SIMULATION OF TOPPLING FAILURE OF ROCK SLOPE BY NUMERICAL MANIFOLD METHOD

2010 ◽  
Vol 07 (01) ◽  
pp. 167-189 ◽  
Author(s):  
GUOXIN ZHANG ◽  
YAN ZHAO ◽  
XIAOCHU PENG
Keyword(s):  
Rock Slope ◽  
Limit Equilibrium ◽  
Failure Process ◽  
Numerical Manifold Method ◽  
Left Bank ◽  
Rock Slopes ◽  
Rock Bridges ◽  
Toppling Failure ◽  
Numerical Manifold ◽  
Discontinuous Problems

As one type of rock slope failures, topping failure can be accurately simulated only when several aspects are correctly calculated such as deformation and stress, contacts between blocks, contact stress, movement of blocks, open/close of contacts between blocks, development of failure plane, and crack generation and propagation. Current numerical methods encounter many difficulties in simulating toppling failure, especially for rock slope with lots of rock-bridges. Numerical manifold method (NMM) can deal with these highly discontinuous problems and be used to model the toppling failure of rock slopes. This paper first introduces the fundamental principles, modeling of contacts, calculation of contact force and stress, and modeling of failure in NMM. Then, several case studies are conducted to testify the accuracy and convergence of method; comparisons with method, based on limit equilibrium principle, which was proposed by Goodman and Bray (G–B method) and centrifuge test are conducted. Finally, the topping failure of left bank of one high dam is simulated. Results show that the NMM can be used to correctly calculate the toppling safety factor, simulate the failure process of slope toppling, and accurately model the whole failure process of rock slopes with many rock-bridges.

Numerical Simulation on Failure Mechanism of Rock Slope Using RFPA

2011 ◽  
Vol 50-51 ◽  
pp. 568-572 ◽  
Author(s):  
Nu Wen Xu ◽  
Chu Nan Tang ◽  
Chun Sha ◽  
Ru Lin Zhang
Keyword(s):  
Rock Slope ◽  
Slip Surface ◽  
Process Analysis ◽  
Failure Process ◽  
Numerical Code ◽  
Natural State ◽  
Left Bank ◽  
Good Tool ◽  
Deep Rock ◽  
The Stability

This research applied a numerical code, RFPA2D (Realistic Failure Process Analysis) to evaluate the stability and investigate the failure mode of the high rock slope during excavations based on Strength Reduction Method (SRM). The corresponding shapes and positions of the potential slip surfaces are rationally simulated in different stages, and the related safety coefficients are obtained, which agrees well with the allowable minimum safety factors of the slope. The numerical results show that the safety coefficient drops from 1.25 at the natural state to 1.09 after excavation, and then increases to 1.35 after slope reinforcement. Moreover, the potential slip surface of the left bank moves into deep rock mass after taking support measures, which demonstrates the reinforcement is reasonable and efficient. The study shows that cracks and faults will cause crucial influences on the slope stability, and RFPA2D is a good tool to directly display the potential slip surface of the slope, which will offer valuable guidance for bolt support.

APPLICATION OF BLOCK THEORY MODELING ON SPATIAL BLOCK TOPOLOGICAL IDENTIFICATION TO ROCK SLOPE STABILITY ANALYSIS

2013 ◽  
Vol 11 (01) ◽  
pp. 1350044 ◽  
Author(s):  
SHUHONG WANG ◽  
PENGPENG NI
Keyword(s):  
Stability Analysis ◽  
Slope Stability ◽  
Rock Slope ◽  
Limit Equilibrium ◽  
Slope Stability Analysis ◽  
Rock Slope Stability ◽  
Rock Slopes ◽  
Block Theory ◽  
Joint Plane ◽  
Identification Techniques

Rock slopes stability has been one of the fundamental issues facing geotechnical engineering researchers. Due to the pre-existing joints, the intactness of the rock is weakened. The mechanical characteristics are changed correspondingly along with joint-induced stress redistribution within the rock mass if the sliding limit at the joint or part of it is exceeded. In this study, spatial block topological identification techniques are applied to distinguish all blocks cut by 3D finite random or fixed discontinuities. Based on the available photographic information of rock slopes, the sliding forces and the corresponding factor of safety are evaluated through limit equilibrium conditions by the classic block theory. The rock slope stability analysis software, GeoSMA-3D (Geotechnical Structure and Model Analysis), satisfying the requirements of spatial block modeling, joint plane simulation, key block identification and analysis and sliding process display, was developed. The application of such a software on the analysis of a rock slope, which is located near the inlet of Daiyuling No. 1 tunnel on the Zhuanghe–Gaizhou highway networks, was performed. The assessed results were compared with the monitored data to validate the effectiveness of such software.

Study on the mechanisms of flexural toppling failure in anti-inclined rock slopes using numerical and limit equilibrium models

2018 ◽  
Vol 237 ◽  
pp. 116-128 ◽  
Author(s):  
Yun Zheng ◽  
Congxin Chen ◽  
Tingting Liu ◽  
Haina Zhang ◽  
Kaizong Xia ◽  
...  
Keyword(s):  
Limit Equilibrium ◽  
Rock Slopes ◽  
Equilibrium Models ◽  
Toppling Failure ◽  
Flexural Toppling ◽  
Flexural Toppling Failure

scholarly journals AN EVALUATION OF ROCK SLOPE STABILITY USING LIMIT EQUILIBRIUM ANALYSES

2015 ◽  
Vol 6 (2) ◽  
Author(s):  
Faridha Aprilia ◽  
I Gde Budi Indrawan
Keyword(s):  
Slope Stability ◽  
Rock Slope ◽  
Limit Equilibrium ◽  
Rock Slope Stability ◽  
Rock Slopes ◽  
Plane Failure ◽  
General Limit ◽  
The Stability ◽  
Equilibrium Analyses ◽  
Limit Equilibrium Analyses

The stability of rock slopes is controlled by several factors, such as the intact rock strength, discontinuity characteristics, groundwater condition, and slope geometry. Limit equilibrium (LE) analyses have been commonly used in geotechnical practice to evaluate the stability of rock slopes. A number of methods of LE analyses, ranging from simple to sophisticated methods, have been developed. This paper presents stability analyses of rock slopes at the Batu Hijau open mine in Sumbawa Barat using various methods of LE analyses. The LE analyses were conducted at three cross sections of the northern wall of the open mine using the Bishop Simplified, Janbu Simplified, Janbu Generalised, and General Limit Equilibrium (GLE) methods in Slide slope stability package. In addition, a Plane Failure (PF) analysis was performed manually. Shear strength data of the discontinuity planes used in the LE analyses were obtained from back analyses of previous rock slope failures. The LE analysis results showed that the rock slopes were likely to have shallow non-circular critical failure surfaces. The factor of safety (Fs) values obtained from the Bishop Simplified, Janbu Simplified, Janbu Generalised, and GLE methods were found to be similar, while the Fs values obtained from the PF method were higher than those obtained from the more rigorous methods. Keywords: Batu Hijau mine, Bishop Simplified, Janbu Simplified, Janbu Generalised, limit equilibrium analyses, general limit equilibrium, rock slope stability, plane failure.

scholarly journals Analysis of Progressive Failure Mechanism of Rock Slope with Locked Section Based on Energy Theory

Energies ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1128 ◽  
Author(s):  
Qifeng Guo ◽  
Jiliang Pan ◽  
Meifeng Cai ◽  
Ying Zhang
Keyword(s):  
Evolution Equation ◽  
Safety Factor ◽  
Rock Slope ◽  
Dynamic Instability ◽  
Progressive Failure ◽  
Deformation Energy ◽  
Rock Slopes ◽  
Energy Evolution ◽  
Rock Bridges ◽  
Slope System

Progressive failure in rock bridges along pre-existing discontinuities is one of the predominant destruction modes of rock slopes. The monitoring and prediction of the impending progressive failure is of great significance to ensure the stability of the rock structures and the safety of the workers. The deformation and fracture of rocks are complex processes with energy evolution between rocks and the external environment. Regarding the whole slope as a system, an energy evolution equation of rock slope systems during progressive failure was established by an energy method of systemic stability. Then, considering the weakening effect of joints and the locking effect of rock bridges, a method for calculating the safety factor of rock slopes with a locked section was proposed. Finally, the energy evolution equation and the calculation method of safety factor are verified by a case study. The results show that when the energy dissipated in the progressive failure process of rock bridges is less than the energy accumulated by itself, the deformation energy stored in the slope system can make the locked section deform continuously until the damage occurs. The system energy equal to zero can be used as the critical criterion for the dynamic instability of the rock slope with locked section. The accumulated deformation energy in the slope system can promote the development of the cracks in the locked section, and the residual energy in the critical sliding state is finally released in the form of kinetic energy, which is the main reason for the progressive dynamic instability of rock slopes.

New method for dynamic stability analysis of rock slope under blasting vibration based on equivalent acceleration and Sarma method

2014 ◽  
Vol 51 (4) ◽  
pp. 441-448 ◽  
Author(s):  
Ming Chen ◽  
Wenbo Lu ◽  
Peng Yan ◽  
Chuangbing Zhou
Keyword(s):  
Dynamic Stability ◽  
Rock Slope ◽  
Limit Equilibrium ◽  
Equilibrium Analysis ◽  
New Method ◽  
Vibration Velocity ◽  
Blasting Vibration ◽  
Analytic Method ◽  
Rock Slopes ◽  
Limit Equilibrium Analysis

Dynamic stability of rock slopes under dynamic blasting disturbance and its analytic method are key problems in slope engineering. Based on wave theory, the relationship between blasting vibration velocity, acceleration, and stress state of slopes is studied. The results indicate that with the same blasting vibration velocity, peak stress of the slopes is identical. An equivalent acceleration calculation method is proposed for the limit equilibrium analysis of rock slope stability under blasting vibration. Considering the dynamic time-varying characteristics of the blasting vibration loading, a time-history method based on the equivalent acceleration and the Sarma method of limit equilibrium analysis is then presented for the dynamic stability analysis of rock slopes. On the basis of this new method, the high rock slopes on the left bank in the Jinping I Hydropower Station are analyzed. Results of the case study derived from the new analytic method indicate that this new method is reasonable.

Research of Cutting Slop Process by Strength Reduction FDM

2014 ◽  
Vol 962-965 ◽  
pp. 868-872
Author(s):  
Li Yan ◽  
Hou Li Fu
Keyword(s):  
Slip Plane ◽  
Rock Slope ◽  
Reduction Method ◽  
Limit Equilibrium ◽  
Failure Process ◽  
Strength Reduction ◽  
Instability Criterion ◽  
Flow Rule ◽  
Strength Reduction Method ◽  
Gradual Development

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.

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