scholarly journals Slope mass rating of rock slopes of the Malekhu River, central Nepal Lesser Himalaya

2014 ◽  
Vol 47 (1) ◽  
pp. 36-46
Author(s):  
Naresh Kazi Tamrakar ◽  
Jaya Laxmi Singh
Keyword(s):  
Rock Mass ◽  
Slope Stability ◽  
Failure Mode ◽  
Rock Mass Rating ◽  
Rock Slopes ◽  
Plane Failure ◽  
Central Nepal ◽  
Slope Mass Rating ◽  
Unstable Slope ◽  
Rock Mass Slopes

The Malekhu River is one of the major tributaries of the Trishuli Ganga River fl owing from the south in Malekhu region, central Nepal. Riverbank slope stability is a topic of concern as rock mass condition and slope stability of riverbank slopes are important parameters for riverbank erodibility. Fourteen sites in the Malekhu River were selected for rock mass rating (RMR) and then slope mass rating (SMR) by using a graphic method. The potentially vulnerable sites were identifi ed after conducting field study in different slopes. The results indicate that there occur modes of failures ranging from stable (good rock mass) to partially stable (normal rock mass) in all the study sites. The unstable (bad rock mass) and completely unstable (very bad rock mass) slopes are, however, distributed only in some slopes. The unstable slope of plane failure mode is Ka1, whereas the completely unstable slopes of plane failure mode are Rb2, Ml1 Slope 1 and Ml2. The unstable slope of toppling failure mode is Ml2. When wedge failure mode is considered, the slopes at Ti1 and Ka1 are unstable while the slopes at Kh1, Ka1, Ml1 Slope 1 are completely unstable. The rock slopes with unstable to completely unstable states are considered bad (SMR Class IV: 21–40) to very bad (SMR Class V: 0–20) rock mass with fair to poor rock mass rating, respectively. These bad to very bad rock mass slopes are vulnerable to slope movements and river erosion, and they require mitigative measures.

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 Field-based assessment of rock discontinuity and geological attributes of rock mass for stones for various engineering applications

2018 ◽  
Vol 55 (1) ◽  
pp. 123-132
Author(s):  
Sunita Bhattarai ◽  
Naresh Kazi Tamrakar
Keyword(s):  
Rock Mass ◽  
Field Study ◽  
Block Size ◽  
Rock Mass Rating ◽  
Building Stones ◽  
Engineering Applications ◽  
Rock Mass Characterization ◽  
Rock Types ◽  
Central Nepal ◽  
Short Span

Because of the occurrence of various rock types within the short span of areas, the Malekhu Khola area is one of the most promising areas where scope of stones is high. This paper presents recognition of the most promising rock types in terms of their geology and discontinuity for evaluating suitability for building stones. The research focuses on the assessment of nine different rock types allocated along the Malekhu Khola, central Nepal. Geological parameters, rock mass characterization and discontinuity analysis were carried out in each of allocated sites. During field study, rock masses were categorised based on different geological parameters, and on number of joint set, tentative block shape, size and volume. Field-based data were tabulated, analysed, and finally identified for the block size and geometry, and rock mass quality for stones. The number of major joint set ranges from one to four with random joint sets. The study shows that the outcrop condition of rock is faintly to slightly weathered and strongly indurated. The study shows that the rock types depending on the Rock Mass Rating (RMR) system vary from poor to very good. The block types that could be extracted are flat, long and compact. The probable end uses of these rock types could be armourstone, interior and exterior paving, cladding and foundation.

scholarly journals Rock Mass Rating and Geological Strength Index of rock masses of Thopal-Malekhu River areas, Central Nepal Lesser Himalaya

2013 ◽  
Vol 16 ◽  
pp. 29-42 ◽  
Author(s):  
Jaya Laxmi Singh ◽  
Naresh Kazi Tamrakar
Keyword(s):  
Rock Mass ◽  
Surface Condition ◽  
Geological Strength Index ◽  
Rock Mass Rating ◽  
Rock Slopes ◽  
Lesser Himalaya ◽  
Rock Masses ◽  
Strength Index ◽  
Rock Mass Structure ◽  
Exposed Rock

The rock slopes of the Thopal-Malekhu River areas, Lesser Himalaya, were characterized applying various systems of rock mass classification, such as Rock mass Rating (RMR) and Geological Strength Index (GSI), because the study area comprises well exposed rock formations of the Nawakot and Kathmandu Complexes, across the Thopal-Malekhu River areas. In RMR system, mainly five parameters viz. Uniaxial Compressive Strength (UCS) of rock, Rock Quality Designation (RQD), spacing of discontinuity, condition of discontinuity, and groundwater condition were considered. The new GSI charts, which were suitable for schistose and much disintegrated rock masses, were used to characterize rock slopes based on quantitative analysis of the rock mass structure and surface condition of discontinuities. RMR ranged from 36 to 82 (poor to very good rock mass) and GSI from 13.5±3 to 58±3 (poor to good rock mass). Slates (of the Benighat Slate) are poor rock masses with low strength, very poor RQD, and close to very close spacing of discontinuity, and dolomites (Dhading Dolomite) are fair rocks with disintegrated, poorly interlocked, and heavily broken rock masses yielding very low RMR and GSI values. Phyllites (Dandagaun Phyllite), schist (Robang Formation) and quartzite (Fagfog Quartzite, Robang Formation and Chisapani Quartzite), dolomite (Malekhu Limestone), and metasandstone (Tistung Formation) are fair rock masses with moderate GSI and RMR values, whereas quartzose schist and gneiss (Kulekhani Formation) are very good rock masses having comparatively higher RMR and GSI. The relationship between GSI and RMR shows positive and good degree of correlation. DOI: http://dx.doi.org/10.3126/bdg.v16i0.8882   Bulletin of the Department of Geology Vol. 16, 2013, pp. 29-42

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 Desain Lereng Final Dengan Metode Rmr, Smr Dan Analisis Kestabilan Lereng: Pada Tambang Batubara Terbuka, Di Kabupaten Tanah Laut, Provinsi Kalimantan Selatan

2012 ◽  
Vol 7 (2) ◽  
pp. 92-108 ◽  
Author(s):  
Galih W. Swana ◽  
Dicky Muslim ◽  
Irvan Sophian
Keyword(s):  
Rock Mass ◽  
Rock Mass Rating ◽  
Slope Mass Rating

Dalam menentukan kemiringan desain final lereng yang dibentuk, salah satu caranya ialah dengan menggunakan metode geomekanik melalui penentuan nilai Rock Mass Rating(RMR) dan nilai Slope Mass Rating (SMR). Namun, dari nilai SMR tidak diketahui faktor keamanan dari lereng tersebut sehingga diperlukan analisis kestabilan lereng. Nilai kemiringan lereng dan faktor keamanannya dapat menjadi acuan untuk membuat desain lereng final yang representatif. Penelitian dilakukan di tambang terbuka yang terdapat di Kecamatan Jorong Kabupaten Tanah Laut, Provinsi Kalimantan Selatan. Daerah penelitian terletak pada Formasi Warukin dengan unit stratigrafinya yaitu batupasir (pasir kasar - halus), mudstone dan carbonaceous mudstone, serta batubara dengan jurus N 80°– 90° E dan kemiringan 29°-35°. RMR pada section Sidewall berkisar antara 25- 59, dan SMR berkisar antara 30,1°– 59°; pada section Western Lowwall atau data bor AGT-02 dan AGT-03 berkisar antara 20 - 55 dan SMR berkisar antara 20°– 55°. Pada section Western Highwall RMR berkisar antara 34 -71 dan SMR berkisar antara 33,06° – 71°. Pada section Eastern Lowwall RMR berkisar antara 20-55 dan SMR berkisar antara 20° – 54,96°. Pada section Eastern Highwall RMR berkisar antara 29-79 dan SMR berkisar antara 29°–52°. Dari hasil analisis kestabilan lereng, pada umumnya nilai kemiringan lereng hasil dari nilai SMR berada pada kondisi labil sampai stabil sehingga perlu dilakukan penurunan muka air tanah pada beberapa bagian agar dihasilkan desain final lereng yang stabil.

scholarly journals Geology and rockmass condition of Dhulikhel-Panchkhal area, Kavre District, Central Nepal Lesser Himalaya

2013 ◽  
Vol 15 ◽  
pp. 1-14
Author(s):  
Prem Nath Paudel ◽  
Naresh Kazi Tamrakar
Keyword(s):  
Rock Mass ◽  
Rock Type ◽  
Physical And Mechanical Properties ◽  
Geological Mapping ◽  
Rock Mass Rating ◽  
Lesser Himalaya ◽  
Rock Masses ◽  
Northern Limb ◽  
Rock Types ◽  
Central Nepal

A geological mapping was carried out and the rock mass characteristics of the Lesser Himalayan rocks distributed in the Dhulikhel-Panchkhal area (Kavre Distric) were studied along with their physical and mechanical properties. The lithological units distributed in the study area belong to the Benighat Slate of the Upper Nawakot Group and the Bhimphedi Group as separated by the Chak-Rosi Thrust. The lithological units strike NW-SE and dip southwards forming the eastern closure of part of the northern limb of the Mahabharat synclinorium. The area comprises mainly micaceous quartzite, psammitic schist, metasandstone and metasiltstone. Micaceous quartzite is a rock type of the Kalitar Formation, Chisapani quartzite and the Markhu Formation. The Markhu quartzite is slightly calcareous. Psammitic schist is a rock type of the Kulekhani Formation and the Markhu Formation. Metasandstone and metasiltstone are the rock types of the Tistung Formation. The rock masses consist mainly of three to four major joint sets including the joint parallel to foliation. The discontinuity characteristics indicate that the rocks are blocky in nature, and nearly smooth to rough surface with soft filling aperture. The rock mass is nearly fresh, indurated and stiff. The slopes are influenced by stable and unstable wedges, plane and toppling failures. The rock masses are classified into fair to good rock classes according to rock mass rating system. DOI: http://dx.doi.org/10.3126/bdg.v15i0.7412 Bulletin of the Department of Geology, Vol. 15, 2012, pp. 1–14

scholarly journals Clustering Slope Stability from Using Drone, DEM Lineament Extraction And Rock Mass Rating In Pangkalan Koto Baru, West Sumatra, Indonesia

2018 ◽  
Vol 2 (2) ◽  
pp. 124-129
Author(s):  
Tiggi Choanji ◽  
Yuniarti Yuskar ◽  
Dewandra BE Putra ◽  
Catur Cahyaningsih ◽  
Winanda Sakti
Keyword(s):  
Rock Mass ◽  
Slope Stability ◽  
Disaster Management ◽  
Rock Mass Rating ◽  
Class Iii ◽  
Class V ◽  
West Sumatra ◽  
Lineament Analysis ◽  
Lineament Extraction ◽  
Integration Data

Clustering slope stability in the Pangkalan Koto Baru, West Sumatra has become one of priority in disaster management. The method used for this study are using the combination of structural lineament analysis, scanline with window sampling and Rock mass rating (RMR) calculations. The analysis results of the fourteen observed slope sites showed significant outcome, which seen in the structural lineament show dominant trend from northwest-southeast, which also correlate from the measurement of discontinuity by using scanline with window sampling. From RMR calculation, value showed range between 17 - 42 which belonged to class V (Very Poor Rock) - class III (Medium Rock ). Integration data of structural lineament, scanline method and RMR analysis suggested that 1 slope included in the very poor rock category, 12 slopes are poor rock category, and 1 slope in the medium rock category. So, it can be ascertained that most of the slopes will potentially be prone to landslides. Keywords: Slope Stability, RMR, Structural Lineament, Pangkalan Koto Baru, West Sumatra.

scholarly journals Classification of cut slopes in weathered meta-sedimentary bedrocks

2016 ◽  
Vol 20 (2) ◽  
pp. 1 ◽  
Author(s):  
Johnbosco Ikenna Nkpadobi ◽  
John Kuna Raj ◽  
Tham Fatt Ng
Keyword(s):  
Rock Mass ◽  
Sedimentary Rocks ◽  
Rock Mass Rating ◽  
Rock Quality Designation ◽  
Rock Quality ◽  
Slope Mass Rating ◽  
Field Investigations ◽  
Kinematic Analyses ◽  
Cut Slopes

In order of abundance, the meta-sedimentary rocks along Pos Selim Highway in Perak state Malaysia comprise quartz mica schist, graphitic schist, and quartzite layers. Field investigations revealed that these meta-sedimentary rocks have gradational weathering profile based on differences particularly in textures, hardness, lateral changes in colour, and consistency of material extension. The results from uniaxial compressive strength tests confirmed field observations whereby failure occurred mostly on outcrops having joints almost perpendicular to foliation. From the kinematic analyses, the investigated cut slopes are unstable with possibilities of wedge and planar failures. Application of rock mass classification schemes including Rock Quality Designation (RQD) and Rock Mass Rating (RMR) yielded almost similar poor to good quality ranges for each investigated rock mass. While Slope Mass Rating (SMR) classified the cut slopes from stable to unstable slopes, this study categorized them into one actively unstable, four marginally stable and five stable slopes.  ResumenEn orden de abundancia, las rocas metasedimentarias a lo largo de la carretera Pos Selim, en el estado Perak de Malasia, se componen de esquistos de cuarzo mica, esquistos de grafito y capas de cuarzo. Las investigaciones de campo revelan que estas rocas metasedimentarias tienen perfiles de meteorización progresiva basados en diferencias particulares como textura, dureza, cambios laterales de color y consistencia del material de extensión. Los resultados de los ensayos uniaxiales de esfuerzo de compresión confirmaron las observaciones de campo por las cuales se estableció que las fallas ocurrieron mayormente en los afloramientos con coyunturas perpendiculares hacia la foliación. De los análisis cinemáticos se desprende que los taludes de corte investigados son inestables con posibilidades de fallas planas y de cuña. La utilización de esquemas de clasificación rocosa como el índice RQD (del inglés Rock Quality Designation) y la clasificación geomecánica de Bienawski o RMR (del inglés Rock Mass Rating) evidencia rangos similares de baja y buena calidad para cada masa rocosa estudiada. Mientras que el índice de taludes SMR (del inglés Slope Mass Rating) clasificó los taludes de corte de estables a inestables, este estudio los categorizó de uno activamente inestable, cuatro marginalmente estables y cinco estables.

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