Land subsidence calculation model under the coupling effect of groundwater and coal mining

Land subsidence has become a widespread engineering geological problem due to human-induced causes such as the withdrawal of groundwater and the extraction of coal and ores. There is a relative lack of research on land subsidence under the coupling effect of groundwater and coal mining. This paper uses numerical and theoretical computational models to study land subsidence under the coupling effect of groundwater and coal mining. The study area is a coal mine in Jining City from 2000 to 2020. Numerical results show that groundwater withdrawal induces substantial land subsidence over a long period and that the rate of land subsidence decreases over time. The maximum land subsidence was 128 mm in 2010. Due to coal extraction (2015), the area induces significant land subsidence in the short term. The maximum land subsidence in 2016 was 305 mm. Based on the stochastic medium theory, this paper establishes a theoretical model for land subsidence under the coupling effect of groundwater and coal mining. And based on the numerical results, the theoretical subsidence equation applicable to the area is calculated. By comparing the theoretical results with the actual measurement results, the analysis proves that the equation can better calculate the land subsidence of the model.