Extraction of Irregularly Shaped Coal Mining Area Induced Ground Subsidence Prediction Based on Probability Integral Method

Abstract

Underground coal mining-induced ground subsidence (or major ground vertical settlement) is a major concern to the mining industry, government and people affected. Based on the probability integral method, this paper presents a new ground subsidence prediction method for predicting irregularly shaped coal mining area extraction-induced ground subsidence. Firstly, the Delaunay triangulation method is used to divide the irregularly shaped mining area into a series of triangular extraction elements. Then, the extraction elements within the calculation area are selected. Finally, the Monte Carlo method is used to calculate extraction element-induced ground subsidence. The proposed method was tested by two experimental data sets: the simulation data set and direct leveling-based subsidence observations. The simulation results show that the prediction error of the proposed method is proportional to mesh size and inversely proportional to the amount of generated random points within the auxiliary domain. In addition, when the mesh size is smaller than 0.5 times the minimum deviation of the inflection point of the mining area, and the amount of random points within an auxiliary domain is greater than 800 times the area of the extraction element, the difference between the proposed method-based subsidence predictions and the traditional probability integral method-based subsidence predictions is marginal. The measurement results show that the root-mean-square error of the proposed method-based subsidence predictions is smaller than 3 cm, the average of absolute deviations of the proposed method-based subsidence predictions is 2.49 cm, and the maximum absolute deviation is 4.05 cm, which is equal to 0.75% of the maximum direct leveling-based subsidence observation.

Land Subsidence Estimation for Aquifer Drainage Induced by Underground Mining

“…Land subsidence's spatial extent and value are primarily determined by the depth of exploitation, seam thickness, panel dimensions, overlying rock mass geomechanical conditions, geological defects, surface topography, production methods and post-mining void reclamation method [30,52,53]. Many research papers have been presented in recent years documenting the land subsidence phenomenon caused by mining [47,49,[54][55][56][57][58][59][60][61][62][63]. As a result, one can be stated that the spatial extent of the phenomenon can range from several km 2 [49] to tens of km 2 [15], while its values can range from a few mm/year [64] to several cm/day [65].…”

Estimation of Ground Subsidence Deformation Induced by Underground Coal Mining with GNSS-IR

“…In the past several decades, many mathematical models have been proposed to describe the ground subsidence pattern caused by underground coal mining, e.g., Knothe model, Reddish Model, and probability integral model (PIM) [18][19][20]. Among these models, the PIM has been widely used in many countries especially in China, because of clear physical mechanism and concise coefficients of the model.…”

Model Construction and Parameters Acquisition of the Predicted Surface Movement Deformation under Thick Loose Layer Mining Area

“…Te third category is the infuence function method. Tis method is based on the distribution function and the principle of equal infuence superposition to construct the surface movement deformation formula [22,23]. Liu developed the probability integral method based on the stochastic medium, which is most widely used in China because of its good universality, the clear physical meaning of parameters, and high accuracy [24].…”