【作者】 刘志祥；

【导师】 李夕兵；

【作者基本信息】 中南大学 ， 采矿工程， 2005， 博士

【摘要】 充填体力学是随着充填采矿技术发展而形成的一门新型学科。VCR采矿法与高阶段嗣后充填工艺相结合,扩大了充填采矿技术的应用领域,在深部厚大矿床安全高效开采具有广阔的应用前景,同时也为充填体力学增加了新的研究内容。目前由于对高阶段充填体力学机理及其相关理论缺乏系统的研究,高阶段充填设计大都采用经验法或经验类比法,往往造成不必要的水泥浪费或充填体强度达不到工程实际要求。为此,有必要根据深部高阶段充填工艺特征,建立高阶段充填体力学模型,开展降低成本的优化设计研究,以实现深部资源安全高效开采。本文主要研究内容如下: 对尾砂胶结充填体进行了力学试验,建立了不同配比胶结充填体损伤本构方程,分析了不同配比充填体力学特性与能量释放规律。根据充填体损伤本构模型,从岩体开挖释放能量与充填体峰值应力变形能相近的原则探讨了充填体与深部岩体的合理匹配,并确定了冬瓜山矿床深部开采所要求的充填体强度,论证了安庆铜矿深部矿体采用最小充填配比1:12是可行的。 为实现深部开采高质量充填,用分形理论研究了分级尾砂级配。通过对大量尾砂充填矿山的试验数据分析,建立了分级尾砂强度与水泥含量、浓度、孔隙分维数及分维数相关率的神经网络模型,从大量研究数据中揭示了尾砂级配与其强度的内在规律。研究结果表明,分级尾砂颗粒间孔隙分维数减小,充填体强度增高;尾砂分维数相关性越好,充填体强度越高。根据尾砂级配模型,用混沌优化方法研究了使充填体达到最佳强度的选矿尾砂合理分级。该模型与理论应用于安庆铜矿选矿尾砂分级设计,不仅提高了充填体强度,而且增加了尾砂使用率,节约了充填成本。 针对高阶段嗣后充填工艺特点,分析了深部开采围岩对充填体的力学作用,建立了高阶段分层充填体力学计算模型,研究了充填体可暴露任意高度的力学条件,并用分形树和重整化群方法建立了深部开采充填体强度模型。基于深部开采的复杂性和充填体强度的不确定性,根据所建立的高阶段充填体力学模型,用可靠性理论和博弈树方法,成功解决了高阶段充填体配比优化难题。该研究方法应用于安庆更多还原

【Abstract】 Backfill mechanics is a new subject that is formulated with the development of the technology of filling mining. Coupling the Vertical Crater Retreat method with delayed backfill in high-level mining, the applying ranges of filling technology are extended, especially in deep, thick and large-scale deposit, and at the same time new research contents are tabled for backfill mechanics. Because there are not systematical researches on mechanical mechanism of high backfill and its correlative theories at present, the design of high level backfill is mainly carried out by experience method or analogical method which often leads the cements being wasted or the strength being lower than that of the requirement in engineering. In order to mine safely and effectively, it is necessary to establish the mechanical models of high backfill according to filling technology in deep mining, and to optimize design to reduce production cost. The main contents of this paper are included as follows.Via mechanical experiment to backfills with different cement-tailing ratios, their damage constitutive equations were established, and their mechanical characters and laws of energy releasing were analyzed. According to the damage constitutive models and the principle that the deformation energy of backfill under peak stress corresponds with releasing energy from excavated rock mass during deep mining, the reasonable match relationship between backfill and deep rock mass was explored, and the required strength of backfill in Dongguashan deep mine, Anhui province, was ascertained, as well as the feasibility of the minimal cement-tailing ratio being determined as 0.0833 in Anqing copper mine was investigated.For improving filling quality in deep mining, the gradation composition of classifying tailings was researched on fractal theory. Analyzing the data tested in a lot of mines, a neural network model which embodied the relations between strength of cemented tailings and content of cement, consistence, fractal dimension of porosity and correlating coefficient of fractal dimension was established, and the intrinsic laws between strength of classifying tailings and its gradation compositionwere researched. The research results show that the strength of cemented tailings increases with the decrease of fractal dimension of porosity, and the higher the correlating coefficient of fractal dimension is the higher the strength will be. According to the gradation composition model, with a method of chaotic optimization, the reasonable classification of mill tailings that owned optimum strengths was given, which has been applied in classifying design of mill tailings in Anqing copper mine. The applying results in Anqing copper mine show that not only the supply of tailings was increased, but also the strength of cemented backfill was enhanced, and filling cost was saved.According to the technologic characters of delayed high backfill, analyzing the mechanical actions between wall rock and backfill during deep mining, a mechanical model of layered filling body and the mechanical condition that backfill can be exposed at a random height were obtained. And with the method of fractal tree and renormalization group, a strength model of backfill in deep mining was established. Because of the complexity of deep mine and indeterminateness of backfill strength, according to the mechanical models proposed above, and using dependability theory and a method of game tree, a complicated problem to optimize the cement-tailings ratios for high backfill was solved successfully, of which the excellent effects were applying in optimizing the ratios of cement to tailings in No. 5 stope in Anqing copper mine.Being complicated deformation of backfill in deep mining condition, such as indeterminateness, randomicity etc., on basis of monitoring the deformations of high backfill in Anqing copper mine, their laws were analyzed with chaotic theory, and the results proved that the deformations of backfill hold the characters of chaos. Reconstructing phase space to time series of deformation of backfill with different cement-tailing ratios, their grey prediction models was established, and a reasonable period of high-level pillar stopping in deep mining was ascertained.更多还原