scholarly journals Soil-Rock Slope Stability Analysis under Top Loading considering the Nonuniformity of Rocks

2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Huang Xian-Wen ◽  
Zhi-Shu Yao ◽  
Wang Bing-Hui ◽  
Zhou Ai-Zhao ◽  
Peng-Ming Jiang
Keyword(s):  
Slope Stability ◽  
Failure Modes ◽  
Shear Failure ◽  
Rock Slope Stability ◽  
Western China ◽  
Triaxial Tests ◽  
Distribution Characteristics ◽  
Rock Slopes ◽  
Rock Skeleton ◽  
Ultimate Loading

Soil-rock slopes are widely distributed in central or western China. With the development of transportation, many subgrades are being built on mountainsides and therefore, slope stability has to be estimated under high loadings. To obtain better estimation results, a new rock contour establishing algorithm was developed, capable of considering interlock effect between rocks. Then, computed tomography (CT) and unconfined triaxial tests with ring top loadings were conducted. Based on rock distribution characteristics (obtained by CT photos) and the appearance of shear failure surfaces in slopes under ring top loadings, four rock skeleton status and five shear failure surface developing models were introduced. Based on the developed rock contour establishing algorithm, ten groups (twelve models per group) were established and calculated by finite element method (FEM). After this, normalized ultimate loading increasing multiple N, which was the ultimate loading ratio of rock-containing slope to uniform soil slope, was introduced to evaluate the influence of rock distributions on slope stability. The value of N was increased with the increase of rock content due to rock skeleton status. The values of N in slopes with angular rocks were about three times higher than those with round rocks which was due to complex geometric shape and distribution characteristics of angular rocks. Then, considering different slope angles (50°–60°), rock contents (0%–60%), and rock shapes (round and angular), the ultimate loading increasing multiple N of soil-rock slopes under high loadings was calculated and suggested for engineering designs. Finally, based on the failure surfaces of numerical modes, three typical failure modes were developed, which could be reference for designers to deal with slopes.

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.

scholarly journals Stability assessment of degrading permafrost rock slopes based on a coupled thermo-mechanical model

2020 ◽  
Author(s):  
Philipp Mamot ◽  
Samuel Weber ◽  
Saskia Eppinger, ◽  
Michael Krautblatter
Keyword(s):  
Slope Stability ◽  
Rock Slope ◽  
Fracture Network ◽  
Slope Instability ◽  
Rock Slope Stability ◽  
Permafrost Degradation ◽  
Rock Slopes ◽  
High Mountains ◽  
Permafrost Rock ◽  
Wide Range

Abstract. In the last two decades, permafrost degradation has been observed to be a major driver of enhanced rock slope instability and associated hazards in high mountains. While the thermal regime of permafrost degradation in high mountains has already been intensively investigated, the mechanical consequences on rock slope stability have so far not been reproduced in numerical models. Laboratory studies and conceptual models argue that warming and thawing decrease rock and discontinuity strength and promote deformation. This study presents the first general approach for a temperature-dependent numerical stability model that simulates the mechanical response of a warming and thawing permafrost rock slope. The proposed procedure is applied to a rockslide at the permafrost-affected Zugspitze summit crest. Laboratory tests on frozen and unfrozen rock joint and intact rock properties provide material parameters for the discontinuum model developed with the Universal Distinct Element Code (UDEC). Geophysical and geotechnical field surveys deliver information on the permafrost distribution and fracture network. The model demonstrates that warming decreases rock slope stability to a critical level, while thawing initiates failure. A sensitivity analysis of the model with a simplified geometry and warming trajectory below 0 °C shows that progressive warming close to the melting point initiates instability above a critical slope angle of 50–62°, depending on the orientation of the fracture network. The increase in displacements intensifies for warming steps closer to zero degree. The simplified and generalised model can be applied to permafrost rock slopes (i) which warm above −4 °C, (ii), with ice-filled joints, (iii) with fractured limestone or probably most of the rock types relevant for permafrost rock slope failure, (iv) with a wide range of slope angles (30–70°) and orientations of the fracture network (consisting of three joint sets). The presented model is the first one capable of assessing the future destabilisation of degrading permafrost rock slopes.

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 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 Failure of Rock Slope with Heterogeneous Locked Patches: Insights from Numerical Modelling

2021 ◽  
Vol 11 (18) ◽  
pp. 8585
Author(s):  
Bin Fu ◽  
Yingchun Li ◽  
Chun’an Tang ◽  
Zhibin Lin
Keyword(s):  
Slope Stability ◽  
Failure Mode ◽  
Rock Slope ◽  
Failure Modes ◽  
Process Analysis ◽  
Failure Process ◽  
Shear Loading ◽  
Constitutive Relationship ◽  
Rock Slope Stability ◽  
Geometrical Properties

Rock slope stability is commonly dominated by locked patches along a potential slip surface. How naturally heterogeneous locked patches of different properties affect the rock slope stability remains enigmatic. Here, we simulate a rock slope with two locked patches subjected to shear loading through a self-developed software, rock failure process analysis (RFPA). In the finite element method (FEM)-based code, the inherent heterogeneity of rock is quantified by the classic Weibull distribution, and the constitutive relationship of the meso-scale element is formulated by the statistical damage theory. The effects of mechanical and geometrical properties of the locked patches on the stability of the simulated rock slope are systematically studied. We find that the rock homogeneity modulates the failure mode of the rock slope. As the homogeneity degree is elevated, the failure of the locked patch transits from the locked patch itself to both the interfaces between the locked patched and the slide body and the bedrock, and then to the bedrock. The analysis of variance shows that length and strength of locked patch affect most shear strength and the peak shear displacement of the rock slope. Most of the rock slopes exhibit similar failure modes where the macroscopic cracks mainly concentrate on the interfaces between the locked patch and the bedrock and the slide body, respectively, and the acoustic events become intensive after one of the locked patches is damaged. The locked patches are failed sequentially, and the sequence is apparently affected by their relative positions. The numerically reproduced failure mode of the rock slope with locked patches of different geometrical and mechanical properties are consistent with the laboratory observations. We also propose a simple spring-slider model to elucidate the failure process of the rock slope with locked patches.

scholarly journals Stability Assessment of High and Steep Cutting Rock Slopes with the SSPC Method

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Hongliang Tao ◽  
Guangli Xu ◽  
Jingwen Meng ◽  
Ronghe Ma ◽  
Jiaxing Dong
Keyword(s):  
Slope Stability ◽  
Rock Slope ◽  
Equilibrium Analysis ◽  
Rock Slope Stability ◽  
Rock Slopes ◽  
Evaluation Indexes ◽  
Weathering Degree ◽  
Slope Rock ◽  
The Stability

The stability of high rock slopes has become a key engineering geological problem in the construction of important projects in mountainous areas. The original slope stability probability classification (SSPC) system, presented by Hack, has made obvious progress and been widely used in rock slope stability analysis. However, the selection and determination of some evaluation indexes in the original SSPC method are usually subjective, such as intact rock strength and weathering degree. In this study, the SSPC method based on geological data obtained in the prospecting tunnels was presented and applied. According to the field survey and exploration of the prospecting tunnels, the weathering degree of the slope rock mass was evaluated. The empirical equation for the maximum stable height of the slope was applied to the slope stability evaluation in the presented SSPC method. Then, the slope stability probability of numerous cutting slopes in the sandstone unit was evaluated using the presented system. Results of the Geostudio software based on the limited equilibrium analysis of the investigated slopes were compared with the results obtained by the SSPC method. The results indicate that the SSPC method is a useful tool for the stability prediction of high and steep rock slopes.

scholarly journals Application of a Probabilistic Method Based on Neutrosophic Number in Rock Slope Stability Assessment

2019 ◽  
Vol 9 (11) ◽  
pp. 2309 ◽  
Author(s):  
Bo Li ◽  
Kaifeng Zhou ◽  
Jun Ye ◽  
Peng Sha
Keyword(s):  
Slope Stability ◽  
Wide Spectrum ◽  
Probabilistic Method ◽  
Rock Slope Stability ◽  
Stability Assessment ◽  
Rock Slopes ◽  
Good Efficiency ◽  
Natural Rock ◽  
The Stability ◽  
Neutrosophic Number

The stability of natural rock slopes is influenced by a wide spectrum of factors, such as mechanical properties of bedrocks and spatial distribution of discontinuities. Their specific values are typically incomplete, due mainly to the lack of effective and comprehensive methods to accurately characterize these factors, especially those inside of the slopes. The neutrosophic number is a useful tool to solve problems in indeterminate environment. This study introduces the neutrosophic theory into slope stability assessment. A vector similarity measure developed under neutrosophic environment was employed to establish a stability assessment method considering multilevel attributes of slopes. Using this method, the level of stability for studied slopes, i.e., stable, mostly stable, less stable, and instable, was determined by computing the relation indices. The method was applied to a group of rock slopes located in Zhejiang province, China, and the calculated results were compared with the reality of in situ survey. The field application showed that the developed method has a good efficiency and precision in assessing the stability of rock slopes. The obtained weight vector can reveal the key influential parameters that inherently control the stability of rock slopes.

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