Anisotropic modelling of Opalinus Clay behaviour: From triaxial tests to gallery excavation application

François Bertrand, Frédéric Collin
2017 Journal of Rock Mechanics and Geotechnical Engineering  
Deep repository in geological formations is the preferential solution considered by many countries to manage high-level nuclear wastes. In Switzerland, the Opalinus Clay is a candidate host rock. In this context, in situ and laboratory tests are conducted on Opalinus Clay to demonstrate the feasibility of deep disposal in this argillaceous formation. This paper presents a constitutive model able to fit the experimental data obtained from some triaxial tests conducted by Jahns [1] on cores from
more » ... [1] on cores from bore hole Schlattingen SLA-1. The elasto-plastic behaviour of Opalinus Clay is reproduced thanks to a Drucker-Prager model, taking into account the anisotropy behaviour of this sedimentary rock. The objective is to employ a single set of parameters representative of the material. In a second version of the model, the stress-dependency of the elastic properties and damage are taken into account. Finally, the parameters calibrated with experimental tests are used to simulate the excavation of a gallery with a second gradient approach.
doi:10.1016/j.jrmge.2016.12.005 fatcat:eplgqsp67ffohfqmu3clvceeae