层次分析法在大冶高陡边坡危险性分析中的应用

大冶铁矿申报为首批国家矿山公园,为了保证游客和采矿人员与设备的安全,合理分析和评价高陡边坡的危险性具有很重要的意义.在野外研究的基础上,根据岩体结构、地质构造等特征,将大冶铁矿东露天采场高陡边坡分为8个区,分析出影响东露天采场高陡边坡的稳定性因素主要有岩土类型和性质、岩体结构及地质构造、地形地貌、水、诱发因素等.利用层次分析法建立的递阶层次结构,采用专家打分平均法对每个影响因子给予主观定量赋值,通过公式计算,可以得出每个区的相对危险性程度.分析结果表明Ⅵ区是最不稳定区;Ⅰ区和Ⅲ区是不稳定区,Ⅴ区和Ⅶ区是欠稳定区.     

露天采场高陡岩质边坡典型地段稳定性分析

对大冶铁矿东露天采场高陡岩质边坡狮子山F9断裂带西侧的稳定性进行了研究．总结分析该地段工程概况、边坡地层岩性、岩石变形破坏模式、岩体结构特征,并运用ANSYS数值建模法验算该边坡的稳定性,结果表明,在天然状态和饱水情况下该剖面均处于欠稳定状态．     

露天采场高陡岩质边坡典型地段稳定性分析

对大冶铁矿东露天采场高陡岩质边坡狮子山F9断裂带西侧的稳定性进行了研究.总结分析该地段工程概况、边坡地层岩性、岩石变形破坏模式、岩体结构特征,并运用ANSYS数值建模法验算该边坡的稳定性,结果表明,在天然状态和饱水情况下该剖面均处于欠稳定状态.     

基于重度增加法的大冶铁矿边坡稳定性分析

结合大冶铁矿东露天采场F9断裂带内的边坡实际情况,借助大型有限元软件ANSYS,采用重度增加法对大冶典型地段的边坡进行了稳定性分析及评价,最后应用有限元强度折减法进行验证,并对两种方法进行分析和比较.结果表明,基于重度增加技术的ANSYS程序用于高陡岩质边坡稳定性分析是可行的,与实际情况较为吻合,能合理简便地确定边坡的稳定性系数,是进行高陡边坡稳定性评价的有效方法之一,对工程实践具有一定的指导意义.     

大冶铁矿东露天采场边坡破坏判据的研究

通过对大冶铁矿东露天采场F9,F13断裂带内边坡的深入研究,从整体与局部稳定性系数等方面探讨了边坡破坏判据．利用有限元强度折减法和极限平衡法计算边坡的体稳定性,得出边坡处于极限平衡状态时的塑性应力及塑性应变,提出边坡破坏判据．     

大冶铁矿东露天采场边坡破坏判据的研究

通过对大冶铁矿东露天采场F9、F13断裂带内边坡的深入研究,从整体与局部稳定性系数等方面探讨了边坡破坏判据.利用有限元强度折减法和极限平衡法计算边坡的体稳定性,得出边坡处于极限平衡状态时的塑性应力及塑性应变,提出边坡破坏判据.     

金属矿山地下开采引起地面塌陷的规律

金属矿山地下开采引起地表塌陷已经成为一种主要的矿山地质环境问题．地面塌陷受多方面因素影响,各因素相互作用使得金属矿山地表塌陷形成机理复杂．本文以大冶铁矿东露天采场地面塌陷为例,从采场地质环境、矿体特征、采矿方法、崩落角、地面塌陷的形式等方面,综述了地面塌陷的特征,并探讨了地面塌陷的形成规律,该研究为矿山地面塌陷的成因及控制对策研究提供了帮助．     

聚能预裂爆破与边坡稳定性分析

某大型露天铁矿山开采已进入末期,在采场西部端帮已形成了近200m高、平均边坡角50．5°、局部53°的高陡边坡。为回收端帮残存矿石,关键因素是防止边坡的坍塌破坏。文中在对边坡岩体性质和节理裂隙分析的基础上,利用极限平衡原理对边坡的稳定性与爆破振动的关系进行了分析,确定了边坡潜在的破坏模式。根据聚能射流原理,提出了通过大孔径聚能预裂爆破两阶段降低爆破地震效应,保证生产过程中边坡安全的方法。     

姑山露天采场边坡失稳致因探讨

针对姑山矿露天采场出现的失稳现象,分析两种主要岩体边坡的破坏机理、破坏模式,结合实际采取相应的处理措施。     

金属矿山地下开采引起地面塌陷的规律

金属矿山地下开采引起地表塌陷已经成为一种主要的矿山地质环境问题.地面塌陷受多方面因素影响,各因素相互作用使得金属矿山地表塌陷形成机理复杂.本文以大冶铁矿东露天采场地面塌陷为例,从采场地质环境、矿体特征、采矿方法、崩落角,地面塌陷的形式等方面,综述了地面塌陷的特征,并探讨了地面塌陷的形成规律,该研究为矿山地面塌陷的成因及控制对策研究提供了帮助.     

Quantitative hazard assessment system(Has-Q) for open pit mine slopes

Rock slope hazard assessment is an important part of risk analysis for open pit mines. The main parameters that can lead to rock slope failures are the parameters traditionally used in geomechanical classifications, the slope geometrical parameters and external factors like rainfall and blasting. This paper presents a methodology for a hazard assessment system for open pit mine slopes based on 88 cases collated around the world using principal components analysis, discriminant analysis and confidence ellipses. The historical cases used in this study included copper, gold, iron, diamond, lead and zinc, platinum and claystone mines. The variables used in the assessment methodology are uniaxial compressive strength of intact rock; spacing, persistence, opening, roughness, infilling and orientation of the main discontinuity set; weathering of the rock mass; groundwater; blasting method; and height and inclination of the pit. While principal component analysis was used to quantify the data, the discriminant analysis was used to establish a rule to classify new slopes about its stability condition. To provide a practical hazard assessment system, confidence ellipses were used to propose a hazard graph and generate the HAS-Q. The discriminant rule developed in this research has a high discrimination capacity with an error rate of11.36%.     

Determination and stability analysis of ultimate open-pit slope under geomechanical uncertainty

In open-pit mines, pit slope as one of the important parameters affects the mine economy and total minable reserve, and it is also affected by different uncertainties which arising from many sources. One of the most critical sources of uncertainty effects on the pit slope design is rock mass geomechanical properties. By comparing the probability of failure resulted from deterministic procedure and probabilistic one, this paper investigated the effects of aforesaid uncertainties on open-pit slope stability in metal mines. In this way, to reduce the effect of variance, it implemented Latin Hypercube Sampling (LHS) technique. Furthermore, a hypothesis test was exerted to compare the effects on two cases in Middle East. Subsequently, the investigation approved high influence of geomechanical uncertainties on overall pit steepness and stability in both iron and copper mines, though on the first case the effects were just over.     

Comprehensive analysis of slope stability and determination of stable slopes in the Chador-Malu iron ore mine using numerical and limit equilibrium methods

One of the critical aspects in mine design is slope stability analysis and the determination of stable slopes. In the Chador Malu iron ore mine, one of the most important iron ore mines in central Iran, it was considered vital to perform a comprehensive slope stability analysis. At first, we divided the existing rock hosting pit into six zones and a geotechnical map was prepared. Then,the value of MRMR (Mining Rock Mass Rating) was determined for each zone. Owing to the fact that the Chador-Malu iron ore mine is located in a highly tectonic area and the rock mass completely crushed, the Hock-Brown failure criterion was found suitable to estimate geo-mechanical parameters. After that, the value of cohesion (c) and friction angle (e) were calculated for different geotechnical zones and relative graphs and equations were derived as a function of slope height. The stability analyses using numerical and limit equilibrium methods showed that some instability problems might occur by increasing the slope height.Therefore, stable slopes for each geotechnical zone and prepared sections were calculated and presented as a function of slope height.     

大冶铁矿滑坡预测模型研究

在深入研究滑坡变形特征的基础上,以大冶铁矿东露天采场狮子山北帮滑坡位移监测数据为依据,采用灰色理论,将滑坡的预测模型与滑坡运动特征相结合,推导出传统GM（1,1）模型和优化的GM（1,1）模型,通过验算比较,优化的GM（1,1）模型预测曲线与实测曲线的拐点及发展趋势高度吻合,模拟精度高,预测值可信度大,对临滑滑坡也有一定的预警意义．优化的GM（1,1）模型可以用于中长期预测模型．     

Quantitative analysis of biotechnical reinforcement for a steep slope consisting of composite coal-gangue-soil medium adjacent to a mined-out area

The engineering and geological characteristics of a steep slope consisting of coal gangue, rock and soil medium in Huating coal mine have been comprehensively investigated. Owing to humid weather, heavy rainfall, vegetation and porous characteristics of the soil and rock mass, the steep slope will be destabilized and induce mud-rock flow or derive hazard easily. Firstly, based on the classical slope reinforcement theory, some regularity between the shear and displacement in the destabilized zone of the slope with or without root strength contribution is presented. Then, based on the experimental and statistical analysis of root strength, hydrological characteristics and stability status, etc., some possible biotechnical techniques for reinforcement of the steep slope have been suggested. These methods are important for quantitative analysis of destabilization of the slope and design of the biotechnical reinforcement.     

Prediction of blast boulders in open pit mines via multiple regression and artificial neural networks

The most important objective of blasting in open pit mines is rock fragmentation.Prediction of produced boulders(oversized crushed rocks) is a key parameter in designing blast patterns.In this study,the amount of boulder produced in blasting operations of Golegohar iron ore open pit mine,Iran was predicted via multiple regression method and artificial neural networks.Results of 33 blasts in the mine were collected for modeling.Input variables were:joints spacing,density and uniaxial compressive strength of the intact rock,burden,spacing,stemming,bench height to burden ratio,and specific charge.The dependent variable was ratio of boulder volume to pattern volume.Both techniques were successful in predicting the ratio.In this study,the multiple regression method was superior with coefficient of determination and root mean squared error values of 0.89 and 0.19,respectively.     

岩质高边坡岩体力学参数确定及稳定性研究

以云南某露天矿采场岩质高边坡工程为研究对象,阐述了岩体力学参数在边坡稳定性分析中的重要性,因原位试验对于坚硬岩体或极软岩体的不适用性,对坚硬岩体,以室内试验得出的岩石物理力学参数和岩体质量评价RMR评分值为依据,并综合考虑岩体中节理裂隙、岩体结构、地下水的影响,运用霍克-布朗(Hoek-Brown)强度准则将岩石力学参数进行折减修正后换算成岩体力学参数,并与现场原位试验所得软弱岩体力学参数结果相结合得到最终岩体力学参数.在上述调查、研究基础上,采用有限差分法(FLAC数值分析软件)对现状边坡进行静态的稳定性分析,提出合理的最终边坡角及总台阶高度,保证矿山正常生产和经济效益的提高.     

露天煤矿端帮残煤开采及边坡暴露时间分析

为了提高露天开采的煤炭资源回收率，掌控露天煤矿端帮残煤开采工程安排，提出了水平和近水平大型露天煤矿汽车运输内排条件下，露天煤矿端帮露井联采、端帮陡帮开采、减少露天煤矿端帮边坡暴露时间的措施．结果表明：采掘工作帮帮坡角越大、内排土场工作帮帮坡角越大、工作线推进强度越大、内排土场下部水平排土台阶高度越大、采场坑底宽度越小露天煤矿端帮边坡的暴露时间越短；当露天煤矿端帮实行陡帮开采时，汽车运输内排通路可设在采场中部回填搭建。