| Summary: | 碩士 === 淡江大學 === 土木工程學系碩士班 === 96 === The seismic lateral response of the single pile is modeled in this study using the wave equation analysis. The structural system was decomposed into substructures where the corresponding individual responses were solved and integrated to obtain the results. To obtain the solution, the seismic free-field response of the site was computed from the lumped mass analysis and pore water pressure model, and the soil deformations were than imposed onto the pile foundation to conduct the wave equation analysis. The soil springs along the pile are calculated from the p-y curves. They are implemented with the transformed dampers to model the seismic forces. Modified Bouc-Wen model is used to obtain nonlinear pile responses. Validations of the analysis are made with the Cyclic-1D solutions.
The observation are summarized as follows: (1) The seismicity source, PGA, depth of ground water table, site stiffness, soil spring and damping, and even the pore water pressure model parameters will all affect the pile responses. Among them, PGA and the site stiffness are the most two significant ones. (2) The changes of pile length and external loads are not sound to the pile displacements and the corresponding pile moments and shears. (3) The solutions from this study were found similar to those of Hamada (1992) and Ishihara and Cubrinovski (2004). The maximum bending moment of the pile occurs at the interfaces between the liquefied layer and the non-liquefiable layers. Peak pile displacement occurs at the pile head. Maximum relative pile displacement between the pile head and pile tip agree well with the field observation. (4) The pore water pressure model can reflect clearly the time-dependence of the trigger of soil liquefaction on seismic response of the pile. (5)The lumped mass analysis of the seismic site responses could provide similar results to those obtained from Cyclic-1D analysis, however it saves more time in computations.
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