Simplified Nonlinear analysis for settlement prediction of pile groups

An approximate approach has been proposed for the analysis of nonlinear responses of vertically loaded pile groups. The nonlinear pile-soil-pile interaction is modeled by hyperbolic load-transfer functions. To evaluate the practical applicability of the proposed approach, a back analysis of a number of published case histories referring to single pile loading tests was carried out. Discovered by the back analysis were the more appropriate values of the main model parameters. To extend the solution of single pile to the case of a pile group, an equivalent pier interacting with surrounding soil by means of the hyperbolic load transfer functions was considered. The load-settlement response of the equivalent pier can be calculated using solutions for the response of a single pile, but, to take into account the group action due to pile-soil-pile interaction, load-transfer functions have been modified. The behavior of three full scale instrumented pile groups was studied, and the computed results using the proposed model compare favorably with the measured values. The performed study of the three field tests on pile groups indicates that the load-deformation behavior, leading up to failure, can be reasonably predicted.