scholarly journals Characterization of Pare Rock Mass and Support System Design for Head Race Tunnel

2020 ◽  
Vol 8 (6) ◽  
pp. 5546-5552
Keyword(s):  
Rock Mass ◽  
Support System ◽  
Critical Examination ◽  
Hydroelectric Power ◽  
Bedding Planes ◽  
Rock Mass Quality ◽  
Rock Structure ◽  
General Response ◽  
Power Project

The Head Race Tunnel (HRT) of Pare Hydro-Electric Power Project in Arunachal Pradesh, India, traverses through the Upper-Siwalik Sub-Group of the Sub-Himalayan Range, exhibiting spatial heterogeneity with respect to geotechnical and geological properties. In such complex geological set up, consisting of bedding planes, joints, fractures,varied hydrological conditions etc., prediction of rock mass quality or the characterization of the rock massis a difficult task. Although challenging, it is important to predict the general response of the rock massto tunnel excavation. This paper attempts to characterize Pare Rock Mass around the HRT, based on Rock Quality Designation (RQD), Terzaghi’s Rock Load Theory, Rock Structure Rating (RSR), Rock Mass Rating (RMR), and, Rock Mass Quality (Q) system. An attempt is also made to design the support system for HRT through Pare Rock Mass, based on these parameters. A critical examination of various support systems derived from the above mentioned methods and the support system actually provided at the HRT at Pare Hydroelectric Power Project is also presented in the paper. The study presented in this paper will providean insight about the suitability of a particular method in the design of support system in a rock mass similar to Pare rock mass.

Guidelines for selecting ground support system for the Talnakh operations based on the rock mass quality assessment

2018 ◽  
pp. 101-106
Author(s):  
V. A. Eremenko ◽  
◽  
I. I. Ainbinder ◽  
V. P. Marysyuk ◽  
Yu. N. Nagovitsyn ◽  
...  
Keyword(s):  
Rock Mass ◽  
Quality Assessment ◽  
Support System ◽  
Ground Support ◽  
Rock Mass Quality

scholarly journals Analysis of Support Systems and Excavation Methods Based on Rock Mass Quality in the Intake Tunnel of the Jlantah Dam

2021 ◽  
Vol 325 ◽  
pp. 02009
Author(s):  
Doni Apriadi Putera ◽  
Heru Hendrayana ◽  
Hendy Setiawan
Keyword(s):  
Rock Mass ◽  
Support System ◽  
Support Systems ◽  
Geological Mapping ◽  
Tunnel Support ◽  
Rock Mass Quality ◽  
System Method ◽  
Geological Conditions ◽  
Q System ◽  
Excavation Methods

Research on the classification of rock mass quality in the intake tunnel Jlantah dam has not been carried out in detail because the research focuses on the location of the main dam so that empirical excavation methods and support systems have not been carried out. 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 investigation was carried out through engineering geological mapping, core drill evaluation, and supported by laboratory test data based on the Rock Mass Rating (RMR) and Q-system rock mass classification. The rock mass at the research location based on the RMR classification is in class IV (poor rock). Based on the Q-system method, a very poor rock class is obtained. Based on the analysis of the RMR and Q-system methods, the suitable support system for engineering geological conditions such as the intake tunnel of the Jlantah Dam is shotcrete 10 cm thick, steel set with a distance of 1.5 m and rockbolt length of 1.6 m with a distance of 1.5 m. The proper excavation method for the tunnel intake is top heading and bench.

scholarly journals APPLICABILITY OF THE GEOLOGICAL STRENGTH INDEX (GSI) CLASSIFICATION FOR THE TRUSMADI FORMATION AT SABAH, MALAYSIA

2020 ◽  
Vol 4 (1) ◽  
pp. 77-81
Author(s):  
Rodeano Roslee ◽  
Jeffery Anak Pirah ◽  
Ahmad Nazrul Madri ◽  
Mohd Fauzi Zikiri
Keyword(s):  
Rock Mass ◽  
Geological Strength Index ◽  
Tectonic Deformation ◽  
Low Grade ◽  
Strength Index ◽  
Bedding Planes ◽  
Discontinuity Sets ◽  
Rock Structure ◽  
Considerable Benefit ◽  
Slope Condition

During the feasibility and preliminary design stages of a project, when very little detailed information on the rock mass and its geomechanic characteristics is not available, the use of a Rock Mass Classification Scheme (RMCS) can be of considerable benefit. Various parameters were used in order to identify the RMCS. The parameter comprised of Rock Quality Designation (RQD), Rock Mass Rating (RMR), Rock Structure Rating (RSR), Geological Strength Index (GSI), Slope Mass Rating (SMR), etc. In this paper, we present the results of the applicability of the Geological Strength Index (GSI) classification for the Trusmadi Formation in Sabah, Malaysia. The GSI classification system is based on the assumption that the rock mass contains a sufficient number of “randomly” oriented discontinuities such that it behaves as a homogeneous isotropic mass. In this study, the GSI relates the properties of the intact rock elements/blocks to those of the overall rock mass. It is based on an assessment of the lithology, structure and condition of discontinuity surfaces in the rock mass and is estimated from visual examination of the rock mass exposed in outcrops or surface excavations. A total of ten (10) locations were selected on the basis of exposures of the lithology and slope condition of the Trusmadi Formation. The Trusmadi Formation regionally experienced of two major structural orientations NW-SE and NE-SW. It consists mostly of dark grey shale with thin bedded sandstones, typical of a turbidite deposit. This unit has been subjected to low grade of metamorphism, producing slates, phyllites and meta-sediments and intense tectonic deformation producing disrupted or brecciated beds. Quartz vein are quite widespread within the joints on sandstone beds. The shale is dark grey when fresh but changes light grey to brownish when weathered. The results are classified as “Poor Rock” to “Fair Rock” in term of GSI. The poor categories (TR2 and TR7) represent slickensided, highly weathered surfaces with compact coatings or fillings or angular fragments. It is also characterized as blocky/ disturbed/seamy, which folded with angular blocks formed by many intersecting discontinuity sets. The fair categories can be divided into two (2) types; type 1 (TR1, TR6 and TR8) which represent as smooth, moderately weathered and have altered surfaces. It is also characterised as very blocky rock, which indicates interlocked, partially disturbed ass with multi-faceted angular blocks formed by 4 or more joint sets. Type 2 (TR3, TR4, TR5, TR9 and TR10) which represent as smooth, moderately weathered and have altered surfaces but characterized as blocky/disturbed/seamy, which folded with angular blocks formed by many intersecting discontinuity sets. It also has persistence of bedding planes or schistosity.

scholarly journals Empirical Support Design for Proposed Diversion Tunnels at Dasu Dam Site Pakistan

2021 ◽  
Vol 64 (2) ◽  
pp. 131-136
Author(s):  
Muhammad Bilal ◽  
Muhammad Zaka Emad ◽  
Fawad Ul Hassan ◽  
Zaheer Ahmed
Keyword(s):  
Rock Mass ◽  
Support System ◽  
Research Work ◽  
Empirical Support ◽  
Left Bank ◽  
Hydroelectric Power ◽  
Support Design ◽  
Tunnel Support ◽  
Dam Site ◽  
Q Index

  This research work presents the rock mass characteristics and tunnel support system recommendations for hydroelectric power tunnels at Dasu dam site Pakistan. Two inverted U-shaped tunnels are proposed at the left bank of Indus river. The tunnels have inlet portals at an elevation of 773.00 m and outlet portals at an elevation of 758.00 m. The thickness of rock cover above the tunnels is between 100 and 200 m. Three types of rock are encountered at project site including Granulite, Amphibolite and Gabbronorite. Granulite rocks are encountered along the alignment of tunnels. Rock mass is classified using Rock mass rating (RMR) and Tunneling quality index (Q system). Support system is suggested based on values of Q and RMR. Correlation between Q-index and RMR is also derived.    

ethodical principles of designing the formation of rock mass quality for lump sorting scheelite-containing ores at the stage of mining

2019 ◽  
Vol 8 (29) ◽  
pp. 3-17
Author(s):  
V.A. Khakulov ◽  
◽  
V.A. Shapovalov ◽  
V.N. Ignatov ◽  
Zh.V. Karpova ◽  
...  
Keyword(s):  
Rock Mass ◽  
Rock Mass Quality

scholarly journals Weightage Effect during Back-Calculation of Rock-Mass Quality from the Installed Tunnel Support in Rock-Mass Rating and Tunneling Quality Index System

2019 ◽  
Vol 9 (10) ◽  
pp. 2065 ◽  
Author(s):  
Jonguk Kim ◽  
Hafeezur Rehman ◽  
Wahid Ali ◽  
Abdul Muntaqim Naji ◽  
Hankyu Yoo
Keyword(s):  
Rock Mass ◽  
Quality Index ◽  
Rock Bolt ◽  
Rock Mass Rating ◽  
Rock Mass Quality ◽  
Back Calculation ◽  
The Difference ◽  
Bolt Spacing ◽  
Q System ◽  
Selection Of

In extensively used empirical rock-mass classification systems, the rock-mass rating (RMR) and tunneling quality index (Q) system, rock-mass quality, and tunnel span are used for the selection of rock bolt length and spacing and shotcrete thickness. In both systems, the rock bolt spacing and shotcrete thickness selection are based on the same principle, which is used for the back-calculation of the rock-mass quality. For back-calculation, there is no criterion for the selection of rock-bolt-spacing-based rock-mass quality weightage and shotcrete thickness along with tunnel-span-based rock-mass quality weightage. To determine this weightage effect during the back-calculation, five weightage cases are selected, explained through example, and applied using published data. In the RMR system, the weightage effect is expressed in terms of the difference between the calculated and back-calculated rock-mass quality in the two versions of RMR. In the Q system, the weightage effect is presented in plots of stress reduction factor versus relative block size. The results show that the weightage effect during back-calculation not only depends on the difference in rock-bolt-spacing-based rock-mass quality and shotcrete along with tunnel-span-based rock-mass quality, but also on their corresponding values.

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