scholarly journals An Application of the Stability Analysis Method Based on the Homogenization Theory to a Rock Slope.

2002 ◽  
pp. 13-23 ◽  
Author(s):  
Takashi KYOYA ◽  
Lizhu OUYANG
2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Changqing Qi ◽  
Jiabing Qi ◽  
Liuyang Li ◽  
Jin Liu

Landslide developed in rock mass usually has irregular shear plane. An approach for calculating distributed factor of safety of the irregular shear plane was put forward in this paper. The presented method can obtain not only the detailed stability status at any grid node of a complex shear plane but also the global safety of the slope. Thus, it is helpful to thoroughly understand the mechanism of slope failure. Comparing with the result obtained through the limit equilibrium method, the presented method was proved to be more accurate and suitable for stability analysis of rock slope with a thin shear plane. The stability of a potentially unstable rock slope was analyzed based on the presented method at the end of this paper. The detailed local stability, global stability, and the potential failure mechanism were provided.


Author(s):  
K. Al-Durgham ◽  
D. D. Lichti ◽  
I. Detchev ◽  
G. Kuntze ◽  
J. L. Ronsky

A fundamental task in photogrammetry is the temporal stability analysis of a camera/imaging-system’s calibration parameters. This is essential to validate the repeatability of the parameters’ estimation, to detect any behavioural changes in the camera/imaging system and to ensure precise photogrammetric products. Many stability analysis methods exist in the photogrammetric literature; each one has different methodological bases, and advantages and disadvantages. This paper presents a simple and rigorous stability analysis method that can be straightforwardly implemented for a single camera or an imaging system with multiple cameras. The basic collinearity model is used to capture differences between two calibration datasets, and to establish the stability analysis methodology. Geometric simulation is used as a tool to derive image and object space scenarios. Experiments were performed on real calibration datasets from a dual fluoroscopy (DF; X-ray-based) imaging system. The calibration data consisted of hundreds of images and thousands of image observations from six temporal points over a two-day period for a precise evaluation of the DF system stability. The stability of the DF system – for a single camera analysis – was found to be within a range of 0.01 to 0.66 mm in terms of 3D coordinates root-mean-square-error (RMSE), and 0.07 to 0.19 mm for dual cameras analysis. It is to the authors’ best knowledge that this work is the first to address the topic of DF stability analysis.


Heliyon ◽  
2020 ◽  
Vol 6 (5) ◽  
pp. e03907 ◽  
Author(s):  
Mohammad Azarafza ◽  
Haluk Akgün ◽  
Mohammad-Reza Feizi-Derakhshi ◽  
Mehdi Azarafza ◽  
Jafar Rahnamarad ◽  
...  

2015 ◽  
Vol 26 (08) ◽  
pp. 1550092 ◽  
Author(s):  
Jie Zhou ◽  
Zhong-Ke Shi

Considering the effect of density difference, an extended lattice hydrodynamic model for bidirectional pedestrian flow is proposed in this paper. The stability condition is obtained by the use of linear stability analysis. It is shown that the stability of pedestrian flow varies with the reaction coefficient of density difference. Based on nonlinear analysis method, the Burgers, Korteweg–de Vries (KdV) and modified Korteweg–de Vries (MKdV) equations are derived to describe the triangular shock waves, soliton waves and kink–antikink waves in the stable, metastable and unstable regions, respectively. The results show that jams may be alleviated by considering the effect of density difference. The findings also indicate that in the process of building and subway station design, a series of auxiliary facilities should be considered in order to alleviate the possible pedestrian jams.


2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Shan Wu ◽  
Chao Li ◽  
Yipan Deng

Taking into account the deformation of a designed direct-operated seawater hydraulic relief valve in deep sea, which might have a great influence on the stability of the valve, a mathematic model of the relief valve was established and stability analysis was conducted. As the fitting clearances between the damping sleeve and the damping bar play a key role in the performance of the relief valve, the fitting clearances after deformation under pressure of different ocean depths were obtained using finite element method. Applying the deformation data to the relief valve model, the stability and relative stability could be analyzed quantitatively through both the frequency domain analysis method and the time domain analysis method to detect the influence of the fitting clearance after deformation. The simulation results show that the seawater relief valve has a stable performance within 4000 meters deep under the sea.


Energies ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6580
Author(s):  
Yixing Wang ◽  
Qianming Xu ◽  
Josep M. Guerrero

Due to the internal dynamics of the modular multilevel converter (MMC), the coupling between the positive and negative sequences in impedance, which is defined as frequency coupling, inherently exists in MMC. Ignoring the frequency coupling of the MMC impedance model may lead to inaccurate stability assessment, and thus the multi-input multi-output (MIMO) impedance model has been developed to consider the frequency coupling effect. However, the generalized Nyquist criterion (GNC), which is used for the stability analysis of an MIMO model, is more complicated than the stability analysis method applied on single-input-single-output (SISO) models. Meanwhile, it is not always the case that the SISO model fails in the stability assessment. Therefore, the conditions when the MIMO impedance model needs to be considered in the stability analysis of an MMC system should be analyzed. This paper quantitatively analyzes the effect of frequency coupling on the stability analysis of grid-connected MMC, and clarifies the frequency range and grid conditions that the coupling effect required to be considered in the stability analysis. Based on the quantitative relations between the frequency coupling and the stability analysis of the grid-connected MMC system, a simple and accurate stability analysis method for the grid-connected MMC system is proposed, where the MIMO impedance model is applied when the frequency coupling has a significant effect and the SISO impedance model is used if the frequency coupling is insignificant.


2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Shijie Chen ◽  
Ming Xiao ◽  
Juntao Chen

A numerical analysis method for block failure is proposed that is based on continuum mechanics. First, a mesh model that includes marked blocks was established based on the grid-based block identification method. Then, expressions of the contact force under various contact states were derived based on the explicit contact force algorithm, and a contact simulation method between blocks and the surrounding rock was proposed. The safety factors of the blocks were calculated based on the strength reduction method. This numerical analysis method can simulate both the continuous deformation of the surrounding rock and the discontinuous failure processes of the blocks. A simple example of a sliding block was used to evaluate the accuracy and rationality of the numerical method. Finally, combined with a deep underground excavation project under complex geological conditions, the stability of the blocks and rock were analyzed. The results indicate that the key blocks are damaged after excavation, the potentially dangerous blocks loosen and undergo large deformations, and the cracks between the blocks and the rock gradually increase as the excavation proceeds. The safety factors of the blocks change during the excavation. The numerical results demonstrate the influence of the surrounding rock on the failure process and on the stability of the blocks, and an effective analysis method is provided for the stability analysis of blocks under complex geological conditions.


2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Qibing Zhan ◽  
Xinjian Sun ◽  
Cheng Li ◽  
Yawei Zhao ◽  
Xinjie Zhou ◽  
...  

This study presents a stability analysis of a high-steep rock slope with two faults during excavations and evaluates the effectiveness of a proposed reinforcement method using prestressed anchor cables. A 3D finite difference model was established based on the strength reduction method using FLAC3D software. The influence of various fault conditions and the effectiveness of the reinforcement on the slope stability during the excavation process were analyzed and compared to field monitoring data. The numerical analysis and field monitoring results showed that the fault close to the slope surface (f20) was prone to the local instability under external forces caused by the excavation, but a fault further away from the slope surface (f14) had insignificant influence on the stability of the slope. Based on the numerical analysis results, the proposed reinforcement measure can increase the factor of safety (FOS) of the slope by 19.2%. The field monitoring data also showed that the displacement of the monitoring point gradually decreased after the reinforcement, and the deformation of the slope was effectively controlled.


2015 ◽  
Vol 733 ◽  
pp. 464-467
Author(s):  
Yong Kang Shen ◽  
Zheng Zhong Wang ◽  
Chun Long Zhao

The new arms form of radial gate—dendritic arms is introduced for the proper mechanical mechanism, however the stability design is very difficult. According to the stability theory of structure, the stability analysis model of step column with lateral restraints was proposed for dendritic arms, some equations was derived from the principle of minimum potential energy, the practical formulas of buckling bearing capacity and effective length coefficient were provided. According to an example, the accuracy on formulas was verified by finite analysis method.


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