Applied Mechanics and Materials Vols. 295-298

Abstract: This thesis, making research on 4224 Mining District of Zhangcun Mine and combining with the geological features of the good lithological conditions of the roof and floor of the mining district and low gas content，etc, put forward the maintain roadways pattern of gob-side entry retaining, adopt adding anchor cables and erecting monomer pillar and other methods as the means to strengthen support, and effectively prevent the gangue to flow into the roadway by hanging grid on the up-side, and make research on ground behavior regular of gob-side entry retaining. Raise the transporting method that the face support move along the Gob-side Entry to the Open-Off Cut of the next section，which shorten the face moving route and moving time, achieve quick successival of the adjacent face. Meanwhile, continuous mining makes the surface appear continuous sinking, avoid the adverse impact on the surface of the sinking marginal basin, and minimize damage to the environment. Achieve the maximum recovery of coal resources, and minimize damage to the environment.

Abstract: In order to study the stress distribution and its dynamic influence law while the protective layer mining, based on the transfer law of mining-induced stress in the coal seam floor and in front of the working face, using numerical simulation software to simulate the surrounding rock stress under the different pillar width mining conditions, and carried through the roadway deformation engineering practice observations. It is shown that reserved 110m coal pillar could weaken the impact on the front of the floor tunnel under the protective layer mining process. When the top liberated layer mining to reduce the impact of mining stress superposition, it should avoid the terminal lines on the two coal seams at the same location and may be staggered at least about 30m ~ 50m. And it obtained that the roadway deformation not only by mining impact, but also considering the geological environment surrounding rock conditions, tunnel position in which layers of rock, rock properties and other factors. The research guided the engineering practice successfully.

Abstract: Degree of mechanization of extremely thin coal seam mining is growing, with introducing the main mining method currently used by the different inclination of the extremely thin coal seams in China, focusing on the different mining technology and related ancillary mining equipment development status and existing problems, and discuss the extremely thin coal seam in the future to realize the remote control, automatic monitoring and unmanned mining development trend.

Abstract: The variation of coal body electrical parameters are important parameters for researches on the propagation of electromagnetic radiation and acoustic emission in coal. Therefore, experiments of coal body electrical parameters under triaxial stress are carried out. Studies have shown that, the resistivity of coal body decreases with the loading of axial compression and confining pressure. And the decline of raw coal is relatively more obvious, while the decline of briquette is smaller. Moreover, the resistivity of coal body retains relatively stable when the stress is greater than 3MPa. With the increase of axial compression and confining pressure, the dielectric constant of coal body will also increase and it will be basically stable when the stress is greater than 3MPa.

Abstract: Mining project investment has a lot of features, such as long period, slow effect, big capital size, irreversible investment, the numerous and complicated risk factors. Therefore, it is necessary to analyze and evaluate the investment risk before accepting project. On the basis of analyzing the mining project risk factors, establishing the risk evaluation index system, establishing the risk assessment model based on fuzzy comprehensive method, then evaluating the investment risk of mining project quantitatively, which provides the decision-making basis, makes the investment more scientific and safer and reduces the risk of investment.

Abstract: The vast majority of China's coal mine was located in mountains and multi-seam mining and seam slice mining were the most common type. With the depth of our mining coal seam increased, it is important to research the regularity that the repeated mining affected the surface subsidence. The current paper used the measured data of Jia Lequan and simulated the surface deformation after removed the impact of the mountainous terrain to compare the trend and mechanism of the surface movement and parameters in repeated mining. Proposed the surface movement and deformation under the multi-seam repeated mining, and laid the foundation for the future research in repeated mining.

Abstract: Mine disasters frequently occur with serious consequences, so additional research is needed to effectively deal with mine disasters especially the secondary catastrophes. Modularization modeling method was used to develop the dynamic analytical platform for modeling mine ventilation networks. The platform includes models of the ventilation network and the control systems. A small experimental ventilation network was also constructed to validate the platform. The results show that the platform provides accurate real-time simulations of normal operations and accident conditions in the ventilation network. The platform accurately models dynamic spreading of the disaster in the lab with errors of around 5%. Thus, the platform can be used to analyze the mine ventilation systems during accidents and develop methods to prevent the secondary catastrophes and the deterioration of mine disasters.

Abstract: Based on the great thickness of coal seam in Tashan Mine, narrow pillar mining technology was adopted to liberate more coal resources from coal pillars. In this paper, the research status of narrow pillar technology was analyzed, and the main problems of the narrow pillar mining technique were solved by theory research. The method and technical route of this study was offered in final. The results have great reference value to the fully mechanized sublevel caving with great mining height in similar conditions.

Abstract: The paper aims at presenting an organizational social responsibility approach for improving mine safety and health in China. Through an in-depth comparative analysis of the regulatory mechanisms for mine safety and health in USA and South Africa, it is found that the successful performance of mine safety and health in USA has been contributed by the triangle of effective law enforcement, advanced technology development and qualified labor training, and the impressive improvement of mine health and safety in South Africa has been attributed to the mechanism of tripartite engagement through the state, mine owners and employees. In view of findings from the US and South Africa experiences, an approach of organizational social responsibility through multi-stakeholders is proposed for China to fundamentally improve its performance of mine safety and health by adopting best practices.

Abstract: According to the analysis of the surrounding rock deformation of the buried sandy slate, which is 1500-2000m depth of Diversion Tunnel Jinping-II Hydropower Station, the essay uses FLAC software application to analyze the deformation characteristics and plastic zones of the sandy slate, study comparatively the influence of Mohr-Coulomb model and Cvisc model to the surrounding rock, and then draw some conclusions, including that calculations derived by using Cvisc model is more in line with the actual engineering.