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dc.contributor.advisorBallivy, Gérardfr
dc.contributor.authorMoradian, Zabihallahfr
dc.date.accessioned2014-05-15T12:41:27Z
dc.date.available2014-05-15T12:41:27Z
dc.date.created2011fr
dc.date.issued2011fr
dc.identifier.isbn9780494832998fr
dc.identifier.urihttp://savoirs.usherbrooke.ca/handle/11143/1961
dc.description.abstractA key requirement in evaluation of sliding stability of concrete dams is monitoring shear behavior of 1) concrete joints in dam body, 2) concrete-rock interfaces and 3) rock discontinuities in dam foundation. The methodology consisted of creating a database of observed shear behaviors of the mentioned joints using acoustic emission (AE) technique. Joint samples were fabricated by tension splitting of the cores and pouring concrete on rock joint replica for simulating concrete-rock interfaces. Variations of key parameters including joint geometry, normal stress, displacement rate and bonding percentage were incorporated in the analysis. An analysis was also carried out on natural joints from Daniel Johnson (Manic 5) Dam, Quebec, founded on gneiss to granitic rock. Parametric-based and signal-based analysis methods were used to evaluate the potential of AE for monitoring shear behavior of various kinds of joint with different characteristics. Using AE parameters such as amplitude, count, energy, duration and rise time, this study was done as a feasibility study for AE monitoring of sliding surfaces within dam, dam-rock interface or inside rock foundation. It was found that AE has a good capability for showing the initial shear movement of the non-bonded joints. For bonded joints this technique can show that AE activities are occurring before breaking of adhesive bond. This is important because recording AE signals after an initial breakage of the joint would be too late to install stabilization work to be done beforehand. Of course in the eventuality that a rupture includes a sequence of events even recording AE signals of the first break is still useful. It is recommended to use this method combined with other instrumentation methods (e.g. load measuring instruments) to detect the initial shear movement of the bonded joints. Following experimental work and analysis of crack propagation and asperity degradation along shearing process, four different periods were observed in shear stress-displacement behavior of joints. These periods are: 1) Pre-peak linear period in which AE activities are initiated and show the beginning of shear displacement, 2) Pre-peak non-linear period in which AE signals are generated from crack initiation and degradation of the secondary asperities, 3) Post-peak period where first order asperities are sheared off and joints pass their maximum shear strength and 4) Residual period in which AE activities decrease and reach their minimum values. The applicability. of AE localization technique was evaluated using image analysis and scanned surfaces of the joints by laser. The results indicated that this method can locate regions with rupture governing characteristics. This provides the possibility to reinforce support systems and be aware about possible structure failures before any unexpected mechanical disturbance.fr
dc.language.isoengfr
dc.publisherUniversité de Sherbrookefr
dc.rights© Zabihallah Moradianfr
dc.subjectLocalisation de sources d'EAfr
dc.subjectParamètres d'EAfr
dc.subjectVitesse de déplacementfr
dc.subjectPourcentage de liaisonfr
dc.subjectRugosité du jointfr
dc.subjectCharge normalefr
dc.subjectJoints béton-bétonfr
dc.subjectJoints roche-bétonfr
dc.subjectJoints roche-rochefr
dc.subjectComportement en cisaillementfr
dc.subjectÉmission acoustiquefr
dc.titleApplication de la méthode d'émission acoustique pour la surveillance du comportement au cisaillement des joints actifsfr
dc.typeThèsefr
tme.degree.disciplineGénie civilfr
tme.degree.grantorFaculté de géniefr
tme.degree.levelDoctoratfr
tme.degree.namePh.D.fr


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