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Coupled Systems Mechanics Volume 4, Number 1, March 2015 , pages 37-65 DOI: https://doi.org/10.12989/csm.2015.4.1.037 |
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On validation of fully coupled behavior of porous media using centrifuge test results |
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Panagiota Tasiopoulou, Mahdi Taiebat, Nima Tafazzoli and Boris Jeremić
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| Abstract | ||
| Modeling and simulation of mechanical response of infrastructure object, solids and structures, relies on the use of computational models to foretell the state of a physical system under conditions for which such computational model has not been validated. Verification and Validation (V&V) procedures are the primary means of assessing accuracy, building confidence and credibility in modeling and computational simulations of behavior of those infrastructure objects. Validation is the process of determining a degree to which a model is an accurate representation of the real world from the perspective of the intended uses of the model. It is mainly a physics issue and provides evidence that the correct model is solved (Oberkampf et al. 2002). Our primary interest is in modeling and simulating behavior of porous particulate media that is fully saturated with pore fluid, including cyclic mobility and liquefaction. Fully saturated soils undergoing dynamic shaking fall in this category. Verification modeling and simulation of fully saturated porous soils is addressed in more detail by (Tasiopoulou et al. 2014), and in this paper we address validation. A set of centrifuge experiments is used for this purpose. Discussion is provided assessing the effects of scaling laws on centrifuge experiments and their influence on the validation. Available validation test are reviewed in view of first and second order phenomena and their importance to validation. For example, dynamics behavior of the system, following the dynamic time, and dissipation of the pore fluid pressures, following diffusion time, are not happening in the same time scale and those discrepancies are discussed. Laboratory tests, performed on soil that is used in centrifuge experiments, were used to calibrate material models that are then used in a validation process. Number of physical and numerical examples are used for validation and to illustrate presented discussion. In particular, it is shown that for the most part, numerical prediction of behavior, using laboratory test data to calibrate soil material model, prior to centrifuge experiments, can be validated using scaled tests. There are, of course, discrepancies, sources of which are analyzed and discussed. | ||
| Key Words | ||
| verification and validation; finite elements; fully coupled analysis; porous media | ||
| Address | ||
| Panagiota Tasiopoulou: National Technical University of Athens, Athens, Greece Mahdi Taiebat: Department of Civil Engineering, The University of British Columbia, Vancouver, Canada Nima Tafazzoli: GeotechnicalEngineer, Tetra Tech EBA, Vancouver, BC, Canada Boris Jeremic: Department of Civil and Environmental Engineering, University of California, Davis, CA, and Faculty Scientist, Earth Science Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA | ||
