Control Of Coal-gas Outburst Accident Chains And Its Application

With mining work getting deeper, the ground stress, gas pressure and gas content increase, coal-gas outburst disasters are becoming more serious. Relying on national natural science foundation key project"Research of Formation Mechanism and Management Method for Coal-gas Outburst Accidents"(NO.70533050,start/end time: 2006-2009), research was conducted into control and application of coal-gas outburst accident chains by using accident cause theory, accident chain theory and gas outburst control technology. The main conclusions are presented as following:1) The technological and management factors are taken as two nodes of coal-gas outburst accident chains. The technical factors form the technical cause chain, which includes basic technological work, reliability of each system, prevention technology, innovation in ideology and technology and technical equipment. The management factors constitute the management cause chain, which consists of the input, management, institution and manpower for gas control. The simultaneous occurrence of technical and management cause chains would lead to coal-gas outburst accidents. The model for coal-gas outburst accident chains is built based on the theory.2) An indicator system for coal-gas outburst accident was built by using the model for coal-gas outburst accident chain. Subsequently, safety standard establishment and grading were performed by referencing to the rules and research results relevant to coal-gas outburst prevention. Base on the above achivement, the standard safety table of the indicator system for coal-gas outburst accident was obtained, which thus realized the standardization process for coal-gas outburst prevention engineering.3) An algorithm for critical factors of coal-gas outburst accidents was compiled based on principal component theory. To check its reliability, the algorithm was used to build the prediction model of PCA-BP neural network which was trained and tested by employing the typical coal-gas outburst cases in China. The simulation results showed that the prediction model of PCA-BP neural network was superior to the traditional BP network. Hence, the algorithm could be used to determine the critical chain of the coal-gas outburst accidents.4) Chain-breaking technology for coal-gas outburst accident at coal seams with different outburst risk was analyzed by using the coal-gas outburst accident chain, six kinds of regional chain-breaking technologies for controlling coal-gas outburst accident were achieved, and management strategies for controlling coal-gas outburst accident chain were rendered. As a result, success was achieved in controlling the basic, technological and management factors, cutting off coal-gas outburst accident chain and preventing coal-gas outburst accidents.5) Case study was investigated with the theory. The safety values corresponding to the indicators of Daping coal mine outburst accidents were determined using the indicator system for coal-gas outburst accident and standard safety table. By utilizing the compiled algorithm for critical factors of coal-gas outburst accidents, the accident critical chain was determined. Comparison with the'10.20'extraordinarily serious coal-gas accidents revealed that the obtained accident critical chain agreed well with the investigation results of experts. Based on these results, several chain-breaking technologies for coal-gas outburst accident were proposed such as bedding layer bore gas drainage for unsteady'three fragility'extremely-thick outburst coal seam. The chain-breaking technologies were also applied to Daping coal mine 16071 working face. The results showed that gas drainage rate for bedding layer bores could exceed 31.5%, and that the content of residual gas could decrease to below 6.7m3/t. The gas drainage technology for bedding layer bores successfully broke the coal-gas outburst accident chain and consequently ruled out the risk of outburst in the tested coal seam region.