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.

scholarly journals Engineering Gology Model of Bener Dam Diversion Tunnels in Geological Risk Disaster Mitigation

2020 ◽  
Vol 6 (3) ◽  
pp. 205-215
Author(s):  
Daru Jaka Sasangka ◽  
Dian Insani ◽  
I Gde Budi Indrawan
Keyword(s):  
Rock Mass ◽  
Laboratory Data ◽  
Poor Quality ◽  
Disaster Mitigation ◽  
Primary Data ◽  
Diversion Tunnel ◽  
Rock Mass Quality ◽  
The Difference ◽  
The Stability ◽  
Quality Type

The Bener Dam Diversion Tunnel Plan is located in Bener District, Purworejo Regency. Engineering geology mapping data, drillimg data and laboratory data used as primary data. Surface and subsurface analysis show that each rock unit has different index and mechanical properties. Generally, the rock mass quality conditions in the dam belonged to good Rock (80%) in the Rock Mass Rating (RMR) system (Bieniawski, 1989).  The other rock mass quality type also found among them fair rock (5%), poor rock (5%), and very poor rock (10%). Poor rock mass quality conditions were controlled by geological structures, especially faults that partially cut through the tunnel geometry. The very poor quality of rock mass was in the volcanic lens (loose sand material) did not cut through the tunnel path. The difference stand-up time of the rock on the tunnel requires proper mitigation (Nguyen Nguyen, 2015). The stand-up time belonged to the dangerous condition was in the fault zone with poor rock mass quality, while the lens with very bad rock mass quality did not affect the stability of the excavation of the tunnel.

scholarly journals Analysis of engineering geology conditions based on the quality of rock mass in the Tiga Dihaji Dam’s diversion tunnel, South Sumatera, Indonesia

2021 ◽  
Vol 325 ◽  
pp. 05001
Author(s):  
Zekrinaldi ◽  
Ferian Anggara ◽  
Hendy Setiawan
Keyword(s):  
Rock Mass ◽  
Geological Strength Index ◽  
Strength Index ◽  
Diversion Tunnel ◽  
Rock Mass Quality ◽  
Geological Conditions ◽  
Q System

This research has examined the rock mass quality case study in the Tiga Dihaji Dam’s diversion tunnel. Observations of geological conditions were carried out on the surface and subsurface of the study site and show that the study area consists of tuffaceous sandstone and carbonate interbeds. The method of this study is based on the classification of the Geological Strength Index (GSI), Rock Mass Rating (RMR), and the Q-system. The results indicate that tuffaceous sandstone has a GSI value of 15 - 87.5 (very poor - very good), RMR 48 - 82 (fair - very good), and Q-system 0.01 – 60.0 (exceptionally poor - very good). Meanwhile, carbonate interbeds have a low value, with a GSI value of 10.5 - 77.5 (very poor to very good), RMR 17.0 – 56.0 (very - poor fair), and Q-system 0 - 35.2 (exceptionally poor - good). Moreover, a correlation was made between rock mass quality for conditions in the study area. The correlation between GSI and RMR was obtained by the equation GSI = 2.2885RMR 82.567 (R2 = 0.6653), RMR and Q-system RMR = 2.0175ln(Q) + 63.061 (R2 = 0.4987), and GSI and Q-system GSI = 7.2119ln(Q) 54.578 (R2 = 0.8095).

scholarly journals Rock mass quality effected by lineament using rock mass rating (rmr)-case study from former quarry site

2017 ◽  
Vol 1 (2) ◽  
pp. 13-16 ◽  
Author(s):  
Hamzah Hussin ◽  
Nurhazren bt Fauzi ◽  
Tajul Anuar Jamaluddin ◽  
Mohd Hariri Arifin
Keyword(s):  
Rock Mass ◽  
Rock Mass Rating ◽  
Rock Mass Quality

scholarly journals Review of Rock-Mass Rating and Tunneling Quality Index Systems for Tunnel Design: Development, Refinement, Application and Limitation

2018 ◽  
Vol 8 (8) ◽  
pp. 1250 ◽  
Author(s):  
Hafeezur Rehman ◽  
Wahid Ali ◽  
Abdul Naji ◽  
Jung-joo Kim ◽  
Rini Abdullah ◽  
...  
Keyword(s):  
Rock Mass ◽  
Quality Index ◽  
Classification Systems ◽  
Design Tools ◽  
Rock Mass Rating ◽  
Rock Mass Properties ◽  
Rock Engineering ◽  
Mass Properties ◽  
Tunnel Design ◽  
Empirical Design

Although rock-mass rating (RMR) and tunneling quality index (Q) systems are used in different rock engineering projects as empirical design tools, their application in tunnel design is widely accepted as these systems were developed and updated for this purpose specifically. This paper reviews the work conducted by various researchers since the development of these two systems with respect to tunneling only. Compared to other empirical classification systems, these systems received international acceptance and are still used as empirical design tools in tunneling due to their continuous updates in the form of characterization and support. As the primary output of these systems is the initial support design for tunnel, however, their use in the calculation for rock-mass properties is an essential contribution of these systems in rock engineering design. Essential for the tunnel design, these rock-mass properties include the modulus of deformation, strength, Poisson’s ratio, Mohr-Coulomb parameters and Hoek-Brown constants. Other application for tunneling include the stand-up time and rock load. The uses and limitations of these systems as empirical tunnel design tools are also included in this review article for better results. Research to date indicates that if the ground behavior is also taken into account, the application of these empirical systems will be more beneficial to the preliminary design of tunnels.

scholarly journals Empirical Evaluation of Rock Mass Rating and Tunneling Quality Index System for Tunnel Support Design

2018 ◽  
Vol 8 (5) ◽  
pp. 782 ◽  
Author(s):  
Hafeezur Rehman ◽  
Abdul Naji ◽  
Jung-joo Kim ◽  
Han-Kyu Yoo
Keyword(s):  
Rock Mass ◽  
Index System ◽  
Quality Index ◽  
Empirical Evaluation ◽  
Rock Mass Rating ◽  
Support Design ◽  
Tunnel Support

scholarly journals APLIKASI METODE EMPIRIS MINING ROCK MASS RATING DAN MATHEWS STABILITY GRAPH DALAM ANALISIS KESTABILAN OPEN STOPE PADA TAMBANG EMAS BAWAH TANAH

2017 ◽  
Vol 2 (2) ◽  
Author(s):  
Erick Alan Deratama ◽  
Romla Noor Hakim ◽  
Eko Santoso ◽  
Bayu Budi Santoso ◽  
Ashri Kurniawan
Keyword(s):  
Rock Mass ◽  
Quartz Vein ◽  
Hanging Wall ◽  
System Stability ◽  
Rock Mass Rating ◽  
Hydraulic Radius ◽  
Stability Graph ◽  
Q System

PT. Natarang Mining merupakan tambang emas bawah tanah yang menerapkan metode sublevel open stoping. Untuk memaksimalkan kapasitas produksi akan dibuat open stope pada Drift West Level 4 di kedalaman 165 m. Penelitian ini dlakukan untuk mengevaluasi kestabilan sill drift dan optimalisasi dimensi stope pada lokasi Drift West Level 4 dengan menggunakan metode Mathews Stability Graph dan Mining Rock Mass Rating (Laubscher and Jacovec, 2001). Metode ini dipilih karena penentuan parameter disesuaikan dengan kondisi tambang bawah tanah seperti efek peledakan, tegangan terinduksi, tingkat pelapukan, kondisi air dan orientasi kekar. Dalam karaketerisasi massa batuan, terdapat tiga jenis batuan pada lokasi penelitian yaitu andesitic massive, prophylitic andesitic vulcanic breccia dan brecciated quartz vein. Berdasarkan pendekatan empiris MRMR dan Mathews Stability Graph lokasi drift west dalam kondisi stabil dengan nilai hydraulic radius 1.16 m. Optimalisasi dimensi pada perencanaan open stope dapat dilakukan dengan memaksimalkan nilai hydraulic radius dengan perencanaan tinggi stope adalah 50 m.  Berdasarkan pendekatan empiris MRMR panjang optimal stope dalam kondisi stabil adalah 39 m pada hanging wall dan 28 m pada vein. Sedangkan pada metode Mathews Stability Graph diperoleh nilai panjang optimal sebesar 15 m pada hangingwall dan 12.5 m pada vein. Kata-kata kunci : MRMR, Q System, Stability Graph, Hydraulic Radius

Rock Mass Quality Q-System

2011 ◽  
pp. 85-118
Author(s):  
Bhawani Singh ◽  
R.K. Goel
Keyword(s):  
Rock Mass ◽  
Rock Mass Quality ◽  
Q System

Rock mass quality (Q) — System

1999 ◽  
pp. 62-91 ◽  
Author(s):  
Bhawani Singh ◽  
R.K. Goel
Keyword(s):  
Rock Mass ◽  
Rock Mass Quality ◽  
Q System
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