Numerical Modelling of Stress-Strain Analysis in Underground Thick Coal Mining

Abstract

Thick coal mine operations have various methods. If the thick coal seam cannot be mined by single pass longwall (SPL), then Longwall top coal caving (LTCC) method or multi slice longwall (MSL) can be employed. In Turkey, caving methods are commonly used in mining of thick coal seams as long as the roof strata are suitable for their use. Longwall with caving is always preferred to filling methods because of its simplicity, favorable economics. In the literature, underground production methods are studied oftenly on the contrary rock mechanics and roof conditions. Rock mechanics and roof strata conditions examining with Finite Element Methods (FEM) are very important in terms of efficiency and continuous production. In this study, FEM analysis are made for thick coal mining methods. Numerical modelling from the field for laboratory tests on samples obtained after the Mohr-Coulomb and/or Hoek-Brown rock failure criteria determining the rock mass properties modeling has been performed. Similar strain values are computed in front of the face in all three methods considered. However, when stress-strain values on the gob area are measured, stress-strain distribution in lower face method is found to be more stabilized and proper.