Rainfall-triggered waste dump instability analysis based on surface 3D deformation in physical model test

Landslide is the second largest natural disaster after earthquake. It is of significance to study the evolution laws and failure mechanism of landslides based on its surface 3D deformation information. Based on the rainfall-triggered waste dump instability model test, we studied the failure mechanisms of the waste dump by integrating surface deformation and internal slope stress and proposed novel parameters for identifying landslide stability. We developed a noncontact measurement device, which can obtain millimeter-level 3D deformation data for surface scene in physical model test;Then we developed the similar materials and established a test model for a waste dump. Based on the failure characteristics of slope surface, internal stress of slope body and displacement contours during the whole process, we divided the slope instability process in model test into four stages: rainfall infiltration and surface erosion, shallow sliding, deep sliding, and overall instability. Based on the obtained surface deformation data, we calculated the volume change during slope instability process and compared it with the point displacement on slope surface. The results showed that the volume change can not only reflect the slow-ultra acceleration process of slope failure, but also fully reflect the above four stages and reduce the fluctuations caused by random factors. Finally, this paper proposed two stability identification parameters: the volume change rate above the slip surface and the relative velocity of volume change rate. According to the calculation of these two parameters in model test, they can be used for study the deformation and failure mechanism of slope stability.

A Coal Mine Dump Stability Analysis—A Case Study

The present paper mainly deals with a case study of failed dump slope in western coalfield limited, Nagpur, India. A huge mass of debris flow had happened during the routine the activity of mining. The failed dump had a height of 75 m with 43? slope angle which had slipped forward by 18m. Representative loose dump material samples were collected from the site and tested to determine the physico-mechanical properties of dump material. The dump material consisted of loose fragments and lumps of friable sandstone, shale, clay and carbonaceous shale. To evaluate the condition of failure, a well known, shear strength reduction tech-nique has been applied to achieve the desired factor of safety using two dimensional finite element code. Fi-nally, a economical, sustainable and stable dump angle and height has been suggested for smooth and safe disposal of the dump.

Pre-evaluation on stability of proposed expressway embankment with existing geothermal regulation measures in permafrost regions

Embankment stability is the primary problem for the expressway construction in permafrost regions.The proposed Qinghai-Tibet Expressway(QTE)is planned to construct along the Qinghai-Tibet Project Corridor.Confronted with harsh environmental condition and intense heat exchange between earth and atmosphere,it is necessary to predict and evaluate the stability of the proposed QTE.In this study,the factors affecting the embankment stability are analyzed firstly.And then,a scheme for the stability evaluation of the embankment is established.Finally,the evaluation scheme is used for the pre-evaluation of the stability for the proposed QTE with different geothermal regulation measures(GRMs).The results indicate that the influencing factors include climatic environment,permafrost property,engineering condition and geological condition,and among them,engineering condition and permafrost property are the main influence factors for embankment stability.The stability of the proposed QTE varies greatly in the different geomorphological regions.The application effect and contribution to embankment stability of the existing GRMs are different,and using GRMs cannot completely overcome the influence of various factors on expressway stability.In the construction process,different GRMs should be adopted depending on the geomorphological environment where the embankment is located to ensure the embankment stability.

Research About Measures of Enhancing Stability of Competitive Strategic Alliance

With the global economy and the intensification of market competition, more and more enterprises in the same industry to establish a new alliance---competitive strategic alliance. Competitive strategic alliance is not only in the strategic choice of the existence of a potential to create value, but also the existence of synergy. Competition and cooperation between the two conflicting complex logic relations coexist in the competitive strategic alliances （CSA）. Therefore maintaining the relative stability of alliance is the premise and necessary condition of alliance to success. In this paper, on the basis of the literature review, we discuss the significance and principles of improving CSA＇s stability; in the way of case analysis and expert interviews construct the hierarchy analysis model of improving CSA＇s stability; and then further put forward a series of measures which can maintain the CSA＇s stability, such as strengthen the ability of technological innovation, protection and development of the core ability of the enterprise, to develop a coherent strategy alliance target, choose a suitable alliance partner, coordinate the corporate culture between partners, establish alliance risk prevention mechanism, and so on. It will provide theoretical support and practical guidance to relevant departments and relevant personnel in policy decision-making and problem-solving

Stability of inner dump slope under coal pillar support:case study in an open‑pit coal mine

The stability of an inner dump slope was investigated under the efect of coal pillar support considering the development position of dumping.Based on the instability mechanism and load distribution characteristics of the supporting coal pillar,the three-dimensional mechanical efects of the supporting coal pillar are characterized.Using the two-dimensional equivalent principle and the residual thrust method,the stability of the inner dump slope was analyzed under the efect of pillar support at diferent dump development positions.The quantitative efects of various factors on the inner dump slope stability were revealed,and the coal pillar shape parameters were optimized through numerical simulations.The results indicate that the slope stability coefcient is linearly related to the top width and height of the coal pillar,slope angle,and base inclination angle,and has an exponential relation with the coal pillar strike length and slope height increment.There are quadratic and absolute value relations with the coal pillar outer and the inner bottom angle,respectively.The top width of the coal pillar in the inner dump of Shengli East No.2 open-pit coal mine should be at a level of+824 m,and the optimal top width and height are 15 and 36.7 m,respectively.The instability mechanism of the supporting and retaining coal pillar obtained by numerical simulations and the stability of the inner dump are in good agreement with the theoretical analysis.Our results provide a theoretical basis for the design,treatment,and safe implementation of similar open-pit mine slope engineering.

STABILITY CRITERIA IN TERMS OF TWO MEASURES FOR DELAY DIFFERENTIAL EQUATIONS

By using the variational Liapunov method, stability properties in terms of two measures for delay differential equations are discussed. In the case that the unperturbed systems are ordinary differential systems, employing auxiliary measure h*(t, x), criteria on nonuniform and uniform stability in terms of two measures for delay differential equations are established.

Stability and boundedness in terms of two measures for nonlinear impulsive control systems

In this paper we study stability and boundedness in terms of two measures for impulsive control systems. By using variational Lyapunov method, a new variational comparison principle and some criteria on stability and boundedness are obtained. An example is presented to illustrate the efficiency of proposed result.

Stability analysis and treatment of No.2 dump of Nanfen iron mine

On the basis of the study on the engineering geological characteristics of No.2 dump of Nanfen iron mine and the analysis of the failure mode of dump landslide,the stability of the present dump,the stability of the dump 20 years later and the stability of double-bench dump are analyzed.Then,the debris flow risk is evaluated by fuzzy mathematics method.Finally,the comprehensive treatment for the dump is suggested.It is concluded that ① In rainy and snowmelt period,the stability would be decreasing sharply when ground water is not drained out in time;② Double-bench dumping mode will improve stability of the dump little;③ Debris flow risk is middle danger.The interim debris flow with medium scale may occur.④ Monitoring,draining and baffling work ought to be well done.⑤ In order to prevent the damage of landslide and debris flow,three measures are adopted,including setting rockfall net,setting the debris flow barrier and removing the residents.

Transient Stability Analysis Using Transmission Line Measurement

The novel quantitative assessment method using transmission line measurement was developed. A new style of stability criterion was suggested which is based on the line measurement. The stability indices for lines, cutsets and power system according to features of transient energy in the lines were given, which not only provide a reliable and accurate assessment of the transient stability of power system, but also can be used to assess the effect of lines and cutsets on the transient stability and identify the weak transmission segment. Examples were presented by simulation on the IEEE-39 buses test system.

Safety assessment of waste rock dump built on existing tailings ponds

The construction of waste rock dumps on existing tailing ponds has been put into practice in China to save precious land resources. This work focuses on the safety assessment of the Daheishan molybdenum mine waste rock dump under construction on two adjoining tailings ponds. The consolidation of the tailings foundation and the filling quality of the waste rock are investigated by the transient electromagnetic method through detecting water-rich areas and loose packing areas, from which, the depth of phreatic line is also estimated. With such information and the material parameters, the numerical method based on shear strength reduction is applied to analyzing the overall stability of the waste rock dump and the tailings ponds over a number of typical cross sections under both current and designed conditions, where the complex geological profiles exposed by site investigation are considered. Through numerical experiments, the influence of soft lenses in the tailings and possible loose packing areas in the waste rock is examined. Although large displacements may develop due to the soft tailings foundation, the results show that the waste rock dump satisfies the safety requirements under both present and designed conditions.

Stochastic stability of FitzHugh-Nagumo systems perturbed by Gaussian white noise

The current paper is devoted to the study of the stochastic stability of FitzHugh-Nagumo systems perturbed by Gaussian white noise. First, the dynamics of stochastic FitzHugh-Nagumo systems are studied. Then, the existence and uniqueness of their invariant measures, which mix exponentially are proved. Finally, the asymptotic behaviors of invariant measures when size of noise gets to zero are investigated.

A drone‑and feld‑based investigation of the land degradation and soil erosion at an opencast coal mine dump after 5 years’evolution of natural processes

Opencast coal mining has a large impact on the land surface,both at the mining pits themselves and at waste sites.After artifcial management is stopped,a reclaimed opencast coal mine dump is afected by wind and water erosion from natural processes,resulting in land degradation and even safety incidents.In this paper,the soil erosion and land degradation after 5 years of such natural processes,at the Xilinhot opencast coal mine dump in Inner Mongolia,were investigated.A multisource data acquisition method was applied:the vegetation fraction coverage(VFC)was extracted from GF-1 satellite imagery,high-precision terrain characteristics and the location and degree of soil erosion were obtained using a drone,and the physical properties of the topsoil were obtained by feld sampling.On this basis,the degree and spatial distribution of erosion cracks were identifed,and the causes of soil erosion and land degradation were analyzed using the geographical detector.The results show that(1)multi-source data acquisition method can provide efective basic data for the quantitative evaluation of the ecological environment at dumps,and(2)slope aspect and VFC are the main factors afecting the degree of degradation and soil erosion.Based on above analysis,several countermeasures are proposed to mitigate land degradation:(1)The windward slope be designed to imitate the natural landform.(2)Reasonable engineering measures should be applied at the slope to restrain soil erosion.(3)The Pioneer plants should be widely planted on the platform at the early stage of reclamation.

The Challenge of Standard Stability in LC-MS Based Multi-Analyte Approaches for Veterinary Drugs

The short-and long-term stability of multi-component mixtures and intermediate mixtures of analytical standards of veterinary drugs,which can potentially occur in food and feed chains,was examined by an isochronous measurement approach.Short-term stability testing of calibrants included storage for 1,2,4,and 7 days at-20℃(as a baseline)4℃,and 23℃(with and without exposure to sunlight),respectively.Long-term stability testing conditions of intermediate mixes were-20℃,4℃,23℃(with and without exposure to sunlight),and control temperature at-80℃while the testing period was 2,4,8,and 12 weeks,respectively.Results indicated that calibration standards should ideally be stored at 4℃for only 1~2 days,without the presence of acid.Neutral storage conditions were acceptable even at room temperature.Storage of intermediate mixtures containingß-lactams and cephalosporins for longer than 1 month under 4℃ and room temperature resulted in a loss of almost 90%.When it comes to the intermediate mixtures with penicillin V and G,acceptable storage conditions were 2 weeks at-20℃,without the presence of acid.Other classes of veterinary drugs were less critical as considers long-term stability.Overall,storage conditions at-20℃were considered optimal for long-term storage of intermediate mixes of veterinary drug standards.

IN SITU MEASUREMENT OF BREEDING-FIRE OF SULPHIDE ORE DUMPS

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Numerical analysis of rainfall effects in external overburden dump

The effect of slope angle for external overburden dump in response to average and heavy rainfall has been analyzed using a two dimensional finite difference method of transient water flow through unsaturated–saturated soil. The external dump stability is evaluated for five geomaterial types on the basis of globally accepted safety factor analysis technique, based on shear strength reduction approach using finite difference method. The results obtained from the finite difference method of analysis indicate that the external dump with more than 30° slope angle is greatly influenced by the rainfall under the studied conditions for geomaterial 3, 4 and 5, whereas dumps with geomaterial 1 and 2 remain safe. The analysis shows that major slope failure is out of preview for the studied rainfall conditions.

State Estimation of the Electric Drive Articulated Dump Truck Based on UKF

The requirements of vehicle dynamic stability control are higher than ever as the significant increase of electric drive articulated vehicle speed. According to the construction features of articulated dumping truck and nonlinear characteristics of moving vehicles,nonlinear observer of vehicle status is designed to strength robustness of dynamic control system in this paper. A 4-degree-of-freedom nonlinear dynamic model of articulated electric drive vehicle is built as reference model to estimate the state of the articulated vehicle. And by adopting Unscented Kalman Filter( UKF) algorithm,a series of state parameters such as longitudinal velocities of front and rear frames,yaw rate and side-slip angle are estimated. During the test of 60 t articulated electric drive vehicle,2 inertial navigation modules are installed in the front frame and rear frame respectively and the speed of each electric drive wheel is obtained simultaneously. As the test results suggest,in various working conditions,the algorithm based on UKF is able to accurately estimate the state parameters of articulated vehicle with the estimated error less than 5%. The proposed method is justified to be the theoretical basis and application guidance for articulated vehicle stability control.

Optimization of Dump Bench Configuration to Improve Waste Dump Capacity of Narynsukhait Open Pit Coal Mine

In next two years, the current waste dump of Narynsukhait coal mine is predicted insufficient to accommodate the overburden as limited of the waste dump capacity. Thus, redesigning waste dump is paramount to increase capacity of the dump in future. This paper describes current condition of waste dump of Narynsukhait coal mine and then discusses the optimization of waste dump geometry by analyzing the effect of different waste dump’s bench configuration on slope performance. Optimization of the geometry is carried out by investigating and comparing the performance of geometrical combinations of bench height, bench angles and number of safety berm by means of numerical modeling. The model shows that increasing height of bench is able to induce shear stress in the bench and may initiate bench instable. However, the shear stress can be limited by having safety berm and/or reducing bench angle to satisfy the stability criteria.

Roadbed, embankment, tower support and culvert stability problems on permafrost

The history of railway and highway construction in permafrost zones in Russia, the United States, Canada, and China spans more than 110 years. Nonetheless, no railway track or highway has yet been built in such area that is impervious to deformation caused by subsidence resulting from the thawing of ice-rich subgrade soils. This paper presents data on the roadbed states of the Trans- baikalian and the Baikal-Amur Railways as well as the Russian ＂AMUR＂ Chita-Khabarovsk Highway. It also discusses the feasi- bility of roadbed stability maintenance using methods based on the reduction of the mean annual ground temperature and roadbed preservation in a permafrost state by means of the natural cooling and heating factors ratio regulation resulting in a reduction of the heat generation in the roadbed and the adjoining area accompanied by an increase of heat consumption with help of the sun-precipitation protective sheds （awnings）, rock covers, dolomite powder （reflective paint）, cooling tube and thermosyphons as well as tower supports and corrugated pipe culverts stability.

Global Stability of SEIRS Model in Epidemiology

In this article, an infectious model with saturation effect is considered. By using compound matrix theory and a series of theorems associated to qualitative theory of differential equations which are introduced by Muldowney and Micheal Li, we study globally stable problem of the model.

Fuzzy Global Stability Analysis of the Dynamics of Malaria with Fuzzy Transmission and Recovery Rates

In this paper, fuzzy techniques have been used to track the problem of malaria transmission dynamics. The fuzzy equilibrium of the proposed model was discussed for different amounts of parasites in the body. We proved that when the amounts of parasites are less than the minimum amounts required for disease transmission (), we reach the model disease-free equilibrium. Using Choquet integral, the fuzzy basic reproduction number through the expected value of fuzzy variable was introduced for the fuzzy Susceptible, Exposed, Infected, Recovered, susceptible-Susceptible, Exposed and Infected (SEIRS-SEI) malaria model. The fuzzy global stabilities were introduced and discussed. The disease-free equilibrium is globally asymptotically stable if or if the basic reproduction number is less than one (). When and , there exists a co-existing endemic equilibrium which is globally asymptotically stable in the interior of feasible set . Finally, the numerical simulation has been done for showing the effectiveness of our analytical results.