共查询到18条相似文献，搜索用时 187 毫秒
1.
铁矿尾矿料力学特性及坝体变形稳定性研究 总被引：1，自引：0，他引：1
尾矿料矿物成分复杂,物理力学特性区域差异性大。本文以西南地区某铁矿拟建尾矿库为研究对象,对粗、细两种尾矿料进行了系统的物理力学特性试验,获得了粗细尾矿料物理力学指标并应用到尾矿库坝数值分析,分析了该尾矿库坝的应力变形特性,对不同堆积高程、不同工况下尾矿库坝的安全稳定性进行计算分析。此外采用拟静力法对地震荷载作用下尾矿坝的稳定性进行分析。结果表明,粗尾矿料会呈现出剪胀和软化力学特性,而细尾矿料则无明显剪胀;尾矿坝坝体内以压应力为主,坝体表面出现小范围拉应力区;高堆积高程,坝体倾向于发生深层滑动,坝体最小安全稳定性系数较大;干滩长度增大明显提高坝体稳定性;最后对该尾矿库的安全运行提出了一些针对性措施及建议。 相似文献
2.
通过对某大型尾矿库坝体勘察新技术、新工艺和尾矿砂土沉积环境、固结特征分析以及对尾矿砂土的静力、动力物理力学性质进行大量的试验研究,分区研究了淋滤固结、化学固结作用的特征,建立了3种固结作用在尾矿砂土静力抗剪强度(T值)中权重分配的计算式,揭示了尾矿砂土的静力、动力基本特性.在岩土工程理论研究及实践应用上具有较重要的意义. 相似文献
3.
尾矿坝垮塌机制与溃决模式试验研究 总被引：1，自引：0，他引：1
基于云南拉拉铜矿小打鹅尾矿库工程设计资料,采用现场排放尾矿砂为试验材料,进行了尾矿堆积坝在洪水情况下发生垮塌破坏的模型试验。通过水流控制系统模拟尾矿坝遭遇洪水情况,采用侧面示踪点、水位测压管、应力传感器以及数码摄像机等设备获得了尾矿坝溃决过程中坝坡的位移矢量演化、浸润线与应力的变化特性以及坝体破坏发展过程,揭示了洪水作用下尾矿坝的垮塌机制和溃决模式。试验结果发现：尾矿堆积坝的浸润线变化存在滞后性;在洪水入库致库区最高设计洪水水位过程中,靠近坝坡中部处水平方向的总应力增量较垂向总应力增量大,增大的水平应力是坝体产生破坏的重要因素之一;洪水导致坝坡尾矿砂所受的渗透力、上浮力、重力以及孔隙水压力增大,削弱了坝体材料的黏聚力,并加大了自身荷载,降低了坝体的稳定性;尾矿坝溃决模式一般为逆流渐进型,破坏先是从坡脚处发生,继而向上游发展,呈现牵引式发展,破坏的滑动面由多个弧形滑移面构成。研究成果加深了对尾矿堆积坝垮塌机制和溃决模式的认识,并在洪水灾害的预防和控制方面作了一些新的探索 相似文献
4.
尾矿库的浸润线对坝体的稳定安全至关重要。尾矿坝体内的化学淤堵会使介质渗透系数减小,坝内地下水位升高,增加渗流破坏发生的可能性。因此,研究化学淤堵对尾矿砂渗透系数的影响规律显得尤为重要。以栗西尾矿库为研究对象,通过现场调研和室内试验相结合的方式,分析了不同浓度的二价铁离子溶液对均质尾矿砂渗透系数的影响规律。结果显示,栗西尾矿库排水设施周边伴有化学淤堵现象发生;粒径为0.315 mm的砂粒质量占尾矿砂总质量的38.82%,比重最大;尾矿废水中二价铁离子的浓度为0.13~0.49 mg/L;二价铁离子引起的化学淤堵使尾矿砂渗透系数的变化规律符合指数函数,其中浓度为0.4~0.5 mg/L、0.2~0.3 mg/L工况下渗透系数的变化过程比较接近,二价铁离子浓度为0.3~0.4 mg/L工况下化学淤堵发生最为迅速,稳定时间最短。 相似文献
5.
基于离心机振动台,分别针对典型软基尾黏土尾矿库及加高扩容后的尾矿库开展了动力离心模型试验,重点探究了加速度分布规律、软土及尾矿内部孔压变化规律以及“软基?库内尾矿?尾矿坝”系统的变形规律等内容。试验结果表明：软基对地震动的放大效应较为微弱,而坝体加速度沿高程逐渐放大,高层子坝加速度响应最为强烈,加高扩容后的现坝顶加速度响应可达原坝顶的2.2倍;地震作用下软土与库内尾矿内部均会产生一定的孔压增量,但未达到液化状态。地震动强度、软基及库内尾矿的固结状态对尾矿库的变形模式影响较大。当固结不充分时,在强震作用下易发生尾矿的水平滑移,进而造成坝顶及下游软土隆起。在固结较为充分且地震动强度较弱的情况下,变形模式以震陷为主。该试验成果将为此类尾矿库的动力稳定分析及抗震加固设计提供一定参考。 相似文献
6.
地震作用下尾矿坝有液化失稳的危险,尾矿动孔压的演化规律可以间接体现其液化过程。为研究尾矿动孔压的演化规律,开展了一系列的动三轴试验。结果表明：尾矿动孔压演化具有明显的阶段性,在等压固结时可用S形反正弦函数曲线描述,在偏压固结时可用J形指数函数曲线描述;尾矿材料在等压固结条件下临界孔压接近于围压,在偏压固结条件下临界孔压小于围压,且随围压及固结应力比的增大而减小,随尾矿平均粒径的增大而增大。基于极限平衡理论推导了等压固结和偏压固结条件下的临界孔隙水压力方程,从理论上阐释了试验结果所揭示的动孔压演化规律,可以为地震区上游式尾矿坝的抗震设计提供参考。 相似文献
7.
《岩土力学》2017,(1):49-60
针对白鹤滩大型水电站揭露的错动带,探索了一种反映原岩应力状态的错动带试样制备方法,采用替代法对错动带进行超粒径处理,同时控制先期固结压力和稳压时间进行静载固结,并基于不同先期固结压力、不同高围压下的不固结、不排水三轴试验,结合矿物成分分析试验和扫描电镜试验,分析了不同先期固结压力下错动带的力学和变形特性。试验结果表明,不同高围压、不同固结压力下错动带应力-应变关系曲线基本表现为有剪胀行为的应变硬化型力学行为,且多为腰鼓型塑性破坏;在相同固结压力条件下,随着围压升高,错动带试样破坏应力、变形模量和泊松比均呈增大趋势,扩容效应更明显;相同围压条件下,随着先期固结压力的增大,错动带破坏应力逐步提高,弹性模量逐渐增大,而泊松比略有减小,敏感性不大;同时黏聚力和内摩擦角随固结压力的增加而分别减小和增大,呈劣化趋势。错动带微观结构的定性和定量分析进一步揭示了错动带作为一种夹杂错动后残留有岩石碎屑(块)软弱物质的颗粒类材料,在高应力下其塑性变形主要来源于颗粒破碎和颗粒的定向排列。因此,先期固结压力是影响错动带性质的重要因素。 相似文献
8.
疏浚淤泥含水率高、强度极低,真空梯度作用下排水板周围会快速形成致密“土柱”,导致排水固结能力迅速下降,即出现淤堵现象。由疏浚淤泥真空固结室内模型试验获得了出水量变化情况和土体含水率、渗透系数的时空分布情况,确定了排水体周围淤堵区的形成时间与范围,提出了考虑时间效应与淤堵效应的真空度传递模式,同时考虑疏浚淤泥土体压缩和渗透的非线性,建立了考虑淤堵效应的固结分析模型,获得了相应的解析解,通过与已有数据和现场试验结果对比验证了该解答的有效性。利用该解析解,分析了真空度传递模式、淤堵系数λ和淤堵比c对沉降的影响。结果表明,淤堵效应明显减缓了沉降速率,也严重降低了疏浚淤泥的最终沉降量。 相似文献
9.
高压下尾矿材料幂函数型摩尔强度特性研究 总被引：1，自引：0，他引：1
高压下尾矿材料的强度特性是高尾矿坝稳定性分析的基础。理论推导了幂函数型摩尔（Mohr）强度通式 须满足的条件为 , , ;基于高压三轴试验研究了尾矿材料的强度特征,研究表明：幂函数型摩尔强度包络线能较好地反应尾矿材料在高压下的强度特征;尾矿材料在高压作用下试验前、后的颗粒分析结果表明：当围压达到某一阈值时,尾矿材料在剪切过程中将发生颗粒破碎,对于德兴铜矿尾粉砂,阈值为1 200 kPa;对于德兴铜矿尾亚砂,阈值为1 600 kPa。研究成果可为高尾矿坝坝体稳定性评价提供理论依据。 相似文献
10.
水库松散质坝基淤堵渗透治理是筑建牢固安全的大型高原水利工程的关键性技术之一。依据所收集的新疆高山宽谷流区水库松散质坝基淤堵渗透文献资料,采用CGFS模型,运用GENERATE技术,构建渗透淤堵三维颗粒流数理模型,探究渗透形变机理,分析渗透形变过程中松散质颗粒的移动规律,通过数理模拟,从细观和宏观角度探究了渗透淤堵发生发展的整个过程。模拟实验可为高海拔地区水库松散质坝基淤堵渗透治理的工程技术应用提供研究参考。 相似文献
11.
Abolfazl Shamsai Ali Pak S. Mohyeddin Bateni S. Amir Hossein Ayatollahi 《Geotechnical and Geological Engineering》2007,25(5):591-602
Waste management issue in mining industry has become increasingly important. In this regard, construction of tailings dams
plays a major role. Most of the tailings dams require some kinds of remedial actions during their operational lifetime, among
which heightening is the most common. In the first stage of the remedial provisions for Sarcheshmeh Copper Complex tailings
dam in Iran, it has been decided to use hydrocyclone method to provide suitable construction material due to the high cost
associated with using borrow materials for heightening of the dam. To undertake this project a series of laboratory experiments
was performed to determine the copper ‘original tailings’ and ‘cycloned materials’ geotechnical characteristics to evaluate
the applicability of the cycloned materials for construction purposes. Different laboratory experiments were conducted to
determine the grain-size distribution, Atterberg limits, specific gravity, maximum density, shear strength parameters, consolidation
coefficient, and hydraulic conductivity. The results were compared with those of similar mines to check whether they follow
the trends observed in other copper tailing materials elsewhere. Variation of the cohesion and internal friction angle versus
different compaction ratios were studied in order to determine realistic shear strength parameters for tailing dam stability
analysis. In this study, using oedometer test, a mild linear relation between void ratio and the consolidation coefficient
has been found for tailings materials. By considering the effects of void ratio and weight of passing sieve #200 materials,
a new relationship is proposed that can be used for estimating the copper slimes hydraulic conductivity in seepage analysis
of tailings dams. 相似文献
12.
高心墙堆石坝的砾质土筑坝材料含有较大颗粒,又含有大比例的黏性土,渗透系数较低,试验需要用大尺寸的仪器。大尺寸试验排水、饱和困难、试验周期长、难度大,一直是试验工作的难点,在砾质土试样中预留砂芯加速排水饱和的方法可以有效地解决该问题。对掺砾黏土样进行了大型三轴流变试验,通过实测蠕变量和蠕变模型参数对掺砾后黏土样的流变特性进行了分析。研究结果表明,掺砾黏土样的蠕变量与时间关系呈现较好的幂函数关系,采用长江科学院蠕变模型可准确地描述其流变特性;在相同饱和状态下掺砾样的蠕变量和蠕变模型参数指标较低,说明掺砾起到了改善土样工程性状的功能;在均为土样或者掺砾样条件下非饱和状态的蠕变指标明显低于饱和状态下的蠕变指标,说明预留砂芯加速排水的方法起到了明显的作用,促进了试样的充分饱和。 相似文献
13.
A. Gabriel Villavicencio Pierre Breul Claude Bacconnet Daniel Boissier A. Raúl Espinace 《Geotechnical and Geological Engineering》2011,29(6):1073-1084
Dams are often used for storing mine tailings. These structures present failure mechanisms that can lead to major risks for
surrounding populations. In view to managing these risks, it is necessary to take a probabilistic approach in predicting their
behaviour. The application of such approaches is limited by the difficulty of obtaining experimental data to estimate the
variability of the parameters and conditioned by the relevance of the probability models chosen to represent this variability.
This article proposes (1) a probabilistic modelling of the index properties of the mine tailings constituting these dams based
on statistical analyses and (2) a method using dynamic penetration tests to estimate on site the mine tailings friction angle
and its variability. This method, applied to chilean tailings dams proposes a single model for all tailings dams in order
to associate a probability law to the effective friction angle (ϕ′). The procedure is illustrated on the probabilistic study
of slope stability carried out at the global scale of a dam and also at the local scale of each of its constituent layers. 相似文献
14.
堰塞坝是由于崩塌、滑坡、泥石流等形成的天然坝体,不同于人工土石坝,堰塞坝坝体结构松散,颗粒级配不均匀,在较高水头作用下坝体可能发生渗透破坏而导致溃坝,严重威胁下游人民群众的生命及财产安全。由于堰塞坝存在较大粒径颗粒,常规的渗透试验装置难以满足要求,本文研制了直径为60cm的大直径渗透试验仪,进行了不同堰塞坝级配材料的渗透破坏试验,并探讨了堰塞坝体材料渗透特性的主要影响因素。研究发现:（1）堰塞坝材料的渗透破坏形式取决于材料级配,粗颗粒含量较多时为管涌破坏,细颗粒含量较多或粒径缺失时为流土破坏;（2）堰塞坝渗透系数随干密度的增大而减小,主要取决于细料填充粗料孔隙的程度,单独使用不均匀系数或曲率系数不适用于评价渗透系数的变化;（3）基于试验数据提出了用于堰塞坝渗流破坏形式的判别公式,并推导出堰塞坝管涌破坏的临界水力坡降计算公式。 相似文献
15.
The Athabasca Oil Sands contain one of the world's largest oil reserves consisting of approximately 168 billion barrels of currently recoverable bitumen. With 20% recoverable through open pit mining methods, this extraction process produces a considerable amount of fluid fine tailings (FFT) waste material, which must be deposited on site in tailings ponds. These ponds allow the waste sand, clay and residual bitumen to settle out of the water column, allowing for the water to be recycled for use again in the extraction process. It is vital to gain a better understanding of the processes contributing to the development of physicochemical gradients (pH, Eh, Oxygen etc…) that form in these tailings ponds over time, with the goal of remediation and subsequent construction of end-pit lake systems once oil extraction has ceased. To differentiate between the impacts of biotic and abiotic processes in fresh (newly processed material) and mature FFT (∼38 year old tailings) over a 52-week study, a specific experimental design was utilized in accordance with novel microsensor profiling techniques. The sulfide diffusive fluxes within mature biotic systems measured 37.6 μmol m−2 day−1 at the onset of the experiment, decreasing over time, as FeS mineralization progressed. In addition, DO fluxes also showed strong correlation to the physical affects of consolidation, and overall biological consumption of O2 at the FFT-water interface. This holistic study comparing different tailings pond materials provides insight regarding biotransformation and physicochemical controls effecting sediment oxygen demand associated with reclaimed wetlands and end pit lake development. 相似文献
16.
《Applied Geochemistry》2005,20(3):661-667
This paper describes the geochemical testing of mine tailings sourced from the Black Swan Ni Mine located near Kalgoorlie, Western Australia. Acid–base accounting was used to provide an indication of the acid generating capacity of two kinds of mining tailings: disseminated-ore tailings from the Cygnet Tailings Dam Storage Facility (CTDSF) and massive-ore tailings from the Silver Swan Tailings Dam Storage Facility (SSTDSF). All of the tailings in SSTDSF have acid generating potential which is consistent with previous research reports. New findings in this paper reveal that approximately 16% of the tailings in CTDSF have the potential to be acid generating. In contrast, previous reports state that the disseminated-ore tailings are classified as non-acid forming. Most of the potential acid generating tailings in the CTDSF are found in the upper-middle sections of the tailings profile, but some are located at the bottom of the tailings dam. The upper-middle section of the tailings is oxidized because these tailings have interacted with atmospheric O2 and rain and surface water. Oxidation of the bottom tailings in the CTDSF may be due to infiltration of ground water into hidden fractures under the east bank of CTDSF, which caused these tailings to oxidize under closed and reduced conditions.The acid drainage in the tailings dam storage facility was observed 3 a, after the development of the Black Swan Nickel project. This delayed production of acid drainage was likely due to the slow rates of acid neutralization provided by alteration gouge minerals such as Mg/Fe-carbonates (magnesite–siderite series) associated with the Ni ores. The acid drainage leaking from the tailings dams has contaminated neighboring ground water via increased acidity and heavy metals.Because of the potential acid generation in some of the disseminated ore tailings, it is inadvisable to use disseminated ore tailings as cover materials in the storage facility to isolate the underlying potentially-acid-forming tailings from O2 and water, as proposed by previous research reports. 相似文献
17.
Geological impact of some tailings dams in Sardinia,Italy 总被引：2，自引：0，他引：2
This article deals with the results of a survey carried out in Sardinia on both active and abandoned tailings dams, and we also discuss the geological impact of tailings dams of two mines: the Masua mine, a large syngenetic Pb-Zn deposit located in Cambrian limestones, and the Montevecchio mine, a Pb-Zn vein deposit near a Hercynian granite intrusion. The characteristics and metal content of material in the dams were analyzed. A high contamination of heavy metals (Pb, Zn, Cd, Cu) was found both in the soils and water of Rio Montevecchio, a stream draining the tailings dams and other mining operations in the area.The study indicates that a control plan to minimize heavy metal pollution must be drawn up for all mines of the area, whether active or abandoned. 相似文献
18.
由长期工程实践和试验研究可知,尾矿的工程性质除与尾矿的矿石成分、筑坝方式以及矿浆的沉积特性有关外,重要的是与尾矿的颗粒粒度组成有关。为了分析上游式尾矿库尾矿经排放、沉积、分选等作用下颗粒组成的变化特征及其对尾矿工程性质的影响规律,通过对上游式尾矿库沉积滩面不同距离处尾矿进行颗粒级配分析、力学性质和渗透性质试验,重点分析了细颗粒含量（颗粒直径小于0.075 mm）对尾矿工程性质的影响规律。研究表明,随着距离上游式尾矿库滩顶长度的增大,尾矿颗粒组成中的细粒含量逐渐增多,颗粒级配情况由一般到良好再到一般,孔隙比也呈现出随之先减小后增大的变化趋势。受原尾矿颗粒组成的影响,尾矿黏聚力随细粒含量的增加呈逐渐增大,而内摩擦角相对变化较小,其渗透系数受细颗粒含量影响较大,随含量增大迅速减小。 相似文献