Deformation and failure of a high-steep slope induced by multi-layer coal mining

During underground mining,accurate revelation on the deformation and failure mechanisms of a high-steep slope under multi-layer mining conditions facilitates the prevention and control of geological disasters in mines.Numerical simulation based on discrete element theory can be used to explore the characteristics and mechanism of action of deformation and failure of a slope under complex geological and multi-layer mining conditions.By utilising PFC2 D(particle flow code) software,the deformation and failure characteristics of a high-steep slope in Faer Coal Mine in Guizhou Province,China were investigated.Additionally,the mechanism of influence of different numbers of mining layers on the deformation and failure of the high and steep slope was elucidated.The result showed that after the goaf passed by the slope toe,multi-layer mining aggravated the subsidence and deformation of the slope toe:the slope toppled forward as it sank.The toppling of the slope changed the slope structures:the strata in the front of the slope were transformed from anti-dip to down-dip features.Extruded by collapsedtoppled rock mass,the slope toe and the rock mass located in the lower part of the slope toe generally exhibited a locking effect on the slope.Multi-layer mining degraded the overall stability of the slope,in that the total displacement of the slope was much greater than the total mining thickness of the coal seams.Based on the aforementioned research,ideas for preventing and controlling geological disasters during mining operations under a high-steep slope were proposed.

Application of open-pit and underground mining technology for residual coal of end slopes

Given the conditions of residual coal from the boundary of a flat dipping open-pit mine,which uses strip areas mining and inner dumping with slope-covering,we propose an open-pit and underground integrated mining technology for residual coal of end slopes.In the proposal a conveyance road and ventilation conveyance near the slope are built,corresponding to the pit mining area and the surface coal mine dump,as well as an interval haulage tunnel and air-inlet tunnel.The outcome shows that such mining method may reduce the effect to slope stability from underground mining,it does not affect the dumping advance and has a high recovery rate of residual coal resources.The working face is timbered by single hydraulic props,transported by a scraper conveyor and supported by coal walls.This method of mining is one of layered top coal caving,with high resource recovery,low production cost where positive economic benefit can be realized.

Comparative study of mining methods for reserves beneath end slope in flat surface mines with ultra-thick coal seams

The paper aims to identify a reasonable method for mining ultra-thick coal seams in an end-slope in surface mine, With a case study of Heidaigou surface coal mine(HSCM), the paper conducted a comparative research on three mining methods, namely Underground Mining Method(UMM), Highwall Mining System(HMS) and Local Steep Slope Mining Method(LSSMM). A model was firstly established to simulate the impact that UMM and HMS exert on monitoring points and surface deformation. The way that stripping and excavation amount varies with different slope angle, and the corresponding end slope stability were analyzed in the mode of LSSMM. Then a TOPSIS model was established by taking into account six indicators such as recovery ratio, technical complexity and adaptability, the impact on surface mining production, production safety and economic benefits. Finally, LSSMM was determined as the best mining method for mining ultra-thick coal seams in end slope in HSCM.

Stability analysis of new safety cleaning bank in steep slope mining

Based on the study of the slope with gently granular structure in Xingqiao open mine, a new safety cleaning bank mode for steep slope mining was developed, including setting up dint cut, and forming natural retaining wall based on the character of gentle incline slope. It can effectively eliminate the impact of sliding body on the bottom working place and slope body, reduce the dilution of ore, keep rainwater from upper steps away, decrease influence of the weak intermediate layer, and cut cost of disposal waste rock. The safety and reliability of the mode were analyzed and verified from 3 aspects: static load calculation, ANSYS simulation of dynamic loading and spot experiment. The result of static loading calculation shows that the retaining wall can support accumulation and extrusion of granular body, and the glide or overturn disaster will not take place. The simulations of dynamic loading show that the retaining wall remains stable until sliding body collapses from 360 m (10 sublevels). Only one new safety cleaning bank in each 15 sublevels can fully meet the need of engineering. The new mode sustains steep slope (mining,) increases the angle of ultimate slope, and reduces invalid overburden amount of rock by 3%5%. The result of spot experiment has verified the exactness of the above calculations and simulations.

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.

露天矿高陡复杂边坡软弱岩层组“坐落-滑移式”破坏模式研究

边坡稳定性问题随露天矿开采的进行不断突出,而边坡软弱岩层严重影响边坡稳定性。大量工程实例显示,露天矿含软弱岩层组的高陡复杂边坡失稳模式通常为“坐落-滑移式”破坏。为明晰露天矿高陡复杂边坡软弱岩层组“坐落-滑移式”破坏模式的破坏机理,以某露天矿为例,提出一种针对露天矿含软弱岩层组高陡复杂边坡的综合分析方法。研究结果表明:采用工程地质分析、传统极限平衡方法和数值模拟分析相结合的综合分析方法,针对该类型复杂边坡可发挥不同分析方法的优势,较全面地从地质自然环境条件、定性定量方面、应力应变角度分析边坡破坏机理及模式,总结归纳出含软弱层组露天矿高陡复杂边坡“坐落-滑移式”破坏的“坐落-滑移-剪出”三段式破坏特征,为其他类似复杂边坡稳定性的分析和防治提供思路和手段。

露天矿地下水控制技术及对边坡稳定性的影响

我国富水露天矿多且涌水量大,若矿山地下水或边坡处治不当,将面临着“水患难止、边坡难固、有矿难采”的窘境。为解决露天矿遇到的水患和边坡失稳的问题,基于我国露天矿先后发展的垂直疏水孔、水平疏水孔、坑下大口径疏水孔和井群疏水等抽排方式,坑底泄水巷、基坑降水和辐射井疏干等疏放方式以及钻孔注浆帷幕、地下混凝土连续墙帷幕、钻孔咬合桩帷幕、防渗膜帷幕等截水帷幕和地层回灌水帷幕等多种地下水控制技术;开展了不同露天矿地下水控制技术对地下水位、端帮边坡岩土体力学性质变化、坡体应力变化和边坡稳定性系数影响的研究,分析了截水帷幕作用下地下水位抬升与边坡稳定性变化规律。研究结果表明:通过抽排方式、疏放方式将露天矿山地下水疏干或疏降可有效降低地下水位,减少边坡岩土体含水率,提高边坡岩土体黏聚力和内摩擦角,减小坡体的静水压力和水平推力,整体提高边坡稳定性系数,但大量疏排地下水又造成水资源的浪费和污染;截水帷幕能够解决疏排降水造成的地下水位下降幅度太大、疏排水量巨大、水资源浪费和污染的问题;在截水帷幕作用下,露天矿截水帷幕外侧水位不断抬升,引起截水帷幕外侧边坡岩土体含水率增加、黏聚力和内摩擦角减小、坡体的静水压力和水平推力增大,而截水帷幕内侧边坡岩土体含水率减小、黏聚力和内摩擦角增大、坡体的静水压力和水平推力减小,从而引起露天矿边坡稳定性系数略有降低;通过截水帷幕可以控制露天矿边坡地下水位,进而保持边坡岩土体力学参数在合理范围,维持边坡稳定性系数在安全区间,实现露天矿地下水资源保护与边坡安全的平衡。

平朔东露天矿端帮采煤区边坡稳定性分析与监测方案

为分析平朔东露天煤矿端帮采煤区边坡稳定性,以DB-01、DB-02、DB-03等3个典型边坡剖面为研究对象,选取了合理的边坡稳定性安全储备系数与岩土体物理力学参数,基于极限平衡与有限先强度折减原理进行边坡稳定性分析,确定了各边坡开采到界的稳定系数均满足安全系数规范要求,并提出了端帮采煤区边坡监测治理措施。结果表明:平朔东露天煤矿端帮到界后的稳定系数均在1.2以上,到界端帮处于稳定状态,可进一步实施端帮采煤机开采;确定的4#煤的采硐高度为5 m、宽度为3.3 m,煤柱宽度为5 m;确定的9^(#)煤的采硐高度为5 m、宽度为3.3 m,煤柱宽度为6 m;端帮采煤机开采区的稳定性达到1.1以上,满足安全储备要求。

某石灰岩矿山典型边坡稳定性分析研究

本文以四川省某新建露天矿山为例,选取某一典型危险设计剖面,采用赤平投影分析法、简单平面滑动分析、楔形体破坏分析和极限平衡法进行综合评价,以期为类似新建矿山高陡边坡设计提供参考。结果显示:岩层结构面切割对该边坡影响较大,坡顶部分中风化泥岩由于受矿区界线限制,无法越界开采,将其清除,有可能发生楔形体破坏,该区开采方案需进一步调整;该典型剖面坡顶局部稳定性不满足规范要求,为确保矿山安全生产,终了边坡结构参数需进一步调整。

红沙泉露天矿工作帮陡帮开采方案研究

工作帮坡角大小直接影响剥离量和生产剥采比的大小,增大工作帮坡角可以减少超前剥离量,降低生产剥采比,节省运距,降低生产成本。但在提高工作帮坡角的同时,需要注意露天矿“二量”,保证露天矿能够持续稳定地生产。以红沙泉露天煤矿为工程背景,研究工作帮坡角与超前剥离量、生产剥采比的变化关系,并结合现场生产实际条件,提出实现工作帮陡帮开采方案。结果表明:工作帮坡角每增加2°,减少超前剥离量4.84 Mm^(3),生产剥采比降低0.22 m^(3)/t;确定将剥离台阶两两组合时,工作帮坡角提高至12°,生产剥采比可降低至2.7 m^(3)/t,同时保证露天矿“二量”要求。

金属露天矿山高陡顺倾边坡稳定性分析研究

金属露天矿山高陡顺倾边坡易形成大规模变形体或大型滑坡,防治难度大,是矿山安全高效生产的重大隐患。本文通过系统开展滇西北衙金多金属矿区万硐山矿段露天采场顺层边坡稳定性分析实例,研究了不同计算方法和不同工况下该类边坡滑坡失稳条件,采用数值模拟计算分析相结合的方法得出其滑坡类型及失稳模式,并提出了这类结构的露天矿山边坡风险管控措施建议,为矿山后续开采提供依据,指导矿山实际生产。

综合监测手段对露天高陡边坡局部垮塌的分析研究

本文通过对福建省上杭县紫金山金铜矿露天采场东帮进行综合监测,结合边坡雷达预警数据、GNSS监测数据、内部位移计监测数据,分析因降雨引起的采场东北帮820~868边坡在重力及雨水冲刷的双重作用下突破临界约束而出现的突然性垮塌。边坡雷达有监测到位移加速变形的趋势,但未及时发出预警。利用综合监测手段,更进一步准确分析高陡边坡。为解决边坡雷达预警问题更进一步监测边坡局部垮塌变形,本文设置预警分区,对采场东北帮820~868边坡进行区域圈定,设置更为敏感的预警阈值。减小圈定区域边坡雷达监测黄色预警和红色预警的短期预警值、长期预警值和预警面积,对曾经出现垮塌区域设置预警分区,从而做出更加准确的预警,显示监测数据波动变化的趋势,为类似高陡露天边坡监测提供参考。

砖瓦用黏土矿历史遗留废弃矿山边坡治理浅析

内蒙古呼和浩特市和林格尔县是构建我国北方生态安全屏障的重要组成部分。为系统解决该地区历史遗留废弃矿山以往矿山开采过程中所引发的崩塌、滑坡等一系列地质灾害问题,提升区域生态系统质量,选用削坡垫坡工程对和林格尔县某区域21处砖瓦用黏土矿历史遗留废弃矿山图斑的高陡边坡进行治理。在对项目区内各边坡实际情况进行具体分析后,通过公式计算出是否需要削垫坡及削垫坡范围,采用南方CASS11软件DTM三角网两期土方法精确计算土(石)方量。此治理工程可最大程度上消除地质灾害隐患且使治理后边坡与周边原始地形相协调,为内蒙古地区其他历史遗留废弃矿山边坡治理工程提供方法和经验。

微生物在露天矿高陡坡面生态修复中的应用与展望

露天矿高陡坡面的开采活动导致了严重的生态破坏,诸如土壤退化、重金属污染及水土流失等问题显著增加了生态修复的难度。综述了露天矿高陡坡面生态修复面临的关键挑战,系统分析了微生物在土壤改良、重金属污染控制及与植物协同作用中的机制。微生物通过分解有机质、形成团粒结构、固定和转化重金属,显著改善土壤结构,增强保水能力,并降低重金属的迁移性和生态毒性。同时,微生物与植物共生的协同作用显著提升了植被恢复的成功率,促进了生态系统的重建。结合典型案例分析,说明微生物修复技术在无客土条件下展现出卓越的修复效果,特别是在重金属污染严重的区域。提出未来的发展方向应聚焦于菌种筛选优化、修复策略调整及技术标准化的建立,以推动微生物修复技术在矿区生态修复中的广泛应用。

端帮采煤机在露天煤矿中的发展和应用

为了解决露天煤矿端帮压煤问题,特别是端帮下压煤量非常大的埋藏较深、煤层较厚露天矿,提高露天矿的原煤回收率,减少煤炭资源浪费,提升露天矿整体经济效益,分析了端帮采煤机在国内外的发展和应用情况,论述了端帮采煤安全保障技术和优劣势。端帮采煤机作为露天矿端帮特定条件下开采设备,是露天矿专属的开采工艺,可以更多地回收煤炭资源,可降低露天煤矿生产剥采比提升矿山整体经济效益。

露天矿陡帮开采工艺分析

在当今的岩矿露天开采作业中,陡帮开采是一项重要的工艺措施。为实现此项开采工艺的合理应用,本文特以福建省漳州市华安县水空矿区露天陡帮开采项目为例,对其露天开采过程中的陡帮开采工艺应用进行分析,包括凿岩设备选择、爆破技术应用、铲装技术应用以及防洪排水技术应用等。希望通过本次的分析,可以为陡帮开采工艺的应用与岩矿露天开采质量的提升提供一定参考。

基于采硐开采技术的端帮煤回采及边坡稳定性分析研究

为研究新疆某露天煤矿端帮煤回采技术及边坡稳定性,采用理论分析与数值模拟相结合的方法,分析了采硐开采到不同时期的边坡稳定性,研究了露天矿推进度与端帮回采煤量间关系。结果表明:单采硐开采过程中边坡稳定性系数随开采深度增加而不断下降,开采到最大深度250 m时降低至1.09,趋于临界平衡状态;露天矿推进度对端帮回采煤量的影响较大,随着推进度增大,每年能够进行的端帮采煤周期越多,因此在一定区间内资源回收量逐渐上升;当推进度增加到一定程度时,端帮采煤窗口期时间缩短,导致能够进行端帮采煤的层数减小,端帮资源的回采量骤降。

复杂环境下超浅埋地铁隧道施工技术研究

地铁隧道建设已成为我国当前社会发展的重要组成部分,在很多城市中都扮演着越来越重要的角色。南京地铁7号线马家园车辆出入段区间线路下穿铁路咽喉区,具有超浅埋、大下坡、小净距的工程特点,同时存在施工难度大、安全风险高的问题。文章以该工程项目为背景,提出了矿山法、盾构法与明挖法相结合的多工法组合方案,并着重对盾构法施工技术开展了重难点分析。在此基础上,针对性地提出了相应的解决方案,为今后类似工程提供参考。

露天石灰岩矿山高陡岩质边坡治理

因不规范开采形成的高陡边坡,易引发滑坡、坍塌等地质灾害,给矿山安全稳定带来极大影响。文章以溧阳某采石灰岩矿山为例,分析了该矿山地质环境条件,探讨了高陡岩质边坡整治及生态修复策略,希望可以为类似边坡治理提供借鉴。

废弃矿山高陡边坡生态修复治理技术研究与实践

随着矿山开采进程的深入,因矿山地质生态环境破坏引发的地质灾害和安全隐患已成为制约部分地区发展的瓶颈。为修复矿山地质地貌、消除矿山地质安全隐患、提高废弃矿山绿植覆盖率,以某典型废弃露天矿山为例,针对该矿山存在的高陡边坡、废渣堆积、地貌破坏等地质环境问题,基于“防治结合”的原则,提出了“坡面削(清)方+挡土墙+排水沟+封边墙+场地平整+客土喷播绿化+覆土绿化”的生态环境保护与修复治理技术,介绍了该技术施工工艺和质量控制措施。项目实施后,不仅有效消除了地质灾害隐患,改善了矿区地貌景观及周边生产生活环境,更为矿山生态环境修复治理探索了一条新路径。