Simulation Study On Strata Movement And Deformation Laws Of Roadway Cemented Filling Mining

The roadway cemented filling mining technique has the advantages of short solidification time and high strength of filling body, which can keep steady and control the strata movement significantly during the underground mining. In order to evaluate methodically the surface movement and deformation law caused by the roadway cemented filling mining technique in the similar extra-thick coal seam regions, a comprehensive research was conducted using multivariate methods such as mechanics experiment, physical simulation and numerical simulation based on the geological and mining conditions of Gonggeyingzi coal mine, Chifeng. The results reveal the following points:(1) In order to prevent the water from bursting into the working space and ensure the safety of surface buildings, the extra-thick coal seam slicing mining of the roadway cemented filling was proposed, and its principle and technology was introduced particular.(2) By means of the uniaxial compressive strength test, the compression characteristic of filling body was studied, meanwhile, the relationship between the mechanical properties of filling body with different ratios and solidification time was obtained.(3) Through the matching experiment, the similar material of dedicated cementation filling body was developed for the similar material model, the similarity of physical simulation of filling body was guaranteed.(4) According to the geological and mining conditions of Gonggeyingzi coal mine, the similar material simulation was built which is a better supplement to analyze the strata movement and deformation. Two kinds of observation methods were employed which can ensure the accuracy of observations. The height of water flowing fracture zone was analyzed. The result show that this proposed mining technique can control the strata movement significantly which is consistent with the field survey.(5) According to the geological and mining conditions of Gonggeyingzi coal mine, the three-dimensional numerical model was established using FLAC3 D. The strata dynamic deformation law of roadway cemented filling slicing mining was studied. The surface movement basin angle parameter and mobile deformation characteristics was analyzed when the slice layer was mined out, as well as the plastic damage area of overburden rock evolution law. The impact of mining width and the filling mining spacing on roof settling was obtained in the roadway cemented filling mining.Thus, the study will provide a scientific basis of extra-thick coal seam slicing mining safely under strong aquifer for Gonggeyingzi coal, enriching subsidence control theory of extra-thick coal filling mining.