Updating of the hierarchical rock mass rating (HRMR) system and a new subsystem developed for weathered granite formations
Autor: | Tiago F. S. Miranda, Joaquim Agostinho Barbosa Tinoco, L. Ribeiro e Sousa |
---|---|
Přispěvatelé: | Universidade do Minho |
Rok vydání: | 2014 |
Předmět: |
lcsh:TN1-997
0211 other engineering and technologies Decision tree Energy Engineering and Power Technology Context (language use) Classification scheme 02 engineering and technology 01 natural sciences Mining engineering Geochemistry and Petrology Rock mass rating Rock mechanics 0101 mathematics Rock mass classification lcsh:Mining engineering. Metallurgy Weathered granite formations 021101 geological & geomatics engineering Science & Technology Feature (archaeology) 010102 general mathematics Rock mass classification system Geotechnical Engineering and Engineering Geology Light rail Geology |
Zdroj: | Repositório Científico de Acesso Aberto de Portugal Repositório Científico de Acesso Aberto de Portugal (RCAAP) instacron:RCAAP International Journal of Mining Science and Technology, Vol 24, Iss 6, Pp 769-775 (2014) |
ISSN: | 2095-2686 |
Popis: | The RMR system is still very much applied in rock mechanics engineering context. It is based on the evaluation of six weights to obtain a final rating. To obtain the final rating a considerable amount of information is needed concerning the rock mass which can be difficult to obtain in some projects or project stages at least with accuracy. In 2007 an alternative classification scheme based on the RMR, the Hierarchical Rock Mass Rating (HRMR) was presented. The main feature of this system was the adaptation to the level of knowledge existent about the rock mass to obtain the classification of the rock mass since it followed a decision tree approach. However, the HRMR was only valid for hard rock granites with low fracturing degrees. In this work, the database was enlarged with approximately 40% more cases considering other types of granite rock masses including weathered granites and based on this increased database the system was updated. Granite formations existent in the north of Portugal including Porto city are predominantly granites. Some years ago a light rail infrastructure was built in the city of Porto and surrounding municipalities which involved considerable challenges due to the high heterogeneity levels of the granite formations and the difficulties involved in their geomechanical characterization. In this work it is intended to provide also a contribution to improve the characterization of these formations with special emphasis to the weathered horizons. A specific subsystem applicable to the weathered formations was developed. The results of the validation of these systems are presented and show acceptable performances in identifying the correct class using less information than with the RMR system. Keywords: Rock mass classification system |
Databáze: | OpenAIRE |
Externí odkaz: |