Numerical modelling of a laterally loaded pile group by finite element method

The main purpose of this research is to create a nonlinear finite element computer program (LPG) specifically for analyzing a laterally loaded pile group. In the program, piles are modeled by 3-D finite beam elements. Pile-soil and pile-soil-pile interaction among the piles and soil within the group is modeled by soil springs. The interaction is assumed to be effected by two types of springs, near-field and far-field soil springs. The near-field soil springs are nonlinear and their stiffnesses are obtained from p-y curves. The far-field soil springs are linear and their stiffnesses are obtained from Mindlin's flexibility equations. Axial loads are transferred to the soil through the axial linear soil springs attached to the tips of the piles. Input parameters for all the soil springs can be obtained from insitu and/or laboratory tests.; The program gives both linear and nonlinear solutions comparable to the solutions of a commercially available software (COM624) for a laterally loaded single pile. It also gives Poulos's Integral Solution for a laterally loaded linear elastic pile group system.; Finally, the program was used to predict both a single pile and pile group response at a Houston, Texas, site for static and cyclic loadings. Good results were obtained for both cases using the same soil parameters obtained from the site.