Stability analysis of the sliding process of the west slope in Buzhaoba Open-Pit Mine

To study the stability of the west slope in Buzhaoba Open-Pit Mine and determine the aging stability coefficient during slide mass development, the deformation band of the west slope and the slide mass structure of the 34,600 profile are obtained on the basis of hydrology, geology, and monitoring data.The residual thrust method is utilized to calculate the stability coefficients, which are 1.225 and 1.00 under sound and transfixion conditions, respectively. According to the rock damage and fragmentation and the principle of mechanical parameter degradation, the mechanical models of the slide mass development of the hard and soft rock slopes are established. An integrated model for calculating the slope stability coefficient is built considering water, vibration, and other external factors that pertain to the structural plane damage mechanism and the generating mechanism of the sliding mass. The change curve of the stability coefficient in the slide mass development is obtained from the relevant analyses,and afterwards, the stability control measures are proposed. The analysis results indicate that in the cracking stage of the hard rock, the slope stability coefficient decreases linearly with the increase in the length Lbof the hard rock crack zone. The linear slope is positively correlated to rock cohesion c. In the transfixion stage of the soft rock, the decrease speed of the stability coefficient is positively correlated to the residual strength of the soft rock. When the slope is stable, the stability coefficient is in a quadratic-linear relationship with the decreased height Dh of the side slope and in a linear relationship with anchoring force P.

Numerical Modelling for Dynamic Instability Process of Submarine Soft Clay Slopes Under Seismic Loading

Marine geological disasters occurred frequently in the deep-water slope area of the northern South China Sea,especially submarine landslides,which caused serious damage to marine facilities.The cyclic elastoplastic model that can describe the cyclic stress-strain response characteristic for soft clay,is embedded into the coupled Eulerian-Lagrangian(CEL)algorithm of ABAQUS by means of subroutine interface technology.On the basis of CEL technique and undrained cyclic elastoplastic model,a method for analyzing the dynamic instability process of marine slopes under the action of earthquake load is developed.The rationality for cyclic elastoplastic constitutive model is validated by comparing its calculated results with those of von Mises model built in Abaqus.The dynamic instability process of slopes under different conditions are analyzed.The results indicate that the deformation accumulation of soft clay have a significant effect on the dynamic instability process of submarine slopes under earthquake loading.The cumulative deformation is taken into our model and this makes the calculated final deformation of the slope under earthquake load larger than the results of conventional numerical method.When different contact conditions are used for analysis,the smaller the friction coefficient is,the larger the deformation of slopes will be.A numerical analysis method that can both reflect the dynamic properties of soft clay and display the dynamic instability process of submarine landslide is proposed,which could visually predict the topographies of the previous and post failure for submarine slope.

Scattering Process of Internal Waves Propagating over a Subcritical Strait Slope onto a Shelf Region

The scattering process, which means the redistribution of energy fluy in modenumber space, is analyzed for internal waves propagating from the abyssal ocean onto a subcritical strait slope and then a shelf region. In light of Wunsch's work, the waves are analytically expressed as superimposition of eigensolutions. Two parameters have evident effects on the distribution of energy flux in the shelf region: one is the ratio of water depth in the shelf region to that in the abyssal ocean and the other is the ratio of the slope of the internal tide rays to the topographic slope. Generally, there are two patterns of energy flux distribution: the energy flux is focused around one modenumber or focused around two modenumbers. In any case, the range of modenumbers where energy flux is distributed is narrow.

Progressive failure processes of reinforced slopes based on general particle dynamic method

In order to resolve grid distortions in finite element method(FEM), the meshless numerical method which is called general particle dynamics(GPD) was presented to simulate the large deformation and failure of geomaterials. The Mohr-Coulomb strength criterion was implemented into the code to describe the elasto-brittle behaviours of geomaterials while the solid-structure(reinforcing pile) interaction was simulated as an elasto-brittle material. The Weibull statistical approach was applied to describing the heterogeneity of geomaterials. As an application of general particle dynamics to slopes, the interaction between the slopes and the reinforcing pile was modelled. The contact between the geomaterials and the reinforcing pile was modelled by using the coupling condition associated with a Lennard-Jones repulsive force. The safety factor, corresponding to the minimum shear strength reduction factor "R", was obtained, and the slip surface of the slope was determined. The numerical results are in good agreement with those obtained from limit equilibrium method and finite element method. It indicates that the proposed geomaterial-structure interaction algorithm works well in the GPD framework.

The intensity of slope and fluvial processes after a catastrophic windthrow event in small catchments in the Tatra Mountains

Strong wind events frequently result in creating large areas of windthrow, which causes abrupt environmental changes. Bare soil surfaces within pits and root plates potentially expose soil to erosion. Absence of forest may alter the dynamics of water circulation. In this study we attempt to answer the question of whether extensive windthrows influence the magnitude of geomorphic processes in 6 small second-to third-order catchments with area ranging from 0.09 km^(2) to 0.8 km^(2). Three of the catchments were significantly affected by a windthrow which occurred in December 2013 in the Polish part of the Tatra Mountains, and the other three catchments were mostly forested and served as control catchments. We mapped the pits created by the windthrow and the linear scars created by salvage logging operations in search of any signs of erosion within them. We also mapped all post-windthrow landslides created in the windthrow-affected catchments. The impact of the windthrow on the fluvial system was investigated by measuring a set of channel characteristics and determining bedload transport intensity using painted tracers in all the windthrow-affected and control catchments. Both pits and linear scars created by harvesting tend to become overgrown by vegetation in the first several years after the windthrow. The only signs of erosion were observed in 10% of the pits located on convergent slopes. During the period from the windthrow event in 2013 until 2019, 5 very small(total area <100 m^(2)) shallow landslides were created. The mean distance of bedload transport was similar(t-test, p=0.05) in most of the windthrow-affected and control catchments. The mapping of channels revealed many cases of root plates fallen into a channel and pits created near a channel. A significant amount of woody debris delivered into the channels influenced the activity of fluvial processes by creating alternating zones of erosion and accumulation.

Spatio-temporal variation of water conservation and its impact factors on the southern slope of Qilian Mountains

The ecology of Qilian Mountains has been seriously threatened by uncontrolled grazing and wasteland reclamation. This study examined the ecological changes on the southern slope of Qilian Mountains in China from the perspective of water conservation by classifying different clusters of water conservation functional areas to efficiently use limited human resources to tackle the water conservation protection problem. In this study, we used Integrate Valuation of Ecosystem Services and Tradeoffs(InVEST) model to estimate water conservation and analyzed the factors that influence the function. The results of this study include:(1) from 2000 to 2015, the water conservation of the southern slope of Qilian Mountains generally showed an increasing trend, and the total water conservation in 2015 increased by 42.18% compared with that in 2000.(2) Rainfall, fractional vegetation cover(FVC), and evapotranspiration have the most significant influence on the water conservation of the study area. Among them, water conservation is positively correlated with rainfall and FVC(P<0.05) and negatively correlated with evapotranspiration(P<0.05).(3) The importance level of water conservation functional areas gradually increases from northwest to southeast, and the region surrounding Menyuan Hui Autonomous County in the southeast of the southern slope of Qilian Mountains is the core water conservation functional area. And(4) the study area was divided into five clusters(Cluster Ⅰ–Cluster Ⅴ) of water conservation, with the areas of Clusters Ⅰ through Ⅴ accounting for 0.58%, 13.74%, 41.23%, 32.43%, and 12.01% of the whole study area, respectively.

Simulation analysis of construction process of high rock slope's stabilization

A self-developed elasto-plastic finite element program was used to analyze the construction sequence of high rock slope's stabilization in a coal-coking plant, and the result was compared with that employing the ultimate equilibrium method. Based on the results of finite element analysis, the stress contour graphs and displacement vector graphs at different construction steps were obtained, and the behavior of the slope during stabilization construction process was analyzed quantitatively. Based on the analysis of safety factors of three different schemes of stabilization and two different construction schemes, the assessment of stability and bracing design of the construction process were performed. The results show that the original reinforcement design is improper; the stability of the rock slope is controlled by a developed structural plane, the stability factor after excavation is less than 1, and the free surface should be braced in time; for stability, the construction sequence should adopt that bracing follows excavation step by step up to down; the local slide occurred during the construction process agrees with the dangerous slide determined by the numerical analysis, which proves the validity and rationality of the adopted method.

Weathering Processes on Martian Craters: Implications on Recurring Slope Lineae and the Location of Liquid Water

Recent attention has been put into recurring slope lineae (RSL), after the discovery that water is present in them. It is assumed that RSL are due to flowing water. However, even though that might be the case, the general characteristics of RSL as well as their seasonal and spatial distribution in Mars, and their occurrence within craters, suggest that RSL correspond to the weathering of frozen aquifers, which coincides with slope stability processes occurring in impact craters and scree slopes from Earth. In this study, we associated RSL with similar weathering processes occurring on impact craters and hydrogeological processes occurring on Earth (including ice, water, and wind erosion and natural aquifer recharge processes). We were able to create a conceptual model on how RSL develop, why are they found mostly in mid latitudes around craters, why are they present in more frequency in one side of crates in high latitudes, and why are there more RSL in the Martian southern hemisphere. Considering the whole hydrogeological processes occurring in craters that experience RSL, we were able to predict where large quantities of liquid water are most likely to be present in the red planet.

Strategies for Advancing Road Construction Slope Stability: Unveiling Innovative Techniques for Managing Unstable Terrain

This comprehensive review paper explores various aspects of geotechnical engineering, with a focus on the management of unstable terrains, numerical methods for solving complex soil and consolidation problems, rheological analysis of suspensions and muddy soils, and stability analysis of slopes. It begins by examining the unique physicochemical properties of cohesive sediments, including cohesion and specific surface area. The temporal evolution of deposit concentration and average bed concentration in unstable terrains is discussed, along with settling behavior of isolated particles and hindered settling using empirical equations. Key sedimentation theories, such as Kynch’s theory, and geotechnical consolidation theories, including Terzaghi’s consolidation equation and Gibson’s theory, are presented. The investigation interrelates these theories and principles to offer a holistic view of managing unstable terrains. It also addresses the challenges associated with experimental determination of constitutive relationships and presents alternative simplification methods proposed by researchers. Additionally, it delves into numerical methods for solving nonlinear partial differential equations governing soil behavior, emphasizing the need for numerical frameworks and discussing various techniques and associated challenges. The rheological analysis section covers material flow behavior, rheological behavior models, and the rheological properties of water and cohesive sediment mixtures. Fundamental geotechnical calculations, constitutive laws, and failure criteria are explained, highlighting their relevance in geotechnical engineering applications. This paper provides a multidimensional perspective on geotechnical engineering, offering valuable insights into soil properties, consolidation processes, numerical methods, rheological analysis, and slope stability assessment for professionals in the field.

边坡支护工程设计和施工阶段关键技术分析

工程项目在进行建设过程中,不可避免地会出现开挖情况,对于地质较差的地方,为减小开挖工作量,常设置相关边坡防护措施进行及时防护。而边坡的防护形式和措施较多,其应用条件和经济性均不一致,若不进行相关现场分析和评估,盲目采用过大的防护,容易造成经济浪费,因此如何根据设计过程中的数据采用贴合的边坡防护是施工所希望达到的目的。本文以娄底市某边坡工程开挖为例,结合当地场地条件,分别从设计和施工角度对其在项目进行中的关键性技术进行分析,从而提出相关解决方案,达到经济适用性目的。最终结果证明,在施工完成后,该边坡情况良好。拟为相关类似工程提供参考。

基于Geo-Slope的拜耳法干式赤泥堆场稳定性分析

针对拜耳法工艺生产赤泥的特点,分析了平果铝赤泥堆场的特征以及堆场内赤泥的物理力学指标;结合干法排放、堆存赤泥所引起的堆场表面裂缝问题,阐述了裂缝产生的具体成因,并采用Geo-Slope软件中的SLOPE/W模块计算裂缝条件下赤泥堆积坝边坡稳定性,结果表明,裂缝的存在使赤泥坝静力安全系数降低0.5%左右,赤泥坝在当前堆积到二级子坝正常工况下是稳定的。

基于层次分析法和模糊数学理论的露天矿边坡稳定性分析

为综合评价生产过程中露天矿边坡稳定性,基于层次分析法及模糊数学理论建立分析模型对边坡稳定性进行评价。充分考虑影响露天矿边坡稳定性的工程地质、几何条件、水文气象及外加荷载等要素,建立共14项分指标的两级评价指标体系。根据不同分指标对露天矿边坡稳定性影响的趋势特征,建立相应指标的隶属度模糊矩阵和权重集合;构造基于二级层次分析的模糊综合评判体系,并对露天矿山边坡稳定性进行评价。研究表明,基于层次分析法及模糊数学理论的露天矿边坡稳定性评判方法计算简单、实用,评判结果与实际情况较为吻合,可为露天矿边坡稳定性评价提供指导与帮助。

基于改进层次斜率熵(IHSloE)的信号低频和高频故障特征提取方法

采用传统的基于粗粒化处理的多尺度特征提取方法,无法提取故障信号中的高频部分的故障信息,导致其提取到的故障特征难以准确地表征滚动轴承的故障状态和动态特性,无法保证故障诊断的可靠性和准确性。针对该缺陷,提出了一种基于改进层次斜率熵(IHSloE)和随机森林(RF)的滚动轴承故障诊断方法。首先,利用改进层次化处理代替粗粒化处理,实现了信号的多尺度分析目的,基于斜率熵,提出了改进层次斜率熵的非线性动力学指标;随后,利用IHSloE方法提取了滚动轴承振动信号的故障特征,建立了表征滚动轴承故障特性的故障特征;最后,基于RF模型建立了多故障分类器,并将故障特征输入至RF分类器进行了训练和测试,以实现滚动轴承的故障识别目的;利用滚动轴承数据集进行了实验,并将其与其他的故障特征提取指标进行了对比。研究结果表明:IHSloE方法采用改进的层次化处理,能够快速有效地提取出振动信号中的高频故障特征,诊断准确率达到了99%,而特征提取时间仅为149.35 s;相较于采用粗粒化处理和层次处理的特征提取方法,其准确率至少提高了2%和1%,证明该方法适用于滚动轴承的故障诊断。

基于外部气相沉积的S+C+L波段低色散斜率大有效面积非零色散位移光纤的设计与制备

针对现有光纤无法满足宽带光密集波分复用系统传输和S+C+L波段粗波分复用的要求,设计了一种具有中心凹陷的三角形芯+环形的折射率剖面,利用外部气相沉积工艺制备了一种非零色散位移光纤,并通过调整第一芯层的相对折射率和第二芯层与第一芯层的半径比,探究了其对光纤衰减、色散斜率和有效面积等参数的影响。研究发现,当第一芯层的相对折射率逐渐增大且第二芯层与第一芯层半径比逐渐减小时,零色散波长和有效面积逐渐减小。当第一芯层的相对折射率在0.52%~0.53%,芯层半径比在2.6~2.7时,光纤的有效面积接近70μm^(2),零色散波长在1420 nm附近,在1550 nm波段的色散系数大于8 ps·nm^(-1)·km^(-1),色散斜率为0.059 ps·nm^(-2)·km^(-1),可以较好地抑制传输过程中光非线性效应,满足长途干线网与城域网的使用要求。

基于视觉测量的公路边坡位移监测技术工程应用研究

公路边坡的稳定性监测是运营期的重要工作之一。目前的公路边坡监测仍以人工监测和自动化监测为主,人工监测工作量大且人工成本高,而传统的自动化监测设备价格昂贵且安装较为繁琐。因此,降低自动化监测成本并提高工作效率是当前公路边坡安全监测的重点发展方向。得益于图像处理技术的发展,研究提出基于视觉测量的公路边坡位移监测技术,在隐患边坡上布设视觉监测标靶,利用高清摄像头拍摄的视觉标靶图像,通过图像灰度化、图像滤波、角点检测和位移量计算等一系列图像处理技术,将图像中像素的变化还原为视觉标靶的实际位移,从而判断公路边坡状态。研究通过室内试验和现场验证,证明视觉测量技术在公路边坡位移监测上的可行性,对公路边坡安全监测具有重要意义。

基于博弈论综合评价云模型的露天矿边坡岩体稳定性分析

为了对露天矿山边坡稳定性进行可靠分析,从采矿地质、水文特征和工程施工3个层面选取14项评价指标建立稳定性评价体系,并基于博弈论构建露天矿边坡岩体稳定性综合评价云模型。以云南某露天矿边坡为工程案例,通过数学计算并评估其稳定性等级。结果表明:优化后的层次分析法能够明显改善主观权重的计算精度;选取的模型评价指标符合工程实际需要,且具有良好的独立性与代表性;博弈论可以较好地求出评价指标的综合权重,云模型能够逐级分析出各层指标与稳定性等级的相关程度,并根据最大隶属度原则,得出露天矿边坡岩体稳定性等级。

基于GRA-AHP联合极差分析复合算法的边坡稳定性影响因素敏感性分析

针对AHP和GRA单一算法应用过程中受主观影响导致评价结果与实际结果偏差较大的问题,提出了GRA-AHP联合极差分析复合算法,并以西南某磷矿A区边坡为例,运用该算法分析了重度、内摩擦角、黏聚力、弹性模量和泊松比对边坡稳定性的敏感性。结果表明,A区边坡稳定性影响因素敏感性从大到小顺序为:内摩擦角、黏聚力、重度、弹性模量、泊松比,分析结果与矿山实际情况相符。

秦岭北麓生态安全性时空迁移特征及影响因素分析

为深入了解秦岭北麓地区生态状况,利用高分遥感数据,借助模糊层次法构建生态安全演变评估模型,并结合时空变异及其驱动因子分析,探讨秦岭北麓的生态安全现状。研究发现:秦岭北麓地区的生态安全性整体呈增长趋势,生态安全中级以上区域面积占比从67.5%增长到71.9%;生态安全性在南部整体高于北部,并存在明显的地带性分布特征;生态安全演化呈先下降后增长的态势,其中土地利用、归一化植被指数和PM_(2.5)被确认为主要的驱动因素,相关系数分别为0.90、0.86和0.79,说明城市化进程的人为活动和生态保护政策对秦岭北麓地区的生态安全性有显著影响。研究结果不仅为秦岭北麓地区的生态安全性提供了科学评估,还为区域生态保护与可持续发展策略制定提供了有力的决策支持。

窄板沟坡面泥石流形成机理与演化过程分析

坡面泥石流爆发突然、破坏力强、预测困难,在暴雨或特大暴雨的激发下常成群发生,危害极大。基于窄板沟坡面泥石流现场调查与分析,结合发生泥石流的3个基本条件进行了该泥石流形成机理及演化过程的探讨。初步分析该坡面泥石流形成机理及演化过程为:在强降雨的作用下首先局部饱和,逐步孕育滑动,再到加速滑流,直至堆积的一个过程,共分为6个阶段,并给出了相应的防治措施建议,为今后类似区域防灾减灾积累一定的经验。

安太堡露天矿边帮压煤回收技术

选用EML型边帮采煤机,以安太堡露天煤矿东帮为研究对象,通过对边帮煤回采工艺下煤柱群变化和扰动情况下的边坡稳定性分析,论证了边帮煤回采工艺的可行性;明确了边帮压煤回收的技术方案及开采技术参数。在可回收范围内有3层主要可采煤层的边帮煤,最先回收4^(-1)煤再回收9煤,11号煤层暂不进行回收;其中4^(-1)、9、11号煤层的煤柱高度分别为5.5、5.5、4.0 m;支撑煤柱宽度分别为3.2、3.5、3.8 m,隔离煤柱宽度分别为5.0、5.5、5.5 m;每10个采硐设置1个隔离煤柱;边帮采煤作业的最小平盘宽度为80 m。安太堡露天矿边帮压煤回收技术保证了安太堡露天矿边帮压覆资源高效回收,形成了边帮煤与采剥工程之间的协调开采。