A Review on Factors affecting Seismic Pile Response Analysis: A Parametric Study

The seismic soil-pile-superstructure interaction (SSPSI) is one of the most important sources of nonlinear dynamic response of any pile supported structure such as jacket type offshore platforms (JTOP). In recent years, some researchers have studied experimental and real cases of JTOP response under earthquake or cyclic loading using OpenSees software. Throughout a parametric study, the main goal of this paper is to provide designers of pile supported structures supplemental insight into the amount of importance of different parameters included in the SSPSI response. To this end, a beam on nonlinear Winkler foundation numerical model of a single pile embedded in layers of soft clay and dense sand tested in a geotechnical centrifuge was created using OpenSees. The created numerical model was able to successfully capture the response in elastic and intermediate range of nonlinear response. However, the rate of excess pore pressure generation in the model was observed to be faster than the real test results in highly nonlinear events. Subsequently, the sensitivity of the analyzed response to soil shear strength and stiffness parameters was evaluated. The response sensitivity to various input parameters used for definition of pressure sensitive material constitutive behavior - especially the influence of parameters on pore pressure generation – was also investigated. The effects of degradation of p-y behavior after liquefaction on ARS of superstructure and moment distribution of pile were investigated. Moreover, a sensitivity analysis has been carried out to explore the systematic effects of various parameters of clay soil layer on dynamic pile analysis results.