Modeling of laterally loaded shaft foundations using continuous soil medium

Current Code requirements for bridge design require considerable increased capacity in lateral strength and displacement demand. These requirements for increased lateral capacity is very significant in foundation design and detailing as well as in other portions of the bridge structure. Moreover, rational models for the substructure design and evaluation are needed for the development of a Load and Resistance Factor Design (LRFD) code format. Therefore, modeling of soil and structure as well as the interface between them becomes very important and will have an impact on the design as well as evaluation. In this study, a non-linear finite element program (ABAQUS) is used to model the soil as a continuous medium around the pile. Cohesive and cohesionless soils are investigated using different soil models as well as different support conditions at the top and bottom of the pile. The results of the continuous soil analysis will be used to calibrate the discrete spring model and provide information on the accuracy and the applicability of these models. The results of this investigation will help to better understand the effect of soil stiffness on the structure and the accuracy of soil-spring models. The accuracy and applicability of these models for structural analysis under lateral loads will be verified.