Forecast and Analysis on the Stability of Open-Pit Ultra-High Slope

2012 ◽  
Vol 152-154 ◽  
pp. 802-808
Author(s):  
Fei Zhang ◽  
Jing Cao ◽  
Ming Chen ◽  
Lei Peng

Combining the explicit Lagrangian difference method for the continuum body and strength reduction technology, this paper analyzed the stability of Xian Feng open-pit. The generalized shear strain and plastic strain interconnected within the weak structural plane of slope are used as criterion to identify slope failure state. Analysis of the example verifies that the criterion is rational. With the calculate model, it can predict the open-pit ultra-high slope stability after five years. Its results are similar to the traditional limit equilibrium method. Therefore, the method is reasonably practicable. So the result will be important significance to guide the post-construction of mine.

2013 ◽  
Vol 671-674 ◽  
pp. 245-250
Author(s):  
Wen Hui Tan ◽  
Ya Liang Li ◽  
Cong Cong Li

At present, in-situ stress was not considered in Limit Equilibrium Method (LEM) of slopes, the influence of in-situ stress is very small on the stability of conventional slopes, but in deep-depressed open-pit mines, the influence should not be neglected. Formula for calculating the Factor of Safety (FOS) under the effect of horizontal in-situ stress was deduced using General Slice Method (GSM) of two-dimensional (2D) limit equilibrium method in this paper,a corresponding program SSLOPE was built, and the software was used in a deep- depressed open-pit iron mine. The results show that the FOS of the slope decreased by 20% when horizontal in-situ stress is considered, some reinforcements must be taken. Therefore, the influence of in-situ stress on slope stability should be taken into account in deep open –pit mines.


2021 ◽  
Author(s):  
Tesfay Kiros Mebrahtu ◽  
Thomas Heinze ◽  
Stefan Wohnlich

<p>Landslides and ground failures are among the common geo-environmental hazards in many of the tectonically active hilly and mountainous terrains of Ethiopia, such as in the western margin of the Main Ethiopian Rift in Debre Sina area. Besides the geological preconditioning, bi-modal monsoon and seismic events in the tectonically highly active region are usually suspected triggers. In order to minimize the damage caused by the slope failure events, a detailed investigation of landslide-prone areas using numerical modelling plays a crucial role. The aim of this study is to assess the stability of slopes, to understand the relevant failure mechanisms, and to evaluate and compare safety factors calculated by the different available numerical methods. The stability was assessed for slopes of complex geometry and heterogeneous material using the limit equilibrium method and the shear strength reduction method based on finite elements. Furthermore, numerical analysis was done under static and pseudo-static loading using the horizontal seismic coefficient to model their stability during a seismic event. The slope stability analysis indicates that the studied slopes are unstable, and any small scale disturbance will further reduce the factor of safety and probably causing failure. The critical strength reduction factors from the finite element method are significantly lower than the factor of safety from the limit equilibrium method in all studied scenarios, such as Bishop, Janbu Simplified, Spencer and Morgenstern-Price. The difference is especially evident for heterogeneous slopes with joints, which often are initiation points for the failure planes. The simulations show that slope stability of landslide prone hills in the study area strongly depends on the saturation conditions and the seismic load. The studied slopes are initially close to failure and increased pore-pressure or seismic load are very likely triggers.</p>


2014 ◽  
Vol 919-921 ◽  
pp. 637-640 ◽  
Author(s):  
Qi Zhang

The slope failure of high fill embankment have a large proportion under self-weight and external conditions,Because of the complexity of the soil deformation and stress,General methods such as the limit equilibrium and numerical analysis have their own limitations,The paper takes high fill subgrade engineering in Fujian province as the background.Adopting analytical method and finite element method calculate the stability coefficient and lateral displacement of high fill embankment slope.moreover,Making a comprehensive judgement to the stability of the slope by comparing with the actual value.The results show that calculation results of these two methods are close.Which can make accurate predictions on high slope stability and determine a judgement.and provides an effective method for the design and construction of the similar project.


2015 ◽  
Vol 777 ◽  
pp. 106-111 ◽  
Author(s):  
Zhen Hua Xie ◽  
Ran Yi Xie ◽  
Xiao Yue Lu

The stability of slope in open-pit affects the economic benefits and safety production of mining enterprises. From the two aspects of internal factors and external factors, this paper analyses the factors affecting the slope stability of open-pit, discusses the basic theory of slope stability analysis, and puts forward the criterion of slope stability based on the safety coefficient. The limit equilibrium method is chosen to analyze the stability of the high and steep slope of open-pit in this paper, and the SLIDE software is used for numerical simulation according to the actual slope model of certain open-pit. The simulation results show that the slope safety coefficient of the instance is 1.01, which is unstable slope. When the number of the slope blocks is more than 40, the safety coefficient tend to be stable. Blasting vibration has a great influence on slope stability. The results of slope stability analysis provide a scientific guidance for the prevention and control of the slope instability.


2011 ◽  
Vol 243-249 ◽  
pp. 2690-2693
Author(s):  
Lin Yan Li ◽  
Yin Liu ◽  
Hao Chen ◽  
Heng Bin Wu

Present methods for stability analysis of underwater slopes are mostly confined to laboratory experiments and limit equilibrium method. This paper is based on strength reduction method, considering the deformation parameters of rock mass to discuss the stability of underwater slopes. Comparing the consequences, the sliding planes and safety factors agreed well with the result of limit equilibrium method. The applicability of strength reduction method for underwater slopes stability was well proved. When analyzing after changing the water depth, it was showed that there are more erosion effect induced and reduction for the parameters of rock mass, but little influence on the safety factor of underwater slopes.


Water ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1229
Author(s):  
Hung-En Chen ◽  
Yen-Yu Chiu ◽  
Tung-Lin Tsai ◽  
Jinn-Chuang Yang

To analyze the effect of runoff on shallow landslides, a model coupling one-dimensional rainfall–runoff and two-dimensional infiltration was established to simulate rainfall, infiltration, and runoff processes. Based on Bishop’s limit equilibrium method, the slope failure of a hypothetical footslope was studied. First, conditions with and without inflow were compared. The results reveal a remarkable difference in factors of safety (FS) between the two conditions, suggesting that considering the effect of runoff is crucial for landslide modeling. In terms of a series of tests of the various magnitudes, durations, lag-time, and peak position of the hydrograph, analyses show that larger inflow leads to more accumulated infiltration and triggers landslides earlier. A long-term duration inflow decreases the stability more than short intensive inflow does. With subsequent surface inflow, slope failure may occur after rainfalls stop, owing to the inflow, and the shape of inflow hydrographs could slightly affect the variance in FS. Results also indicate the necessity of considering the surface runoff when using a numerical model to analyze landslide, particularly on a footslope.


2012 ◽  
Vol 446-449 ◽  
pp. 1524-1530
Author(s):  
Ting Ai ◽  
Ru Zhang ◽  
Li Ren ◽  
Wen Xi Fu

In order to implement the non-linear Hoek-Brown (HB) shear strength reduction (SSR) on commercially available softwares, this paper derives the relationship between the Drucker-prager (DP) criterion and HB criterion under the condition of plane strain. The equivalent DP parameters can be approximately estimated after serious transformations of parameters between the HB and Mohr-Coulomb (MC) yield functions. To assess the effect of dilation on the stability of slope, the non-associated flow rule, which cannot be contained in the existing limit equilibrium methods, is selected in our analysis, and the SSR-based results of a simple slope indicate that: If the angle of dilatancy ψ is taken to be zero, the factor of safety calculated by the SSR method is very close to that by the limit equilibrium method; if ψ is greater than zero, the factor of safety calculated by the SSR method is greater than that by the limit equilibrium method, and the effect of dilation on the stability of slope can be approximately described by a liner function.


2012 ◽  
Vol 204-208 ◽  
pp. 241-245
Author(s):  
Yang Jin

The stability of soil slope under seepage is calculated and analyzed by using finite element method based on the technique of shear strength reduction. When the condition of seepage or not is considered respectively, the critical failure state of slopes and corresponding safety coefficients can be determined by the numerical analysis and calculation. Besides, through analyzing and comparing the calculation results, it shows that seepage has a negative impact on slope stability.


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.


1983 ◽  
Vol 20 (4) ◽  
pp. 661-672 ◽  
Author(s):  
R. K. H. Ching ◽  
D. G. Fredlund

Several commonly encountered problems associated with the limit equilibrium methods of slices are discussed. These problems are primarily related to the assumptions used to render the inherently indeterminate analysis determinate. When these problems occur in the stability computations, unreasonable solutions are often obtained. It appears that problems occur mainly in situations where the assumption to render the analysis determinate seriously departs from realistic soil conditions. These problems should not, in general, discourage the use of the method of slices. Example problems are presented to illustrate these difficulties and suggestions are proposed to resolve these problems. Keywords: slope stability, limit equilibrium, method of slices, factor of safety, side force function.


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