Rock Slope Stability Assessment Research Articles

A novel proposed classification system for rock slope stability assessment

The present study introduces “rock slope instability score (RSIS)” a novel classification system for assessing rock slope stability. It takes into account geological and geotechnical parameters, as well as the impact of human activities and triggering parameters, which have become more frequent due to climate change and few of them have been ignored in existing classifications. The study focuses on rock slopes of various lithologies from the Indian Himalayas. The development of this new classification system is based on the examination of 81 different rock slopes from various states of the Indian Himalayas. Extensive field surveys, rock sampling, geotechnical laboratory tests, and ground measurements have been conducted at the various slope sites to establish a comprehensive scoring system for the stability assessment. The distributions of weightage to each parameter have been considered, corresponding to its degree of impact in causing slope instability. Sensitivity analysis of all defined parameters of RSIS system has revealed that the majority of the parameters exhibit a strong positive correlation, with Pearson correlation coefficients ranging from 0.74 to 0.61. However, two parameters, namely discontinuity dip and the relationship between slope & discontinuity direction, gives moderate relationship with correlation coefficient values of 0.48 and 0.41, respectively. To avoid any designer biasness in the system, several individuals gathered data set at different times. The proposed classification system has demonstrated a strong correlation with the actual slope condition, and it is quite promising. The outcome of RSIS classification for studied 81 slopes classified 2 slopes under stable condition, 21 slopes as partially stable, 44 as unstable, and 14 as completely unstable.

Numerical research method of rock slope with intermittent fractures based on parallel bond contact model

Within the domain of rock slopes characterized by intermittent fracturing, the fracture distribution and the mechanical properties of the interstitial rock bridges significantly influence the stability of the slope. The parallel bond contact model is advantageous in replicating the mechanical behavior of rock particles. This research introduces a numerical methodology for analyzing rock slopes with intermittent fractures using the parallel bond contact model. Initially, the model’s microscale parameters are refined through calibration with empirical data derived from macroscopic mechanical tests on rocks. Following this, the discrete element modeling software is employed to construct a detailed rock slope model. This model incorporates a smooth joint approach to define the intermittent fractures, enabling the creation of slope models with varying configurations of coplanar rock bridges and diverse rock types. The research methodologically investigates the mechanical properties and failure patterns of rock slopes under a spectrum of variable combinations. The findings reveal that slopes with multiple rock bridges demonstrate progressive failure and interlocking phenomena during their load-deformation cycles. These insights provide a foundational understanding for the analysis of catastrophic mechanisms and the stability assessment of rock slopes.

Quick Extraction of Joint Surface Attitudes and Slope Preliminary Stability Analysis: A New Method Using Unmanned Aerial Vehicle 3D Photogrammetry and GIS Development

The present study proposes a preliminary analysis method for rock mass joint acquisition, analysis, and slope stability assessment based on unmanned aerial vehicle (UAV) photogrammetry to extract the joint surface attitude in Geographic Information Systems (GIS). The method effectively solves the difficulties associated with the above issues. By combining terrain-following photogrammetry (TFP) and perpendicular and slope surface photogrammetry (PSSP), the three-dimensional (3D) information can be efficiently obtained along the slope characteristics’ surface, which avoids the information loss involved in traditional single-lens aerial photography and the information redundancy of the five-eye aerial photography. Then, a semi-automatic geoprocessing tool was developed within the ArcGIS Pro 3.0 environment, using Python for the extraction of joint surfaces. Multi-point fitting was used to calculate the joint surface attitude. The corresponding attitude symbols are generated at the same time. Finally, the joint surface attitude information is used to perform stereographic projection and kinematic analysis. The former can determine the dominant joint group, and the latter can obtain the probability of four types of failure, including planar sliding, wedge sliding, flexural toppling, and direct toppling. The integrated stability evaluation method studied in this paper, which combines a 3D interpretation of UAV and GIS stereographic projection statistical analysis, has the advantages of being efficient and user-friendly, and requires minimal prior knowledge. The results can aid in the geological surveys of slopes and guide engineering practices.

Rock slope stability assessment based on the critical failure state curve for the generalized Hoek‒Brown criterion

Rock slope stability assessment based on the critical failure state curve for the generalized Hoek‒Brown criterion

Rock mass permeability evolution during triaxial shearing based on three-dimensional distinct element model (3DEC) simulation

The evolution and change in jointed rock mass hydraulic conductivity (krm) during triaxial compression was investigated using the discrete element method code 3DEC bonded block model approach. The code’s fluid flow logic was used to simulate flow tests at various stages, from the initial confined state through to the post-peak (i.e., failed) state. A target percent of joint contacts were randomly “broken” to produce different initial fracture intensities. The rock mass fluid flow behaviour was compared with laboratory flow tests of thermally brecciated granular marble. A new joint constitutive model was developed to account for nonlinear, hysteretic load–displacement behaviour to accurately reproduce changes in joint aperture due to complex inter-block stress changes. The simulations provided quantifiable measurements of krm evolution with axial strain throughout the test for several rock mass quality conditions. The evolution of krm with loading was found to be nonlinear, with significant increases associated with yielding-induced dilation, followed by relatively minor changes in the post-peak loading range. These trends are similar to the laboratory tests conducted on intact rock and on rock joints. The findings will be useful for improving groundwater flow models for stability assessment of rock slopes, particularly where significant shearing is expected.

Assessment of Rock Slope Stability Along Degala-Koya Road, Erbil, NE Iraq

This article addresses the issue of instability in rock slopes along the main Degala-Koya road in Erbil northeastern Iraq, which poses a significant threat to human safety and property. the use of Slope Mass Rating Tool software and various techniques such as kinematic analysis and geomechanical classification to investigate cut slopes and assess slope stability. Geotechnical tests, including a point load test, were performed at eight stations in the study area to determine the unconfined compressive strength. comparison between discrete and continuous Slope Mass Rating values for rock slopes was carried out. The most unstable slope was identified as Station 4, while Stations 2, 5, 6, and 8 were deemed the most stable. The study found that rock fall accompanied by direct toppling was the most common type of failure, with plane sliding, rock fall, toppling, and wedge sliding as likely dominant failures. The Slope Mass Rating Tool-v205 software is more accurate When evaluating slope stability when strengthen with kinematic analysis by Dips-v6.008 software.

An interpretable evolutionary extreme gradient boosting algorithm for rock slope stability assessment

An interpretable evolutionary extreme gradient boosting algorithm for rock slope stability assessment

Fuzzy-Based Intelligent Model for Rapid Rock Slope Stability Analysis Using Qslope

Artificial intelligence (AI) applications have introduced transformative possibilities within geohazard analysis, particularly concerning the assessment of rock slope instabilities. This study delves into the amalgamation of AI and empirical techniques to attain highly precise outcomes in the evaluation of slope stability. Specifically, our primary objective is to propose innovative and efficient methods by investigating the integration of AI within the well-regarded Qslope system, renowned for its efficacy in analyzing rock slope stability. Given the complexities inherent in rock characteristics, particularly in coastal regions, the Qslope system necessitates adjustments and harmonization with other geomechanical methodologies. Uncertainties prevalent in rock engineering, compounded by water-related factors, warrant meticulous consideration during all calculations. To address these complexities, we present a novel approach through the infusion of fuzzy set theory into the Qslope classification, leveraging fuzziness to effectively quantify and accommodate uncertainties. Our approach employs a sophisticated fuzzy algorithm encompassing six inputs, three outputs, and 756 fuzzy rules, thereby enabling a robust assessment of rock slope stability in coastal regions. The implementation of this method capitalizes on the high-level programming language Python, enhancing computational efficiency. To validate the potency of our AI-based approach, we conducted preliminary tests on slope instabilities within coastal zones, indicating a promising initial direction. The results underwent thorough evaluation, affirming the precision and dependability of the proposed method. However, it is crucial to emphasize that this work represents a first attempt to apply AI to the evaluation of rock slope stability. Our findings underscore a high degree of concurrence and expeditious stability assessment, vital for timely and effective hazard mitigation. Nonetheless, we acknowledge that the reliability of this innovative method must be established through broader applications across diverse scenarios. The proposed AI-based approach’s effectiveness is validated through a preliminary survey on a slope instability case within a coastal region, and its potential merits must be substantiated through broader validation efforts.

Dynamic stability assessment of consequent rock slopes considering multiple transmissions and reflections of stress waves

In this work, Based on the conservation of momentum at the wave fronts and the displacement discontinuity method, a theoretical approach for calculating the dynamic safety factor of consequent rock slopes is proposed. The multiple transmissions and reflections of stress waves on the joints and free surfaces are taken into account. A comparison of UDEC simulation and theoretical calculation was carried out to verify the feasibility of the proposed method. Moreover, parametric studies were conducted to investigate the effects of free surfaces, joint stiffness, amplitude of incident waves, and frequency of incident waves. The results show that the proposed method can predict the time history curve of the safety factor of a slope readily and accurately. Waves reflected from both the slope and top surfaces are found to have a significant effect on the stability of the slope – considering them or not can cause a difference in the safety factors up to 32.5%. The greater the joint stiffness is, the greater the safety factor fluctuates with time. However, when the joint stiffness is sufficiently high, the effect of joint stiffness on the safety factor can be neglected. The approach proposed in this work provides a theoretical tool for the dynamic assessment and design of consequent rock slopes. Highlights An analytical method is proposed for calculating the dynamic safety factor of rock slopes. Multiple transmissions and reflections of stress waves are considered. The proposed method has high calculation accuracy and can be applied in practice.

Stability Assessment of Rock Slopes Using the Q-Slope Classification System: A Reliability Analysis Employing Case Studies in Ecuador

Q-slope is one of the most recent empirical geomechanical classification systems and the least studied in South America. This study aims to expand the knowledge base regarding the Q-slope geomechanical method and demonstrate its applicability and reliability in rock slopes of Andean countries, such as Ecuador. To this end, thirty rocky slopes have been characterized considering (1) the physical visual approach—geographic location, climate, lithology, alteration, and stability (to obtain values of Jr, Ja, Jwice, and SRFa)—and (2) geomechanical stations and kinematic analysis (for the determination of the type of failure, Jn, O-factor, and SRFc for Q-slope). Field data were collected in contrasting environments (coastal, mountain, and forest), and different failure modes were considered (planar, wedge, block, and flexural topplings) to better understand the method. The results and main contributions of this research are (i) verifying the applicability of the Jwice parameters in different climatic settings and (ii) validating the Q-slope method by applying a confusion matrix to evaluate its reliability for slope stability assessment. The overall accuracy obtained is 80%, placing the Q-slope geomechanical method in the highest evaluation quartile and thus classifying it as very good for slope characterization.

Geotechnical Assessment of Rock Slope Stability Using Kinematic and Limit Equilibrium Analysis for Safety Evaluation

The purpose of this study is to identify the leading causes of slope instability along a local highway in Anhui, People’s Republic of China. As part of the east expansion project, the mountain range will be excavated to create a two-way, nearly 30 m wide highway. The site’s topography consists of a hill with palm-shaped faces carved from limestone running along its sides. The geological characteristics and slope stability of the research area highlight the possibility of slope failure along both sides of the roadway. Slope stability analysis was performed in order to determine the failure mechanism and create a stable slope. Initial slope characterization and shear properties of the rock were determined by means of fieldwork and laboratory analysis. By causing wedging failure and toppling collapse, the bedding joints and discontinuity orientations increase instability, as determined by a kinematic analysis performed with DIP.6 software. The Limit Equilibrium Method (LEM) of analysis is presented in the software Slide 6.020 to illustrate the instability of the slope. The unstable condition of the slopes was determined using empirical methods that were validated and enhanced by limit equilibrium analysis.

A Review of Rock Slope Stability Assessment Practice in Malaysia

Rock slope stability assessment in Malaysia has become increasingly important as new developments encroach hillsides around major cities. This article reviews historical case studies to present a general picture of rock slope assessment practice in Malaysia, especially on methods and output of the case studies. Common methods include use of locally developed rating systems, Rock Mass Rating (RMR) and its derivatives, kinematic analysis, and numerical analysis. Application of these methods must be suitable with site conditions, while its advantages and disadvantages must be recognized by the assessor. Emergence of new technologies greatly improves the speed and quality of data acquisition provided. A total of 39 case studies on different lithologies were examined, in which progress were notable from kinematic analysis-based assessments to incorporation of rating systems and numerical analysis. This article recommends several improvements for rock slope assessment practice. These include an establishment of a local good practice guide in the assessment, incorporation of numerical analysis into standard practice, improving utilization of new technologies, more attention to the influence of weathering, and consideration of seismic influence in seismically active regions. Utilization of numerical methods and other contemporary methods reflects increasing understanding of rock mechanics which is vital to rock slope stability assessment among local practitioners. Improved rock slope assessment allows for a more accurate stability determination and decisive mitigation measure recommendations, which is to be done by competent engineering geologists, in line with Geologist Act 2008.

Assessment of rock Slope Stability on Shaqlawa – qoysinjaq Road, North Eastern Iraq by using kinematic analysis

This study aims to assess the stability of the rock slopes on both sides of the road linking (Shaqlawa- qoysinjaq) to some of the exposed geological formations within the northeastern limb of the Safin anticline (Qamchuqa, Bakhma, Shiranish), where (6) stations were selected and a classification was made. An engineering description of the rock layers through a comprehensive survey of the study area, the results of the kinematic analysis by the kinematic analysis software (DIPS) showed that the possible percentage failures were represented by rock toppling (83.33%), planar sliding by (58.33%) and then wedge sliding by percentage (83.34%), By studying the factors affecting the stability of slopes in the region, it was found that the main factor causing the failures is the result of cutting the fold for the purpose of road construction, in addition to the structural and lithological factors.

Stability analysis of rock slopes using the interface contact model and strength reduction method

The assessment of rock slope stability is usually controlled by the presence of discontinuities. The block theory is an established method in practical engineering to predict the stability of rock slopes. A maximum of two discontinuity planes are considered in the application of the block theory. It would lead to inaccurate prediction of slopes with multiple discontinuity planes. A novel method for estimating the safety margin of rock slopes is proposed, which is capable of considering the contribution of all discontinuities to the stability problem. The discontinuity planes are simulated by an interface contact model within the theoretical framework of the finite difference method. The factor of safety is obtained by the strength reduction method. The failure criteria of rock slopes are also discussed. The proposed model can simulate discontinuous planes in a more realistic manner and thus is more effective in engineering practice. To demonstrate the effectiveness of the proposed model, several numerical examples are presented, which showcase its superiority for predicting the stability of blocks composed of multiple discontinuities. Several numerical examples are analyzed to confirm the effectiveness of the proposed model and its superiority in stability prediction of blocks formed by multiple discontinuities.

Slope Stability Assessment of The Garin Majjed Archeological Village Area, East of Yemen

The stability assessment of sedimentary rock slopes of the area surround Garin Majjed archeological village which lay on cuesta shape hill in Wadi Dawa'an - East of Yemen was carried out. All important factors affecting slope stability in the area such as differential weathering, rainfall and runoff, sewage, discontinuities trends and inclinations, slope face orientation, and mechanical properties of rocks and joints filling materials were evaluated. Direct shear test of joints filling materials showed that the friction angle (Φ) values range between 11˚ and 31˚ and cohesion (C) Values between 0.00 and 0.5 MPa. The compressive strength (cσ) values of the nodular limestone rocks is 66 MPa and for shaley marly sandstone it is 12 MPa. It was found that rock fall is the main mode of failure in the area, while secondary toppling and/ or plane sliding are probable to occur. Some remedial measures are proposed to protect the slopes like erect well seal drainage path, supporting the toe of the dip slope and the overhanging parts, as well as grouting of joints by convenient filling material.

Geological strength index-slope: an adaptation of the geological strength index system for use in the rock slope stability assessment

Geological strength index-slope: an adaptation of the geological strength index system for use in the rock slope stability assessment

Stability Assessment of Siwalik Rock Slopes — A Case Study from Dehradun Area, Uttarakhand, India

Stability Assessment of Siwalik Rock Slopes — A Case Study from Dehradun Area, Uttarakhand, India

Multi-approach for the assessment of rock slope stability using in-field and UAV investigations

Multi-approach for the assessment of rock slope stability using in-field and UAV investigations

Preliminary analysis of rock mass weathering grade using image analysis of CIELAB color space with the validation of Schmidt hammer: A case study

Rock slope instability causes rock slope failure with intense weathering processes in tropical regions. In addition to the various advanced numerical rock slope stability assessment techniques that have been developed thus far, simple evaluation techniques characterizing the rock slope weathering degree based on color changes of the rock surface remain one of the main techniques used by most geologists onto the rock slope stability assessment. The present study proposed a new evaluation method for weathering assessment of the limestone rock slope with computer-assisted image processing technologies to reduce human-induced errors based on a manual characterization process. The color changes of the limestone rock referring the CIELAB color space, which indirectly indicated the differential weathering of the rock mass, were measured in-situ using the FRU colorimeter with a 40 mm aperture. The Schmidt hammer was used to determine the intact rock strength and validate the color changes of the limestone rock to the International Society For Rock Mechanics (ISRM) weathering grade standard. Results indicated that a* and b* correlated strongly with R2 = 0.7404, underscoring the consistency of the CIEL*a*b color space data obtained in situ. The a* and b* correlated strongly with the uniaxial compressive strength result obtained via the rock Schmidt hammer test, with R2 of 0.7058 and 0.7011, respectively. The results were verified with the weathering grades analyzed using image analysis technique. In conclusion, the CIELAB color space is an effective tool in the preliminary assessment of rock mass weathering, particularly for slightly vegetated rock slope outcrops.

Slope Mass Rating (SMR) Classification for Rock Slope Stability and Geohazard Vulnerability Assessment

Quantitative classification from the Slope Mass Rating (SMR) has introduced an empirical assessment for rock slope stability rating. This stability classification enables us to foreseethe magnitude and susceptibility of rock mass failure towards adjacent infrastructure and human life. In this study, the stability of quarry rock slope was classified using SMR classification system and kinematic stability analysis before being correlatedwith geohazard vulnerability assessment. Geological formation study with site geographical survey from aerial photogrammetry technique provided comprehensive data for the study area. Fieldwork to evaluate the SMR assessment parameters was conducted by discontinuity mapping using scanline method. In-situ evaluation of rock mass such as rebound surface hardness and discontinuity characterization was carried out with rock material sampling for laboratory testing. Kinematic stability analysis presented an estimation for the direction and mode of rock slope failure. The SMR classification that constitutes geomechanics attributes had introduced the global stability rating of rock mass structure, thus facilitating the prediction of potential failure magnitude. Hence, the integration of these stability indications provides sufficient empiricalestimation for geohazard vulnerability zoning for the studied area.