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dc.contributor.advisorAndrew J. Whittle.en_US
dc.contributor.authorOrazalin, Zhandos Yen_US
dc.contributor.otherMassachusetts Institute of Technology. Department of Civil and Environmental Engineering.en_US
dc.date.accessioned2017-09-15T15:34:22Z
dc.date.available2017-09-15T15:34:22Z
dc.date.copyright2017en_US
dc.date.issued2017en_US
dc.identifier.urihttp://hdl.handle.net/1721.1/111442
dc.descriptionThesis: Ph. D., Massachusetts Institute of Technology, Department of Civil and Environmental Engineering, 2017.en_US
dc.descriptionCataloged from PDF version of thesis.en_US
dc.descriptionIncludes bibliographical references (pages 269-281).en_US
dc.description.abstractAlthough finite element (FE) methods are well established for modeling geotechnical problems in soil masses and soil-structure interaction, most prior research on large deformation problems has been limited to simplified assumptions on drainage conditions and constitutive behavior. This thesis investigates two large deformation problems in soft clay and proposes a methodology for performing coupled flow and deformation analyses with advanced effective stress models. The first part of the research focuses on realistic 3-D finite element analyses (using AbaqusTM Standard) of a conductor (steel pipe pile) embedded within soft marine clay subjected to large lateral deformations caused by drift/drive-off of a drilling vessel. The proposed analyses use coupled pore pressure-displacement procedures together with the MIT-E3 soil model to represent the anisotropic, non-linear and inelastic effective stress-strain-strength properties of deepwater marine sediments with input parameters derived from a series of laboratory element tests performed on reconstituted Gulf of Mexico (GoM) clay. The numerical predictions are evaluated through comparison with experimental results from centrifuge tests with a well-instrumented model conductor. The FE results accurately predict the measured bending moment distribution along the length of the conductor and the spread of plastic strains within the conductor itself. The study has also shown the effects of soil behavior on local pile-soil interactions, enabling simplified analyses using macro-elements. The FE results have been used to calibrate input parameters for BWGG framework (Gerolymos & Gazetas, 2005), the Bouc-Wen (BW) model extended by Gerolymos and Gazetas (GG), that simulates generalized hysteretic pile-soil interactions and allows for degradation in soil resistance associated with geometric non-linearities. The second application considers the effects of partial drainage for large deformation, quasi-static piezocone penetration in clay. The proposed axisymmetric FE analysis procedure introduces automated remeshing and solution mapping technique (similar to RITSS; Hu & Randolph, 1998) within a commercial FE solver. We have analyzed the penetration resistance for a piezocone device using two elasto-plastic soil models (MCC, MIT-E3) and the recent elasto-viscoplastic MIT-SR soil model (Yuan, 2016) over a range of steady penetration velocities. The MCC predictions are in very good agreement with laboratory measurements of tip resistance and penetration pore pressures measured in centrifuge model tests in reconstituted kaolin. The results from more advanced soil models illustrate the impacts of anisotropic, rate dependent soil behavior on penetration tests in natural clays and are within the range of empirical measurements. The proposed analyses provide a complete framework that can now be used to investigate effects of partial drainage that occurs in piezocone tests for soils (such as silts) of intermediate permeability.en_US
dc.description.statementofresponsibilityby Zhandos Y. Orazalin.en_US
dc.format.extent303 pagesen_US
dc.language.isoengen_US
dc.publisherMassachusetts Institute of Technologyen_US
dc.rightsMIT theses are protected by copyright. They may be viewed, downloaded, or printed from this source but further reproduction or distribution in any format is prohibited without written permission.en_US
dc.rights.urihttp://dspace.mit.edu/handle/1721.1/7582en_US
dc.subjectCivil and Environmental Engineering.en_US
dc.titleAnalysis of large deformation offshore geotechnical problems in soft clayen_US
dc.typeThesisen_US
dc.description.degreePh. D.en_US
dc.contributor.departmentMassachusetts Institute of Technology. Department of Civil and Environmental Engineering
dc.identifier.oclc1003292842en_US


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