复杂条件下某矿体双中段回采开采效应研究

发布时间：2018-10-29 17:31

【摘要】：矿产资源是矿山可持续发展的基本条件。为减少矿物资源的损失,不仅要回采容易开采的矿体,还需要尽可能的回采各种复杂地质条件的矿体。为保证井下矿体回采的安全性,通常会留大量的矿柱来支撑顶板和上下盘围岩。为不造成矿柱上矿石资源的损失,通常会在采完矿房后进行矿柱的回采工作。由于矿房回采后造成矿柱上应力集中,增大了矿柱回采的难度,水平矿柱下和大型充填体中的矿柱回采是其中最为复杂的情况之一。因此,研究充填体包裹住的、水平矿柱下的矿柱的回采方法及回采效应,对类似情况下的矿柱回采具有重要意义。本文针对安庆铜矿-520~-640 m中段二步骤回采的矿柱5号柱的回采进行研究。通过现场的地质调查和文献阅读了解矿山的地质情况,和地应力的分布规律。应用理论分析、数值模拟、现场监测等手段,分析了采场的稳定性和回采效应,并对空区的治理提出了充填方案。论文主要研究内容和结论如下:(1)对矿区的地质条件、岩石性质、地应力等进行了简要分析,得到了矿岩性质为一般、地应力随深度的线性变化关系。(2)采用太沙基模型法和Thomas模型法对充填体的稳定性进行理论分析,得到了5号柱回采过程中两侧充填体及顶板能保持稳定的结论。在此基础上,选择了5号柱的采矿方法为垂直深孔球状药包落矿阶段矿房法(VCR法)。为保证矿山生产能力,提出双中段VCR法嗣后充填采矿方法。(3)将安庆铜矿的采掘计划图经过处理后用实体建模软件SURPAC打开,建立了矿体和围岩的实体和块体模型并导出质心坐标。以块体质心的坐标在FLAC3D中建立了矿体网格模型。参考前人对安庆铜矿的围岩、矿体、充填体的强度测量结果,通过FLAC3D对矿体的回采过程进行模拟,得到了5号柱回采过程中顶板与两侧充填体的应力、位移变化规律,验证了上一章回采过程中顶板和充填体能维持稳定的论述。(4)采用光弹性应力计对采场顶板的二次应力进行监测,得到了顶板的二次应力变化规律,并验证了模拟计算的可靠性。采用三维激光探测系统(C-ALS)对5号柱空区进行现场探测,通过空区剖面是矿体设计边界的对比,发现5号柱两侧充填体没有发生垮落,证明了双阶段VCR法高强度回采下充填体确实能维持稳定。(5)根据模拟研究和空区探测结果,提出了空区顶部和底部采用胶结充填、中部采用尾砂充填的空区治理方案。采场底部采用胶结充填40 m,中间尾砂充填40 m,顶部胶结充填40 m。采用FLAC3D对充填效果进行模拟,得到充填后5号柱充填体两侧的塑性区和水平位移减小的结论,证明了尾砂胶结充填和尾砂充填的有效性。
[Abstract]:Mineral resources are the basic conditions for the sustainable development of mines. In order to reduce the loss of mineral resources, not only the orebodies which are easy to be mined, but also the orebodies with various complicated geological conditions should be recovered as much as possible. In order to ensure the safety of underground orebody mining, a large number of pillars are usually left to support the roof and upper and lower wall rocks. In order to avoid the loss of ore resources on the pillar, the pillar recovery is usually carried out after the mining house is finished. Because of the stress concentration on the pillar caused by the mining of the mine house, the difficulty of the pillar mining is increased, and the pillar mining under the horizontal pillar and in the large filling body is one of the most complex cases. Therefore, it is of great significance to study the stoping method and the recovery effect of the pillar under the horizontal pillar encased by the filling body. In this paper, the mining of pillar 5 pillar in the middle section of -520 ~ 640m in Anqing Copper Mine is studied. Through the field geological survey and literature reading to understand the geological situation of the mine and the distribution of stress. By means of theoretical analysis, numerical simulation and field monitoring, the stope stability and recovery effect are analyzed, and the filling scheme for the treatment of the empty area is put forward. The main contents and conclusions of this paper are as follows: (1) the geological conditions, rock properties and in-situ stress of the mining area are briefly analyzed, and it is concluded that the ore and rock properties are general. (2) the stability of backfill is theoretically analyzed by using the method of Terzaghi model and Thomas model, and the conclusion that the backfill and roof can keep stable during the mining process of column No. 5 is obtained. On this basis, the mining method of No. 5 pillar is VCR method in the stage of vertical deep hole pellet. In order to ensure mine production capacity, a method of subsequent filling mining with double middle section VCR method is put forward. (3) after processing, the excavation plan map of Anqing Copper Mine is opened up with entity modeling software SURPAC. The solid and block models of orebody and surrounding rock are established and the coordinate of center of mass is derived. The orebody mesh model is established in FLAC3D with the coordinate of block body center. Referring to the results of strength measurement of surrounding rock, orebody and filling body of Anqing Copper Mine, the stress and displacement of roof and filling body of pillar No. 5 are obtained by simulating the mining process of orebody by FLAC3D. This paper verifies the discussion of the stability of roof and filling ability in the previous chapter. (4) the secondary stress of roof is monitored by photoelastic stress meter, and the change law of secondary stress of roof is obtained. The reliability of the simulation calculation is verified. Three-dimensional laser detection system (C-ALS) was used to detect the hollow area of column 5. By comparing the section of the hollow area with the design boundary of the orebody, it was found that there was no collapse of the filling body on both sides of column 5. It is proved that the two-stage VCR method can maintain the stability of the high strength stoping filling body. (5) according to the simulation study and the results of the empty area detection, the paper puts forward the project of treating the hollow area with cemented filling at the top and bottom of the hollow area and filling with tailings in the middle part. The stope bottom is cemented 40 m, middle tailings 40 m, top cemented 40 m. FLAC3D is used to simulate the filling effect, and the conclusion of plastic zone and horizontal displacement decrease on both sides of the filling body after filling is obtained, which proves the effectiveness of tailing cemented filling and tailings filling.
【学位授予单位】：江西理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TD853.391

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