Design of Laterally Loaded Driven Piles Using the Flat Dilatometer

The nonlinear subgrade reaction method (P-y curves) is widely used for the design of laterally loaded piles. This method replaces the soil reaction with a series of independent nonlinear Winkler springs.

A preliminary semi-empirical approach for the determination of P-y curves using data obtained from a flat dilatometer test (DMT) is presented and evaluated. A brief description of the equipment, testing procedures, and the theory that enables the family of P-y curves to be determined are presented. The P-y curves are used as input for an existing finite-difference program, which calculates pile deflection versus depth at various lateral loads.

An evaluation of the proposed method is presented using data from three full-scale laterally loaded test piles. A comparison and discussion are provided between the predicted and measured behavior of the piles during lateral loading.