Numerical Modeling of Lateral Response of Long Flexible Piles in Sand

The behavior of a steel pipe pile in sand subjected to lateral load is examined by finite element (FE) analysis. Three-dimensional finite element analyses are performed for pure lateral load applied at 0.3m above the ground surface. The FE analyses are performed using the commercially available software package ABAQUS/Standard. The sand around the pile is modeled using a modified form of Mohr-Coulomb soil constitutive model. The modification involves the variation of mobilized angle of internal friction and dilation angle with plastic shear strain. The nonlinear variation of elastic modulus with mean effective stress is also considered in the present FE analyses. These important features of soil constitutive model have been implemented in ABAQUS/Standard using a user subroutine. Numerical analyses are also performed by using the LPILE software, which is based on the p-y curve. The FE and LPILE results are compared with the results of a full-scale test. It is shown that the FE analysis with modified Mohr-Coulomb soil model can successfully simulate better the response of a pile under lateral load. Comparing the numerical results with the full-scale test results some limitations of the p-y curve method are highlighted.