Variability of the engineering properties of rock masses quantified by the geological strength index: The case of ophiolites with special emphasis on tunnelling

Marinos, P; Hoek, E; Marinos, V

dc.contributor.author	Marinos, P	en
dc.contributor.author	Hoek, E	en
dc.contributor.author	Marinos, V	en
dc.date.accessioned	2014-03-01T01:25:28Z
dc.date.available	2014-03-01T01:25:28Z
dc.date.issued	2006	en
dc.identifier.issn	14359529	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/17676
dc.subject	Geological strength index	en
dc.subject	Ophiolites	en
dc.subject	Rock mass classification	en
dc.subject	Tunnels	en
dc.subject.other	Deformation	en
dc.subject.other	Mechanical properties	en
dc.subject.other	Petrography	en
dc.subject.other	Rocks	en
dc.subject.other	Tectonics	en
dc.subject.other	Tunneling (excavation)	en
dc.subject.other	Geological model	en
dc.subject.other	Geological strength index (GSI)	en
dc.subject.other	Ophiolites	en
dc.subject.other	Rock mass classification	en
dc.subject.other	Rock mass properties	en
dc.subject.other	Rock masses	en
dc.subject.other	Structural geology	en
dc.subject.other	ophiolite	en
dc.subject.other	rock mass classification	en
dc.subject.other	strength	en
dc.subject.other	tunneling	en
dc.title	Variability of the engineering properties of rock masses quantified by the geological strength index: The case of ophiolites with special emphasis on tunnelling	en
heal.type	journalArticle	en
heal.identifier.primary	10.1007/s10064-005-0018-x	en
heal.identifier.secondary	http://dx.doi.org/10.1007/s10064-005-0018-x	en
heal.publicationDate	2006	en
heal.abstract	The paper presents a quantitative description, using the Geological Strength Index (GSI), of the rock masses within an ophiolitic complex including types with large variability due to their range of petrography, tectonic deformation and alteration. This description allows the estimation of the range of rock mass properties and the understanding of the dramatic changes in behaviour which can occur during tunnelling, from stable conditions to severe squeezing within the same formation at the same depth. The paper presents the geological model in which the ophiolitic complexes develop, their various petrographic types and their tectonic deformation, mainly due to overthrusts. The structure of the various rock masses includes all types from massive strong to sheared weak, while the conditions of discontinuities are in most cases fair to poor or very poor due to the fact that they are affected by serpentinisation and shearing. Serpentinisation also affects the initial intact rock itself, reducing its strength. Associated pillow lavas and tectonic mélanges are also characterised. Based on the GSI, a classification of the behaviour in terms of tunnelling is presented, including stable conditions, structural instability, mild overstressing, stress dependant instability, squeezing and ravelling. © Springer-Verlag 2006.	en
heal.journalName	Bulletin of Engineering Geology and the Environment	en
dc.identifier.doi	10.1007/s10064-005-0018-x	en
dc.identifier.volume	65	en
dc.identifier.issue	2	en
dc.identifier.spage	129	en
dc.identifier.epage	142	en