查看更多>>摘要：The currently applied methodology of absolute gassiness forecasting in road-ways being driven in Polish hard coal mines is based on the results of investigations from before more than twenty years. At present the roadways are being driven in majority of cases in quite different conditions than those which had been the subject of the said inves-tigations. The application of "old" methods of forecasting of methane emission during driv-ing of roadways often brings about great discrepancies between the results of the fore-casts and actual situation. It is firstly necessary to determine a potential set of factors which exert an influence on situation regarding methane emission into roadways being driven in order to prepare a verified mathematical model of absolute gassiness forecasting. On the basis of available literature and the investigations conducted by the Central Mining Institute an initial list of factors has been prepared which can have an impact upon meth-ane emission into roadways being driven. The assumptions of heuristic method have been taken advantage of for selection of parameters and indices describing the phenomenon of methane emission. It has been dictated by the fact that the available literature is lacking a pretty unambiguous viewpoint on the subject under consideration and at the same time it is necessary to perform an a priori assessment of the information contained in a given feature (factor). A prepared initial set has been scrutinized to be verified on the basis of a conducted expert survey among seventy specialists in this field. After collecting of the re-sults of the survey their statistical elaboration was prepared. The co-efficient of agreement of multiple ordering, the so called concordance co-efficient has been taken advantage of in order to check the competency of experts. The investigations prove that the experts are in agreement in their opinions. The estimation of a collective assessment of all participants of the survey was conducted with the use of the rank sum's test by J. Gren. The results of the conducted analysis allowed determining a potential set of factors which influence the situation of methane emission into roadways being driven. This set, after conductance of further detailed investigations, can constitute a base for elaboration of a function describ-ing methane emission into roadways being driven in hard coal mines.
FAN Gang-weiZHANG Dong-shengZHAI De-yuanWANG Xu-feng...
346-350页
查看更多>>摘要：Based on the results of similar material simulation, the laws of slope movement due to mining under a gully were analyzed. Selected a slope rock as objective, the mecha-nisms of slope movement influence upon underground mining were proposed, and respec-tive structural models were built by means of numerical modeling and physical simulation. It holds the point that the influence of slope movement on underground mining could be controlled to some extent by appropriate measures. The results indicate that, for gully-ward mining, which mines toward a gully, the slope rock slides horizontally and ro-tates in layers; for gully-away mining, which mines away from the gully, the slope rock ro-tates in a reversed polygon. The slope movement associated with mining under a gully is attributed to pre-existing free faces in the ground gully and underground mining-induced free faces.
查看更多>>摘要：The basics of mining landslides were first summed up based on the analysis of actual materials by the application of mining subsidence and landslide theories. Further, the mechanism of along-layer landslide by mining was studied with the example of the Xiangshan mining landslide at Hancheng, Shaanxi Province. Meanwhile, the state of stress, and the mechanism of deformation and destruction of the Xiangshan mining slope were analyzed by the Finite Element Method.
查看更多>>摘要：The loading on U-steel yieldable support cannot be organically combined with the law of strata behaviors from the surrounding rocks of roadway. In order to effectively solve the problem, U-steel yieldable support with backfill material and the performance requirements of backfill material were analyzed on the basis of structural mechanics. The mechanical properties of backfill material selected were tested in the laboratory, and the test results show that the ratio of the backfill material complies with the requirements of backfill technology; it can effectively optimize the relationship between the support and the surrounding rock, and the filling layer can avoid the partial stress concentration and fully improve the support performance. Compared with U-steel yieldable support with gangue filling, the filed application shows that the supporting result of U-steel yieldable support with backfill technology is satisfactory, the stress on U-steel yieldable support with backfill technology decreases greatly and distributes uniformly, convergence of the surrounding rock of roadway is decreased by more than 50%, and the surrounding rocks of roadway are controlled effectively.
查看更多>>摘要：The three-dimensional (3D) deformation effect of the slope engineering under the step-by-step excavation for the Antaibao surface mine was analyzed using the FLAC3D technique. An optimal excavated scheme with a relatively steeper slope angle of 47° in-stead of 30° was successfully implemented at the west wall in the geological section 73200 of the mine area, where the 3D effect of the nonlinear large deformation of the slope was taken into account. Based on the above research conclusion, put forward the countermeasures of shortening mining length, excavating by different regions, timely foot backfilling to protect the excavated slope, and monitoring and feedback adjustment by studying the nonlinear effect. The results show that these countermeasures are effective in controlling maximum deformation and increasing the stability of the slope.
查看更多>>摘要：A new method based on rough set theory and genetic algorithm was proposed to predict the rock burst proneness. Nine influencing factors were first selected, and then, the decision table was set up. Attributes were reduced by genetic algorithm. Rough set was used to extract the simplified decision rules of rock burst proneness. Taking the prac-tical engineering for example, the rock burst proneness was evaluated and predicted by decision rules. Comparing the prediction results with the actual results, it shows that the proposed method is feasible and effective.
查看更多>>摘要：Based on the theory of geomechanics and using geologic analytical methods, analyed the fault characteristics, mechanical properties, displacement mode, tectonic sys-tem, structural pattern, activity mode of stress, tectonic activity, and tectonic evolution of the area of the Xiamen submarine tunnel, the strike NWW 295°, which is the main unfa-vorable geological structure that affects the safety of the tunnel construction; the macro geological prediction concludes that weathered troughs and groundwater-rich zones formed by its larger-scale fault fracture zones are the main unfavorable geological bodies provides a basis for preventing the geo-logical hazards in the tunnel construction.
查看更多>>摘要：In view of the measurement difficulties of indexes recommended by the 50 Items Experience of Coal Mine Gas Prevention in the process of the nonoutburst coal seam upgrade, this paper took the No.8 coal seam of Huainan Mining Group as re-search object. Discussed the suitability of indexes and corresponding critical values, put forward method in determining the indexes and its critical values by analysis and inves-tigation of the gas geological condition and the-spot tracking near position where an outburst occurred combined with laboratory experiment, and established the indexes and its critical values of nonoutburst coal seam upgrade in No.8 coal seam of Huainan Mining Group. The results show that it is suitable to take gas content and tectonic soft coal thickness easily to gain in routine production as primary upgrade indexes that its critical values are 7.5 m3/t and 0.8 m, respectively. In addition, take f vatue and Δp value as auxiliary indexes.
查看更多>>摘要：Used genetic algorithm (GA) to optimize the network of ventilation in order to avoid artificial convergence and speed up the convergence rate to introduce the Powell algorithm. The Powell algorithm had been integrated into GA. Powell had the effective capacity of solving the local optimal solution. Powell and the cross as a method of choice, a variation of the parallel operator, can be a better solution to the premature convergence of the GA problem. The two methods will be improved to make it an effec-tive combination of hybrid GA called hybrid genetic algorithm (HGA) for the introduction of mine ventilation network optimization and to be used to solve the problem of regulat-ing mine optimization.
查看更多>>摘要：In order to explore the reason for the frequency explosion of spontaneous combustion coal gangue dump and get to know their explosion mechanism, established the experiment platform about spontaneous combustion coal gangue dump interoperable water. The gangue dump was heated using the external heat source, and rainy weather through water mist was simulated. Simulated experiment about explosion of spontaneous combustion coal gangue dump was carried out on the different conditions of the rainfall or not. The unusual gases produced in the course of gangue combustion and the changes in temperature were observed, and their impacts on the explosion of gangue dump were analyzed. The experimental results show that overall warming phenomenon of the gangue dump after watering occurred, the amount of H2 iS three times than that before watering, and the amount of CO is far greater than that on the conditions of no-watering, at the same time combining with local observation and tests. It is found that the content of the oxygen reduce with the temperature increasing; however, gangue dump internal hydrogen content increase unusually on the rainfall conditions at 90℃, but the local measuring points reach the explosion limit. The existence of the CO and H2 is the main reason for inducing the explosion of spontaneous combustion coal gangue dump.
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