According to the appeared incident dynamic pressure of 1304 working face in a mine, the characteristics of electromagnetic emission signal were analyzed before the dynamic pressure occurred; FLAC3D was used to simulate the impact on pressure relief effect under the conditions of different borehole diameter, space and depths. The results showed that: electromagnetic emission intensity and pulse signals continual increase could be a symbol of shock hazard; the larger the borehole diameter, the smaller the borehole space, the greater the depth of the borehole, and the better relief; borehole depth must exceed a certain range of stress concentration area, otherwise pressure relief effect was not obvious, and even increased the possibility of shock hazard. Based on the above findings, rock burst local prevention and control integration technology of "electromagnetic emission forecasting technology → drilling to determine the range of the risk → large-diameter borehole pressure relief technology → effects checking through electromagnetic emission" which was applied successfully was established.
-In order to optimize and upgrade the pressure releasing effect of blasting breaking hard roof, influence factors of it was analyzed by theoretical analysis, numerical simulation and field practice. Firstly, the impact on charge structure (charge uncoupling coefficient K, charge axial coefficient l e and charge radius r b ) was analyzed by indexes of fracture zone radius and crush zone radius. Secondly, the evolution trend of pressure releasing effect of different blasting parameters (angle of blasting hole, length of blasting hole and explosive charge) was studied by numerical simulation. Results show that blasting effect improves obviously with increase of charge radius and explosive charge. Reducing charge uncoupling coefficient K under the premise of using uncoupling charge ways and taking axial continuous charge way are beneficial for improving blasting effect. When the angle of blasting hole is 45° and it penetrates hard roof rock, pressure releasing effect is better. Combined with the construction equipment and materials in a mine, the charge structure and blasting parameters were designed, and a good application effect was got
Stress concentration caused by deep strip-pillar mining will give rise to rockburst. Mining and retaining parameters have a major influence on stability of coal pillar. Ideally, FLAC3D was used to analyze the distribution and evolution of vertical stress, deformation, advanced abutment pressure and elastic strain energy density under the conditions of different mining and retaining which determined the scope of the dangerous zone ahead the mining face, and basis was provided for rockburst prevention in deep strip-pillar mining.
Macroscopical analysis model of SMW composite retaining structure was made based on composite material mesoscopic structural mechanics theory. compound enhanced rule of transverse elastic modulus and transverse poisson ratio were studied theoretically. Theory results were corrected considered of Not coordinate deformation of structural steel and cement soil. modified formula of SMW composite structure equivalent parameters was made. Theory foundation is formed for study of flexural performance and interfacial interaction law of structural steelcement soil.
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