Study on deformation laws of inclined shaft with different filling rates during coal paste filling mining in industrial square

In order to study the deformation laws of inclined shaft after filling mining, the main inclined shaft of Yuecheng Coal Mine is taken as the research object, and the equivalent mining height model suitable for paste filling mining is established. It is concluded that the filling rate under paste filling mining is the key factor affecting the deformation of inclined shaft. Numerical simulation of inclined shaft deformation under four different filling rates is carried out to reveal the deformation and failure laws of inclined shaft. By analyzing the maximum and minimum principal stresses and the deformation of the inclined shaft under ultimate conditions, the critical filling rate at the moment of shaft failure is inversely derived. Settlement predictions are used to estimate the settlement values at different positions of the inclined shaft, and the tensile and compressive deformation values of the shaft are calculated. The research results indicate that: the stress and displacement of the inclined shaft are mainly reflected in the vertical direction, and have little effect in the horizontal direction, and he most severe deformation and failure of the inclined shaft occur at the deep burial zone, specifically in the lower section of the shaft, where the stress and deformation reach their peak values. The maximum and minimum principal stresses with low filling rate mainly appear in the bottom plate of the wellbore, and transfer to the intersection of the bottom plate and the two sides with the increase of the filling rate. The inversion results show that 87.3% is the critical filling rate. Through the prediction of subsidence, the maximum compression deformation is 1.51 mm/m, and the maximum tensile deformation is 2.8 mm/m, which is within the allowable range. The warning section of deformation and failure of inclined shaft in filling mining is obtained, which provides an important reference for the protection of inclined shaft in similar paste filling mining.