Anisotropic deformability and strength of slate from NW-Spain
| Autor: | Jordi Delgado-Martín, Andrea Muñoz-Ibáñez, J. Alvarellos, N. A. González-Molano, Leandro R. Alejano, M.A. González-Fernández, X. Estévez-Ventosa, Fei Song |
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| Přispěvatelé: | Universitat Politècnica de Catalunya. Departament d'Enginyeria Civil i Ambiental |
| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
Fissility
SLATES Slate Metamorphic rock Cleavage (crystal) Geometry Mecànica de roques Transversely isotropic elasticity Geotechnical Engineering and Engineering Geology JPW Physics::Geophysics Transverse isotropy Rock mechanics Foliation (geology) Anisotropy Enginyeria civil::Geotècnia::Mecànica de roques [Àrees temàtiques de la UPC] 2506.17 Mecánica de las Rocas Compression (geology) Strength Geology 2599 Otras Especialidades de la Tierra Espacio o Entorno |
| Zdroj: | UPCommons. Portal del coneixement obert de la UPC Universitat Politècnica de Catalunya (UPC) RUC. Repositorio da Universidade da Coruña instname Investigo. Repositorio Institucional de la Universidade de Vigo Universidade de Vigo (UVigo) |
| Popis: | Slates are metamorphic rocks characterized by the pervasive occurrence of cleavage or foliation producing a highly anisotropic mechanical behavior characterized by fissility. Deformability and strength of these rocks are therefore dependent on the cleavage plane orientations relative to the principal stresses. In this study, the failure and deformability of these rocks are experimentally investigated by means of a set of standard uniaxial and triaxial compression tests on samples cut with the cleavage forming different angles. Propagation velocity measurements have also been taken in a good number of specimens. Compression tests show that deformability and strength are clearly anisotropic for this rock and that failure through the cleavage plane is observed in the range of dip angles from 15 to 75°. Transversely isotropic elastic parameters are fit based on improved existing approaches. Moreover, the strength of tested samples cut normal and parallel to foliation relevantly differ, something noted qualitatively in the past by some authors in some metamorphic anisotropic rocks. However, this difference has neither been explicitly reported for the case of other foliated sedimentary rocks such as shales, nor formalized in theoretical strength approaches. The triaxial compression experimental data on slates were fit with the Jaeger's plane of weakness (JPW) model. Strength criteria differentiating the strength in directions normal and parallel to foliation are proposed to adapt the JPW model to the observations in slate strength behavior. Other model improvement is proposed, the use of a non-linear strength criterion for the intact rock (Hoek-Brown), which shows to better represent observed strength laboratory results. The experimental part of this work was funded by REPSOL S.A. The three first authors acknowledge the Spanish Ministry of Universities for funding of the project, awarded under Contract Reference No. RTI2018-093563-B-I00, partially financed by means of ERDF funds from the EU, which permitted to complete the interpretative part of this study. The fourth author acknowledges the CSC scholarship (No. 201706260240) for financing his stay at the University of Vigo, where he was involved in part of this work. Funding for open access charge: Universidade de Vigo/CISUG. |
| Databáze: | OpenAIRE |
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