytechnic University；State Key Laboratory of Groundwater Protection and Utilization by Coal Mining
Guo Junting / State Key Laboratory of Groundwater Protection and Utilization by Coal Mining
Chen Junjie / Henan Polytechnic University
Tan Yi / Henan Polytechnic University
Yan Yueguan / China University of Mining and Technology-Beijing
In the process of coal mining, the support of goaf and coal pillar to overlying strata is different, which makes the static and dynamic subsidence of overburden and surface lose spatial symmetry. To solve the problem that the prediction error of traditional symmetrical subsidence function model is large, this paper takes the subsidence velocity as an example. Firstly, based on the viscoelastic theory, the subsidence functions of overlying strata on goaf side and coal pillar side are constructed, and the spatial distribution function of subsidence velocity of overburden rocks on both sides is deduced. Based on the spatial change rate of subsidence velocity functions, the right skew distribution law of dynamic subsidence of overburden rocks on both sides is revealed. Secondly, based on the idea of lossless propagation of harmonic wave and idealized the propagation environment, the spatial propagation relationship of surface subsidence velocity in time domain is established; Then, the Box-Cox transform function is introduced to improve the normal distribution probability density function, and a new dynamic subsidence prediction model based on the Box-Cox transformation is obtained, which is suitable for the full mining stage. Finally, The reliability of this model is verified by the measured data. The results show that the prediction results of the prediction model are consistent with the actual situation, and the relative error is less than 7%, which meets the requirements of engineering prediction accuracy.