Fushun West open-pit Mine has been mined for 100 years. Under the influence of multi-chain disasters such as landslide, ground fissure and debris flow, buildings have produced irreversible damage. Although the slope treatment project has been basically completed, there is still a risk of further damage to the building. Therefore, the damage characteristics of the surrounding buildings were sorted out and the damage grade area is divided into four levels. A reinforcement system combining rigid anti-deformation reinforcement and flexible absorption deformation of buildings was proposed. According to the simulation results of the whole building model and the key bearing component model, it can be seen that the damage volume of the building structure can be reduced by about 6.05 percentage points by using the underground continuous wall reinforcement, and the damage volume of the building foundation can be reduced by about 3.67 percentage points by using the foundation bolt reinforcement. The flexible absorption deformation method filled with ductile mortar can reduce the damage volume of components by about 11.15 percentage points. Therefore, the reinforcement system can provide technical support and reference for the reinforcement project of urban buildings around open-pit mines.
In order to study the influence of the number of cracks(0, 1,2 and 3) on the mechanical properties and failure mode of sandstone under the condition of acid dry wet cycle, the specimens were immersed in solutions with pH of 2.0, 4.5 and 7.0 for 0, 1, 3 and 5 times and then subjected to uniaxial compression tests. The results show that the peak strength and elastic modulus of the specimens immersed in different pH solutions gradually decrease with the increase of the number of dry wet cycles and the number of cracks, and the deterioration of the damage caused by it aggravates the corrosion damage of the specimens immersed in chemical solutions. When the pH is 7.0, macro cracks induce the development of cracks in sandstone failure, and with the increase of the number of cracks, the failure mode of sandstone changes from shear failure to tension-shear failure.
优化喷雾雾化特性是提高矿井喷雾降尘效率的有效方法.为研究矿井水Na+、K+离子浓度对其雾化特性的影响,提高矿井粉尘治理效果,采用表面张力测量仪和激光粒度测试系统表征不同矿井水的表面张力和雾化特性,分析矿井水中Na+、K+离子浓度引起的表面张力差异及其对雾化特性的影响.结果表明:低离子浓度条件下,矿井水表面张力与其Na+、K+离子浓度呈正相关.在相同喷雾压力下,雾滴粒径与表面张力成正相关,降低矿井水表面张力可提高降尘效率;表面张力减小可延长雾化区分布范围,延长粉尘捕集范围,增加粉尘沉降数量;雾场中各雾滴粒径随表面张力减小而逐渐呈现均一性分布,这有利于提升雾滴对粉尘的润湿能力.研究结果对优化喷雾雾化特性,提高喷雾降尘效率,促进矿井水资源治理具有重要意义.
The study on the competitive adsorption characteristics in carbon dioxide displacement of coalbed methane is of great significance for improving coalbed methane recovery by carbon dioxide injection（CO 2 -ECBM）. Based on Darcy seepage, Fick diffusion and extended Langmuir equation, a multi-field coupling mathematical model of migration, displacement and desorption of methane and carbon dioxide in coal seam was established. The effects of different carbon dioxide gas injection pressure and the arrangement of injection and extraction boreholes on improving coalbed methane recovery were numerically simulated. The results show that in the process of carbon dioxide displacing methane, a “methane enrichment area” will appear in the coal seam near the gas injection borehole, and with the increase of gas injection time, the “methane enrichment area” will gradually move to the exhaust borehole until the methane concentration distribution in the coal seam is stable, and the average methane concentration in the coal seam is 56.5% of the original methane concentration. The methane flow rate in the exhaust borehole first decreases, then increases rapidly to a peak, and then decreases slowly to a stable value. In addition, the distance between injection and extraction boreholes has no effect on the methane flow after the methane concentration at the exhaust borehole is stable, but has an obvious effect on the peak value of methane flow and the time of peak value.
为解决某铅锌矿细粒级、高含硫尾砂充填时强度偏低、后期强度劣化的问题,通过对充填材料进行分析,采用粗骨料与全尾砂作为充填骨料进行充填,开展了充填材料配比、强度特性室内试验研究,并根据高硫尾砂特性研发了 CKY充填外加剂.结果表明:全尾砂与粗骨料配比为8:2和7:3时,充填料浆保水性均较好,质量浓度为76％～78％的料浆具有较好的和易性,不发生沉降或有少部分尾砂沉降,适合充填;尾砂含硫量达32％,充填体试块在60 d、90 d龄期时出现不同程度劣化,加入了 2％添加剂后,全尾砂:粗骨料为8:2的充填体前、后期强度增长明显,全尾砂:粗骨料为7:3的充填体前期强度虽未增长,但后期强度增长明显,且未出现强度劣化现象,表明CKY添加剂对于维持充填体强度的效果较好.
针对暗通道先验理论在煤矿井下尘雾图像处理中出现的图像失真、颜色偏暗、细节丢失等问题,提出了一种基于亮暗通道先验理论的煤矿井下图像除雾算法.首先,融合暗、亮双通道先验知识,重构局部大气光;其次,分析双边滤波的滤波特性,建立基于局部像素差值的改进加权引导滤波算法;最后,利用暗通道大气光和原始图像的像素差值自适应调节图像的整体亮度.试验结果表明,改进加权引导滤波算法能够有效除去煤矿井下图像中的尘雾影响,与基于引导滤波的He算法和Retinex-MSR算法相比,本算法拥有较高的平均梯度和标准方差,复原后的图像清晰度更高,单张图像处理时间均低于1 s,比Retinex-MSR算法运行时间缩短了近 1/2.
In order to study the interaction of simultaneous open-pit and underground mining in Shizhuyuan Polymetallic Mine, according to the actual production situation of the mine, the surface model, the final boundary model of the open pit, the ore body model, the collapse area and the goaf models of the mine were constructed to truly reflect the deformation characteristics of mining and overburden rock as much as possible. The overall mining sequence of the mine was divided into six stages from top to bottom according to different mining heights and mining areas. Among them, the first to fifth stages were combined open-pit and underground mining, open-pit mining of ore bodies above 684 m in the east and the north, and mining of ore bodies above 612 m in the west and south. At the same time, open stoping method of sub drilling stage was used to mine the ore bodies of 407-610 m in the east and 470-536 m in the north, and sublevel caving method was used to mine the ore bodies of 530-610 m in the west and 490 m in the middle. At the end of the sixth stage, all underground mining will be converted to open-pit mining. Through the numerical model, the maximum displacement of surface and stope, the maximum tensile stress of stope roof, as well as the location and magnitude of maximum compressive stress in each mining stage were obtained. The displacement and stress of underground stope, goaf roof and slope during open-pit mining were monitored and analyzed. The results show that during the open-pit and underground collaborative mining, there is no obvious stress concentration on the open-pit slope and platform formed in the open-pit mining area, and the displacement, tensile stress and shear stress values of the open-pit slope are small. The open-pit and underground mining of the mine have little impact on the final slope stability, and the displacement and stress concentration caused by mining will not pose a threat to the safety and stability of the open-pit slope.
为提高超细粒级尾砂消纳量,降低充填成本,以尾砂替代部分水泥,研究尾砂取代率、粉煤灰掺量和偏高岭土掺量对复合充填材料流动性能、抗压强度、抗氯离子渗透能力、抗硫酸盐侵蚀性能及抗冻融性能的影响.研究结果表明:料浆流动度和抗压强度与尾砂取代率呈负相关,粉煤灰能够改善料浆流动性能,对充填体早期强度具有削弱作用,对后期强度的发展具有改善效果,当粉煤灰掺量为12％时,28 d和90 d抗压强度分别达最大值,为8.03 MPa和8.92 MPa;偏高岭土能够吸附自由水,加速水化反应进程,对料浆具有明显的增稠作用,促进C-S-H凝胶成核,改善充填体内部孔细结构,阻断氯离子传输通道,提高充填体力学性能和抗氯离子渗透性能;在硫酸盐和温度协同侵蚀作用下,充填体试块质量和抗压强度均呈先升高后降低的趋势,钙矾石和石膏的生成,增加了试块质量和抗压强度,但过量的钙矾石导致结构挤压膨胀,充填体出现损伤劣化;随着冻融循环次数的增多,充填体质量损失率和强度损失率逐渐增大,低温降低了水化反应速率,冰晶的膨胀作用,导致水化产物对骨料颗粒的黏结包裹作用减弱.
复杂地质条件下软岩巷道围岩稳定控制是技术性难题.以现场实测为主、理论分析为辅的研究方法,构建了非等压巷道围岩弹性-损伤力学模型,对荣华矿西翼运输大巷围岩变形特征及控制方法进行了研究.研究结果表明:断层形成后,水平应力和初始水平应力比值为4.3～8.5;较小的内摩擦角、内聚力及较大的侧压系数对应较大的塑性区半径及较高的蝶形塑性区概率,塑性区半径扩展速度可间接表征蝶叶塑性区是否形成;对于易松动软岩,应在支护初期保持支护阻力及改善围岩性质;巷道前方水平裂隙较为发育,围岩整体变形量较小,两帮移近量和顶板下沉量分别在150 mm、40 mm以内,验证了分区支护策略及支护参数的合理性.
为了优化露天矿山道路粉尘的控制措施,揭示自卸卡车扬尘规律,通过数值模拟方法,建立几何模型,采用离散项模型及动网格技术,对自卸卡车行驶过程中粉尘分布特征和车身周围气流进行数值计算.研究结果表明:随着自卸卡车车速提高,扬尘高度与浓度均增加,车速越快,车尾粉尘浓度越高,当车速达到40 km/h时,道路粉尘浓度为358 mg/m3;在车尾附近,扬尘浓度随着地面粉尘粒径减小而增加,平均粉尘粒径为1pm时,扬尘浓度最高;地面粉尘质量流率越大,扬尘浓度越高.基于自卸卡车运输粉尘扩散规律和模拟结果,建议自卸卡车运行车速为25 km/h,同时增加粉尘粒径和地面粉尘质量,为下一步实施降尘措施打下基础.
以湖北祥云磷矿矿区含水层的砂岩为研究对象,开展了水-力耦合试验,探讨围压和孔隙水压对岩石变形特性和强度特性的影响.研究结果表明:水-力耦合作用下砂岩试件的应力-应变曲线的发展趋势基本一致,其轴向应变-应力曲线均经历了原生裂隙压缩闭合阶段、线弹性阶段、裂纹稳定扩展阶段、裂纹不稳定发展阶段和峰后残余阶段等5个阶段;试件的峰值轴向应变与孔隙水压呈负相关,与围压呈正相关,而峰值环向应变和体积应变随着孔隙水压的增大而上下波动;砂岩的峰值偏应力、残余偏应力、起始扩容偏应力与孔隙水压呈线性正相关关系,而与围压呈现负相关.研究成果展现了地下水对祥云磷矿砂岩力学性能的影响规律和影响程度,可为该矿区砂岩的稳定性分析提供参考.
为探讨岩体中不同角度结构面对爆破振动波传递的影响,借助分离式霍普金森压杆(SHPB)动力冲击试验装置,对预制结构面角度为30°、60°和90°的岩样分别进行SHPB动力冲击试验.基于试验结果,提出最大振速折减系数k与结构面角度关系的计算公式,并结合周盘沟隧道现场监测数据对计算公式进行验证.结果表明:结构面角度为30°时对爆破振动波的衰减作用最为显著,随着结构面角度的增加,衰减作用逐渐减小;基于试验结果得到的最大振速折减系数计算公式具有较高的拟合性;通过现场监测数据对计算公式进行验证,计算结果与实际结果十分接近,表明计算公式具有较强的适用性.研究结果可为地下工程爆破安全施工提供指导和参考依据.
In the construction of cutting shaft, ordinary method, tank climbing method, hanging tank method and other traditional construction techniques have problems, such as low efficiency, high labor intensity, poor operating environment, high cost, and poor safety. Generally, the height of one-time shaft excavation by medium-deep blasting technique is less than 7 m, and few cases are more than 8 m, and most of them are failure ones. Through specific industrial practice, the feasibility of blast hole parameters, main blasting techniques, construction key points, blast hole blockage, blasting network connection and other details of the one-time shaft excavation by medium-deep blasting technique with hole height of 16 m were verified. Each cutting shaft can save costs of 80 000 RMB and improve efficiency by more than 10 times. This study can provide a reference for the promotion and application of the one-time shaft excavation by medium-deep blasting.
In order to further study the influence of excavation speed on the mechanical and damage characteristics of coal rock in coal mining, the true triaxial unloading test of coal rock under different unloading rates was carried out through the self-developed geoacoustic process simulation test system. The results show that with the increase of unloading rate from 0.05 MPa/s to 0.4 MPa/s, the maximum principal strain value, the minimum principal strain value and the volume strain value of coal rock during unloading failure decrease by 48.2%, 73.8% and 113.1%, respectively, and the intermediate principal strain value increases by 16.3%. The larger the unloading rate, the more obvious the expansion of coal rock. The failure mode of coal rock under low unloading rate is shear failure, while under high unloading rate is tension-shear composite failure. The test data show that the modified Drucker-Prager strength criterion is more suitable for the unloading failure of coal rock. The greater the unloading rate, the greater the cumulative ringing count of acoustic emission corresponding to the failure of coal rock, and the higher the energy. The damage evolution equation of coal rock based on cumulative ring count can better describe the damage process of coal rock during unloading process. The research results can provide a reference for the prediction of excavation stability in practical engineering.
In view of the unstable and uncontrollable underflow concentration of the common thickener in the paste filling system of the main-western ore body in Chambishi Copper Mine, and even the cliff-like drop phenomenon, the causes of underflow concentration instability were analyzed and the corresponding measures were put forward by monitoring the data of the thickener on the spot. The two-system industrial concentration tests were carried out, and the mathematical models of underflow concentration and mud pressure of deep cone thickener were obtained. The industrial test shows that the operation of two thickeners can maintain the stability of mud pressure and underflow concentration. Through the regulation measures of “inlet and outlet balance”and “high material level operation”, when the discharge flow is 60 m~3/h and the mud pressure is 204-215 kPa, the underflow concentration fluctuates in the range of 67%-69.5%, which can ensure the quality of underground filling.
以刚果(金)某露天矿边坡滑坡监测为例,结合FLAC3D数值模拟和真实孔径边坡雷达(RAR)两种手段,进行边坡稳定性分析和监测预警研究,实现了滑坡区域、滑坡时间的精准预报,为现场争取了 2.5 h以上的临滑应急处置时间,有效避免了滑坡损失;在边坡风险区域位移发展变化特征、滑动破坏初始位置和滑动区域等方面,RAR边坡雷达监测数据均验证了 FLAC3D数值模拟结果的准确性;同时表明FLAC3D可及时发现当前滑坡隐患区域之外的风险,为雷达监测做必要的补充,为充分处置滑坡隐患提供依据,提高了露天矿边坡管控水平.研究成果可为同类边坡的蠕动型滑动破坏预警提供参考.
针对黄金尾矿堆存量大、处置困难、资源化利用率低等问题,为实现矿山尾砂的资源化利用,将黄金尾矿替代传统砂石骨料制备碱激发矿渣泡沫混凝土,并分析水灰比、稳泡剂掺量、泡沫掺量和水玻璃模数对浆体流动性、干密度、导热系数及抗压强度的影响规律.试验结果表明:水灰比从0.3增加至0.5的过程中,浆体流动度不断增加,干密度不断降低,导热系数和抗压强度呈先增加后降低的趋势,当水灰比为0.35时,导热系数和抗压强度达最大值;0.1％～0.4％的稳泡剂掺量对混凝土性能影响不显著;随着泡沫掺量的增加,混凝土结构形成大量连通孔,孔隙率增加,混凝土各性能均呈不断降低趋势;水玻璃模数是改善混凝土性能的关键因素,当水玻璃模数为1.6时,浆体流动度为149 mm,干密度为872 kg/m3,导热系数为0.088 W/(m·K),试样的3 d、7 d、28 d 抗压强度分别为 10.16,14.67,18.82 MPa.
为探究给料速度、泥层沉降速率、底流质量浓度和屈服应力等多因素耦合条件下中细粒全尾砂絮凝沉降规律,在静态絮凝沉降试验的基础上,利用 自主研发的连续浓密测试系统模拟立式砂仓内尾砂的动态絮凝沉降过程.研究结果表明,不同砂浆质量、不同絮凝剂添加量条件下,静态絮凝沉降曲线均呈现出先快速下降后基本趋于水平的形态;在给料速度为0.6 t/(m2·h)时,动态絮凝沉降的底流质量浓度最高;底流质量浓度与底流屈服应力呈正相关关系,与泥层沉降速率呈负相关关系,并随着给料速度的增加而增大;絮团通过紊流区后呈现先加速沉降后稳定沉降的规律.研究结果指导了某矿实现了立式砂仓絮凝浓密中细粒全尾砂的工业应用.
针对一种非离子型聚氧乙烯表面活性剂与酸值165、碘值110的脂肪酸组成的复合捕收剂,从红外光谱、矿物Zeta电位测定、接触角的角度对复合捕收剂的协同效应进行了研究.基于白云鄂博磁选铁矿高氟低硅的矿物特点开展了一粗二精一扫闭路试验,得到品位66.25％的精矿,比现场提高0.63个百分点,精矿含氟量0.38％,比现场降低1.93个百分点.红外光谱测试结果表明,复合捕收剂中C—O键可以稳定地与活化后的萤石表面发生化学吸附;矿物Zeta电位测定表明,脂肪酸根离子与钙离子生成疏水的脂肪酸钙吸附于萤石表面,促进矿物上浮;接触角测定表明,吸附复合捕收剂后萤石的接触角由50.50°增大到77.43°,表明疏水性增强,有利于萤石上浮.研究结果证明复合捕收剂对萤石有较好的捕收效果,可为磁铁矿低温反浮选设计提供依据.
单轴压缩过程中,岩石内部区域化结构的演化导致破裂,破裂同样与区域化结构互相作用.为研究二者耦合作用下岩石破裂的演化规律,通过声发射-声波成像技术获取岩石内部波速数据,将其与颗粒流程序导出的颗粒信息自动匹配成组,针对加载过程中区域化结构的动态演化行为,进行模型优化,对区域化结构与破裂耦合作用下的岩石破裂演化规律展开研究.结果表明:构建出的动态演化模型,其破裂形态与室内试验具有良好的相似性;在时间上,裂纹萌生于区域化结构退化演化阶段,在空间上,裂纹萌生于退化后的Ⅲ类区域化结构内部;当区域化结构强化演化时,裂纹多在边界处扩展,在力学属性较弱区域聚集成核,当区域化结构持续劣化演化时,裂纹汇集成裂纹带,并在靠近边界位置处向演化方向扩展.
