The load-transfer method has usually been used for an analysis of nonlinear behavior of vertically loaded piles. In this method, a hyperbolic function has often been assumed as the analytical model for curves of skin friction versus settlement along the pile or point resistance versus settlement at the pile tip. This paper deals with the method of inverse analysis to estimate the constants of the hyperbolic function.
The inverse analysis was applied to an numerical example. It is found out that in this method there is not difficult problem such as the existence of multi-extremum. Furthermore the inverse analysis was applied to the full-scale experimental results of a bored pile. The constant values of the hyperbolic function were determined from the test results. And then the forward analysis of nonlinear vertical behavior of the pile was made on the basis of the constant values. As a result, the forward analysis was in good agreement with the experimental results. This result means that the actual relationships between skin friction and settlement or between point resistance and settlement can be well simulated by the hyperbolic function, and that the proposed inverse analysis is applicable to estimate the constants of hyperbolic functions for test results.