000183565 001__ 183565
000183565 005__ 20190604054643.0
000183565 0247_ $$2doi$$a10.1007/s00603-013-0389-4
000183565 022__ $$a0723-2632
000183565 02470 $$2ISI$$a000329997500005
000183565 037__ $$aARTICLE
000183565 245__ $$aLaboratory and in situ simulation tests of the Excavation Damaged Zone around galleries in Opalinus Clay
000183565 269__ $$a2014
000183565 260__ $$bSpringer Verlag$$c2014$$aWien
000183565 300__ $$a14
000183565 336__ $$aJournal Articles
000183565 520__ $$aIn the context of nuclear waste disposal in clay formations, laboratory and in situ simulation experiments were performed to study at reduced scale the Excavation Damaged Zone (EDZ) around tunnels in the indurated Opalinus Clay at Mont Terri, Switzerland. In the lab, thick-walled hollow cylindrical specimens were subjected to a mechanical unloading mimicking a gallery excavation. In samples cored parallel to bedding, cracks sub-parallel to the bedding planes open and lead to a buckling failure in two regions that extend from the borehole in the direction normal to bedding. The behaviour is clearly anisotropic. On the other hand, in experiments performed on specimens cored perpendicular to bedding, there is no indication of failure around the hole and the response of the hollow cylinder sample is mainly isotropic. The in situ experiment at Mont Terri which consisted in the overcoring of a resin-injected borehole that follows the bedding strike of the Opalinus Clay, showed a striking similarity between the induced damaged zone and the fracture pattern observed in the hollow cylinder tests on samples cored parallel to bedding. Such a bedding controlled “Excavation” Damaged Zone is as well consistent with the distinct fracture patterns observed at Mont Terri depending on the orientation of holes/galleries with respect to the bedding planes. Interestingly, the damaged zone observed in the hollow cylinder tests on samples cored parallel to bedding and in situ around URL galleries is found to develop in reverse directions in Boom Clay (Mol) and in Opalinus Clay (Mont Terri). This most probably results from different failure mechanisms: i.e. shear failure along conjugated planes in the plastic Boom Clay, but bedding plane splitting and buckling in the indurated Opalinus Clay.
000183565 6531_ $$aHollow cylinder test
000183565 6531_ $$aIn situ simulation test
000183565 6531_ $$aExcavation Damaged Zone
000183565 6531_ $$aX-Ray Computed Tomography
000183565 6531_ $$aOpalinus Clay
000183565 6531_ $$aNuclear waste disposal
000183565 700__ $$0241814$$g114728$$aLabiouse, Vincent
000183565 700__ $$aVietor, Tim
000183565 773__ $$j47$$tRock Mechanics and Rock Engineering$$k1$$q57-70
000183565 8564_ $$uhttps://infoscience.epfl.ch/record/183565/files/Labiouse%20Vietor%20RMRE%20author%20version.pdf$$zPostprint$$s2513601$$yPostprint
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000183565 937__ $$aEPFL-ARTICLE-183565
000183565 973__ $$rREVIEWED$$sPUBLISHED$$aEPFL
000183565 980__ $$aARTICLE