scholarly journals Simulating Crack Development and Failure Characteristic of Toppling Rock Slope under Seismic Loading on Lancang River in China

Lithosphere ◽  
2021 ◽  
Vol 2021 (Special 4) ◽  
Author(s):  
Shiqi Liu ◽  
Huanling Wang ◽  
Qingxiang Meng ◽  
Long Yan
Keyword(s):  
Rock Mass ◽  
Rock Slope ◽  
Seismic Loading ◽  
Seismic Intensity ◽  
Particle Flow Code ◽  
Mountainous Area ◽  
Rock Slopes ◽  
Lancang River ◽  
Loading Method ◽  
Potential Failure

Abstract Toppling rock slopes, induced by rapid and continuous downcutting of Lancang River, are widely distributed in the mountainous area of southwest China. To investigate the instability mechanism of 1# toppling rock slope of Huangdeng Hydropower Station under seismic loading, particle flow code (PFC) is applied to simulate the dynamic response and failure mode. The study considers the particle characteristics of displacement, velocity, energy, and cracks. According to numerical results, the potential failure mechanism of toppling rock slope is identified: multisliding surfaces form at the interfaces between the highly and moderately toppled rock mass and between the highly/moderately and weak toppled-crept rock mass; intersecting faults cut rock mass at the toe, leading to shear-toppling deformation; tension cracks develop, penetrate, and coalesce in the weak toppled-crept rock mass, resulting in tension-toppling-bending deformation. During the 2 to 5 s of strong seismic intensity, crack increases sharply and energy of particles fluctuates greatly. The impacts of the amplitude of seismic loading and loading method in PFC are investigated. This study will provide a practically useful reference for seismic design of rock slopes.

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.

scholarly journals Assessment of a Modified Rock Mass Classification System for Rock Slope Stability Analysis in the Q-system

2015 ◽  
Vol 19 (2) ◽  
pp. 147-152 ◽  
Author(s):  
Davood Fereidooni ◽  
Gholam Reza Khanlari ◽  
Mojtaba Heidari
Keyword(s):  
Rock Mass ◽  
Slope Stability ◽  
Classification System ◽  
Rock Slope ◽  
Rock Mass Classification ◽  
Classification Systems ◽  
Rock Slope Stability ◽  
Rock Slopes ◽  
El Sistema ◽  
Mass Classification

<p>This paper explores the applicability of a modified Q classification system and its component parameters for analysis and conclusion of site investigation data to estimate rock slope stability. Based on the literature, Q classification system has high applicable potential for evaluation of rock mass quality. Therefore, in this study, it was used with RMR and SMR rock mass classification systems to assess stability or instability of different rock slopes along the Hamedan-Ganjnameh-Tuyserkan road, Hamedan province west of Iran. Furthermore, a modified rock mass classification system namely Slope Quality Rating (SQR) was proposed based on the correction of the Q classification parameters and calculating some new parameters such as dip and strike of discontinuities and the method of rock excavation or blasting. For this purpose, the SMR and RMR rock mass classifications were also needed. By measuring SQR for different rock slopes, it will be possible to measure Slope Mass Rating (SMR).</p><p> </p><p><strong>Evaluación del sistema Q modificado de clasificación del macizo rocoso para el análisis de estabilidad de pendiente de roca</strong></p><p> </p><p><strong>Resumen</strong></p>Este artículo explora la aplicabilidad del sistema de clasificación Q modificado y sus parámetros para analizar y determinar la información estimada de estabilidad de pendiente de roca en el sitio determinado de estudio. Según la literatura, el sistema de clasificación Q tiene un alto potencial de aplicabilidad paral a evaluación de la calidad del macizo rocoso. En este estudio además se utilizó el sistema Q junto con los sistemas Índice de Masa de Pendiente (SMR) y Clasificación Geomecánica de Bienawski (RMR) para evaluar la estabilidad e inestabilidad de diferentes pendientes rocosas en la carretera Hamedan-Ganjnameh-Tuyserkan, de la provincia de Hamedan, en el Oeste de Irán. Además, se propone el Índice de Calidad de Pendiente (SQR), un sistema de clasificación de macizo rocoso modificado, a partir de la corrección de los parámetros de clasificación Q y el cálculo de nuevos parámetros como pendiente y caída de las discontinuidades y el método de excavación o explosión de la roca. Para esta propuesta también se utilizaron las clasificaciones SMR y RMR. La medición SQR en diferentes pendientes hizo posible el cálculo del sistema SMR.</p>

scholarly journals Study on the Influence of Rainfall Infiltration on the High rock Slope of Open-pit Mine Stability using a New Nonlinear Strength Reduction Method

2021 ◽  
Author(s):  
Tianbai Zhou ◽  
Lingfan Zhang ◽  
Jian Cheng ◽  
Jianming Wang ◽  
Xiaoyu Zhang ◽  
...  
Keyword(s):  
Rock Mass ◽  
Rock Slope ◽  
Reduction Method ◽  
Strength Reduction ◽  
Open Pit Mine ◽  
Open Pit ◽  
Strength Reduction Method ◽  
Rock Slopes ◽  
High Rock Slope ◽  
The Stability

Abstract Due to long-term mining, a series of high and steep rock slopes have been formed in the open-pit mine. For high rock slopes, rainfall infiltration is the main cause of landslide. Therefore, the stability analysis of high rock slope under rainfall has become a key issue in the open-pit mine engineering. In this work, aiming at the high stress condition of high rock slope, the instantaneous internal friction angle and instantaneous cohesion of rock mass under different stress states are deduced, and the a nonlinear strength reduction method for high rock slope is established according to the relationship between normal stress and shear stress of rock mass under the Hoke-Brown criterion. The numerical calculation results show that the factor of safety (FOS) for high rock slope calculated by the proposed method is more reasonable. Taking the southwest slope of Dagushan Iron Mine as the research background, the safety factors of high rock slope under different rainfall conditions are calculated by COMSOL Multiphysics. And the stability analysis of high rock slope in open-pit mine under rainfall are carried out.

scholarly journals Three-Dimensional Physical and Numerical Modelling of Fracturing and Deformation Behaviour of Mining-Induced Rock Slopes

2019 ◽  
Vol 9 (7) ◽  
pp. 1360 ◽  
Author(s):  
Guoxiang Yang ◽  
Anthony K. Leung ◽  
Nengxiong Xu ◽  
Kunxiang Zhang ◽  
Kunpeng Gao
Keyword(s):  
Rock Mass ◽  
Numerical Modelling ◽  
Physical Model ◽  
Rock Slope ◽  
Rock Joint ◽  
Three Dimensional ◽  
Physical Modelling ◽  
Rock Slopes ◽  
Rock Mass Structure ◽  
Iron Mine

Fracturing behaviour of jointed rock mass subjected to mining can significantly affect the stability of the rock structures and rock slopes. Ore mining within an open-pit final slope would lead to large-scale strata and surface movement of the rock slope. Rock mass structure, or more specifically, the strength, spacing and distribution of rock joints, are the controlling factors that govern the failure and deformation mechanisms of the final slope. Two-dimensional (2-D) physical modelling tests have been conducted in the literature, but in general, most of them have simplified the geological conditions and neglected some key features of rock mass structure in the field. In this study, new three-dimensional (3-D) physical modelling methods are introduced, with realistic modelling of mechanical behaviour of rock mass as well as identified properties of predominant rock joint sets. A case study of Yanqianshan iron mine is considered and the corresponding 1:200 model rock slope was created for studying the rock joint effects on the strata movement and the subsidence mechanism of the slope. The physical model test results are subsequently verified with 3-D discrete element numerical modelling. Due to the presence of the predominant joints, the observed well-shaped strata subsidence in Yanqianshan iron mine was successfully reproduced in the 3-D physical model. The failure mechanism of rock slopes differs from the trumpet-shaped subsidence observed in unconsolidated soil. Due to the formation of an arching mechanism within the rock mass, the strata deformation transferred gradually from the roof of the goaf to the slope surface.

scholarly journals Stability evaluation and potential failure process of rock slopes characterized by non-persistent fractures

2020 ◽  
Author(s):  
Wen Zhang ◽  
Jia Wang ◽  
Peihua Xu ◽  
Junqing Lou ◽  
Bo Shan ◽  
...  
Keyword(s):  
Statistical Analysis ◽  
Rock Slope ◽  
Slip Surface ◽  
Fractured Rock ◽  
Failure Process ◽  
Comprehensive Approach ◽  
Rock Slopes ◽  
Critical Slip Surface ◽  
Gravity Increase Method ◽  
Potential Failure

Abstract. Slope failure, which causes destructive damage and fatalities, is extremely common in mountainous areas. Therefore, the stability and potential failure of slopes must be analyzed accurately. For most fractured rock slopes, the complexity and random distribution of structural fractures make the aforementioned analyses considerably challenging for engineers and geologists worldwide. This study aims to solve this problem by proposing a comprehensive approach that combines the discrete fracture network (DFN) modeling technique, synthetic rock mass (SRM) approach, and statistical analysis. Specifically, a real fractured rock slope in Laohuding Quarry in Jixian County is studied to show this comprehensive approach. DFN simulation is performed to generate non-persistent fractures in the cross section of the slope. Subsequently, SRM approach is applied to simulate the slope model using 2D particle flow code software (PFC2D). A stability analysis is carried out based on the improved gravity increase method, emphasizing the effect of stress concentration throughout the formation of the critical slip surface. The collapse, rotation, and fragmentation of blocks and the accumulation distances are evaluated in the potential failure process of the rock slope. 100 slope models generated with different DFN models are used to repeat the aforementioned analyses as the result of a high degree of variability in DFN simulation. The critical slip surface, factor of safety, and accumulation distance are selected by statistical analysis for safety assurance in slope analysis and support.

Influences of Joint Persistence and Groundwater on Wedge Failure Potential of Jointed Rock Slope

2020 ◽  
Author(s):  
Yu-Hsuan Chang ◽  
Cheng-Han Lin ◽  
Ming-Lang Lin
Keyword(s):  
Rock Slope ◽  
Water Pressure ◽  
Jointed Rock ◽  
Slope Instability ◽  
Rock Slope Stability ◽  
Rock Slopes ◽  
Wedge Failure ◽  
Large Landslide ◽  
Potential Failure ◽  
The Stability

&lt;p&gt;Joint persistence and groundwater are critical factors that influence the stability of rock slope. Persistence dominates the extent of pre-existing potential failure surfaces. Under certain conditions, slope instability may vary with time, as the propagation of existing joints leads to the development of fully persistence failure surfaces. At the same time, groundwater may travel through the fracture network and provides an external force to unstable rock masses, resulting in the damage of rock slope failure hard to predict. In general, when a rock slope consists of two or more sets of joints, the wedge failure often becomes the initial structurally controlled failure of a progressive large landslide. A classic case, which was occurred at a steep cut rock slope on 32.5k, Provincial Highway 7, Taiwan, had been completely recorded with UAV-surveys, field investigations and witness. The landslide first occurred on 13th May 2019 as a wedge failure with the magnitude of the volume of 892 m&lt;sup&gt;3&lt;/sup&gt; and resulted in a large landslide on 29th July 2019 with the magnitude of the volume of 37234 m&lt;sup&gt;3&lt;/sup&gt;, destroyed the protection measures and roads. According to the field investigation, groundwater was discovered flowing out from the line of intersection of persistence joints, which could be the main reason leads to the wedge failure and the progressive large rockslide. Hence, the couple mechanics-hydraulic behavior in a rock slope should be studied in more detail to mitigate such hazards.&lt;/p&gt;&lt;p&gt;In this study, sandbox model was applied to clarify the effects of the groundwater and joint friction on failures of single rock wedge. In addition, the software 3DEC, which is based on Distinct Element method, was carried out to extent the analysis conditions. The results of sandbox simulations were used to calibrate the performance of the numerical model, especially the coupled hydro-mechanical analysis. The stability of jointed rock slopes under different persistence and various water pressure conditions has been studied. It is believed that the study can enhance the way for stability analysis and monitoring of the potential failure of jointed rock slopes.&lt;/p&gt;&lt;p&gt;Keywords: Wedge failure; Joint persistence; Groundwater; Rock slope stability.&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;

Study on the Rock Slope Landslide Caused by Earth Penetrating Weapon Explosion

2013 ◽  
Vol 376 ◽  
pp. 108-112
Author(s):  
Jie Zhong Hao ◽  
Cun Cheng Shi ◽  
Jie Li ◽  
Yun Hou Sun
Keyword(s):  
Rock Mass ◽  
Rock Slope ◽  
Limit Equilibrium ◽  
Seismic Attenuation ◽  
Inertia Force ◽  
Loading Method ◽  
The Earth ◽  
The Stability ◽  
Mass Volume ◽  
The Impact

The rigid limit equilibrium method can be used to analyse the slope stability under the earth penetrating weapon explosion. The explosion seismic inertia force is equivalent by the equivalent static loading method and seismic attenuation is also taken into account, and then the calculating formula is got. The calculation of the example indicates that the stability coefficient increases as the potential sliding rock mass volume increasing and the critical sliding point is corresponding to the maximum sliding rock mass volume. The impact point and explosion center depth influence the slope sliding.

Stability analysis of steep rock slopes

1989 ◽  
Vol 26 (4) ◽  
pp. 595-603 ◽  
Author(s):  
A. Afrouz ◽  
F.P. Hassani ◽  
R. Ucar
Keyword(s):  
Rock Mass ◽  
Failure Criterion ◽  
Variational Calculus ◽  
Failure Surface ◽  
Jointed Rock ◽  
Rock Slopes ◽  
Coulomb Failure ◽  
Potential Failure ◽  
Coulomb Failure Criterion

A simplified method of predicting the shape and location of the potential failure surface in steep rock slopes is suggested. The 1988 updated Hoek and Brown failure criterion is used with Priest and Brown m and s values and Bieniawski's jointed rock mass classification system. This method is demonstrated by an application to the design of slope reinforcement by rock anchoring and by a case study. The validity of the method is assessed by reference to the variational calculus approach, using the linear Mohr–Coulomb failure criterion. Key words: benches, bench design, bench anchoring, quarrying, slope stability, ground control, rock mass rating.

scholarly journals Seismic stability analysis of rock slopes by yield design theory using the generalized Hoek-Brown criterion

2018 ◽  
Vol 149 ◽  
pp. 02026
Author(s):  
Mounir Belghali ◽  
Zied Saada
Keyword(s):  
Rock Mass ◽  
Stability Analysis ◽  
Design Theory ◽  
Rock Slope ◽  
Numerical Solutions ◽  
Stability Study ◽  
Seismic Stability ◽  
Rock Slopes ◽  
The Stability ◽  
Kinematic Approach

The stability of rock slope is studied using the kinematic approach of yield design theory, under the condition of plane strain and by considering the last version of the Hoek-Brown failure criterion. This criterion, which is suitable to intact rock or rock mass highly fractured regarded as isotropic and homogeneous, is widely accepted by the rock mechanics community and has been applied in numerous projects around the world. The failure mechanism used to implement the kinematic approach is a log-spiral rotational mechanism. The stability analysis is carried out under the effects of gravity forces and a surcharge applied along the upper plateau of the slope. To take account of the effects of forces developed in the rock mass during the passage of a seismic wave, the conventional pseudo-static method is adopted. This method is often used in slope stability study for its simplicity and efficiency to simulate the seismic forces. The results found are compared with published numerical solutions obtained from other approaches. The comparison showed that the results are almost equal. The maximum error found is less than 1%, indicating that this approach is effective for analyzing the stability of rock slopes. The relevance of the approach demonstrated, investigations are undertaken to study the influence of some parameters on the stability of the slope. These parameters relate to the mechanical strength of the rock, slope geometry and loading.

scholarly journals Interaction of Strength and Stress in High, Steep Rock Slopes

2016 ◽  
Vol 8 (1) ◽  
pp. 14
Author(s):  
John Victor Smith
Keyword(s):  
Rock Mass ◽  
Rock Slope ◽  
Soil Mechanics ◽  
Slope Angle ◽  
Precise Determination ◽  
Rock Slopes ◽  
Confining Stress ◽  
Slope Engineering ◽  
Steep Slopes

The strength of rock mass and the stress in a slope are each complex fields of investigation. They are also intimately related as increasing confining stress makes a rock mass stronger and the strength of a rock mass can limit the magnitude of stress. Whereas these interactions are comparatively well understood for soils, principally through the advances of laboratory soil mechanics, the scale of rock masses, principally the presence of discontinuity surfaces, limits the capacity for laboratory investigation. The interaction of strength and stress in rock slopes is most evident in high, steep slopes where stress is typically greater. The slope angle and failure mechanisms occurring in the rock slope can reveal the ways that strength and stress interact to produce the observed morphology. McKay Bluff, near Nelson, South Island, New Zealand, is a high, steep rock slope affected by marine coastal erosion at its base. Finite element modeling illustrates sensitivities in determination of the stress magnitude in the slope. Engineering geology methods demonstrate the difficulty in precise determination of the rock mass strength. The ranges of these parameters are compared to find a compatible range for the interacting factors. The stress in a range of other high, steep slope types is reviewed and the implications for geomorphic analysis are discussed.

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