The mathematical model of single-phase flow of gas was established based on the k-ε two-equation model and numerically simulated the eddy air-curtain dust controlled flow field in hard rock mechanized driving face with the help of FLUENT software on account of the collocated grid SIMPLE algorithm. The result showed that, after all the pressure ventilation blown out by the radial clearance of mural cylinder, a full-face eddy air-curtain flow field is formed at the roadway section and with the help of the exhausting cylinder, it keeps pushing toward the tunneling place, forming the air-curtain dust controlled flow field that presses the tunneling place equally in front of the driver of road header. After the application of the development of new light polymer materials radial cylinder eddy air-curtain dust controlled system was adopted in hard rock mechanized driving face of north conveyor main roadway, the average settlement rate of total dust and repairable dust have reached to 97.4% and 96.8%
respectively, reducing the local dust concentration effectively

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in the background of an open-pit slope at warehouse gold mine, the beresitization fractured granite (SγJh) was selected to conduct rock tri-axial creep test subject to different saturation-dehydration cycles. it is found that the creep characteristics conform to Burgers model without considering the change of the creep failure stage. The creep parameters, the principal stress difference and its deviation are analyzed for saturation-dehydration cycles of N = 0, 1, 5, 10, respectively. results show that the parameters of Burgers model are substantially influenced by the load level. G1 and G2 increase with the increase of axial loading. η1 and η2 decrease with the increase of axial loading. The relationship between the four parameters and the stress difference follows exponential trend. an exponential relation is found between the creep parameters and the principal stress difference for constant saturation-dehydration circles. The creep parameters are approximately exponential functions of the cycle number n for the same principal stress difference. Through curve fitting of the test data, the values of the parameters in Burgers model for the beresitization fractured granite (SγJh) are obtained by considering the water-rock interaction and principal stress difference.

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Compared with mining the horizontal coal seam and gently inclined coal seam, steeply inclined and very thick coal seam mining has many differences. Since the fracture development law is not clear, resulting in the application effect limitation of gas extraction, prevention and control of air leakage and other technics. In order to improve the efficiency of gas extraction and prevention of air leakage, laboratory similarly model test and numerical simulation were adopted to study the development law of overburden rock fracture, and the results with similarly model test and numerical simulation was identical. The result showed that: Its fracture development law showed a typical "V" structure, roof collapse and overlying strata movement rule were consistent well with separation and fracture development law. When mining the shallow level, the development degree of fracture was relatively low. With the increase of mining depth, the degree of development of fracture and separation rising. After mining 2~3 levels, vertical cracks appear in the working face overburden and it gradually developed up to the ground with the increase of mining depth. Compared with mining the shallow level, the range and development degree of roof separation in mining the deep shallow was higher.