Rock Slope Stability Analysis by Using Integrated Approach (original) (raw)
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ROCK SLOPE ASSESSMENT USING KINEMATIC AND NUMERICAL ANALYSES
This paper presents stability assessment of rock slopes at Jalan Kuari, Cheras, Kuala Lumpur. The site is a disused quarry slope where a low cost residential area of Pangsapuri Intan was built very close to it. A frequent instability have been occured at the rock slope and the worst case situation happened when there was a rockfall event that hit a taxi that parked under the slope. A detailed discontinuity assessment was carried at the site, then, the kinematic and numerical analyses were performed in order to determine the stability of the rock slope. The kinematic analysis was carried out using DIPS 5.0 software and the results showed that about 19% is the percentage of the wedge failure that is encountered for the rock slope. Meanwhile, the finite element method of analysis in Phase 2 showed that the slope is in stable condition, with the Strength Reduction Factor (SRF) of 2.0. The difference between the results of the kinematic and the finite element analyses is because, the kinematic analysis consider the discontinuities volume and orientations with regards to the slope face, while the finite element, analyse the slope with respect to strength properties. Since that the slope is a disused quarry, where previous blasting work have produced fracture on the rock face, these discontinuities and fracture are more influencing the instability and the result from kinematic analysis shows a good agreement with the field observation.
Stability Analysis and Failure Mechanisms of Open Pit Rock Slope
Journal of the Civil Engineering Forum
Rock mass in nature tend to be unideal, for it is heterogeneous, anisotropic and has discontinuity. The discontinuity makes anisotropic strength and stress in the rock mass, and also controls the changing of the elastic properties of rock mass. This condition results to disruptions in the rock mass strength balance, and finally drives the slopes to collapse. This study aims to determine the slope failure mechanisms in the area of case study, as well as its variations based on the Rock Mass Rating (RMR), Geological Strength Index (GSI), Slope Mass Rating (SMR), kinematic analysis, numerical analysis and monitoring approach slope movement in a coal mine slope applications. The site investigations were implemented to obtain information about slope collapse. Prior to the collapse, the slope inclination was 38° with of 94 meters height, strike slope of N 245 E and direction of slope surface of 335°. After the collapse, the slope was became 25º; and after the collapse materials were clear...
SLOPE STABILITY ANALYSIS IN ANDESITE STONE MINING ROLAS NUSANTARA TAMBANG Ltd. IN PASURUAN REGENCY
Journal of Applied Sciences, Management and Engineering Technology
In mining activities Rolas Nusantara Tambang Ltd. needs to do a slope stability analysis because at that location there has never been a study on the condition of the slopes. In addition, there are several problems that can cause unstable slopes such as slope geometry that is too upright, the presence of discontinuity fields and mining locations that are close to several active volcanoes in East Java, namely Mount Semeru and Mount Bromo so that the potential for earthquakes and vibrations is high and can be affect the stability of the slopes at that location. This study aims to analyze slope stability using the Janbu method in calculating the factor of safety and the Monte Carlo method for the probability of landslides. From the results of the study, the actual slope safety factor (FK) was 1.703 and the probability of landslide (PK) was 0.000% with a slope height of 12 meters and a slope of 850. Then recommendations were given for the overall slope with an overall height of 36 meter...
Journal of Rock Mechanics and Geotechnical Engineering, 2020
Discontinuity waviness is one of the most important properties that influence shear strength of jointed rock masses, and it should be incorporated into numerical models for slope stability assessment. However, in most existing numerical modeling tools, discontinuities are often simplified into planar surfaces. Discrete fracture network modeling tools such as MoFrac allow the simulation of non-planar discontinuities which can be incorporated into lattice-spring-based geomechanical software such as Slope Model for slope stability assessment. In this study, the slope failure of the south wall at Cadia Hill open pit mine is simulated using the lattice-spring-based synthetic rock mass (LS-SRM) modeling approach. First, the slope model is calibrated using field displacement monitoring data, and then the influence of different discontinuity configurations on the stability of the slope is investigated. The modeling results show that the slope with non-planar discontinuities is comparatively more stable than the ones with planar discontinuities. In addition, the slope becomes increasingly unstable with the increases of discontinuity intensity and size. At greater pit depth with higher in situ stress, both the slope models with planar and non-planar discontinuities experience localized failures due to very high stress concentrations, and the slope model with planar discontinuities is more deformable and less stable than that with non-planar discontinuities.
DIPANALYST: A computer program for quantitative kinematic analysis of rock slope failures
Computers & Geosciences, 2013
Kinematic analysis is used to analyze the potential for the various modes of structurally controlled rock slope failures (plane, wedge, and toppling failures) due to the presence of unfavorably oriented discontinuities. Traditionally kinematic analysis is performed after plotting discontinuity orientations, slope angle, slope azimuth and representative friction angle value on a stereonet. Due to large number of discontinuities, only representative orientation values (dip/dip direction) for identified cluster sets are considered. This stereonet-based analysis is qualitative in nature and requires the presence of tight data clusters for which a reasonable representative orientation value can be assigned. However, there are cases when a tight circular clustering of discontinuity orientations does not exist, making stereonet-based analysis unreliable. Also, variability of discontinuity data in cluster sets is not easy to consider using the stereonet-based method. To overcome these problems, an application software, DIPANALYST, has been developed by the first author to perform quantitative kinematic analysis based on not just representative discontinuity values, but all discontinuities and their possible intersections. The software calculates ratios of discontinuities or their possible intersections that can potentially cause failures (plane, wedge or toppling) to the total number of discontinuities or their possible 25 intersections. The calculated ratios are known as failure indices, and the method is termed as the 26 quantitative approach for kinematic analysis. DIPANALYST is also capable of performing the 27 traditional stereonet-based method. 28
Indonesian mining journal, 2022
For an open pit mine, the rock slope stability is one of the major significant challenges at every stage in the operation. It became a concern from the planning until the mining closure. Mining activities in the research location have entered the mining closure phase and produced the final slope that consists of 4 single slopes with an overall slope height of 65m and an angle of 62° that its stability is not yet known. The actual overall slope has discontinuities which affect the potential for failure. Most of the methods used in geotechnical practice for estimating slope stability are based on the traditional limit equilibrium methods. On the other side, very few empirical techniques exist to assess the slope stability. The empirical method of the Q-Slope is a relatively new methodology for assessing the slope stability in terrains built from rock masses. This method was developed over the last decade by Barton and Bar (2015), with modifications to the original Q-System for application in rock slope stability through the parameter of RQD, Jn, Jr, Ja, O-Factor, Jwice, SRFa, SRFb and SRFc. The stability analysis by Q-Slope method has resulted the slope in stable condition because the value of βQ-Slope > βSlope. The factor of safety limit equilibrium method and probability of failure used the actual geometry and Q-Slope geometry is known in stable condition because it fulfils acceptance criteria with FoS ≥ 1.
Systematic Approach to Sustainable Rock Slope Stability Evaluation
Procedia Chemistry, 2016
Geological discontinuities play an important role in the evaluation of rock slope stability. Romana's Slope Mass Rating (SMR) system provides a methodology to quantify rock slope stability. Employing Bieniawski's Rock Mass Rating (RMR) to classify the rock mass of an investigated slope, SMR enables an objective determination of the rating adjustment values based on discontinuity orientation-slope orientation, respective dips angles and slope excavation methods. However the surface roughness of the discontinuities and their peak friction angles (αp) that are fundamental in determining rock slope stability are not directly considered in this evaluation. A more sustainable approach to rock slope stability assessment proposed here combines the SMR determination with the determination of the peak friction angle, αp of the discontinuity surfaces. Based on this proposal, the potential for slope failure can be quantified as follows: if SMR predicts failure and dip angle of the discontinuity (βi) > the peak friction angle (αp) the slope has a very high failure potential; if SMR predicts failure and βi < αp , the slope has intermediate failure potential; if the slope is stable according to SMR & βi > αp, the slope has low failure potential and if stable according to SMR and βi < αp, the slope can be considered as stable.
Geotechnical and …, 2011
Nowadays, there are many new methods for slope stability analysis; including probabilistic methods assessing geotechnical uncertainties to develop safety factors. In this paper, a reliability index analysis for the Sungun copper mine slope stability is evaluated based on three methods of uncertainties consisting Taylor series method, Rosenblueth point estimate method and Monte-Carlo simulation method. Sungun copper mine will be one of the Iran’s biggest mines with final pit’s height of 700 meters. For this study two of its main slopes were assessed, one dipping to the NE (030) and the other to the SE (140). Probability density function of cohesion and angle of friction for the slopes were developed using limit equilibrium methods. These shear strengths were then used to determine the probability density function of safety factor and reliability index using the probabilistic methods. Results of the probabilistic analysis indicate that with ascending values of the uncertainties the reliability index decreases. Furthermore, it was determined that with the Monte Carlo simulation the seed number used has little effect on the reliability index of the safety factor especially with seed numbers in excess of 1200. Variations in the overall reliability index of safety factor were observed between the two slopes and this difference is explained by the differences in complexities of the geology within the cross-section.
Al-Nahrain Journal for Engineering Sciences, 2016
This paper presents a method for choosing the orientation and the dip of an excavated rock slope, to safely serve the intended function of the slope or the excavation.The investigated slope is a rock slope in an open pit mine in Knifes, Syria.This mine is a phosphate mine. The phosphate is covered with the sedimentary organic limestone rocks, which are the subject of this research.The kinematic analysis method is adopted here to analyze the slope stability. This method uses stereographic projection principles and applies them in rock slope stability analysis. Open Stereo program of stereographic projection was used to obtain the required projections.A particular case study was performed in order to ensure that the studied part of the slope is safe, and a general case study was performed to present a suggested procedure for choosing safe dip and dip direction to the face of the studied slope.In this research, the results present the possible choices of the orientation and the dip of ...
Journal of Mining and Environment, 2020
The stability analysis of rock slopes is a complex task for the geotechnical engineers due to the complex nature of the rock mass in a tropical climate that often has discontinuities in several forms, and consequently, in several types of slope failures. In this work, a rock mass classification scheme is followed in a tropical environment using the Rock Mass Rating (RMR) and Geological Strength Index (GSI) combined with the kinematic investigation using the Rocscience Software Dips 6.0. The Lafarge quarry is divided into ten windows. In the RMR system, the five parameters uniaxial compressive strength (UCS), rock quality designation (RQD), discontinuity spacing, discontinuity condition, and groundwater conditions are investigated. The RMR values range from 51 to 70 (fair to good rock mass), and the GSI values range from 62 to 65 (good to fair rock mass). There is a good and positive correlation between RMR and GSI. The kinematic analysis reveals that window A is prone to critical to...