Multifactorial analysis of a gateroad stability at goaf interface during longwall coal mining – A case study

Purpose. Creating a generalized algorithm to account for factors (coal seam thickness, enclosed rock mechanical properties, the dimension and bearing capacity of artificial support patterns) causing gateroad state under effect longwall face goaf. Methods. The assessment stability is based on numerical simulation stress-strain (SSS). finite element method used find out changes in SSS surrounding rocks at various stages mining. elastic-plastic constitutive model Hoek-Brown failure criterion implemented codes RS2 RS3 (Rocscience) are applied determine displacements dependently coal strength, width strength (a packwall comprised hardening mixture “BI-lining”). To specify properties material series experimental tests were conducted. A computational experiment dealing with 81 combinations affecting was carried estimate roof slag floor heaving behind face. group data handling (GMDH ) employed generalize relationships between factors. Findings. roof-to-floor closure has been determined intersection goaf packwall, material. It revealed that gains value 30 MPa 3rd day from its beginning use which fully corresponding requirements protective capacity. possibility using untreated mine water liquefy proved, allows simplifying optimizing solute mixing pumping technology. Originality. This study contributes improving understanding influence underground mining operations highlights importance utilizing simulations designs. impact each factor resulting variable (decrease cross-section gate road by height) combinatorial structural identification estimated as follows: 48%, thickness 25%, enclosing 23%, 4%. Practical implications. findings provide stakeholders technique reasonable parameters systems, predictive developed can be mitigate potential instability issues excavations. results have implications similar geological settings valuable design optimization other regions.