【作者】 卢志刚；

【导师】 龚健雅； 刘兴权；

【作者基本信息】 中南大学 ， 地质资源与地质工程， 2013， 博士

【摘要】 摘要：金属矿床由于成因多样化,岩体地质结构复杂,岩层的力学性质各种各样,边界条件千差万别等特殊因素,煤矿的地表变形预计理论不能直接应用于金属矿山。因此,针对复杂高应力环境下的金属矿山,地下开采引起的地表沉陷规律研究,将为矿山安全高效地回地下矿石资源提供技术保障,对矿山的安全生产具有重要的指导意义。结合现场监测资料,分析了地表监测点水平位移变形规律和沉陷规律,建立了龙桥铁矿数字沉陷模型,绘制了沉陷等值线图和沉陷剖面图,结合矿体回采时空对应顺序,综合挖掘了地表沉陷空间分布演化规律。结果表明：地表变形与空区顶板冒落规律存在关联,地表沉陷空间分布区域明显,在勘探线4线和1线附近存在累积沉陷中心,分别向四周扩展沉陷逐渐变小,1-3线附近地表累积沉陷发育程度比较明显,地下开采与地表沉陷空间演化态势之间的对应关系明显,建议为地表变形重点监控区域。结合钻孔监测资料和地质构造特征及岩体质量分析,解释了空区顶板覆岩冒落的机理原因,提出了空区顶板覆岩冒落状态与对应空区跨度暴露速率成正比的关系。针对金属矿山的关键性开采环境因素和地下开采过程的特点,采用灰色关联分析手段,对关键性开采环境因素诱发的地表沉陷进行关联分析,首次将影响程度进行定量化,弥补了过去定性分析的不足。结果表明,覆岩性质的内聚力C和内摩擦角φ是影响地表沉陷的决定因素,倾角α和采场尺寸A是沉陷的主要影响因素,弹性模量E和采深H对地表沉陷有一定的影响,但关联程度相对较小。同时,建立了影响因素的敏感度函数,深层次地分析了影响因素的变化对地表最大下沉量产生的影响程度。率先提出了基于PCA与BP组合模型用于金属矿山岩层移动角预测,组合预测方法对复杂的影响因素进行了简化,约简了原始输入数据同时保留了主成分信息。结果表明,BP整体预测的稳定性和精确性得到提高。结合岩层上下盘移动角预测结果,引入三维建模技术,首次绘出了龙桥铁矿东部矿区的地表移动范围,弥补了现有地表移动范围模糊性的不足。研究结果发现,地表移动范围整体位于采空区上方且大于采空区范围,主井及附属建筑物、水体和居民区在地表移动范围之外,对矿山安全生产没有影响；水塔及附属设施处于地表移动范围边界上,存在一定的安全风险性,需要加强预防措施。建立FLAC₃D矿区三维数值计算模型,模拟龙桥铁矿地下采矿活动,对比分析了自重应力背景下和水平构造应力背景下地表沉陷的空间演化分布规律,将地表实测资料与数值模拟结果进行验证发现,构造应力的数值模拟结果与地表变形实测结果更为吻合。选择1线和4线典型横剖面作为研究对象,模拟分析了不同跨度条件下龙桥铁矿空区顶板覆岩移动破坏特征和相邻围岩的应力响应特征,得出了空区跨度与空区顶板岩层移动破坏冒落的内在关系,揭示了顶板上覆岩层的垂直变形对应跨度的演化过程。针对构造应力型矿山的地下开采沉陷预计研究还处于空白的不足,明确了构造应力型矿山的概化地应力概念,引入概率积分原理,考虑了地应力的影响,将改进随机介质理论模型应用于龙桥铁矿东区地表变形预计,各地表监测点预计结果表明,自重应力下的地表变形预计结果大于改进的随机介质计算结果,水平构造应力的存在具有减缓地表下沉的影响。结合未测度聚类优化模型对地表沉陷模糊预测结果,研究结果表明：改进随机介质预计结果更接近期望值,预测的精度更高,对矿山安全生产更有指导意义。针对金属矿山开采沉陷管理信息系统功能存在的不足,以龙桥铁矿的地表监测数据为基础,采用MapInfo控件MapX5.0和VB6.0语言工具,设计开发了基于GIS的龙桥铁矿开采沉陷管理信息系统,首次将开采沉陷专业模型与GIS平台耦合于系统,系统通过分析、研究、开发和运行,实现了地表移动变形量的曲线自动绘制,沉陷等值线和剖面图、地表沉陷预测预警、沉陷3维可视化等具体功能,为矿区安全生产提供了非常高效的工作手段。更多还原

【Abstract】 ABSTRACT:Because of the variety cause of metal deposits, complex geological structure of the rock mass, rock mechanical properties of various and different boundary conditions, the surface deformation theory of the coal mine can not be applied directly to metal mine. Therefore, in the complex and high stress environment of metal mine, the research of surface subsidence caused by mining will provide technical support on recovery ore resources safety and efficiently, and has important guiding significance for production safety.It analyzes the horizontal deformation rule and subsidence rule of monitoring sites based on the monitoring data of Long Qiao mine, and establishes the digital subsidence model, and maps the surface subsidence contours and subsidence sections. With the help of the mining space-time order, it mines surface subsidence evolutionary rule of spatial distribution comprehensively. The results show that the surface deformation is association with roof caving rules, and the spatial distribution of surface subsidence areas are obviously, and cumulative subsidence centers are exist in4#exploration line and1#exploration line, which extend to the surrounding and became smaller. The area of accumulated subsidence obvious is1-3#exploration line, in which the correspondence between underground mining and surface subsidence spatial evolution is obvious, it is recommended to focus on surface deformation monitoring area. Based on drilling monitoring data and geological tectonic characteristics and analysis of rock mass quality, it explained caving mechanism reason of goaf roof strata, put forward that the caving state of goaf roof strata is proportional to the corresponding goaf span exposure rate.According to the key mining environmental factors and the characteristics of underground mining process of metal mine. The grey correlation analysis method is used for the correlation analysis of surface subsidence due to the key mining environmental factors, and it makes influence degree of factors quantified for the first time, which makes up the inadequacy of qualitative analysis of the past. The results show that cohesion C and friction angleφ is the determining factor affecting surface subsidence, tilt a and stope dimensions A are the main factors affecting surface subsidence, the elastic modulus E and mining depth H are some effect on surface subsidence, but the relative degree of association are small. At the same time, the sensitivity function of the influencing factors is established, and the effect degree of various factors on the surface subsidence is deeply analyzed.Based on PCA and BP, combined forecasting method is put forward first and applied in rock movement angle prediction of metal mine. The method simplifies the complex influence factors and raw input data, retaining the main component information, improving the whole stability and accuracy of BP prediction. With the prediction result of rock up and footwall movement angle, introduced3D modeling technology, it map out the range of surface movement of Long Qiao mine in the eastern area for the first time, which makes up the deficiency of ambiguity of the existing surface movement range. The results show that the overall range of ground movement is at the top and greater than goaf range, and the main shaft and ancillary buildings, water, and residential are beyond the surface movement, which is no impact on mine safety production, and towers and ancillary facilities are on the boundary range of surface movement, which exist some security risks, and need to strengthen preventive measures.Three-dimensional numerical calculation models based on FLAC3D software are established, and underground mining activities of Long Qiao mine are simulated, and a comparative analysis of the spatial evolution distribution rules of surface subsidence is made on the background of horizontal tectonic stress and gravity stress. The verification results of the surface measured data and the numerical simulation calculation results show that the simulation of tectonic stress is more consistent with the measured data of the surface deformation. Taking the typical cross section of1#and4#exploration lines as the research objects, the movement and destruction characteristics of goaf roof strata and the stress response characteristics of around rock under the condition of different span are simulated and analyzed, which gets inner relationship of the goaf span and the movement damage and cavity of goaf roof strata, and reveals the evolution process of the vertical deformation of overlying rock strata to goaf span.According to the lack of study on underground mining subsidence prediction of tectonic stress mine, the generalized ground stress concept of tectonic stress mine is defined, and by introducing probability integral principle and the influence of ground stress, and the improved random medium theory is applied to surface deformation prediction in the eastern of Longqiao mine. The results of monitoring points show that the calculation result of the surface deformation under weight stress are more than calculation results under the improved random medium, and the existence of tectonic stress can slow the impact of surface subsidence.Based on the unascertained theory of clustering optimization, it verified the calculation accuracy of the improved random medium theory. The results show that the prediction results of the improved random medium is closer to expectations, and higher prediction accuracy, and more instructive on mine safety production.According to the function defects of mining subsidence management information system applying in metal mine, and taking the surface monitoring data of Long Qiao mine as basis, and the MapX5.0control of MapInfo and VB6.0language tools used, it designed and developed Long Qiao mining subsidence management information system based on GIS, which couple the mining subsidence professional models to GIS platform in it for the first time. By means of analysis, research, development and run, the system realizes the drawing function of deformation curve of surface movement and subsidence contours and profiles automatically, and the forecast and early warning function of surface subsidence, and the3D visualization function of subsidence, which provides a very efficient method for the safety production of Long Qiao mine.更多还原