Weak rock mass characterization by RMR and M-RMR systems: A comparative study based on the cases from mines in Turkey
Küçük Resim Yok
Tarih
2012
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
International Society for Rock Mechanics
Erişim Hakkı
info:eu-repo/semantics/closedAccess
Özet
Rock Mass Rating (RMR) and Q systems are the rock mass classification schemes most widely used in mining and tunneling. However, the authors experienced some difficulties in determining some input parameters for geotechnical evaluations at mine sites, such as strength, joint condition and orientation of discontinuities required particularly for RMR system when it is applied to weak, stratified and clay-bearing rocks. Consequently, the engineering applications that would be carried out based on original ratings suggested by these systems could be misleading in making decisions even during the preliminary design stage. In order to overcome these difficulties and to better characterize this kind of rocks, the authors made some attempts to modify the RMR system and recommended the Modified RMR (M-RMR) system. In this paper, first the reason why the RMR system has been modified, the input parameters used by the system and the improvements made by the authors for the system throughout time are briefly given. Then the results obtained from the application of the RMR and M-RMR systems to seven mines selected from Turkey between 1986 and 2009 are compared in terms of engineering applications and design outputs based on the data from 33 geotechnical boreholes with a total length of 3448.45 m. Quantitative comparison of the two systems indicates that there is a significant difference between the rock mass ratings derived from the two systems particularly for weak rock mass regions. When the upper ratings of both systems are compared, M-RMR yields slightly higher ratings. In addition, in weak rock regions, where RMR predicts less support, M-RMR calls for more support to provide stability. © BeFo and ISRM, 2012.
Açıklama
ISRM International Symposium - EUROCK 2012 -- 28 May 2012 through 30 May 2012 -- 138890
Anahtar Kelimeler
M-RMR, RMR, Rock mass characterization, Weak and clay-bearing rocks
Kaynak
ISRM International Symposium - EUROCK 2012
WoS Q Değeri
Scopus Q Değeri
N/A
