Study On Rock Stratum Displacement In Multilayer Containing Vanadium Shale Orebody By Similarity Simulation Experiment And Numerical Simulation

Overlying strata displacement in multilayer containing vanadium shale bedded depositassumes fracture growth in the initial stages. The mining influence scope and the damage degreeof overlying strata are determined by the height of fractured zone and the distribution form of thefractures. The height of fractured zone, the distribution form of fracture and the dynamicevolution have been studied by taking Shanghengshan Vanadium mine as study object throughUDEC numerical simulation and similarity simulation experiment. Preliminary analysis showsthat mining depth, dip angle of ore body, sublevel height and mining thickness are the maininfluencing factors to overlying strata movement and damagement. Based on the discreteelement method and the orthogonal experiment method, The change laws of the height of waterflowing fractured zone followed one of and all of the4influencing factors have been obtained.Combining with the fitting function of the height of fractured zone followed one of the4influencing factors, using the orthogonal experiment range as weight, the predictive function ofthe height of water flowing fractured zone followed multiple factors. According to the fractaltheory, the variation law of the fractures distribution form has been analyzed by takingbox-counting dimension of fractures distribution as analysis index. The result shows that miningdepth, dip angle of ore deposit, and mining thickness greatly affect the distribution range of thefractures while sublevel height makes a strong impact on the damage degree of overlying strata.Meanwhile, the change regulations of the height of water flowing fractured zone and thebox-counting dimension during the process of overlying strata stresses redistribution afterexcavation were obtained. With the passage of time, the height of water flowing fractured zoneachieves the ultimate balance after3growth-balance processes and the box-countingdimension achieves the ultimate balance after2growth-balance processes. Based on thefracture mechanics and the principle of similarity, a large similar material experiment model formining on multilayer containing vanadium shale bedded deposit was built. The overburden’sdestructive rules are analysed on the basis of the strain above goaf within1.8m×0.6m of themodel. The failure process of overlying strata displays remarkable periodicity. Overlying stratain the goaf’s rear is damaged more severely than the overlying strata in the goaf’s ahead. Theresults of similarity simulation experiment agree well with the numerical simulation results.Numerical simulation on the height of water flowing fractured zone, fractal analysis to thedistribution form of the fractures and similarity simulation experiment are effective means forthe study of the overlying strata displacement law in multilayer containing vanadium shalebedded deposit. The results of the research are accord with the practical of Shanghengshanmultilayer containing vanadium shale bedded deposit. The study results can contribute to miningdesign and safety management.