Advanced Materials Research Vols. 734-737

Abstract: Under the condition of the top layered have irregular zone , due to the stress concentration caused by the upper leaf residual coal pillar , lower leaf will increase recovery difficult. This article reappear the scene of irregular top delamination area and the surrounding environment by FLAC3D numerical simulation software, receive the distribution condition of stress, displacement and the elastic energy of media under this condition, provide abundant basis for develop highly targeted production safety measuresa, solve the problem of data range is smaller,because the restriction of the detection equipment and other technical reasons detection equipment under the scene.

Abstract: The related calculation analysis and numerical simulation is the basis of filling pipeline design and installation. Based on characteristics testing of the filling material, the related calculation was performed on the filling slurry gravity transport by pipelines. Chosen pipeline whose diameter was 75 mm, the natural flowing speed can reach 2.6 m/s on condition of the highest concentration for 65%, which is greater than the critical velocity and can meet the needs of the production of the mine. Numerical simulation research shows that the flowing speed of system was relatively ideal, slurry flow rate of bend place has great change while pressure uniformity in the rest parts, and the pressure loss is 0.8 MPa. Therefore, it is capable to achieve gravity flow transporting.

Abstract: Based on the theoretical analysis and field testing, for making clear of the roofs strata behaviors characteristics in the fully mechanized coal mining face in Hongliulin coal mine, and evaluating the adaptability of the support to the roof movement of the working face, this paper gives a collection analysis and evaluation of the rock pressure information during the working faces extraction to get the related technical parameters that can reflect the roof activity rule and the support adaptability analysis and meanwhile to provide some references for the mine pressure monitoring under the similar conditions.

Abstract: Top layered irregular damage zone conditions under stratified due to the stress concentration caused by the upper residual coal will lead to increased recovery difficult. This article by tracking Laokengkou coal mine 7408 face advancing the rock pressure value in the process and analysis, to grasp the distribution of stress concentration in different locations in the process of mining face, for the safety evaluation of the current conditions support improvement measures formulated to provide the necessary reference.

Abstract: Slice mining, when mining lower slice need to consider on the effect of current face from top slice, especially when on top slice mining space irregular, it will make mining more difficult. Hair is drainage of these characteristics the lao keng kou mine by Geophysical means, take advantage of the characteristics of the water content in the mined-out area and media mutation specific master distribution of the residual top delamination, geophysical no damage proved an effective means of underground space structure and highly targeted research stoping methods, based on the conclusions formulated to ensure the safety and production measures in place to provide the necessary reference.

Abstract: According to Yang Zhuang coal mine engineering background and the actual situation, reasonable to determine the test site and experimental programs in this paper, and detailed description of the test method, and the final analysis of the coal seam floor water blocking capability, The results show that In low water pressure, the pressure of injection water in the hole with the water in the aperture of little contact, and in high water pressure will produce a good hydraulic connection. The study provides a theoretical foundation and scientific basis for the actual engineering improves safety.

Abstract: Coal seam burst tendency is one of the main factors of rockburst. The impact energy index is an important indicator to evaluate bursting liability of coal. The research on the impact of coal seam impact energy index on the mining pressure behavior regularity is important for the rockburst prediction and prevention. This paper used FLAC^3D numerical calculation software to simulate the mining process of seam workface with different Ke and studied the strata behavior regularity with different Ke. Calculations indicated that the vertical stress peak increased in the middle of the seam workface with Ke increasing and the peak position closer to face should implement the anti-impact measures. However, with Ke decrease, vertical stress superimposes at peak stress increases sharply, gradually increasing vertical stress peak distance away from the face and roadway coal wall and the peak position of moves away from face and roadway coal wall. Therefore, the stress in the roadway and face superimposed at the scour protection measures should be implemented.

Abstract: Support crushing accidents occur frequently in coal mines, which have a serious impact on their safety production. Usually people adopt the loose blasting technology for processing the pressing frame accidents, that is, using the detonative action generated by explosives to cause the rock mass particles vibration which would spread in the form of stress wave to crush the surrounding rock mass. After the release of the rock mass internal stress, the hydraulic support would make use of its own abutment pressure to prop up again the overlying rock and make it work normally. Based on the research of detonative action and making use of FLAC3D numerical simulation technology, this paper provides a theoretical basis as well as the experience for handling the pressing frame accidents by applying a dynamic load test to theoretically calculate the appropriate explosive amount.

Abstract: This essay is initiated by the question as who take the final interests by the price fluctuation of global mines. By analyzing the share structure of four multinational mines corporations and two commodity exchanges, the conclusion is made as that, under the current circumstances of global mines pricing system, the western developed countries and their financial institutions are the final beneficiaries.

Abstract: This paper establishes the early warning index system for the security of Chinese mining industry. After that, this paper measures the safety situation of mining sub-industries during 2002-2009 by the combination of Information Entropy and Grey Theory. The research results show that during 2002-2009, the mining sub-industries are safe, except in 2002. Then, it simulates and forecasts the safe results of mining sub-industry by building a model based on the back-propagation network method. The results also show that the model is suitable for the results of the early warning outcome and applicable to forecast the security of mining sub-industry.