Simple Assessment Method for Ductility Capacity of a Fixed-Head Pile

Simple Assessment Method for Ductility Capacity of a Fixed-Head Pile

This study develops simple equations to estimate the displacement ductility capacity of a fixed-head pile. The basic form of the equations is derived based on an ideal model of a semi-infinite pile with bilinear moment-curvature property in Winkler-type soils to relate the displacement capacity of the pile with the pile-soil system parameters and the formulation is modified for the effect of soil nonlinearity. Through this model, the displacement ductility capacity of the pile can be explicitly expressed in terms of the pile-soil system parameters, including the sectional over-strength ratio, curvature ductility capacity, and the ratios of characteristic coefficients of the pile-soil system. A series of numerical nonlinear pushover cases of full pile-soil models are conducted to calibrate and validate the proposed equations. Finally, a set of simple equations for the ductility capacity of the pile are built.