【作者】 彭欣；

【导师】 李夕兵；

【作者基本信息】 中南大学 ， 采矿工程， 2008， 博士

【摘要】 大宝山矿采空区体积大、数量多且形状复杂,严重威胁了矿区生产安全。为实现大宝山矿采空区近区安全开采,有必要研究采空区探测技术,对采空区群环境下的关键岩体结构(空区顶板和矿柱)稳定性进行分析,探讨采用何种强度的充填体处理采空区,如何实现采空区近区安全开采,并建立采空区近区开采的岩体稳定性安全预警系统。本文主要研究内容如下:针对大宝山矿采空区特征,采用激发极化电法和激光探测技术对大宝山矿区采空区群进行地表宏观识别和地下精确成像,共计探测地下采空区体积180多万m~3,这些探测结果为采空区稳定性分析和空区充填处理提供了基础数据。综合采用结构力学、鲁佩涅伊特法、荷载传递线交汇法、厚跨比法、长宽比梁板法、有限元数值模拟法等对采空区顶板安全性和合理厚度进行了分析,确定了采空区顶板的安全厚度。利用数值方法分析了爆破震动等动载荷扰动下的空区矿柱动力响应特征,为认识空区矿柱的力学规律和破坏防护提供了理论依据。建立了塌陷区废石与围岩耦合作用力学模型,对大宝山矿区塌陷区域稳定性进行了研究。通过对尾砂胶结充填体强度试验得出了不同配比的胶结充填体损伤破坏规律,首次采用突变理论研究了充填体与岩体的合理匹配,研究结果表明,大宝山矿采空区充填时,最低充填体强度确定为0.5MPa比较合理。对塌陷区近区安全开采建立了力学分析模型,用可靠性理论研究了合理矿柱尺寸,根据研究结果并结合大宝山矿井下开拓情况,对于大宝山矿576采空区以北矿体的安全开采,开采中段高度在70m的条件下,矿柱宽度为12m比较合理。采用极限平衡分析法,建立了胶结充填体力学计算模型,对于不同开采技术条件下充填体力学规律进行了深入研究。研究结果显示,大宝山矿采空区用配比1:10的充填体能满足近区安全开采技术要求,充填体暴露面积宜控制在3500m~2以内。对大宝山矿岩石试件加载及破坏过程的声发射进行了试验,采用混沌理论研究了岩体声发射活动规律。研究结果表明,岩体破坏之前AE出现反常,声发射能率、大事件率急剧减少,混沌吸引子D值减小,岩体出现破坏的前兆特征。采用混沌与神经网络相结合的方法建立了大宝山矿采空区近区开采岩体稳定性智能预警系统。更多还原

【Abstract】 Large amount of Mining cavities in Dabaoshan Mine with big volum and complex shapes have posed serious threaten for the production safety and personnel safety. In order to fulfil production safety for near-cavity excavation, some key problems should be studied: the cavity detecting method, the stability of hanging wall and pillar among cavities, back-filling and strength analyse of fill in cavities, how to realize near-cavity excavation, how to establish the corresponding early warning system. The main contents are as follows.In view of the characteristics of the mining cavities of Dabaoshan Mine, Induced polarization electrical method and laser scan technique were used for large-scale localization at surface and detailed 3D imaging in cavity. More than 1800,000 m~3 minig cavities have been detected, which offer essential data for the stability analyse and back-filling of cavities.Reasonal thichness of cavity roof has been analyzed with structure mechanics law, Lou’s method, load transmission line, ratio between height and span, beam and plate method and numical simulation. The comprehensive method was proposed for safety evaluation and thickness determination for cavity roof.Numerical method was used to investigate the dynamic response of pillar among cavity, which suffers high static load and dynamic loading from blasting simultaneously. The results provide references to understanding the failure mechanism and choosing prevention approach for pillars among cavities. With wedge model, the stability of collapse body of waste rock was analyzed by carrying out coupling analyse bteween collapse body and wall rock.The damage and failure rules were obtained through laboratory tests of tailings with different blending ratio with cement. The optimal blending ratio was investigated with catastrophe theory. The results showed that the minimum strength of back fill for cavities filling should be 0.5MPa.With mechanical model of near-cavity excavation, reliability theory was applied to investigate the reasonable pillar size. The theoretical analyse and in-situ practices showed that, for the excavation of ore body at north of mining cavity 576#, if the middle section is 70m, then the width of pillar should be 12m.With numerical model of back fill, the mechanical rules of fill under different excavating conditions were studied with Limiting equilibrium analytic method. The results showed that, the back fill with blending ratio of 1:10 can satisfiy the technical requirement of near-cavity excavation in Dabaoshan Mine, and the explosure area of back fill should be controlled within 3500m~2.Acoustic emission tests were conducted for specimens from mining cavaties. The AE signals were recorded during the process of loading and failure of specimens. The chaos theory was used to analyze the AE characteristics of rock mass in Dabaoshan Mine. The results showed that, before the failure of rockmass, AE tended to be abnormal with AE energy ratio and AE event ratio decreasing rapidly. The decreasing of chaos attractor D is the premonitor of rockmass failure. Finally, the intellective warning system of rockmass stability for near-cavity excavity in Dabaoshan Mine was established combing chaos method and neural network.更多还原