| Production of large open pits is not only space construction in crust entity, but also a complex process to construct mine entity spatially. Mining exploitation requires large scale blasting and stripping,which inevitably forms pit working slope, pit non-working slope, pit end slope, and high-steep slope of dumping area. The pit working slope, formation of end high-steep slope, geometrical parameters and service state are a dynamic variation process.This dissertation comprehensively applies surface mining theories, reliability theories, disaster prevention and reduction theories, as well as approaches of mining rock mass mechanics. Stability analysis methods of three-dimensional and potential sliding plane on surface mine slope have been established, through investigation researches, laboratory researches, theoretical analysis, numerical simulation and spot engineering practice. Models of three-dimensional slope sliding for prism and cylinder have been created. Relationship between slope exposure length and stability has been analyzed. Based on high-steep slope characteristics of surface mine end wall, model of asymmetrical ground stress unloading arch wall in surface mine has been built, and deformational cooperativity of rock strata is analyzed. Combined with theory of creeping and aging in weak layer, instability estimation criterion of surface mine slope has been developed, which reveals surface mining basic principles in stability analysis of surface mine high-steep slope. Based on three-dimensional construction characteristics of high-steep stripping slope in surface mine working area, mathematical model of utmost advancing speed in mining system has been put forward. Mechanical variation law in mining slope of surface mine working area has been revealed. Attenuation equation matrix of impulsive energy has been brought about. According to ballistic theory, the optimal casting angle has been calculated. Through establishment of the finite element model in surface mine efficient casting and parameter inversion model of casting blast, this dissertation conducts prediction of efficient casting rate. Aiming at the particularity of dragline stripping technology, the dragline stripping system, the recovery coal reserves and semi-continuous mining coal system are regarded as one system. According to the demand of mining intensity and utilization of dragline repair time distribution, calculation formula of the minimum coal reserves volume is obtained, reliability model of the system is built, five states of the system and the their transformation with each other are developed. Besides, transfer matrix and availability are also found. The shifting distance models of crusher station and coal haulage in middle channel transportation mode under dragline stripping system are built and stockpile volume is obtained. Mathematical model of dragline service level is founded to develop the relationship between dragline service level and annual planned productivity, as well as the relationship between dragline operation time and thickness variation of coal seam. The concepts of limit system and non-limit system are put forward to realize dynamic adjustment of dragline operation parameters. According to the example analyses on Hei Daigou Surface Mine, this dissertation verifies the correctness and effectiveness of the research topic, research methodology and research results, which provides great significance for enrichment and development of surface mining theories and practical application.There are 101 figures, 13 tables and 110 references.
|
PDF Full Text Request