羊拉铜矿里农矿段采空区稳定性分析

发布时间：2018-08-19 06:57

【摘要】：里农矿段是羊拉铜矿的主要采矿区之一,采取的采矿方式包括底盘漏斗空场充填法、房柱法、全面法及近地表崩落法,其中主要采矿方法为底盘漏斗空场充填法,当前矿山已开采多年并形成大量采空区,由于原设计的尾砂充填采空区方案应用失败,而新的充填方案也未得到有效的实施,致使大量采空区暴露,局部地段还存在上下两层采空区重叠的现象。到目前为止里农矿段部分地表已经发生山体滑坡,部分采空区顶板有垮落迹象,充填顶沿垮断或受到破坏,对矿山安全生产产生了严重的影响,因此迫切需要对里农矿段现有采空区的稳定性进行研究和治理。通过查阅大量有关空区稳定性影响因素分类的文献,从而提出了影响矿山采空区稳定性的三大类主要因素,并在此基础上进一步细分为十二小类,借助国内外普遍采用的AHP层次分析法获得了各影响因素重要性排序,结果显示影响采空区稳定性的最主要影响因素为地质构造、矿柱尺寸布置、水文地质条件、空区面积、岩石质量指标等。本文分别选取了矿体顶板、含矿层和矿体底板岩体作为研究对象,与现场实际情况相结合,对三种主要岩体进行密度、弹性模量、泊松比、单轴抗压强度、抗拉强度、内聚力、内摩擦角等物理力学试验。最后利用Hoek-Brown强度准则将实验室测定的标准式样的岩石力学参数转变为岩体力学参数。本文作者首先对里农矿段进行详细地野外调查,包括矿山工程地质、水文地质等开采技术条件、采空区分布情况及采空区变形破坏现状等;然后通过现场取样带回实验室进行物理力学试验,并通过分析研究得到里农矿段三种主要矿岩物理力学指标;最终确定如下研究内容,其研究结果如下:1、采空区顶板稳定性分析计算结果显示采空区顶板的冒落带加裂隙带的高度之和为90.32～113.73m;2、采空区允许极限跨度采用Barton“当量尺寸”分析方法的计算结果来看,当采场跨度为21.73m以下时无支护状态下是稳定的,在21.73m以上时,在无支护情况下顶板是不稳定的,极有可能引发采空区顶板冒落;采用工程岩体自稳能力分析结果显示矿体顶板大理岩属于较坚固～坚固岩体,岩石质量等级为中等,等级为Ⅲ级,当采场跨度为20m以下时,可稳定数天到一个月;3、双层矿体隔离层稳定性分析中引用了具有边界约束的三维板状结构受力图,借助该板结构的受力来分析隔离层的稳定性状况。分析结果显示隔离层顶板保持稳定时,其上、下层矿体的矿柱重叠率必须大于65%;4、矿柱稳定性分析中采取了面积承载理论和Bieniawski·矿柱强度计算公式,结果显示本矿山留设的矿柱安全系数F小于其允许值ks=1.5,单纯靠留设的矿柱来支撑采场顶板不可行,应及时对暴露的采空区进行处理;5、数值模拟分析通过建立8号勘探线剖面两侧各100m范围,沿倾向400m范围的矿山开采简化模型,并以此模型为基础模拟了六个步骤的开采分析,得到了模型在不同开挖步骤后的模拟信息及数据。通过矿柱稳定性分析,下层矿体开采对上层采空区稳定性影响分析,矿体开采对覆岩及地表稳定性影响分析,得出结果显示研究区矿段在采矿活动过程中,其采空区存在安全隐患;6、最后在上述分析的基础上并结合研究区矿段现有采空区现状,提出了利用胶结充填的方式对矿山现已暴露的采空区进行综合治理,设计了胶结充填参数及配比方案并提出了采空区治理过程中应注意的事项,借助数值模拟分析技术对本文提出的胶结充填方案效果进行了仿真模拟,模拟结果显示胶结充填能够有效防止采空区灾害的发生。
[Abstract]:The Linong section is one of the main mining areas in Yangla Copper Mine. The mining methods adopted include chassis funnel stope filling method, room-pillar method, comprehensive method and near-surface caving method. The main mining methods are chassis funnel stope filling method. At present, the mine has been mining for many years and a large number of goafs have been formed due to the original design of tailings filling goaf. The application of the case failed, and the new filling scheme was not effectively implemented, resulting in a large number of mined-out areas exposed, part of the upper and lower goafs overlap. So far, landslides have occurred in part of the surface of the Linong mining section, part of the goaf roof caving signs, filling roof broken or destroyed, to the mine safety. It is urgent to study and control the stability of the existing goaf in the Linong Mining Section because of the serious influence of the whole production. Through consulting a large number of literature on the classification of the factors affecting the stability of the goaf, three main factors affecting the stability of the goaf are put forward and further subdivided into twelve small ones. The results show that the most important factors affecting the stability of goaf are geological structure, pillar size arrangement, hydrogeological conditions, goaf area, rock quality index, etc. In this paper, the roof of orebody, ore-bearing strata and floor of orebody are selected respectively. Rock mass is taken as the research object and combined with the actual situation in the field, the physical and mechanical tests of density, elastic modulus, Poisson's ratio, uniaxial compressive strength, tensile strength, cohesion and internal friction angle of three main rock masses are carried out. Finally, the rock mechanics parameters of standard rock samples determined in laboratory are transformed into rock mass mechanics by Hoek-Brown strength criterion. Firstly, the author makes a detailed field investigation of the Linong mining section, including the mining technical conditions such as mine engineering geology, hydrogeology, the distribution of goaf and the deformation and destruction of goaf, etc. The results are as follows: 1. The height of caving zone and fracture zone in goaf roof is 90.32-113.73 m; 2. The limit span of goaf is calculated by Barton's "equivalent size" method. When the stope span is less than 21.73 m, the roof is stable without support. When the stope span is above 21.73 m, the roof is unstable without support, and it is very likely to cause the roof caving in goaf. 3. Three-dimensional plate-like structure with boundary constraint is used to analyze the stability of the isolation layer in the stability analysis of double-layer orebody. The results show that when the roof of the isolation layer is stable, the upper and lower layers of the orebody are stable. The overlap ratio of pillars must be more than 65%. 4. The area bearing theory and Bieniawski pillar strength calculation formula are adopted in the stability analysis of pillars. The results show that the safety factor F of pillars retained in the mine is less than the allowable value ks=1.5. It is not feasible to support the roof of stope by simply retaining pillars, and the exposed goaf should be located in time. 5. By establishing a simplified mining model with 100 meters on both sides of the section of No. 8 exploration line and 400 meters along the inclination, the model is used to simulate the mining analysis of six steps, and the simulation information and data after different excavation steps are obtained. The results show that there are potential safety hazards in the goaf of the study area in the process of mining activities; 6. Finally, on the basis of the above analysis and combined with the present situation of the goaf in the study area, the paper puts forward the method of cemented filling to the mine. The mined-out area which has been exposed in the mountain is treated comprehensively, the cemented filling parameters and proportioning scheme are designed, and the matters needing attention in the process of mined-out area treatment are put forward. The effect of cemented filling scheme proposed in this paper is simulated by means of numerical simulation analysis technology. The simulation results show that cemented filling can effectively prevent the disaster of mined-out area. The occurrence of harm.
【学位授予单位】：昆明理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TD862.1

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