scholarly journals Rock Mass Characterization using Rock Mass Rating and Encountered Geological Problems in TRT’s Component of Tehri Pumped Storage Plant, Uttarakhand, India

2018 ◽  
Vol 23 ◽  
pp. 86-92
Author(s):  
Nishith Sharma ◽  
Rajeev Prasad ◽  
Anand Singh
Keyword(s):  
Rock Mass ◽  
Geological Mapping ◽  
Left Bank ◽  
Rock Mass Rating ◽  
Underground Structures ◽  
Construction Stage ◽  
Hydro Power ◽  
Rock Mass Characterization ◽  
Energy And Environment ◽  
Northern India

As an integral part of Tehri Hydro Power Complex (HPC) located in the state of Uttarakhand in Northern India; an underground 4x250 MW Tehri Pump Storage Plant (PSP) parallel and close to the existing 1000 MW Tehri Hydro Power Plant (HPP). Tehri PSP is located on the left bank of Bhagirathi River in the district of Tehri about 1.5 km downstream of its confluence with River Bhilangana. The major project components are machine hall, upstream surge shafts, Butterfly valve chamber (BVC), Penstock assembly chambers (PAC), downstream Surge Shafts, a pair of Tail Race Tunnels (TRTs) and outlet structures are in construction stage. During underground excavation, one of the important aspects for a speedy and safe excavation is to characterize rock mass for its stand up time. Case history of Himalayan tunnel reveals that Barton’s & Bieniawski’s classification system provide better assessment of the rock mass behavior. In TRTs of Tehri PSP, Rock Mass Rating (RMR) classifications were implemented during excavation and based on their ratings, rock mass was supported. Construction stage geotechnical assessments were made, and suitable remedies were adopted for all the components of the project after geological traverses, detailed geological mapping, drift logs and logging of cores was done. This paper deals with rock mass characterization of underground structures specially in TRT’s using RMR classification and encountered geological problems during excavation.HYDRO Nepal JournalJournal of Water, Energy and Environment Issue: 23Year: 2018

scholarly journals Engineering Geological Characteristics Based on Rock Mass Rating (RMR) and Geological Strength Index (GSI) in Jlantah Dam Intake Tunnel, Karanganyar District, Central Java Province

2021 ◽  
Vol 325 ◽  
pp. 08003
Author(s):  
Doni Apriadi Putera ◽  
Heru Hendrayana ◽  
I Gde Budi Indrawan
Keyword(s):  
Rock Mass ◽  
Research Area ◽  
Geological Mapping ◽  
Geological Strength Index ◽  
Rock Mass Rating ◽  
Strength Index ◽  
Tunnel Support ◽  
Weak Rocks ◽  
Rock Mass Characterization ◽  
Central Java

This paper presents the results of a geological engineering investigation in the form of rock mass characterization at the Jlantah Dam Intake Tunnel. The study was carried out through technical geological mapping, core drill evaluation and supported by laboratory test data. The determination of rock mass classification at the research site has been carried out using the Rock Mass Rating (RMR) method, but it is necessary to use another method that is more suitable based on rock mass for weak rocks, namely using the Geological Strength Index (GSI) method.The rock mass quality will be used as a parameter in determining the excavation method and tunnel support system that will be used in the Jlantah Dam intake tunnel. The results showed that the research area consisted of lithology in volcanic breccias and tuff lapilli. GSI rock mass value at the research location ranged from 15 - 65, while the RMR value ranged from 24 - 70. The correlation between RMR and GSI in the study area is different when compared to Hoek and Brown (1997) but has similarities with Zhang et al (2019).

scholarly journals Engineering Geological and Geotechnical Approaches for the Construction of Powerhouse Cavern of Tehri Pumped Storage Plant (1000 MW) - A Case Study

2019 ◽  
Vol 24 ◽  
pp. 35-44
Author(s):  
Rajeev Prasad ◽  
Nishith Sharma
Keyword(s):  
Underground Structure ◽  
Shear Zones ◽  
Structural Features ◽  
Geological Mapping ◽  
Left Bank ◽  
Rock Composition ◽  
Northern India ◽  
Set Up ◽  
Pumped Storage

Construction of underground Cavern in the Himalayan region is full of challenges and uncertainties. Experience has shown that construction in Himalayan regions requires good understanding of geology, adequate site investigations, proper design and selection of suitable construction methodology and technology. The most commonly encountered geological problems during excavation of underground structure in Hydroelectric Projects are, Fault/Thrust/Shear Zones squeezing and swelling, wedge block failure etc. Tehri Pumped Storage Plant (PSP) is located at the left bank of river Bhagirathi in the state of Uttarakhand in Northern India. This case study indicates about the geological challenges faced and their remedial measures during the construction of Tehri PSP Powerhouse Cavern having dimension of 203m x 24m x 58m.3D-geological mapping with 1:100 scales was carried out in excavated central drift of powerhouse to evaluate the rock composition, behavior of rock mass, structural features and further investigation to finalize the layout and orientation. During the investigation Sheared Phyllite with bands of thinly Phyllite Quartzite rock were encountered in the end portion of central drift of powerhouse which had posed a mammoth challenge in designing the powerhouse cavern. Keeping in view the recommendations of geotechnical experts and the design consultants, decision were made to shift the cavern further by 50 m to avoid Sheared Phyllite bands. The shifting of cavern led to the reorientation of structures like control room, service bay and location of units etc. This paper briefly describes the Engineering Geological and Geotechnical set up of powerhouse with proper investigation approaches and excavation sequences highlighting the importance of orientation and Sheared Phyllite Zone.

scholarly journals Evaluasi Massa Batuan Terowongan Eksplorasi Uranium Eko-Remaja, Kalan, Kalimantan Barat

EKSPLORIUM ◽  
2016 ◽  
Vol 37 (2) ◽  
pp. 89
Author(s):  
Dhatu Kamajati ◽  
Heri Syaeful ◽  
Mirna Berliana Garwan
Keyword(s):  
Rock Mass ◽  
Uranium Deposit ◽  
Rock Mass Rating ◽  
Rock Support ◽  
Safety Level ◽  
West Kalimantan ◽  
Rock Mass Characterization ◽  
Ground Support ◽  
Uranium Exploration ◽  
Weak Zones

ABSTRAKTerowongan eksplorasi uranium Eko Remaja, Kalan, Kalimantan Barat merupakan salah satu sarana penelitian cebakan uranium yang sangat penting. Terowongan ini dibangun tahun 1980 dengan panjang 618 meter dan menembus Bukit Eko di kedua sisinya. Batuan di terowongan ini relatif kompak, tetapi memiliki zona lemah di beberapa bagiannya. Penyanggaan merupakan metode yang digunakan untuk menanggulangi keruntuhan tanah dan batuan yang terjadi pada zona lemah di terowongan. Pemasangan penyangga yang selama ini dilakukan berdasarkan pola keruntuhan yang terjadi pada saat pembukaan terowongan tanpa melalui studi khusus menyangkut karakterisasi massa batuan dan kebutuhan sistem penyangga. Penelitian ini dilakukan untuk mengevaluasi tingkat keselamatan terowongan Eko-Remaja dan kesesuaian lokasi penyangga. Evaluasi dilakukan dengan membandingkan karakteristik massa batuan menggunakan metode Rock Mass Rating (RMR) antara lokasi penyangga batuan terpasang dan lokasi penyangga batuan tidak terpasang. Berdasarkan hasil analisis, nilai RMR pada lokasi terpasang penyangga diklasifikasikan ke dalam kelas IV atau batuan buruk. Sementara itu, di lokasi tidak terpasang penyangga batuan diklasifikasikan ke dalam kelas II atau batuan baik. Berdasarkan korelasi antara hasil perhitungan RMR dengan roof span terowongan Eko-Remaja disimpulkan bahwa posisi penyanggaan terowongan yang diwakili oleh lokasi pengamatan pada kedalaman 38 m, 73 m, dan 165 m sudah sesuai dengan sistem karakterisasi massa batuan menggunakan metode RMR. ABSTRACTEko-Remaja uranium exploration tunnel, Kalan, West Kalimantan is one of the important facilities for uranium deposit research. The tunnel was built in 1980 with a length of 618 meters penetrating Eko Hill on both sides. The rock inside the tunnel is relatively compact, but it has weak zones in some area. Ground supporting is a method used to overcome the soil and rock collapses which occurred in the tunnel weak zones. Installation of ground supporting system throughout the recent time based on the soil collapse pattern, which occurred when the tunnel opened without any specific study related to rock mass characterization and the requirement of ground support system. This research conducted to evaluate the safety level of Eko-Remaja tunnel and the suitability of ground support location. The evaluation performed by comparing the rock mass characteristics using Rock Mass Rating (RMR) method between the installed rock support and uninstalled rock support locations. Based on the analysis result, RMR value on the installed ground support is classified as class IV or poor rock. Meanwhile, on uninstalled location, the rock is classified as class II or fair rock. Based on the correlation between RMR calculation result and Eko-Remaja tunnel roof span, it is concluded that tunnel ground supports position which are represented by observation location on 38 m, 73 m, and 165 m depth are suitable with rock mass characterization system using RMR method.

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 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 Engineering geological characteristics based on rock mass rating (RMR) and geological strength index (GSI) in Tunnel Number 1 of the Sigli-Aceh toll road

2021 ◽  
Vol 325 ◽  
pp. 01014
Author(s):  
Jabnes Satria ◽  
I Gde Budi Indrawan ◽  
Nugroho Imam Setiawan
Keyword(s):  
Rock Mass ◽  
Poor Quality ◽  
Geological Mapping ◽  
Geological Strength Index ◽  
Rock Mass Rating ◽  
Strength Index ◽  
Geological Investigation ◽  
Tunnel Support ◽  
Toll Road ◽  
Tunnel Number

This paper presents engineering geological investigation results in the form of rock mass characteristics for tunnel number 1 of the Sigli-Aceh toll road. The investigation was carried out through geological mapping, core drill evaluation, and laboratory tests. In this research, the rock mass rating (RMR) and Geological Strength Index (GSI) were applied for the rock mass classifications. The measurement of rock mass quality is then used to determine the excavation method and tunnel support system on the SigliAceh toll road. The results showed that the research location consisted of calcareous sandstone with poor to good-quality (GSI (21.7 - 85.5), RMR (32.0 - 67.6)), and sandstone with good quality (GSI (86.3 - 86.9), RMR (64.0 - 65.0)). The poor quality rock masses were mainly caused by weathering effect. In addition, this research also analyzes the relationship between RMR and GSI based on the type and quality of rocks in the research location so that this correlation can be used in other areas with similar rock type and quality to this research location.

scholarly journals ROCK MASS RATING OF CAVITY LIMESTONE LAYER IN REMBANG, CENTRAL JAVA, INDONESIA

2015 ◽  
Vol 6 (1) ◽  
Author(s):  
R. Andy Erwin Wijaya ◽  
Dwikorita Karnawati ◽  
Srijono Srijono ◽  
Wahyu Wilopo
Keyword(s):  
Rock Mass ◽  
Solution Process ◽  
Research Area ◽  
Rock Mass Rating ◽  
Mine Design ◽  
Weak Zone ◽  
Rock Mass Characterization ◽  
Central Java ◽  
Geological Conditions

mine design. Mine design is determined by the rock mass quality, which varies from one mine location to another, depending on the geological conditions. The research area is located in limestone quarry of Sale District, Rembang Regency, Central Java Province, Indonesia. In the study area, a cavity zone is exposed at the wall of quarry bench and occurs by a solution process. The cavity layer zone is a weak zone which has caused bench failures. The objective of this research is to evaluate the quality of the cavity limestone layer for a safe mine design using Rock Mass Rating (RMR) system. Final result of the research is a rock mass characterization, specifically for the cavity limestone layer. Keywords: Rock mass rating, limestone, cavity layer

scholarly journals Geotechnical Assessment of the Foundation of Housing Chamber of Yaragol Gravity Dam, Karnataka State, India

2018 ◽  
Vol 2 (1) ◽  
Author(s):  
Ajay Kumar Naithani ◽  
L. G. Singh, ◽  
Prasnna Jain ◽  
D. S. Rawat
Keyword(s):  
Rock Mass ◽  
Geological Mapping ◽  
Gravity Dam ◽  
Rock Mass Rating ◽  
Engineering Geological Mapping ◽  
Data Set ◽  
Floor Area ◽  
Geotechnical Assessment ◽  
Laboratory Test Results ◽  
Karnataka State

Geotechnical assessment of the foundation including engineering geological investigations are essential for important civil structures to provide permanent data set for geological interpretations and for recommendations of suitable engineering measures for the improvement of the foundation. Yaragol Gravity Dam for drinking water is being constructed across Markandaya river in Karnataka State of India. Engineering geological mapping on 1:200 scale was carried out for Housing Chamber of Yaragol Gravity Dam to evaluate the design basis foundation parameters. 2 m x 2 m grids were prepared for mapping of the floor. Based on the field observations and evidences, it was found that the floor area consists of foliated gneiss and granite. No evidence of faulting or shearing was observed on the surface of the floor area. Geotechnical assessment of the foundations was done on the basis of detailed engineering geological mapping and laboratory test results. Classification of rock mass using Rock Mass Rating (RMR) of Bieniawski (1989) has been attempted and based on investigations recommendations for the treatment of foundation were given. Rock type and Rock Mass Rating (RMR) methods were used for assessing the safe bearing pressure of the foundation. Consolidation grouting up to 6 m depth in the foundation using primary at 6 m spacing and secondary holes at 3 m spacing was recommended. After detailed investigations it was found that, the foundation is suitable to locate a housing chamber.

scholarly journals Geotechnical Assessment of the Foundation of Housing Chamber of Yaragol Gravity Dam, Karnataka State, India

2018 ◽  
Vol 1 (1) ◽  
Author(s):  
Ajay Kumar Naithani ◽  
L. G. Singh, ◽  
Prasnna Jain ◽  
D. S. Rawat
Keyword(s):  
Rock Mass ◽  
Geological Mapping ◽  
Gravity Dam ◽  
Rock Mass Rating ◽  
Engineering Geological Mapping ◽  
Data Set ◽  
Floor Area ◽  
Geotechnical Assessment ◽  
Laboratory Test Results ◽  
Karnataka State

Geotechnical assessment of the foundation including engineering geological investigations are essential for important civil structures to provide permanent data set for geological interpretations and for recommendations of suitable engineering measures for the improvement of the foundation. Yaragol Gravity Dam for drinking water is being constructed across Markandaya river in Karnataka State of India. Engineering geological mapping on 1:200 scale was carried out for Housing Chamber of Yaragol Gravity Dam to evaluate the design basis foundation parameters. 2 m x 2 m grids were prepared for mapping of the floor. Based on the field observations and evidences, it was found that the floor area consists of foliated gneiss and granite. No evidence of faulting or shearing was observed on the surface of the floor area. Geotechnical assessment of the foundations was done on the basis of detailed engineering geological mapping and laboratory test results. Classification of rock mass using Rock Mass Rating (RMR) of Bieniawski (1989) has been attempted and based on investigations recommendations for the treatment of foundation were given. Rock type and Rock Mass Rating (RMR) methods were used for assessing the safe bearing pressure of the foundation. Consolidation grouting up to 6 m depth in the foundation using primary at 6 m spacing and secondary holes at 3 m spacing was recommended. After detailed investigations it was found that, the foundation is suitable to locate a housing chamber.

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