Stability Analysis Of Model Research Articles

Slope Stability Analysis and Sliding Surface Search Model Based on Swedish Slice Method

Slope Stability Analysis and Sliding Surface Search Model Based on Swedish Slice Method

Stability analysis on elite genotypes of Indian Mustard (Brassica Juncea L.) in Terai Agro-Climatic Region

Abstract Among the oilseed crops, mustard has gained precedence in the human diet due to its superior oil quality. Genotype × environment interactions have a significant effect on plant breeding because it reduces the stability of the genotypes in diverse environments. In order to assess the impact of environments on genotypes and determine the stable genotypes in terms of seed yield and yield attributing characters in the terai agro-climatic zone, seventy-one Indian mustard genotypes were evaluated during two consecutive years,namely, 2017-18 and 2018-19, focusing on nine quantitative characters across six environments. Eberhart and Russell model (1966) of stability analysis revealed that various genotypes exhibited adaptability to favourable and unfavourable environments for different characters, influenced by the different sowing dates over the two years. However, Rohini (SC) and KMR-15-14 to be well adapted in terai agro-climatic zone in respect to seed yield and plant height, while Pusa mustard 27 (EJ 17) were adapted to specifically favorable (rich) environment for the seed yield. In terms of secondary branches per plant and number of siliquae on branches, Pusa mustard 27 (EJ 17) showed adaptability across all types of environments. Therefore, Rohini (SC) and KMR-15-14 were identified as stable genotypes for optimum seed yield across different environmental conditions. Keyword: Mustard, G × E interaction, stability, , Regression, Deviation from regression, Brassica juncea

Evolution and stability of liner shipping networks in Northeast Asia from 2018 to 2022

Ports are severely challenged by the uncertainty of the transportation environment. To evaluate the stability of maritime transportation network in Northeast Asia under port disruption, a network stability analysis model based on node failure rate that considers static and structural, dynamic and functional is proposed in this paper. In this model, the stability of the maritime transportation network is redefined. Based on complex network theory, the statistical topological parameters and evolution of the network are quantitatively analyzed. The active response and passive adaptation process of the maritime transportation network to the failure rate of the port are analyzed. The evaluation results illustrate that the initial stability of the port is proportional to the non-redundant connections and independence of the port. Network location advantages profoundly affect the probability of port failures. The diffusion of port failures in maritime transportation is phased, and the network is adaptive to port disruptions and has high stability. These results contribute to better planning of maritime transportation routes and strategies for port calls by strategic planners of shipping companies.

Identification of high-yielding and stable cultivars of wheat under different sowing dates: Comparison of AMMI and GGE-biplot analyses

Evaluating the adaptability and yield stability of wheat varieties across different sowing dates is crucial for the success of breeding programs. In this study, we used Additive Main Effects and Multiplicative Interactions (AMMI) and Genotype × Genotype–Environment (GGE) biplot analyses to evaluate the performance of 13 wheat varieties across eight sowing dates. The main objective was to compare varieties and sowing dates to identify the most stable varieties for cultivation. Both AMMI and GGE biplot analyses showed significant effects of genotype, environment and genotype-environment (GE) interaction on grain yield. The interaction patterns identified by AMMI and GGE-biplots categorized Mihan, Oroom and Pishgam as the most stable, high yielding and early maturing wheat varieties. Furthermore, while the GGE biplot method proved to be more efficient than the AMMI model for stability analysis, our results indicate considerable overlap between the results of these two approaches. These results provide a valuable basis for optimizing genetic improvement strategies in wheat breeding programs.

A Modified SIVR Mathematical Model of Covid-19 Post-vaccination Stability Analysis in Kenya

In this paper, the study focused on carrying out a stability analysis on a modified SIR model for the COVID-19 pandemic for the period after vaccination in Kenya. The purpose of the work was to show that whereas the rate and the extent of disease spread amongst the Kenyan people was not as wide spread as happened in other parts of the world, it was necessary for government and policy makers to roll out a robust civic education to convince the majority of the Kenyan population to embrace vaccination as a major containment measure in curbing the spread of COVID-19 and other infectious diseases since the study revealed that the infections drastically reduced to near zero after vaccination except for a few isolated cases that were and still continue to exhibit mild symptoms to none at all. This was attributed to the development of the vaccine which upon a massive campaign by the Kenyan government, led into a significant portion of the population being vaccinated. It is believed this vaccination drive enhanced herd immunity amongst the population. This development has had a significant effect in the control of more recent COVID-19 variants like JN-1 that have remained largely mild and undetected in the country. Both local and global post vaccination stabilities were analyzed for the system using the Lyapunov function. The main objective of the study was therefore to carry out a post vaccination stability analysis by estimating key parameters such as the basic reproduction number, ( R0) and herd immunity threshold (HIT) for infectious diseases by fitting data into the model to enable predictions of future dynamics of the disease. The study used the Next Generation matrix and the least square method besides the Python software to solve generated differential equations of the model for and HIT parameters. Results obtained showed that, there was a significant reduction in infections due to enhanced herd immunity attributed largely to the roll out of vaccination.

EVALUASI ANALISIS GEOTEKNIK PADA TAMBANG TERBUKA BATUBARA PIT NORTH WEST PT ANAK TAMBANG INDONESIA JOB SITE PT ADIMITRA BARATAMA NUSANTARA, KALIMANTAN TIMUR

On a mine slope there will be a driving force and a resisting force. The mine slope will collapse if the driving force is greater than the resisting force. Thus, the principle of mitigating mine slope failure is to reduce the driving force or increase the resisting force. PT Adimitra Baratama Nusantara intends to develop a new mining area in the North-West area within the IUP area. Therefore, it is necessary to carry out a geotechnical study that focuses on slope stability analysis to support open-pit coal mining plans based on data from geotechnical investigations in the field, secondary data and geotechnical laboratory test data. Geotechnical modeling for slope stability analysis was carried out using the Finite Element Method because the overburden and interburden sedimentary rocks of coal seams are considered to have behavior approaching elasto-plastic, so that it will provide results that are close to the actual situation in the field. Modeling and slope stability analysis of the mine opening design represented by section-01 and section-03 with the height of each opening being 126 m and 119 m shows that the high-wall and low-wall slope designs are not yet stable, so a re-design is necessary. with the mine opening floor simulated at level -110 and level -90.

Thermodynamics-based unsaturated hydro-mechanical-chemical coupling model for wellbore stability analysis in chemically active gas formations

A thermodynamics-based unsaturated hydro-mechanical-chemical (HMC) coupling model is developed to analyze the coupled response and stability of boreholes in chemically active gas formations. The newly coupled constitutive relations are formulated by incorporating the chemical effect into the solid-gas-liquid unsaturated framework to account for the interactions between rock deformation, gas-liquid two-phase flow, and chemical potential difference. Compared with previous models, the present model shows significant prediction differences in field variables and wellbore stability evolution. The maximum absolute difference of pore pressure, effective radial stress, effective tangential stress, and collapse pressure can reach 8.98 MPa, 7.64 MPa, 7.29 MPa, 7.65 MPa, respectively. It is more conservative to select a long-term wellbore collapse pressure rather than a short-term one to guide drilling operations. The two-phase flow behavior, jointly controlled by wellbore pressure, capillary pressure, and chemical osmosis effect, provides a more realistic observation of the mud intrusion process. Compared with low salinity muds, high salinity muds can effectively impede the mud intrusion into the formation, which is more conducive to preventing wellbore collapse, but at the same time increases the risk of wellbore fracture. Sensitivity analysis shows that solute diffusion and reflection coefficients affect early wellbore stability through pore pressure and solute transport, while the chemical swelling coefficient has a long-term effect through chemically induced deformation. The results can provide theoretical guidance for quantitative optimization of mud parameters and prevention of wellbore instability when drilling in chemically active gas formations.

Stability Analysis of Yield and Its Components in Snap Melon (Cucumis melo var momordica)

Snap melon, scientifically known as Cucumis melo L. var. momordica (Roxb.), is a crop native to India and belonging to Cucurbitaceae family. This study was carried out to assess the nature and magnitude of genotype-environment interaction and stability among some parameters in snap melon genotypes. Twenty five local cultivars along with three standard checks were evaluated in randomized block design with three replications at three environments during summer 2023 at Navsari. The Eberhart and Russell model of stability analysis was employed which has been proved to be a reliable model. The study revealed that the mean sum of squares due to genotypes when tested against pooled deviation were highly significant for all the traits studied. Environment ´ Genotype (linear) showed significant differences for all characteristics except fruit weight and yield per vine, indicating that prediction could be possible by considering individual genotypes for these traits. A significant non-linear component (pooled deviation) was observed for fruit weight and fruit yield per vine, suggesting that genotypes varied considerably in terms of stable performance for these traits. The G ´ E interaction was only significant for flesh thickness and yield per vine, with all other traits being non-significant. The genotypes T 14 (HUB 18) and T 17 (HUB 21) were relatively stable and can be further used as parents to develop a more robust stable genotype. We identified genotypes which could pave way introducing high performing snap melon varieties.

Dynamical heterogeneity and universality of power-grids

Electric power systems during transient states are extensively investigated using variations of the Kuramoto model to analyze their dynamic behavior. However, the majority of current models fail to capture the physics of power flows and the heterogeneity of the grids under study. This study addresses this gap by comparing the levels of heterogeneity in continent-sized power grids in Europe and North America to reveal the underlying universality and heterogeneity of grid frequencies, electrical parameters, and topological structures. Empirical data analysis of grid frequencies from the Hungarian grid indicates that q-Gaussian distributions best fit simulations, with spatio-temporally correlated noise evident in the frequency spectrum. Comparing European and North American power grids reveals that employing homogeneous transmission capacities to represent power lines can lead to misleading results on stability, and nodal behavior is heterogeneous. Community structures of the continent-sized grids are detected, demonstrating that Chimera states are more likely to occur when studying only subsystems. A topographical analysis of the grids is presented to assist in selecting such subsystems. Finally, synchronization calculations are provided to illustrate the occurrence of Chimera states. The findings underscore the necessity of heterogeneous grid models for dynamic stability analysis of power systems.

Efficient optimization parameter calibration method-based DEM simulation for compacted loess slope under dry–wet cycling

Dry–wet cycles can cause significant deterioration of compacted loess and thus affect the safety of fill slopes. The discrete element method (DEM) can take into account the non-homogeneous, discontinuous, and anisotropic nature of the geotechnical medium, which is more capable of reflecting the mechanism and process of instability in slope stability analysis. Therefore, this paper proposes to use the DEM to analyze the stability of compacted loess slopes under dry–wet cycles. Firstly, to solve the complex calibration problem between macro and mesoscopic parameters in DEM models, an efficient parameter optimization method was proposed by introducing the chaotic particle swarm optimization with sigmoid-based acceleration coefficients algorithm (CPSOS). Secondly, during the parameter calibration, a new indicator, the bonding ratio (BR), was proposed to characterize the development of pores and cracks in compacted loess during dry–wet cycles, to reflect the impact of dry–wet action on the degradation of bonding between loess aggregates. Finally, according to the results of parameter calibration, the stability analysis model of compacted loess slope under dry–wet cycling was established. The results show that the proposed optimization calibration method can accurately reflect the trend of the stress–strain curve and strength of the actual test results under dry–wet cycles, and the BR also reflects the degradation effect of dry–wet cycles on compacted loess. The slope stability analysis shows that the DEM reflects the negative effect of dry–wet cycles on the safety factor of compacted loess slopes, as well as the trend of gradual stabilization with dry–wet cycles. The comparison with the finite element analysis results verified the accuracy of the discrete element slope stability analysis.

Reservoir recovery study with stability analysis model constructed by water-driven oil flat sand filling experiment: example of well area X in Tankou oilfield, China

Reservoir recovery study with stability analysis model constructed by water-driven oil flat sand filling experiment: example of well area X in Tankou oilfield, China

Rainfall-induced Landslide in the Lesser Himalaya: A Case Study of the Pallotari Landslide, Lamjung, Central-West Nepal

The Pallotari area, located in the Marsyangdi Rural Municipality, Lamjung, central-west Nepal, within the Lesser Himalaya, was impacted by a series of rainfall-induced landslides in July 2020. This study focuses on the Pallotari landslide, one of the major landslides in the area. Geological and engineering geological studies were performed to identify the causes of this landslide, and its impacts to the local community. Our results indicate the major causative factors to be intensive rainfall, steep topography with loose colluvial soil, and some anthropogenic activities such as the construction of the rural roads through the crown area. The study area still has hanging colluvial material on the crown as well as on the left flank of the landslide, and the numerical model for slope stability analysis indicates it to be unstable even in the unsaturated condition. The colluvial material in the middle portion of the landslide also has the risk of failure in the saturation condition which can be due to intensive rainfall. However, the rock slope stability analysis using the kinematic analysis does not show any contribution to the orientation of discontinuities on the slope failure. The presence of several transverse and longitudinal cracks in the surrounding of the landslide are signs of future failure.

Numerical simulation analysis of slope stability from rainwater utilizing the Civil3D+Flac3D coupling

Building Information Modeling (BIM) technology serves as an effective means for engineering modeling and information integration, surpassing traditional two-dimensional approaches with its superior spatial analysis capabilities. While BIM has gained widespread applications in slope engineering, a gap persists in the integration between protective design and simulation analysis in terms of slope stability. This study employs literature review, theoretical analysis, software development, and numerical simulation methods to explore the application of BIM models in slope stability analysis. Through the integrated application of BIM model construction, mesh subdivision, and stability analysis, we address the deficiency in three-dimensional slope stability inherent in BIM by coupling Civil3D’s secondary development with Flac3D, a numerical simulation software. This approach not only addresses the shortcomings of numerical analysis software in constructing complex geological models but also employs a collaborative multi-software approach for comparison to validate its suitability in slope engineering. The results demonstrate that models built using BIM software are more comprehensive and possess high precision in numerical simulation, thus exhibiting significant practical value in real-world engineering applications.

Numerical Investigation of Stratified Slope Failure Containing Rough Non-Persistent Joints Based on Distinct Element Method

To address the critical issue of slope stability in jointed rock masses with complex and rough structural planes, a rough joint network model using the Fourier transform was proposed and applied to the Shilu open pit mine. The on-site structural plane survey results were combined with MATLAB and PFC2D to establish numerical models for slope stability analysis considering both linear-jointed and rough-jointed rock slopes. By comparing the slip body and fracture distribution, it was found that the rough-jointed slope was stabler than the linear-jointed slope. In addition, the fracture patterns and slip displacement were significantly influenced by the inclination and undulation of the bedding planes. Slip failure patterns occurred when the angle of inclination was set at 60°. The joints played a crucial role in inducing the shear strength of slope rock masses, and the slide area was mainly observed in the shallow slope surface for inclination angles of 0° and 45°, and in the middle deep area for 60° and 90°. These results demonstrated the importance of considering rough non-persistent fractures when developing a new numerical model for slope failure modes.

Novel evaluation method based on critical arch height as instability criterion for sustaining arch locked-segment-type slopes

In sustaining arch locked-segment-type slopes, natural soil arches play a key anti-sliding role in the slope's evolution. In this study, a self-developed model test device was used to simulate the whole process of deformation evolution of sustaining arch locked-segment-type slopes, and the formation of natural sustaining arch and its locking control effect on slope stability were studied. The test results show that the continuous formation and progressive destruction of the sustaining arch were observed. The sustaining arch formed in the second time has the best locking effect, and the anti-sliding force reaches its stress peak point. However, the slope is not in a critically unstable state, instead, the stress is continuously adjusted to form a larger range of soil arch to resist the slope thrust. Consequently, the slope destabilizes until the ultimate shear strength of arch foots is exceeded, at which point the critical arch height of the arch is reached. The critical arch height mechanical model for slope stability analysis was developed based on the soil arching effect and limit equilibrium theory. The applicability of the model was demonstrated by the physical test and Xintan slope data, which can provide some guidance for early warning of landslides.

Instability in strongly stratified plane Couette flow, with application to supercritical fluids.

This paper addresses the stability of plane Couette flow in the presence of strong density and viscosity stratifications. It demonstrates the existence of a generalised inflection point that satisfies the generalised Fjørtoft's criterion of instability when a minimum of kinematic viscosity is present in the base flow. The characteristic scales associated with this minimum are identified as the primary controlling parameters of the associated instability, regardless of the type of stratification. To support this finding, analytical stability models are derived in the long wave approximation using piecewise linear base flows. Numerical stability calculations are carried out to validate these models and to provide further information on the production of disturbance vorticity. All instabilities are interpreted as arising from the interaction between two vorticity waves. Depending on the type of stratification, these two waves are produced by different physical mechanisms. When both strong density and viscosity stratifications are present, we show that they result from the concurrent action of shear and inertial baroclinic effects. The stability models developed for simple fluid models ultimately shed light on a recently observed unstable mode in supercritical fluids (Ren et al., J. Fluid Mech., vol. 871, 2019, pp. 831-864), providing a quantitative prediction of the stability diagram and identifying the dominant mechanisms at play. Furthermore, our study suggests that the minimum of kinematic viscosity reached at the Widom line in these fluids is the leading cause of their instability. The existence of similar instabilities in different fluids and flows (e.g., miscible fluids) is finally discussed.

A Sequential SISO Stability Analysis Model for Grid-Connected Converters by Considering the Impact of Power Flow Direction

A Sequential SISO Stability Analysis Model for Grid-Connected Converters by Considering the Impact of Power Flow Direction

Stability analysis of loess fill slope supported by frame prestressed anchors considering tensile strength cut-off

In the stability analysis of loess fill slope, the fissure nature of loess is often ignored, which makes the stability calculation of fill slope too conservative. Based on the upper limit theory of plastic limit analysis, the stability analysis model of loess-filled fissured slope supported by frame prestressed anchors was established. Considering the tensile strength cut-off yield property of soil, the stability coefficient of slope was calculated, and the influence of different factors on slope stability was analyzed. The results show that ignoring the fissures in loess will overestimate the stability of the fill slope, and the support structure can significantly improve the stability of the loess-filled fissure slope. The research results of this paper can further enrich the stability analysis theory of loess-filled fissured slope supported by frame prestressed anchors, which is of great significance to guide engineering practice.

Seismic Stability Analysis of Slope Reinforced by Frame Anchors Considering Prestress

Taking the slope reinforced by frame anchors as the research object, it is assumed that the potential sliding surface of the slope is an arc. Based on the limit equilibrium theory, the seismic stability analysis model of frame anchor reinforced slope considering anchor prestress is established. This study considers prestress as uniformly distributed forces acting on the slope surface and calculates the additional stress induced by prestressing within the slope to investigate its reinforcement effect on slopes. Thus, the stability of the slope is analyzed and calculated. On this basis, the functional relationship between the center position coordinates of the potential sliding surface and the safety factor is established. Using the optimization algorithm toolbox in Matlab, the possible center position area is dynamically searched, and the minimum safety factor and its corresponding center position coordinates are obtained. Taking slope engineering as an example, the calculated results are compared with the finite element calculation results. The results show that the calculation result regarding the anchor prestress as the uniformly distributed force is reliable, and the anchor prestress can significantly enhance slope stability. This calculation method applies to slope engineering in homogeneous soil with circular sliding surfaces.

Finite element model for stability and vibration analyses of bi-directional FG curved sandwich beams

Finite element model for stability and vibration analyses of bi-directional FG curved sandwich beams