【作者】 陈嘉生；

【导师】 吴爱祥；

【作者基本信息】 中南大学 ， 安全技术及工程， 2010， 博士

【摘要】 随着市场对矿产资源的强劲需求,复杂环境条件下矿体的开采已经成为行业关注的热点。由于金属矿体赋存条件的复杂性、岩体变形的各向异性、开采方法的差异性,目前我国金属矿床的“三下”开采技术还不成熟,尚未形成一套成熟的技术和装备,对于特殊条件的“三下”开采还处于探索阶段。由于“三下”开采涉及的危险因素复杂,如何预先评估开采布设工程、外部扰动要素对周边重要构筑物的影响程度,采取相应的预防措施,成为“三下”开采成功的关键。论文以我国第二大硫铁矿山——安徽新桥硫铁矿矶山东部矿体开采的复杂环境为对象展开研究,结合25年从事金属矿山工作的现场实践和理论基础,以水域动荷载限定条件下的复杂矿体安全开采作为一个开放的动态、非线性系统为出发点,在理论分析、现场测试、室内试验、现场试验的基础上,通过帷幕注浆工程,借助数值计算模拟方法,针对复杂矿体开采的关键因素,对铁路线、河流和边坡的作用和影响进行重点研究。论文取得如下创新性成果：(1)自主开发了价格低廉、性能优异的改性粘土固化浆液,首次大规模在新桥矿区高含水区域的截流帷幕使用。固化浆液具有抗冲刷能力、材料费用低、结石率高(近似达100%)、堵水性能稳定等特点,与传统的水泥浆液相比,降低注浆材料费用81%;首创了高速高效粘土输料、自动粉碎、高速搅拌的粘土制浆工艺,制浆速度提高60%,工作效率提高80%,改善了浆液质量,彻底解决了设备经常损坏维修难题。(2)在现场详勘、试验的基础上,提出分区不等距大孔距布设注浆孔方式,利用改良性粘土固化浆液为主(90%)、粉煤灰固化浆液为辅(10%),形成封堵断层、溶洞的大规模、高强度注浆工艺。与传统的等距布孔相比,优化后的布设注浆孔的钻探工程量减少36.01%。帷幕注浆工程的堵水率达77.96%,减少了露天采坑的涌水量,塌陷区地表趋于稳定,公路、铁路及河流等敏感区域塌陷现象消除。(3)克服了3DEC等三维数值分析软件无法进行空间几何凹体运算的限制,根据边坡凹形台阶的坡顶和坡底坐标数据,利用三棱锥逼近法,通过编程自动形成了凹陷露天矿采坑的凹形几何边坡体,真实再现了露天矿边坡的几何形状,满足了节理划分、赋值和计算的需要,提高了分析结果的可靠度和精确度。(4)基于3DEC离散元软件平台,建立了水域动荷载限定条件下的矿体复杂区域的3DEC实体三维模型,论证了开采主体设计的总体布局、开拓工程、采场结构参数等的合理性、安全性,最大限度真实模拟了工程体对外部开挖单因素、多因素激励的响应,评估了敏感区域的应力、位移、速度等特征指数。(5)提出了有效帷幕注浆防止外围水流渗透,定量评估铁路沉降、可靠预控工程灾害发生的“三下”资源安全高效开采模式,减少开采的盲目性,确保地表构筑物(水体)的安全。更多还原

【Abstract】 Great attention has been paid on mining technology of ore deposit with difficult environmental condition along with the increasing requirement on mineral resources. Qualified mining technology and equipment of ore deposit below railway, river and buildings (shortly, DRRB) are limited because of complicated existence condition of ore body and different features of rock deformation. Influence degree of mining activities and surrounding disturbance on surface buildings or structures should be estimated and correspondent preventive measures should be considered, based on evaluation of underground engineering works, in order to extract safely DRRB.Xinqiao Mining Corporation, Ltd. (XMC), Tongling, Anhui province, China, is one of the largest pyrite mines in China. Eastern part of ore deposit located below a railway and a small river and is a kind of typical DRRB. Because safe mining process of ore deposit under dynamic load and water body is a open, dynamic and non-linear system, function and influence of mining activates and surrounding disturbance on railway, river and slope of open-pit are studied in detail using such comprehensive researching means as theoretical analysis, field measurement, laboratorial experiment and numerical simulation in this paper. Main conclusions and creative results are summarized as follows:(1)Improved clay cementing mixture was developed and used in curtain grouting practice in XMC. The mixture is good in crush-resistance, low in material cost (81% lower than that of conventional cement slurry), high in concretion rate (nearly 100%) and excellent in water-blocking result. Clay slurry-making technology characterized in effective transportation, automatic crushing and fast mixing system was also invented. The new technology could not only raise slurry-making capability and effectiveness by 60% and 80% respectively, but also improve slurry quality and system reliability.(2)Grouting drill holes were arranged in varying large space and improved clay or fly ash cementing slurry (10% in proportion) was poured into drill hole so that fault and cave could be filled. Number of drill hole was reduced by 36% and water-block rate was increased by 78%, respectively, compared to conventional hole design with fixed space. Water inflow from open-pit was obviously reduced and serious surface subside within railway and river area was avoided as a result of curtain grouting.(3) Computation method of geometrical dip by three dimensional simulation soft 3DEC was improved. Geometrical slope of dip open-pit was automatically represented by 3DEC soft using triangular pyramid approaching method, according to coordinate data of slope roof and bottom. The numerical model of the slope could meet reliability and accuracy requirement for subsequent numerical simulation.(4)Three dimensional model of ore deposit and related development works below dynamic load and water body was established by 3DEC soft. Overall arrangement of development works and structural size of stope were evaluated, response of development works to influencing factors were simulated, and stress, displacement and velocity of surrounding rocks around DRRB, based on analysis of the model.(5)Curtain grouting engineering based on results of theoretical analysis, field investigation, mechanical parameters measurement, dynamic load survey and CT goaf detection is useful for safe mining of DRRB. Mining model of DRRB based on numerical simulation is helpful to optimize development works including shaft and tunnel.更多还原