Three-dimensional non-linear finite element analysis of laterally loaded piles in clay

Behavior of laterally loaded single piles and pile groups in fine grained soils are investigated using a non-linear finite element methodology. The purpose is to gather behavioral information that would help improve our knowledge of pile behavior and enhance the applicability of some existing methods of analysis.; A three-dimensional non-linear finite element program, PILE3D, has been developed. An anisotropically hardening bounding surface plasticity model is used to model soil behavior. Behavior of soil-pile interface is modeled using thin isoparametric elements. Various geotechnical loading and boundary conditions including drained and undrained loading, water table, in-situ stresses, preconsolidation and formation of gap at the soil-pile interface, have been implemented.; Two full-scale laterally loaded pile tests are analyzed using two- and three-dimensional idealizations and results are compared with observed pile behavior. Good agreement is obtained between measured and computed bending moment, soil resistance and lateral deflection along the length of the pile, load-deflection response at the pile-head and p-y curves at different depths.; Influence on the behavior of the pile-soil system of flexural rigidity and diameter of the pile, shear strength, lateral pressure coefficient, friction angle and preconsolidation of the soil, and gap formation behind the pile at the soil-pile interface are investigated. Results are compared with some existing criteria for the determination of p-y curves.; Effect of interaction between the individual piles in a group is studied using three different configurations: (i) an {dollar}infty{dollar} x 1 group, (ii) a 1 x {dollar}infty{dollar} group and (iii) an {dollar}infty{dollar} x {dollar}infty{dollar} group. Influence of spacing between the piles in a group is investigated. Results are compared with some existing theoretical solutions and with results of full-scale and model-scale pile load tests. Interactions factors are developed to adjust single pile p-y curves to account for group interaction.