Research of Cutting Slop Process by Strength Reduction FDM

2014 ◽  
Vol 962-965 ◽  
pp. 868-872
Author(s):  
Li Yan ◽  
Hou Li Fu

To the problem of slope stability analysis and slope-cutting of rock slope, the traditional method Limit Equilibrium Method has many shortcomings as assuming the position and shape of the slip plane first. However, with the new theory of Strength Reduction Method, the problem can be easily solved. By selecting the appropriate criterion of instability and failure of sliding surface of slope, the Strength Reduction Method simulates the gradual development process of slope-cutting. By this method, we can simulate the failure process of slope and obtain the safety factors and slipping surface. This paper put forward the process of cutting slop by Strength Reduction FDM (Finite Difference Method) which had new insights into the choice of instability criterion, flow rule and slip plane.

2016 ◽  
Vol 858 ◽  
pp. 73-80
Author(s):  
Ying Kong ◽  
Hua Peng Shi ◽  
Hong Ming Yu

With the slope unstable rock masses of a stope in Longsi mine, Jiaozuo City, China as the target, we computed and analyzed the stability of unstable rock masses using a limit equilibrium method (LEM) and a discrete element strength reduction method (SRM). Results show that the unstable rock masses are currently stable. Under the external actions of natural weathering, rainfall and earthquake, unstable rock mass 1 was manifested as a shear slip failure mode, and its stability was controlled jointly by bedding-plane and posterior-margin steep inclined joints. In comparison, unstable rock mass 2 was manifested as a tensile-crack toppling failure mode, and its stability was controlled by the perforation of posterior-margin joints. From the results of the 2 methods we find the safety factor determined from SRM is larger, but not significantly, than that from LEM, and SRM can simulate the progressive failure process of unstable rock masses. SRM also provides information about forces and deformation (e.g. stress-strain, and displacement) and more efficiently visualizes the parts at the slope that are susceptible to instability, suggesting SRM can be used as a supplementation of LEM.


2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Ruili Lu ◽  
Wei Wei ◽  
Kaiwei Shang ◽  
Xiangyang Jing

In order to study the failure mechanism and assess the stability of the inlet slope of the outlet structure of Lianghekou Hydropower station, the strength reduction method considering the ubiquitous joint model is proposed. Firstly, two-dimension numerical models are built to investigate the influence of the dilation angle of ubiquitous joints, mesh discretization, and solution domain size on the slope stability. It is found that the factor of safety is insensitive to the dilation angle of ubiquitous joints and the solution domain size but sensitive to the mesh discretization when the number of elements less than a certain threshold. Then, a complex three-dimension numerical model is built to assess the stability of the inlet slope of the outlet structure of Lianghekou Hydropower station. During the strength reduction procedure, the progressive failure process and the final failure surface of the slope are obtained. Furthermore, the comparison of factors of safety obtained from strength reduction method and analytical solutions indicates that the effect of vertical side boundaries plays an important role in the stability of jointed rock slope, and the cohesive force is the main contribution to the resistant force of vertical side boundaries.


2015 ◽  
Vol 744-746 ◽  
pp. 593-596
Author(s):  
Yuan Meng

When calculating the dam slope failure process, traditional strength reduction method doesn't consider the difference of decay rate between cohesion and internal friction angle and discount the strength parameters for all elements. This paper uses two different reduction factors for material strength parameters, slope cohesion and internal friction angle. Based on the yield approach index criterion, we change the reduction region in time and put forward a double safety factor of dynamic local strength reduction method for engineering analysis of dam slope stability.


2012 ◽  
Vol 170-173 ◽  
pp. 1238-1242
Author(s):  
Xue Wei Li ◽  
Xin Yuan ◽  
Xiao Wei Li

Abstract. Combined the strength reduction method with ABAQUS, the development of the slope plastic strain of different reduction coefficient is obtained by constantly adjusting reduction coefficient to change the strength index of the soil. The reduction coefficient is obtained from the criterion of numerical convergence and displacement mutation and plastic zone breakthrough. Through the analysis and comparison with the results, the reduction coefficient by the criterion of displacement mutation is consistent with the result of the criterion of plastic zone breakthrough. The reduction coefficient is the safety coefficient of the slope, and compared and analyzed with the slope factor of limit equilibrium method Bishop. The result shows that the displacement mutation and the plastic zone breakthrough as criterions to judge the slope instability are reasonable.


2013 ◽  
Vol 368-370 ◽  
pp. 1774-1780
Author(s):  
Shi Yan ◽  
Hai Tao Du ◽  
Qi Le Yu ◽  
Han Yan

This paper focuses on stability analysis of an artificial rock mass slope by a nonlinear finite element method (FEM). For a long time, rock slope stability problem is always an important research issue in the field of geotechnical engineering, which is related to human life and property safety as well as engineering security and efficiency. Therefore, the stability analysis and evaluation on rock slope is of great significance. The static and dynamic stability analysis on the artificial rock mass slope of WuAn power plant in China is carried on respectively in this paper by using the strength reduction method and FLAC3D software. In this analysis, static and dynamic instability criterions are enumerated, and the static and dynamic safety factors are calculated with the developed criterions of the displacement mutation, respectively. The analysis results show that the artificial rock mass slope is basically stable. It indicates that analyzing slope stability with strength reduction method is feasible.


2012 ◽  
Vol 170-173 ◽  
pp. 918-922 ◽  
Author(s):  
Xing Yang ◽  
Gui Yang ◽  
Ting Yu

Strength reduction method is widely used in the slope stability analysis. However, it is short of unified instability evaluation standard at present. And the different numerical calculation methods also influence the safety factor of strength reduction method. Taking a typical slope in this paper, the same model meshes are established in ABAQUS FEM and FLAC3D FDM by using the self-compiled model transformation program ABAQUS-FLAC3D. Then the same elastic-plastic constitutive and yield criterion are both employed in ABAQUS FEM and FLAC3D FDM. The safety factors obtained from the two numerical calculation methods are compared, and the results are also compared with that of Spencer limit equilibrium method. It is observed the safety factors calculated by ABAQUS FEM are slightly higher than that of FLAC3D FDM for the same instability evaluation standards. Moreover, the safety factors obtained from the run-through of plastic zone and the saltation of the displacement at characteristic point are much closer to that of Spencer limit equilibrium method. Hence the combination of the run-through of plastic zone and the saltation of the displacement at characteristic point as the slope instability evaluation standard is suggested in this paper. Meanwhile, the correctness of self-compiled improved strength reduction method is verified by comparing with the result of FLAC3D built-in strength reduction method.


2012 ◽  
Vol 424-425 ◽  
pp. 1187-1190
Author(s):  
Yue Zhai ◽  
Kun Long Yin

With the anti-shear parameters reduction, the nonlinear strength reduction FEM model of slope turns to unstable status and the numerical non-convergence occurs simultaneously. Hence, the safety stability factor obtained based on c-φ reduction algorithm can be regarded as equal to stability factor obtained using limit equilibrium method. In this paper, stability analysis of one reservoir slope is made and the calculation results show that the strength reduction method matches the traditional grid limit equilibrium method well, yet with much more available information. Efficient and accurate, the strength reduction FEM is feasible to examine slope stability and analyze slope movement patterns.


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