节点文献
金川二矿区充填体可靠度分析与1#矿体回采地压控制优化研究
【作者】 韩斌；
【作者基本信息】 中南大学 ， 采矿工程， 2004， 博士
【摘要】 我国三大资源综合利用基地之一的金川镍矿,是国内最大的镍、钴、铂族等有色金属生产基地,由于金川镍矿处于高地应力区,埋藏深,岩体破碎,开采条件极差,所采用的下向进路胶结充填采矿法充填体的稳定性和1#矿体回采地压控制问题一直是金川镍矿开采过程中所面临的难题。 作者结合金川二矿区工程实际,应用现代可靠度理论和岩石力学理论,将现场监测、工程地质调查、理论分析、数值模拟及相似材料模拟等多种方法有机地结合起来,对二矿区回采最基本单元——单个进路充填体稳定性,以及1#矿体回采的地压控制问题进行了系统研究,主要完成了下述工作: 首次将可靠度理论应用于下向进路承载层稳定性的研究,建立了下向进路力学模型,分析了其应力分布规律,在深入探索承载层失稳破坏机理的基础上,提出将承载层稳定性可靠度指标作为评价充填体稳定性的新概念,建立了基于可靠度理论的下向进路充填体稳定性评价方法。 揭示了充填成本与承载层厚度及其强度、进路宽度、承载层稳定性之间的内在联系,提出了基于可靠度理论的下向进路胶结充填技术经济分析方法,建立了金川二矿区充填体稳定性可靠概率在90%条件下充填成本与进路宽度、承载层厚度、充填体强度之间的关系方程,并提出了进一步降低二矿区充填成本的工程技术措施。 突破了确定下向进路胶结充填采矿法充填体强度的传统模式,在考虑了充填体力学性质、进路宽度、所受载荷、充填工艺等各因素随机性的基础上,提出了基于可靠度理论的充填体强度确定新方法,丰富和完善了充填体强度确定理论。并将该方法应用于金川二矿区废石料胶结充填采矿工艺中。 根据下向进路承载层失稳主控因素的分析结果,结合现场实际,提出了二矿区盘区内部回采顺序优化的方法,同时采用三维非线性有限差分数值计算(FLAC3D),对上、下分层进路布置方式进行了研究,得出了采用上、下进路交错布置方式更有利于改善充填体中的应力分布、控制充填体及围岩移动的结论。 采用二维非线性有限差分数值计算(FLAC2D)和大型相似材料模拟实验,对1#矿体六种可行的回采顺序进行了优化研究,结果表明,从1#矿体一端向另一端逐步过度的回采方式为最佳回采顺序。根据数值模拟与相似材料模拟所得结论,对二矿区“十·五”及“十一·五”生产进度规划和今后850m水平开采的回采顺序提出了具体建议。 采用二维非线性有限差分数值模拟、大型相似材料模拟实验及现场工程地质调查等多种方法,对二矿区水平矿柱开采的稳定性进行了研究,揭示了水平矿柱、充填体及围岩在整个开采过程中的动态地压分布规律,探明了水平矿柱、充填体及围岩在开采过程中的
【Abstract】 Jinchuan nickel mine is one of three resources comprehensive utilization bases in China; it is also the largest nickel, cobalt and other non-ferrous metals production base in China. At present, 85% of nickel and 50% of cobalt are produced by Jinchuan nickel mine. Because the mining conditions of Jinchuan ore body are very bad due to the high-stress area, very deep-lying and poor rock mass, the stability of backfill of underhand cut-and-fill drift stoping and the ground control of whole mining area are always the difficult problems faced by Jinchuan nickel mine.Based on the reliability theory and No.2 mine area of Jinchuan nickel mine, in combination with in-situ monitoring, engineering geological investigation, theory analysis, numerical simulations and similar materials simulating tests, the author systemically study the stability of backfill in a single drift mined by underhand cut-and-filling drift stoping, then he firstly studies the mining sequence of a single panel, the drift-layout method between upper slice and lower slice in a panel, and the mining sequence of whole No.1 ore body. Two important problems, i.e. the mining stability of horizontal pillar and the effect of the 16th-line vertical pillar on the ground control of whole mining area in No.2 mine area, are systematically studied.In this paper, the reliability theory is applied for the first time to study the stability of loaded layer of drift, the mechanical model of loaded layer is established, the stress distribution law of loaded layer is analyzed, a new conception is put forward to evaluate the backfill stability by use of the reliability index of stability of loaded layer based on the deep study on the failure mechanism of loaded layer. Based on the reliability theory, an evaluation method of the stability of backfill of underhand drift is established. The intrinsic relation among the thickness and strength of loaded layer, the applied load on loaded layer and the width of drift is revealed. The specific engineering measures are presented to improve the stability of backfill.The mutual relation among the thickness and strength of loaded layer, the width of drift, the stability of loaded layer and the cost of backfill is researched. Based on the reliability theory, the backfill techno-economic analysis method is provided. Based on the reliability index at 90% of the loaded layer stability, the relation formula among the backfill cost and the width of the drift, the thickness and strength of loaded layer is established.The traditional method for determining the strength of the backfill in underhand drift cut-and-fill stoping is broken through, and a new method of determining the strength of backfill, based on the reliability theory, is put forward. The backfill strength determining method is perfected. The method is used for the rock-cemented fill mining technology in Jinchuan No.2 mine area.According to the results from analyzing the main control factors of loaded layer unstability of underhand drifts, in combination with the in-situ situation of mechanized mining panel at Jinchuan No.2 mine area, an optimal mining sequence of a panel is put forward. The FLAC3D numerical simulation analysis is used to study the layout pattern between the upper andlower drifts. It is concluded that intersecting the drifts between the upper slice and the lower slice is more beneficial to stress distribution in the backfill, and controlling the movement of backfill and the surrounding rock.The FLAC2D numerical simulation analysis and the large-scale similar material simulating test are used to research the six kinds of feasible mining sequence of 1# ore body in No.2 mine area. The results shown that the optimal mining sequence of l# ore body in No.2 mine area is from its one end gradually to the other. Based on the conclusions drawn from the numerical simulation analysis and the similar material simulating test, some specific recommendations on adjusting 10th and 11th five-year production scheduling plan, and the mining sequence of Level 850m ore body in the future are made.Combined with the numerical simulation and the large-scale similar material simulating test as well as the in-situ geological engineering survey, the stability of horizontal pillar in the thick ore body mined by multiple levels in Jinchuan No.2 mine area is researched. The dynamic ground stress distribution law of the horizontal pillar, the backfill and the surrounding rock during the whole mining process is discovered. The conclusions show that the horizontal pillar will not instabilize suddenly during the mining process. According to the ground stress characteristics of the horizontal pillar, the specific engineering measures are provided for mining the horizontal pillar in the future.Combined with the analyses method of catastrophe theory and the mechanics model of the horizontal pillar, a CUSP catastrophe model of horizontal pillar is established, the instabilizing criteria of sufficient and necessary mechanical condition of horizontal pillar are derived, and the balance state of pillar is discussed. The research method of the CUSP catastrophe model of horizontal pillar instability based on reliability theory is put forward, and a new idea on the application research of the catastrophe theory is presented.The FLAC2D numerical simulation, the in-situ monitoring and the mechanics analyses are used to evaluate the ground stress control effect of vertical pillar at the 16th line. It is concluded that retaining the vertical pillar at the 16th line plays a important role in the stability of backfill in whole mining area. Also, it is beneficial to the protection of main underground constructions, especially to the west main shaft.Through the study of this paper, backfill mechanics theory is enhanced, and the theory related to underhand cut-and-fill drift stoping method is enriched. The results of this paper provide scientific direction for the dynamic ground stress control of Jinchuan No.2 mine area and similar mines, it is of theoretical significance and engineering application values to the safe, economical, and reasonable mining of the underground mineral resources.