Abstract
The rock mass quality in underground excavations and or tunnelling is a key issue in the design of the most suitable support to ground stability. This work aims to discuss the applicability of the latest version of the geological strength index (GSI|2013) in an anisotropic media during ongoing deep underground excavation by drilling and blasting. The study encompasses a comprehensive geological, geotechnical and geomechanical characterisation and evaluation of the excavation faces in the Marao tunnel (north Portugal). In addition, 305 m (two underground sections) of tunnel were mapped in 74 consecutive face underground excavation advances. Geological, geotechnical and geomechanical data relating to the site investigation were collected and computed in each new face advance. The scanline sampling technique was applied on exposed rock surfaces, a geotechnical analysis of the discontinuities was performed, and the block size of the rock mass was determined. Geotechnical and geomechanical zoning of the studied sections were continuously carried out considering the knowledge of the site rock mass characteristics and behaviour. In addition, a comparison was performed between the version of GSI|2013 and its earlier version (namely, GSI|98) and correlated with rock mass rating. The study will contribute to a better understanding of GSI|2013 and its applicability in geoengineering projects in design or excavation work stages.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: Bulletin of Engineering Geology and the Environment
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
