【作者】 赵国彦；

【导师】 古德生；

【作者基本信息】 中南大学 ， 采矿工程， 2010， 博士

【摘要】 矿业对国民经济的增长可谓居功至伟,但是在持续开采地下资源、为工业提供原料的同时,留下了的大量采空区,对人类生产和生活造成严重危害。因此,迫切需要研究采空区探测技术、采空区岩层移动规律、矿柱安全性及采空区稳定时限等基础理论,确保采空区治理和人民生命财产安全。为此,本文以金属矿隐覆采空区探测及稳定性预测的理论研究为题,开展了如下内容的研究：在全面分析当代采空区探测技术的基础上,从金属矿隐覆采空区特征出发,提出了高密度电法与地震映像法相结合辅以钻孔验证的金属矿隐覆采空区探测方法。采用分形理论对采空区进行了研究,用分形盒维数分析了金属矿采空区复杂程度或不规则程度。利用神经网络的学习和记忆功能,建立了采空区边界的智能预测模型,用以预测未知或仪器测量不到的采空区边界,弥补了测量仪器或工程场地的局限性,为隐覆采空区探测分析提供了极大的便利,同时节省了采空区探测成本,提高了探测效率。分析了影响金属矿采空区稳定性的内在和外在因素,用物质描述有限元方法对采空区稳定性及其岩层移动特征进行了数值模拟分析,揭示了不同采空区面积、不同顶板高度时岩层应力、应变演化规律。分析了岩石破坏能量,建立了岩层破坏的能量准则,用数值模拟方法探索了采空区岩层能量释放规律。研究结果显示,随着开挖体积的增加,采空区岩层能量释放率逐渐增大,且岩层能量释放率随采空区体积增加呈二次曲线增长。采空区充填后围岩应力集中得到一定程度的缓解,采空区充填对于减小岩层能量释放率效果显著。选取影响岩层移动的7个主要因素(矿体上、下盘围岩普氏系数、稳固程度、开采深度、开采厚度、矿体倾角、矿体走向长度和采矿方法)作为输入,上下盘岩层移动角为输出,建立了采空区岩层移动角的神经网络预测模型。工程实例验证结果表明,模型选取的因素合理,预测精度高。应用该模型预测了三山岛金矿开采岩层移动角和大宝山矿27线采空区失稳影响范围,为保障矿山安全提供了理论依据。采空区形成是岩体多次开挖扰动的结果,岩层变形表现出复杂的非线性力学特性,用混沌理论揭示了采空区岩层变形的复杂过程。根据大宝山矿采空区岩层变形监测数据,建立了采空区稳定时限的灰色预测模型,预测了采空区岩层稳定时限。根据地下开采设计方法,对采空区中矿柱进行了分类,探讨了垂直矿柱、人工矿柱和和顶板矿柱的安全理论。研究了单排线状垂直矿柱和顶板矿柱强度设计理论,并用矿柱间距与矿柱大小之比R为参数分析了垂直矿柱结构及其合理布置形式(最佳R值宜控制在2.0-3.0之间),同时探讨了金属矿开采人工点柱力学机制,研究了人工点柱强度设计理论。更多还原

【Abstract】 For mining industry, there are enormous contributions in increase of national economy, but in the condition of continuously exploiting underground resources to supply raw material for other industries, there are many mining cavities which are severely harmful to human production and life, so the researches, such as the technologies of cavity detection, characters of terrane motion, stability of pillars, time limit of cavity stability, and et al, which are concerned about treating cavities and the safety of demos’lives, are no time to delay. Therefore the detection technologies and stability prediction of hidden cavity in metal mine as the theme of this paper, the main contents are included as follows.Based on analyzing the present detection technology and characters of hidden mining cavity, a detection method of hidden cavity in metal mine, which high-dense resistance technique combined earthshock reflection method with drillhole validation, was put forward. Introducing fractal theory, the complex or anomalistic grades of mining cavity were analyzed with fractal box-dimension. Using the learning and memory functions of neural network model, an intellective forecast model of cavity boundary, which forecasted unknowable or unmeasured cavity outline, was established, so the limits of measure apparatus or work field were patched up, and the enormous advantages in decting and analyzing cavity was offered, at the same time, decting cost was saved, as well as the work efficiency was enhanced.Analyzing the intrinsic and extrinsic factors of stability in metal mine cavity, the motion in terrane were simulated with a finite element method of material description, and the change laws of stress and strain in different cavity area and roof high were revealed.Exploring breakage energy of rock, a criterion of breakage energy was estabilished, and the laws of energy release in cavity terrane were researched with a method of numerical simulation. The results showed that energy release in cavity terrane increased with augment of excavated bulk, and the rates of energy release raises in a way of quadratic curve. After mining cavity was filled, stress concentrations in terrane decreased in a certain extent, and there were tremendous effects that reduced the rates of energy release in cavity terrane.Selecting seven main influence factors to terrane moving, which are f coefficient of wall rock in upside and downside ore body, stability extent of terrane, exploiting deepness, excavating thickness, obliquity of ore body, length tend towards ore body and mining method, as input data, and using moving angles of upside and downside ore body as output data, a prediction model of moving angle in cavity terrane was established by a method of neural network. The results of validating with engineering examples show that the selected factors are reasonable, and the neural network method owns high precision. Using the model, the moving angle of terrane in Sanshandao Golden Mine and influencing range of subsiding cavity in Dabaoshan Mine were predicted and the theories of safe mining were provided.Cavities come into being repetitively excavated in rock mass, so the deformations of terrane behave complicated non-linear mechanical characters, and the processes of deformation in rock mass were unfolded with a theory of chaos. According to surveyed deformation data of cavity terrane in Daobaoshan Mine, a grey prediction model of time limit of cavity stability was established, and the stable time was predicted.According to underground mining method, pillars were classified, and the safety theories of upright pillar, artificial pillar and roof pillar were explored. Mechanical models of a single rock pillar and roof pillar were established, and strength design theory of single row pillars was studied. With the parameter R, which is the proportion rock pillars space to their size, the framework and reasonable collocation of pillars were analyzed, and the optimal value of R was 2.0 to 3.0, at the same time the mechanism of prefabricated pillars and their strength-design theories were researched.更多还原