深井矿山联合开采交错区地压显现时空规律研究

为了研究矿山联合开采的地压显现规律,以夏甸金矿为例,其矿体中浅部采用崩落法开采,跨度超过300 m,而两翼采用充填法开采.采用数值模拟与现场监测方法,综合分析了深部联合开采交错区的应力、位移等时空规律.数值模拟结果表明：无底柱分段崩落法与上向水平分层充填法联合开采时,崩落采空区下方应力集中数值较大,矿体两翼略小,交错区应力值最高.地压动态监测发现,无底柱分段崩落法区的顶板沉降位移与巷道水平收敛位移普遍大于上向分层充填法,但围岩二次应力的变化要略小于上向分层充填法,联合开采区域在整体上处于稳定状态.研究实现了多参量联合动态监测,为深部开采过程中地压显现的有效监测预警提供了有效手段,具有良好的推广示范效应.     

利用固体充填开采方法保护建筑群安全的研究

我国煤矿建筑物下压煤量占总压煤量的69%,同时每年要向地面排放4.5亿t以上的固体废弃物,因此,研究利用固体废弃物充填开采方法,在保证地表建筑物安全性的基础上,高效开采出下压煤炭资源意义重大.文章应用数值模拟方法,对建筑物下压煤开采所引起的岩层移动过程进行模拟,系统分析了采场围岩塑性区分布及地表沉陷量变化规律,由计算结果分析得知,应用固体充填开采法与无充填直接开采相比,采场围岩破坏单元数较少,围岩稳定性受影响较小,减少地表沉陷量效果明显.以数值模拟结果作为参考,研制了长臂综采矸石充填开采工艺的配套设备,并在某矿建筑物下压煤炭开采的实际应用中取得良好效果,有效控制了地表变形,保证了建筑物的安全性和资源的高效开采.     

不同采矿方法下采场稳定性数值分析

采用数值分析软件ANSYS对某矿体典型采场顶板与间柱的稳定性及其对采场围岩力学状态的影响进行数值模拟分析,矿山采用浅孔留矿法和分段凿岩阶段矿房法对于不同产状的矿体进行开采,对不同采矿方法下典型采场结构模型的模拟结果进行了分析,根据分析结果,结合矿山生产现状对目前采矿方案提出合理化建议,以便更确切地掌握不同采场地压的发展变化规律,有效地实施地压管理,实现安全高效开采。     

固体充填体压实特征下岩层移动规律研究

基于充填材料压实特性试验,结合具体工程实例,推导出充填体弹性模量与垂直应变之间的关系,利用FLAC3D软件内置FISH语言,编制相应的充填体非线性压实程序,准确地模拟矸石充填采空区后上覆岩层移动规律.研究结果表明:充填采煤工作面顶板下沉量随着工作面的推进而逐渐增大,整体以缓慢弯曲下沉为主,没有出现激增的现象;超前支撑应力分布与垮落法开采相似,其超前支承应力峰值及影响范围均要比垮落法开采低;矸石充填体内部应力呈现"拱形"分布,随着工作面的推进,矸石充填体内部应力逐步升高,增幅逐渐减小.现场实测数据与数值模拟结果基本吻合,验证了研究成果的科学性.     

尾砂胶结充填体与岩体耦合作用机理研究

充填法开采被广泛应用于隐患资源2次开采中,研究充填体与岩体耦合作用机理,对充分利用矿产资源、保护地表建筑物、延长矿山服务年限等方面具有十分积极的作用.以程潮铁矿西区选厂下遗留矿柱2次开采为研究背景,通过对尾砂胶结充填体的无侧限单轴抗压正交力学试验,得到了不同灰砂比、不同浓度、不同龄期参数与充填体单轴抗压强度的曲线关系和多参数线性回归方程式,同时分析了影响充填体抗压强度的主次因素.最终依据充填体与岩体能量匹配原则,通过数值模拟并充分考虑回采中爆破震动对采场稳定性的影响,得出最优充填方案.     

康家湾矿深部难采矿体采场稳定性及结构参数优化研究

采用大型有限元分析软件--ANSYS对康家湾煤矿深部难采矿体典型采场顶板的稳定性及其对采场围岩力学状态的影响进行数值模拟、非线性分析,对9种典型采场结构模型的模拟结果进行了比较分析,根据分析结果结合采掘效率和开采成本等因素确定了采场最优结构参数,并对当前采矿方案提出修正和调整建议,以便更清楚地掌握深部地压变化规律,有效地进行地压管理,实现深部破碎带矿体及顶板不稳固矿体的安全高效开采.     

基于Hoek-Brown准则的深部岩体力学参数及其应用

基于Hoek-Brown经验强度准则,采用最小二乘法拟合出岩体力学强度参数,并与H-B_02ed推荐的等面积拟合结果进行对比,结果发现两种拟合方法得出的岩体内摩擦角数值相差很小,但等面积拟合法得出的黏聚力强度远高于最小二乘拟合法。将两种强度参数拟合结果应用于深部矿体开采的数值模拟,发现采用最小二乘拟合法的岩体强度参数其模拟结果更接近工程实际。该方法对深部岩体力学参数的确定具有一定的借鉴意义。     

固体充填开采地表沉陷数值模拟研究

应用FLAC3 D软件建立了某矿区固体充填开采的三维数值模型,结合固体充填开采等效采厚的相关概念模拟了模型的开挖以及模型在开采后的移动变形情况。使用FLAC3 D内嵌的FISH程序语言,编制了相关程序,提取出两种不同类型的地表移动观测站的沉陷数据。利用提取出的地表移动观测站沉陷数据,结合MATLAB强大的数据处理和可视化功能,对固体充填开采所产生的地表沉陷进行后处理与可视化操作。研究表明：固体充填开采可以有效控制地表沉陷,适用于村庄等建筑物下采煤的情况;运用FLAC3 D并结合MATLAB的方法可以方便、准确的进行开采沉陷的数值模拟与可视化操作。     

煤矿矸石井下处理的研究

针对煤矿矸石地表堆积对人类生存环境和条件带来的威胁与危害，研究了矸石井下处理技术．该项技术运用开采沉陷理论预计地表允许沉陷范围内充填区域矸石充填压实后残余空间的最大高度，确定矸石充填巷的布置；基于数值模拟方法分析了充填巷两侧煤柱应力分布、消除充填巷开掘时的“多洞效应”问题，优化矸石充填巷掘进顺序；设计了矸石充填工艺．此项技术在邢东矿井得到成功应用，实现了矸石井下处理与建筑物下煤炭资源的开采利用．     

部分充填开采围岩活动规律分析

采用适于分析采动影响裂隙岩体活动规律的数值模拟软件UDEC，详细分析了部分充填开采时围岩应力和位移变化规律及特点，重点分析了不同充填方式与关键层断裂的关系，以及不同充填方式对部分充填开采围岩稳定性的影响。研究结果表明，充填空顶间隔大小、充填条带宽度是部分充填开采围岩稳定性的两个主要影响因素。后期开采的条带将扩大先期开采条带的影响，尤其是后期开采两充填条带之间的条带并不充填时，这种影响更大，最后对具体的充填开采方法提出了建议。     

Waste-filling in fully-mechanized coal mining and its application

A fully-mechanized coal mining (FMCM) technology capable of filling up the goaf with wastes (including solid wastes)is described. Industrial tests have proved that by using this technology not only can waste be re-used but also coal resources can be exploited with a higher recovery rate without removing buildings located over the working faces. Two special devices, a hydraulic support and a scraper conveyor, run side-by-side on the same working face to simultaneously realize mining and filling. These are described in detail. The tests allow analysis of rock pressure and ground subsidence when backfilling techniques are employed.These values are compared to those from mining without using backfilling techniques, under the same geological conditions. The concept of equivalent mining height is proposed based on theoretical analysis of rock pressure and ground subsidence. The upper limits of the rock pressure and ground subsidence can be estimated in backfilling mining using this concept along with traditional engineering formulae.     

Evaluation of the use of sublevel open stoping in the mining of moderately dipping medium-thick orebodies

The flow of blasted ore during mining of moderately dipping medium-thick orebodies is a challenge. Selecting a suitable mining system for such ore bodies is difficult. This paper proposes a diamond layout sublevel open stoping system using fan blastholes with backfilling to mine such orebodies. To evaluate the performance of system the relationships between ore recovery and stope footwall dip angle, footwall surface roughness, drawpoint spacing and production blast ring burden were investigated. An ore recovery data set from 81 laboratory physical model experiments was established from combinations of the listed factors. Various modules in a back propagation neural network structure were compared, and an optimal network structure identified. An ore recovery backpropagation neural network (BPNN) forecast model was developed. Using the model and sensitivity analysis of the factors affecting the proposed open stope mining system, the significance of each factor on ore recovery was studied. The study results were applied to a case study at the Shandong Gold Group Jiaojia Gold Mine. The results showed that the application of a BPNN and sensitivity analysis models for ore recovery prediction in the proposed mining system and field experimental results confirm that the suggested mining method is feasible.     

Influence of backfilling rate on the stability of the “backfilling body-immediate roof” cooperative bearing structure

To reduce the cost of backfilling coal mining and utilize the underground space of coal mines, a new backfilling mining method with low backfilling rate called constructional backfilling coal mining (CBCM) is proposed. The “backfilling body-immediate roof” cooperative bearing structure of CBCM is analyzed by establishing the model of the medium thick plate on an elastic foundation. The influence of the backfilling rate on the stability of overlying strata is analyzed by the numerical simulation experiment. The control effect of CBCM is verified by a physic similar simulation test. The economic benefit of CBCM is analyzed. The conclusions are: the deformation characteristics of the immediate roof and critical backfilling spacing in CBCM can be analyzed based on the Hu Haichang’s theory. Exerting the bearing capacity of the immediate roof is beneficial to the stability of the overlying strata. The CBCM has a good control effect on the overburden in Xinyang Mine when the backfilling rate is lower than 25%. The backfilling cost of per ton coal is 37.39 yuan/t when the backfilling rate is 13.7%, with a decrease rate of 56.63% than the full-filling. The research results can provide theoretical support for the application of CBCM in coal mining.     

Investigation and characterization of mining subsidence in Kaiyang Phosphorus Mine

In Kaiyang Phosphorus Mine, serious environmental and safety problems are caused by large scale mining activities in the past 40 years. These problems include mining subsidence, low recovery ratio, too much dead ore in pillars, and pollution of phosphorus gypsum. Mining subsidence falls into four categories： curved ground and mesa, ground cracks and collapse hole, spalling and eboulement, slope slide and creeping. Measures to treat the mining subsidence were put forward： finding out and managing abandoned stopes, optimizing mining method （cut and fill mining method）, selecting proper backfilling materials （phosphogypsum mixtures）, avoiding disorder mining operation, and treating highway slopes. These investigations and engineering treatment methods are believed to be able to contribute to the safety extraction of ore and sustainable development in Kaiyang Phosphorus Mine.     

基于地质三维模拟的攀枝花铁矿块体模型储量估算

攀枝花铁矿属于基性岩浆侵入晚期分异型矿床,其地质环境极其复杂。采用3DMine矿业软件作为平台,对攀枝花尖山矿区地质勘探资料进行全面整理并建库,针对矿区深部铁矿体具有韵律性、顺岩层、单斜产出等特点,改变传统矿体圈定方法,从新的角度探索并建立了尖山矿区的地表模型、构造模型、矿体模型、矿带模型、地质工程模型等,实现了地质体的三维可视化。基于矿体的块体模型、依据采样点的品位信息空间分布形态而采用改进的克里格估算方法,对矿区铁矿储量的估算更为合理。     

An improved method to assess the required strength of cemented backfill in underground stopes with an open face

Backfill is increasingly used in underground mines to reduce the surface impact from the wastes produced by the mining operations. But the main objectives of backfilling are to improve ground stability and reduce ore dilution. To this end, the backfill in a stope must possess a minimum strength to remain self-standing during mining of an adjacent stope. This required strength is often estimated using a solution proposed by Mitchell and co-workers, which was based on a limit equilibrium analysis of a wedge exposed by the open face. In this paper, three dimensional numerical simulations have been performed to assess the behavior of the wedge model. A new limit equilibrium solution is proposed, based on the backfill displacements obtained from the simulations. Comparisons are made between the proposed solution and experimental and numerical modeling results. Compared with the previous solution, a better agreement is obtained between the new solution and experimental results for the required cohesion and factor of safety. For large scale (field) conditions, the results also show that the required strength obtained from the proposed solution corresponds quite well to the simulated backfill response.     

Numerical investigation into the effect of backfilling on coal pillar strength in highwall mining

This paper attempts to quantify the effect of backfilling on pillar strength in highwall mining using numerical modelling. Calibration against the new empirical strength formula for highwall mining was conducted to obtain the material parameters used in the numerical modelling. With the obtained coal strength parameters, three sets of backfill properties were investigated. The results reveal that the behavior of pillars varies with the type and amount of backfill as well as the pillar width to mining height ratio(w/h). In case of cohesive backfill, generally 75% backfill shows a significant increase in peak strength, and the increase in peak strength is more pronounced for the pillars having lower w/h ratios. In case of noncohesive backfill, the changes in both the peak and residual strengths with up to 92% backfill are negligible while the residual strength constantly increases after reaching the peak strength only when 100%backfill is placed. Based on the modelling results, different backfilling strategies should be considered on a case by case basis depending on the type of backfill available and desired pillar dimension.     

Ground movements modeling applying adjusted influence function

Mathematical modeling of surface deformations caused by underground mining operation is commonly carried out with use of empirical, numerical or stochastic models. One of the most frequently applied model for prediction of ground deformation in many countries is Knothe model. The model developed by Knothe belongs to the stochastic methods and is based on the influence function. In China a prediction method named Probability Integration Method(PIF) was established by Liu Baochen and Liao Guohua based on the stochastic medium theory. Modified version of that model allows to predict ground movements caused by mining operation in extremely complex technical and geological conditions. That model is commonly applied for coal, metal ore and salt deposits. The article presents several modifications of the mathematical model used in China and Poland. This model is very widespread in the world, therefore the generalizations proposed in the article can be implemented for the purposes of prediction surface deformations for various types of deposits in many countries. The presented generalizations were then tested on specific examples of coal mining, copper ore mining and rock salt deposit. The obtained results indicate high efficiency of methods based on the influence function in complex geological and mining conditions.     

大姚崩落采矿法借计算机模拟优选采场参数

目前大姚铜矿氧化矿采用的是底盘漏斗崩落采矿法。可是矿石损失值很高,虽然矿山做了大量工作,但是仍然不能将其降至设计的指标。鉴于目前的状况,为了掌握在矿山具体条件下崩落矿岩的流动规律;矿体产状、采场结构参数以及回采工艺与回贫指标之间的关系;以便为改进采矿方法、结构参数和回采工艺提供具有说服力的依据。展开了计算机模拟的最优化研究。论文说明了计算机模拟的试验方法并且分析了所获得的结果,提出了对实际生产具有指导意义的选择与建议。