scholarly journals Three-Dimensional Analysis of Complex Rock Slope Stability Affected by Fault and Weak Layer Based on FESRM

2019 ◽  
Vol 2019 ◽  
pp. 1-14
Author(s):  
Yang Li ◽  
Ling Yu ◽  
Weidong Song ◽  
Tianhong Yang

Slope stability analysis is the most important problem in slope engineering design and construction. Open-pit slope often spans several strata, many of which are relatively weak. There may be faults and weak layers across the whole rock. It is very necessary to study the instability mechanism and stability analysis of multistratigraphic slopes with faults and weak layers. In this paper, taking a complex three-dimensional slope with fault and weak layer as the research object, the evolution laws of the stress field and damage zone of the slope are analyzed by using the finite element strength reduction method. The results show that the fault and weak layer have different degrees of effect on the slope stability. The fault causes stress concentration and damage to nearby rock mass, and the weak layer causes stress concentration on the slope above it and forms a dangerous slip zone. Then the effect of the fault and weak layer on slope stability is discussed. Because the effect of horizontal structural plane on slope stability is greater than that of the vertical structural plane, the effect of weak layer on slope stability is greater than that of the fault in the slope. The research results can provide a theoretical guidance for the study of slope stability in practical engineering.

2011 ◽  
Vol 261-263 ◽  
pp. 1465-1469
Author(s):  
Lan Jia ◽  
Lan Zhu Cao ◽  
Zi Ling Song

As the complexity and the tall of open pit slope, two-dimensional slope stability analysis methods have been unable to meet the needs of the accuracy of stability analysis. Therefore, for the complex situation of Pingzhuang open pit slope, use with three-dimensional rigid body limit equilibrium method to analysisstability of slope.slope3D system, which consists of pre-treatment, limit equilibrium analysis solver and post-processing, the first processing core is to construct three-dimensional geological model of the slope, post-processing mainly results analysis and visualization graphics. The system combined organically the slope engineering geological information three-dimensional visualization and the analysis of stability, which make us to determine the landslide model, reveal the mechanism of landslide more accurately. Make an important contribution for ensuring safety in open pit production, a good foundation for slope stability analysis of other open pit.


2020 ◽  
Author(s):  
Masagus Ahmad Azizi ◽  
Irfan Marwanza ◽  
Muhammad Kemal Ghifari ◽  
Afiat Anugrahadi

The 3-dimensional slope stability analysis has been developing rapidly since the last decade, and currently a number of geomechanical researchers in the world have put forward ideas for optimization of slope design related to the economics and safety of mining operations. The 3-dimensional slope stability analysis methods has answered the assumption of spatial parameters in determining safety factors and the failure probability, thus the volume of failed material and the location of the most critical slopes can be determined. This chapter discusses two methods of 3-dimensional slope stability analysis, namely the limit equilibrium method (LEM) and finite element method (FEM). LEM 3D requires an assumption of failure type with the variable of analysis are the maximum number of columns, the amount of grid points, increment radius, and type of slip surface. On the other hand, FEM 3D requires an assumption of convergence type, absolute force and energy, with the variable of analysis are mesh type and maximum number of iterations. LEM 3D shows that the cuckoo algorithm is reliable in obtaining position and shape of slip surface. Meanwhile FEM 3D, the optimum iteration number needs to be considered to improve analysis efficiency and preserving accuracy.


2014 ◽  
Vol 59 (3) ◽  
pp. 609-620 ◽  
Author(s):  
Marek Cała ◽  
Michał Kowalski ◽  
Agnieszka Stopkowicz

Abstract The purpose of this paper was to perform the 3D numerical calculations allowing slope stability analysis of Hyttemalmen open pit (location Kirkenes, Finnmark Province, Norway). After a ramp rock slide, which took place in December 2010, as well as some other small-scale rock slope stability problems, it proved necessary to perform a serious stability analyses. The Hyttemalmen open pit was designed with a depth up to 100 m, a bench height of 24 m and a ramp width of 10 m. The rock formation in the iron mining district of Kirkenes is called the Bjornevaten Group. This is the most structurally complicated area connected with tectonic process such as folding, faults and metamorphosis. The Bjornevaten Group is a volcano-sedimentary sequence. Rock slope stability depends on the mechanical properties of the rock, hydro-geological conditions, slope topography, joint set systems and seismic activity. However, rock slope stability is mainly connected with joint sets. Joints, or general discontinuities, are regarded as weak planes within rock which have strength reducing consequences with regard to rock strength. Discontinuities within the rock mass lead to very low tensile strength. Several simulations were performed utilising the RocLab (2007) software to estimate the gneiss cohesion for slopes of different height. The RocLab code is dedicated to estimate rock mass strength using the Hoek-Brown failure criterion. Utilising both the GSI index and the Hoek-Brown strength criterion the equivalent Mohr-Coulomb parameters (cohesion and angle of internal friction) can be calculated. The results of 3D numerical calculations (with FLA3D code) show that it is necessary to redesign the slope-bench system in the Hyttemalmen open pit. Changing slope inclination for lower stages is recommended. The minimum factor of safety should be equal 1.3. At the final planned stage of excavation, the factor of safety drops to 1.06 with failure surface ranging through all of the slopes. In the case of a slope angle 70° for lower stages, FS = 1.26, which is not enough to provide slope stability. Another series of calculations were therefore performed taking water table lowering into consideration, which increases the global safety factor. It was finally evaluated, that for a water table level of 72 m the factor of safety equals 1.3, which is enough to assure global open-pit stability.


2011 ◽  
Vol 94-96 ◽  
pp. 516-519
Author(s):  
Qing Lian Shu ◽  
Ling Qiang Yang ◽  
Pan Ying Zang

The analysis of structural plane in rock slope is of vital importance to stability analysis of rock slope. In this paper, Bayesian method was adopted in the analysis of shear strength parameters along the fault in the West Slope of Upper Reservoir, Shisanling Pumped Storage Power Station. Full advantage was taken of the geological information outside the structural plane along with the practical experience of on-site engineers. The statistical estimation problem of small samples thus was successfully solved. The determination of sliding plane in rock slope is another key issue in the stability analysis of rock slope. The cracking process was utilized to track the most possible sliding plane in the slope. In consideration of the randomicity of both mechanical parameters of rock and structural plane and resistance of slide resistant piles, reliability index of slope stability was established with the aid of discretized dimensional reduction method of reliability and conditional probability.


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