Applied Mechanics and Materials Vols. 295-298

Abstract: Based on the analysis of geologic structure evolution and distribution characteristic in the Shengli Mine, which studied the influence that the mine geological structure, roof and floor lithologic of coal seam and elevation of seam floor, made on mine gas occurrence, combined with geological data and a large number of experimental data. Detailed elaboration about the situation in the Shengli Mine gas geology law, and prediction about gas emission and the dangerous of gas regional outburst. The results show that the gas content of the seam would be increases with the depth of the seam increases; There would be an abnormal phenomenon occurred at the geological fault about the gas occurrence, which is especially obvious in fault fracture zone.

Abstract: The principle of green mining is conservation resources, protection environment, people oriented and safety production. According own characteristics of coal industry, this paper built the input and output indicators of green mining, chose eight different coal enterprises in China as decision making units. The date envelopment analysis (DEA) was applied to evaluate and optimize the operating efficiency of coal enterprises from technical efficiency, pure technology efficiency and scale efficiency. At the same time, with an inefficiency enterprise as example, projection analysis was used to give some suggestions to optimization.

Abstract: A study of emulsion explosive of deep-water pressure performance can provide theoretical basis for underwater blasting, deep hole blasting and the design of emulsion explosive. The sensitizer is the heavier components of emulsion explosive, using reusable experimental device to simulate the environment of deep water charge, perlite and glass microspheres in two kinds of commonly used physical sensitizing agent content on properties of emulsion explosives with deep water pressure effect. The experimental results show that : with the increasing of the content of physical sensitizing agent, emulsion explosive of deep-water pressure performance also gradually improve, when the pressure is larger, the effect is particularly pronounced; in a certain range, with the increase of the content of physical sensitizing agent, emulsified explosive performance also gradually improve, but reaches a certain value, the explosion properties but declined; in emulsion matrix under the same conditions, the perlite content of 5%, glass microspheres content is 2%, the emulsion explosive has good resistance to water pressure and explosion properties.

Abstract: Duanwang Coal Mine in Shanxi province, China, is located at north of Qinshui coalfield which gently inclined and thick seams have been mined. Authorized production capacity of the coal mine is 1.8Mt/a. With the increase of mining depth, the mine gas emission quantity increased. The mine became high gassy one from low gassy mine. Using field measurement and theoretical analysis methods, the following conclusion can be drawn. Gas emission quantity of coal face is directly correlated with mining depth. With the increase of mining depth, both absolute and relative gas emission quantities at coal face increased. The gradient of gas emission quantity was 0.0438-0.1338m3/t/m, the average value was 0.1062m3/t/m. These results would provide a foundation for prediction of the gas emission quantity and selection of gas control measures.

Abstract: Overlying strata stress distribution, pressure relief region and crack distribution characteristics are analyzed based on numerical simulation of pressure relief with extremely thin coal seam as protection seam used by UDEC. The result is a true reflection of overlying strata movement and fissures for extremely thin coal seam as protection seam. Studies have shown that the roof displacement in the face of protective layer promoting is big, and as far away from the protective layer, the roof displacement is gradually reduced, the base plate displacement is almost the same, but the roof and floor to stress have been fully release; after protective layer mining, an "O" type pressure relief crack area is formed above the goaf, which is gas rich region and gas channels at the same time and suitable for extracting high concentrations gas.

Abstract: Based on the layout and geological conditions in 10203 test mining face of Gaoyang mine, This paper analyzed the three major factors influencing effects of filling mining that can be summarized as Fulfilling ratio, and goaffilling mining subsidence is expected to be full-span falls method of using calculating mining height prediction method, which provides a new approach for mining under buildings in the future.

Abstract: Based on the analysis of the coal mine accidents dangerous sources and essential factors of occurrence mechanism, the coal mine accidents causation model is built by combing with system security theory and dangerous sources theory. This paper analyzes a large number of accidents causation factors and screens the main factors; finally the coal mine accidents hierarchical structure model is constructed. What’s more, combined with examples, the fuzzy analytic hierarchy process is applied to evaluate the accidents causation analysis.

Abstract: This paper, from the advantages and disadvantages of the conventional judgment methods of ascending mining feasibility, put forward the judgment criterions of near distance coal seam group ascending mining feasibility. And it is used the method of numerical simulation for the correlation analysis and verification. According to the existing ascending mining feasibility the judgment method has certain limitation. Therefore put forward the new determination method. Engineering application has some significance.

Abstract: With the continuous mining of coal, many mine have entered the deep mining mine ranks. Many problems which caused by the deep mining, especially the mine rockburst has had a significant increase, and a more and more serious trend, this has seriously affected the safety production[1]. There are many rockburst factors, and by the mining process and mining, its leading factor was difficult to be determined during mining. However, analyzing the mining process, and researching the influences of mining process on rockburst, making effective means of monitoring, adjusting the recovery process parameters, there are practical significance on mine safety. Reserving stacks along the gob tunnel is a mining technique which many mining often used. The document conducted numerical analysis towards the vertical stress distribution in the stacks, and come to a conclusion about the mining technique influence to shock bump, which has provided the basis for the recovery process parameter adjustment. Practice has proved that the method is feasible. The results of the analysis have practical significance.

Abstract: To solve this difficult technological problem that predicts the surface subsidence that induced by deep mining of large steep deposit. Through understanding engineering geological characteristics and mining conditions for a certain mining area, the three-dimensional simulation model of deep mining with a high degree similarity in space and mechanics morphology have been established, and the exploitation of the mining area has been systematically simulated. After excavation of the third stage, the calculated values of surface subsidence coincided with the measured values of GPS. Then it has been more accurately predicted surface subsidence and displacement angle and the range of surface deformation which were induced by deep mining in fourth stage project. It provides the basis for the positioning of underground engineering and design of the range of ground movement in deep mining.