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Expanded Byrne Model for Evaluating Seismic CompressionJiang, Yusheng 18 September 2019 (has links)
The Byrne (1991) model was developed to predict excess pore water pressure for saturated sands under cyclic loading. However, the model can also be used to predict seismic compression in dry or partially saturated clean sands, which is the focus of this research. The original Byrne (1991) model has two primary limitations. One limitation is that calibration coefficients for the model have only been developed for clean sand, while seismic compression is a concern for a variety of soil types in engineering practice. Another limitation is that the existing calibration coefficients are solely correlated with soil relative density. This is in contrast to findings from studies performed over the last two decades that show various environmental and compositional factors, in addition to relative density, influence seismic compression behavior. To overcome these shortcomings and others the model was transformed to allow it to be implemented in "simplified" and "non-simplified" manners and systematic model calibration procedures were developed by means of MATLAB code. Both "simplified" and "non-simplified" variants of the model are used to analyze a site in Japan impacted by the 2007, Mw6.6 Niigata-ken Chuetsu-oki earthquake. The results from the analyses are in general accord with the post-earthquake field observations and highlight the utility and versatility of the models. / Master of Science / Earthquake shaking can cause compression of volume in soil, which may induce damage to various infrastructures. This phenomenon is known as seismic compression. Byrne (1991) proposed one model that can be used to evaluate the magnitude of seismic compression. However, this model has two significant limitations. One limitation is its coefficient expression is suitable for merely one soil type, while seismic compression is a concern for a variety of soil types in engineering practice. Another limitation is that the existing model coefficients are only correlated with soil density. This is in contrast to findings from research conducted over the last two decades that show many other environmental and compositional factors, in addition to soil density, affect the magnitude of seismic compression. To overcome these shortcomings and others the model was modified and calibrated, where mathematical transformations were performed for the model to allow it to be implemented in “simplified” and “non-simplified” calculation manners. Also, systematic model modification procedures were established by means of codes written by one software called MATLAB. Both the “simplified” and “nonsimplified” calculation methods of the model were used to analyze a site in Japan impacted by an earthquake occurred in 2007, named Niigata-ken Chuetsu-oki Earthquake. The results from the analyses are in general accord with the records obtained after the earthquake and highlight the utility and versatility of the modified models.
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