Study On Expansion Of Concealed Water Filling Fault In Coal Floor By Simulation Experiments

It is a difficulty that how to solving the problem of water inrush from coal floorto make sure the safety production in the North China coal field. It is especially urgentfor the mine which has the concealed fault threat in the coal floor. Because of itsconcealment, it is hard to observe and probe effectively. Thus the research on floorwater inrush mechanism of concealed faults still has many problems. This thesismainly focuses on the mining process of concealed water-filling faults in coal seamfloor. The general rule of water inrush from coal floor under the action of waterpressure and mining pressure is observed and analyzed by the means of similarmaterial simulation, FLAC3D numerical simulation and engineering practice.This thesis has comprehensively analyzed domestic and foreign scholars’important research results on the coal seam floor, fault water inrush, and brieflyderived the mechanical mechanism of fault water inrush. The mining process of coalunder the different conditions of concealed fault in floor combining forms, waterpressure, initial height, and occurrence is observed through the methods of analog andnumerical simulation experiments. Also, this thesis has summarized the extensiondevelopment laws of the floor damage state and fracture belt as well as the dynamicevolution process of plastic failure state. Experimental results show that thedisturbance of floor weak state (fault) has the progressive rise phenomenon under theinfluence of water pressure and mining stress, that is, progressive guide risemechanism of water inrush. The difference in the law of the concealed faults fracturecombining the floor damage state is found under different floor conditions. In addition,tendency is opposite to the direction of working face, and the larger the developmentheight of the fault is, the more drastic the progressive rise will be, then the more likelyto water inrush. Then, the thesis has explained the progressive guide rise mechanismof water inrush, and analyzed the method of obtaining the key parameters in thediscriminant of water inrush.Combing with the engineering example of the working face5124of Liu jialiangcoal in Xuangang, and according to the parameters gained by field test, the reasonableFLAC3D numerical model is designed. The application of water inrush mechanism inpractical engineering is researched through the calculation of the excavation, and theresults of the similar material and numerical simulation experiments are further validated.