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.

scholarly journals The role of cornice fall avalanche sedimentation in the valley Longyeardalen, Central Svalbard

2012 ◽  
Vol 6 (6) ◽  
pp. 4999-5036 ◽  
Author(s):  
M. Eckerstorfer ◽  
H. H. Christiansen ◽  
L. Rubensdotter ◽  
S. Vogel
Keyword(s):  
Rock Slope ◽  
Time Lapse ◽  
Sediment Traps ◽  
Rock Slopes ◽  
Mass Wasting ◽  
Transport Pathway ◽  
Rock Face ◽  
Slope System ◽  
Time Lapse Photography

Abstract. In arctic and alpine high relief landscapes snow avalanches are traditionally ranked behind rockfall in terms of their significance for mass wasting processes of rock slopes. Cornice fall avalanches are at present the most dominant snow avalanche type at two slope systems, called Nybyen and Larsbreen, in the valley Longyeardalen in Central Svalbard. Both slope systems are situated on NW-facing lee slopes underneath large summit plateau, where cornices form annually, and high frequency and magnitude cornice fall avalanching is observed by daily automatic time-lapse photography. In addition, rock debris sedimentation by these cornice fall avalanches was measured directly in either permanent sediment traps or by snow inventories. The results from a maximum of 7 yr of measurements in a total of 13 catchments show maximum avalanche sedimentation rates ranging from 8.2 to 38.7 kg m−2 at Nybyen and from 0.8 to 55.4 kg m−2 at Larsbreen. Correspondingly, the avalanche fan-surfaces accreted annually in a~maximum range from 3.7 to 13 mm yr−1 at Nybyen and from 0.3 to 21.4 mm yr−1 at Larsbreen. This comparably efficient rock slope mass wasting is due to collapsing cornices producing cornice fall avalanche with high rock debris content throughout the entire winter. The rock debris of different origin stems from the plateau crests, the adjacent free rock face and the transport pathway, accumulating distinct avalanche fans at both slope systems and contributing to the development of a rock glacier at the Larsbreen slope system.

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.

Failure Mechanism of an Idealized Layered Rock Slope Subjected to Seismic Loads

2014 ◽  
Vol 574 ◽  
pp. 89-95 ◽  
Author(s):  
Ya Qun Liu ◽  
Hai Bo Li ◽  
Xiang Xia ◽  
Bo Liu ◽  
Qi Tao Pei
Keyword(s):  
Failure Mechanism ◽  
Rock Slope ◽  
Progressive Failure ◽  
Distinct Element ◽  
Three Dimensional ◽  
Normal Displacement ◽  
Seismic Loads ◽  
Rock Slopes ◽  
Layered Rock ◽  
Distinct Element Code

The dynamic response of an idealized layered rock slope with a single joint subjected to seismic loads is investigated using the three dimensional distinct element code in the present study. Based on the numerical modeling, the variations of the stresses of the blocks close to the joint and the deformation of the joint are discussed, and the progressive failure mechanism of the slope is analyzed. It is found that, with the increasing excitations, the tensile stresses and the areas of tension zones in the upper part of the slope near the joint have increased gradually. In addition, the normal displacement at the upper part of the joint also becomes larger and larger, which leads to the gradual split of the upper part of joint. Hence the contact area for blocks at both sides of the joint has decreased, which gradually results in the decrease of the cohesion of the joint. When the induced shear stress for the joint under the applied excitations exceeds its shear strength, the potential sliding blocks will slip along the joint. The results in this paper may provide references for the study on failure mechanism of complicated layered rock slopes subjected to dynamic loads.

scholarly journals Semi-automated regional classification of the style of activity of slow rock-slope deformations using PS InSAR and SqueeSAR velocity data

Landslides ◽  
2021 ◽  
Author(s):  
Chiara Crippa ◽  
Elena Valbuzzi ◽  
Paolo Frattini ◽  
Giovanni B. Crosta ◽  
Margherita C. Spreafico ◽  
...  
Keyword(s):  
Rock Slope ◽  
Progressive Failure ◽  
Principal Component ◽  
Cost Effective ◽  
Displacement Rate ◽  
Machine Learning Classification ◽  
Management Perspective ◽  
Alpine Environments

AbstractLarge slow rock-slope deformations, including deep-seated gravitational slope deformations and large landslides, are widespread in alpine environments. They develop over thousands of years by progressive failure, resulting in slow movements that impact infrastructures and can eventually evolve into catastrophic rockslides. A robust characterization of their style of activity is thus required in a risk management perspective. We combine an original inventory of slow rock-slope deformations with different PS-InSAR and SqueeSAR datasets to develop a novel, semi-automated approach to characterize and classify 208 slow rock-slope deformations in Lombardia (Italian Central Alps) based on their displacement rate, kinematics, heterogeneity and morphometric expression. Through a peak analysis of displacement rate distributions, we characterize the segmentation of mapped landslides and highlight the occurrence of nested sectors with differential activity and displacement rates. Combining 2D decomposition of InSAR velocity vectors and machine learning classification, we develop an automatic approach to characterize the kinematics of each landslide. Then, we sequentially combine principal component and K-medoids cluster analyses to identify groups of slow rock-slope deformations with consistent styles of activity. Our methodology is readily applicable to different landslide datasets and provides an objective and cost-effective support to land planning and the prioritization of local-scale studies aimed at granting safety and infrastructure integrity.

3D modeling of stratified and irregularly jointed rock slope and its progressive failure

2012 ◽  
Vol 6 (6) ◽  
pp. 2147-2163 ◽  
Author(s):  
K. Ma ◽  
C. A. Tang ◽  
L. C. Li ◽  
P. G. Ranjith ◽  
M. Cai ◽  
...  
Keyword(s):  
3D Modeling ◽  
Rock Slope ◽  
Progressive Failure ◽  
Jointed Rock ◽  
Jointed Rock Slope

scholarly journals Assessment of Slope Instability and Risk Analysis of Road Cut Slopes in Lashotor Pass, Iran

2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
Mohammad Hossein Taherynia ◽  
Mojtaba Mohammadi ◽  
Rasoul Ajalloeian
Keyword(s):  
Rock Mass ◽  
Risk Analysis ◽  
Rock Slope ◽  
Classification Systems ◽  
Slope Instability ◽  
Rock Slope Stability ◽  
Rock Slopes ◽  
The Stability ◽  
Cut Slopes ◽  
Road Cut Slopes

Assessment of the stability of natural and artificial rock slopes is an important topic in the rock mechanics sciences. One of the most widely used methods for this purpose is the classification of the slope rock mass. In the recent decades, several rock slope classification systems are presented by many researchers. Each one of these rock mass classification systems uses different parameters and rating systems. These differences are due to the diversity of affecting parameters and the degree of influence on the rock slope stability. Another important point in rock slope stability is appraisal hazard and risk analysis. In the risk analysis, the degree of danger of rock slope instability is determined. The Lashotor pass is located in the Shiraz-Isfahan highway in Iran. Field surveys indicate that there are high potentialities of instability in the road cut slopes of the Lashotor pass. In the current paper, the stability of the rock slopes in the Lashotor pass is studied comprehensively with different classification methods. For risk analyses, we estimated dangerous area by use of the RocFall software. Furthermore, the dangers of falling rocks for the vehicles passing the Lashotor pass are estimated according to rockfall hazard rating system.

An algorithm for the 3D ROck Slope Kinematic Analysis (ROKA) based on RPAS digital photogrammetry data.

2021 ◽  
Author(s):  
Niccolò Menegoni ◽  
Daniele Giordan ◽  
Cesare Perotti
Keyword(s):  
Kinematic Analysis ◽  
Rock Slope ◽  
Traditional Approach ◽  
Rock Slopes ◽  
Digital Photogrammetry ◽  
Modes Of Failure ◽  
Wedge Sliding ◽  
Flexural Toppling ◽  
The Stability ◽  
Digital Outcrop

<p>Among the several adopted methods for the kinematic analysis of the possible modes of failure that could affect a rock slope, the Markland test is the most used. Whereas, it has the advantage of being simple and fast, it has some limits, as the impossibility to manually consider the several different slope orientations and their interaction with the discontinuity dimensions and positions.</p><p>Recently, the improvements in the Remote Piloted Aerial System (RPAS) digital photogrammetry techniques for the development and mapping of Digital Outcrop Models (DOMs) have given the possibility of developing new automatized digital approaches. In this study, ROKA (ROck slope Kinematic Analysis) algorithm is presented. It is an open-source algorithm, written in MATLAB language, which aims to perform the kinematic analysis of the stability of a rock slope using the discontinuity measurements collected onto 3D DOMs. Its main advantage is the possibility to identify the possible critical combination between the 3D georeferenced discontinuities and the local surface of the slope. In particular, the critical combinations that can activate the planar sliding, flexural toppling, wedge sliding and direct toppling modes of failures can be detected and highlighted directly on the DOM. Hence, the ROKA algorithm can make the traditional approach for the kinematic analysis of a rock slope more effective, allowing not only to simplify the analysis, but also to increase its detail. This can be very important, in particular, for the analysis of large and complex rock slopes.</p>

Study on Failure Mechanism and Prevention Measures of Typical Rock Slope in Tibetan Plateau

2014 ◽  
Vol 587-589 ◽  
pp. 1012-1020
Author(s):  
Jie Zhao
Keyword(s):  
Tibetan Plateau ◽  
Positive Reinforcement ◽  
Rock Slope ◽  
Sliding Mode ◽  
Geological Structure ◽  
Climatic Conditions ◽  
Natural State ◽  
Rock Slopes ◽  
Prevention Measures ◽  
Reinforcement Measures

The special geographical, climatic conditions and geological structure in Tibetan Plateau making high steep rock slopes along the valleys wide-spread in this area, and they are especially common in the construction of highways. In this study, geological genesis and potential sliding mode are discussed firstly, then numerical model results as well as actual data are used to analyze the cause and influence depth of unloading fissures. Finally, common problems exist in rock slope are summed up. Based on these, natural state, disturbed state and steady state after reinforcement are analyzed respectively. It is believed that rock slopes in this area should be considered to minimize unloading, changing their shapes, and should try to reinforce actively or take positive reinforcement measures, so that the disturbance caused by rock soil environment will be effectively controlled, and the ecological restoration work will be done.

Twenty-ninth Canadian Geotechnical Colloquium: The role of advanced numerical methods and geotechnical field measurements in understanding complex deep-seated rock slope failure mechanisms

2008 ◽  
Vol 45 (4) ◽  
pp. 484-510 ◽  
Author(s):  
Erik Eberhardt
Keyword(s):  
Rock Mass ◽  
Numerical Modelling ◽  
Slope Failure ◽  
Rock Slope ◽  
Current Knowledge ◽  
Progressive Failure ◽  
Strength Degradation ◽  
Rock Slope Stability ◽  
Clear Understanding ◽  
Rock Mass Strength

The underlying complexity associated with deep-seated rock slope stability problems usually restricts their treatment to phenomenological studies that are largely descriptive and qualitative. Quantitative assessments, when employed, typically focus on assessing the stability state but ignore factors related to the slope’s temporal evolution including rock mass strength degradation, internal shearing, and progressive failure, all of which are key processes contributing to the final collapse of the slope. Reliance on displacement monitoring for early warning and the difficulty in interpreting the data without a clear understanding of the underlying mechanisms has led to a situation where predictions are highly variable and generally unreliable. This paper reviews current knowledge regarding prefailure mechanisms of massive rock slopes and current practices used to assess the hazard posed. Advanced numerical modelling results are presented that focus on the importance of stress- and strain-controlled rock mass strength degradation leading to failure initiation. Efforts to address issues related to parameter and model uncertainty are discussed in the context of a high alpine research facility, the “Randa In Situ Rockslide Laboratory”, where state-of-the-art instrumentation systems and numerical modelling are being used to better understand the mechanisms controlling prefailure deformations over time and their evolution leading to catastrophic failure.

Sign in / Sign up

Export Citation Format

Share Document