【作者】 彭康；

【导师】 李夕兵；

【作者基本信息】 中南大学 ， 采矿工程， 2014， 博士

【摘要】 海下资源绿色开采是采矿工程界中重要的发展方面。目前,有关海底煤炭资源开采已取得了丰硕的成果,然而,我国在海下金属矿床开采方面的研究才刚刚起步。为此,本文作者在国家重点基础研究发展计划、山东黄金集团重点科技攻关项目、国家科技支撑计划课题的资助下,以海下金属矿床开采关键技术为研究课题,在岩石力学基础研究的前提下对合理隔离层厚度、框架式采场结构参数、岩层监测与预警、矿井水系统等问题进行了系统的研究。在海下开采岩石力学基础方面,首先查明所采矿床的矿体赋存条件、矿体形态、矿山工程地质条件、地应力规律,然后,通过室内岩石力学试验测试及现场岩体结构面的调查,选取RMR法的6个评价指标作为新立矿区海下岩体质量评价的基础,应用Hoek-Brown准则得出不同质量等级岩体力学参数,为矿山井下工程布置、采场稳定性分析及参数优化等提供基础研究。在海下开采合理隔离层厚度方面,着重于隔水保护层的厚度研究,基于Mindlin厚板理论与Winkler地基理论建立了不规则形状的保护层模型,利用微分容积法求解并编制了求解程序DCFMP,以最大拉应力准则作为合理保护层的判据,分别确定了三山岛矿区的18个盘区的合理保护层厚度,最终建议的统一的保护层厚度为22.16m(安全系数1.8)。另外还发现了合理的保护层厚度与盘区面积的显著相关性,并得到了回归方程,为以后合理保护层的确定提供了更为简便的方法。在框架式结构参数优化方面,首先计算不同框架式采场结构参数的最大主应力,建立应力约束的体系应变能最大化的目标函数,求响应面函数后采用非线性优化技术对响应面函数进行优化,从而求得点柱的尺寸为4x4m、跨度为12m；然后基于Kirchhoff薄板理论建立中段间不规则顶底柱模型,利用Galerkin法和坐标映射技术求得顶底柱模型的数值解析解,建立综合考虑经济因素、安全因素和充填效果因素的目标函数,对三山岛矿区内的9个盘区的顶底柱分别进行优化设计,最终得到统一的最优厚度为7.16m。最后有限元强度折减法中任意点的应力-应变强度折减过程与莫尔-库仑准则条件下安全系数法接轨对中段内盘区间不同开采顺序的围岩稳定性进行分析,得出“隔二采一"方案最优,安全系数范围为2.5～3.5,未达矿岩失稳的条件。在岩层监测与预警方面,采用位于上盘围岩内的三个专用观测硐室A、B、C的监测数据,在使用小波变换对岩层位移监测数据进行趋势项分离及平稳化处理的基础上,以时间序列AR模型对监测数据进行短期预测,对不同的小波分解层数与预测步长得到的预测值与实测值进行误差分析,选定3-6步为最佳预测步长,预测误差可控制在1%以内。同时,通过研究对比各个岩土工程中预警指标的确定方法,选取单次采样时间内的变形速率vt与前20-80d的平均变形速率的比值作为岩层稳定变形阶段判断预警阀值的指标,对监测安全状态进行判别,可分析海底开采岩层的变形规律,指导海下开采的安全作业。在海下矿井的水系统研究方面,采集了三山岛矿区内的100个裂隙水样和13个特征水样(包括海水、第四系地下水、地表水和雨水),并分析了各个水样中的13项化学物理指标和2项同位素指标,首先利用主成分分析(PCA)获得了四个主成分(信息贡献率分别为48%、25%、10%和7%),通过深入分析各个主成分的水化学指标的特点,并对照相关的地质报告,确定了这四个主成分分别代表海水的浓缩与稀释过程、绢英岩化与碳酸盐化过程、钾长石化过程和二氧化碳溶解过程。然后在主成分分析的基础上利用模糊C均值聚类(FCM)对矿区的100个裂隙水样进行聚类分析,确定了四个空间上连续变化的聚类,并通过了密实度和分离度函数的有效性验证。利用图形技术直观地展示了四个聚类的空间分布,分析了每个聚类的水化学特点,并与相关的水文地质报告相互印证,确定四个聚类分别为深层咸水、浅层咸水、基岩卤水和混合废水。最后,深入分析PCA和FCM的结果,反演得到了矿区地下水运动和演化系统,包括水来源、迁移路径、混合位置、局部裂隙带以及采矿对地下水系统的影响。通过矿井水系统实时动态观测分析可起到海下开采矿井突水预警作用。本文所做的研究工作,不仅立足于学科前沿,而且紧密联系工程实践,着重解决海下金属矿床安全开采中的最关键问题,具有较高的应用价值和前瞻性。更多还原

【Abstract】 Green technique in undersea mining is an orientation in the development of mining engineering industry. At present, the exploitation of undersea coal resources yielded a rich harvest. However, the research work of metal mine in this field is in its infancy. Financed jointly by the National Basic Research Program of China, the Key Science and Technology Project of Shangdong Gold Group CO.,LTD, and Key Technologies Research and Development Program of China, this article deals with the key technology of undersea mental mining. On the premise of the basic research of rock mechanics, reasonable layers of protection, frame stope structure parameters, strata monitoring and early warning and mine water system are discussed in this article.As regards the basic research of rock mechanics of undersea mining, it is important to know the bed of the existence of ore body, morphology of orebody, the geological condition and in-situ rock stress rule. Then, indoor rock mechanics testing and field testing of rock structural plane are carried out, and6evaluation index of RMR evaluation method was selected as a basis for evaluation of rock mass quality in Xinli mining area. Rock mechanics parameters of different quality levels were obtained by the use of Hoek-Brown criterion. All these works provides the research basis for underground engineering layout, stope stability analysis and parameter optimization, etc.The research of reasonable layers of protection in undersea mining focuses on the thickness. According to Mindlin plate theory and Winkler foundation theory, irregularly shaped protective layer model was established. And differential cubature method was used for the solving and programming of solving program DCFMP. As the criterion of reasonable protection layer, maximum tensile stress criterion is applied in the determination of reasonable protective layer thickness of the18panel in Sanshandao mine. The final recommendation uniform thickness of the protective layer is22.16m (the safety factor is1.8). It is also found that there was a significant correlation between reasonable protective layer thickness and area. A regression equation was then obtained and it provides a more convenient way for the determination of reasonable layers of protection.As far as the frame stope structure parameters is concerned, maximum principal stress of different frame stope structure parameters are first calculated. Then the system strain energy maximization objective function for stress constraint was established. In the cases, where response surface function is to be performed, it is better to use the nonlinear optimization techniques where the response surface functions have been calculated. The size of point column and the span are then known. They are respectively4×4m and12m. Based on Kirchhoff plate theory, irregular roof pillar model between the middle parts are established. The top pillar model and numerical analytical solution are also be found by the Galerkin method and coordinate mapping technology. Based on an overall analysis of factors in economic, safety and filling performance, an objective function is build. And the top pillar of the9panel in Sanshandao mine is optimized. The optimal unified thickness is7.16m. Stability analysis of surrounding rock of different excavation sequence within the panel mining stope of ore block was conducted using Stress-strain strength reduction process of any point in strength reduction FEM and safety factor method under the condition of Mohr-Coulomb criterion. And the mining sequence of the"two stope panels"is applied for the mine. Its safety factor range is2.5to3.5, which does not meet the conditions for instability ore.The monitoring data of the three exclusive observations chamber A, B, C in hanging wall rock is used in the research of strata monitoring and early warning. On the basis of the use of wavelet transform, estimation of abnormal tendency and smoothing treatment of the strata displacement monitoring data is carried out. Time series AR model was used for short-term monitoring forecasts. The error between the predicted and measured values of different wavelet decomposition level and forecast step was analyzed. Prediction error can be controlled within1%, and3-6is the best estimate step. At the same time, by comparing each determining method of the warning indicators in geotechnical engineering, the ratio of the deformation rate of vt in a single selected sampling time before and the average strain rate of20-80d, as threshold warning indicator, was used for the monitoring of security status discrimination. Studies show that the early warning system that can analyze the deformation of seabed mining rock, and it also provide guidance for safe operation of undersea mental mine.In the research of underground water system, thirteen physico-chemical indicators and two isotopic indicators were surveyed at100fissure water samples and13characteristic water samples in Xinli, a deposit of Sanshandao gold mine (Jiaodong peninsula, PRC). Firstly, principal components analysis (PCA) was used to extract four principal components (the contribution rates of information are48%,25%,10%and7%, respectively). This article has presented an in-depth look at the characteristics of hydrochemistry indicators of each main component. The four principal components are identified as the process of concentration and dilution of seawater, phyllic and carbonate process, the process of potash feldspathization and carbon dioxide dissolution process by comparing relevant geological reports. Then, based on an analysis of the PCA,100water samples were grouped into spatially continuous four water classes using the fuzzy c-means (FCM) clustering method. The article also takes advantage of graphic technology. It visually shows the spatial distribution of the four clusters. And then the characteristics of hydrochemistry of each cluster are analyzed, which verified the related hydrogeological report. The four clusters are deep saline water, shallow saline water, bedrock brine and mixed wastewater. Finally, a searching analysis of the results of PCA and FCM get to the movement and evolution system for groundwaters-in the pit. These factors include sources of water, flow path, mixing zone, local fissure zone and impact of mining.This research paper has focuses on the problem of how to carry on safe mining for undersea mental deposits. It not only based on the forefronts but it also closely bound up with engineering practice. Therefore, it is a prospective study with characteristics of great application value.更多还原