A RATIONAL WAVE EQUATION MODEL FOR PILE DRIVING ANALYSIS

Abstract

A new one-dimensional wave equation model is proposed for pile driving analysis. In this model, the soil reaction during driving is derived from elasto-dynamic theory. The loss of energy from the pile as a result of shear wave propagation to the soil or radiation damping is properly modelled. In addition, the physical phenomenon of increase in soil resistance when the soil is subjected to rapid loading, or rate effects, is considered. The input soil parameters for this model maybe determined in the laboratory or correlated with standard soil properties. The use of measureable soil parameters in this new model represents a significant improvement over the existing empirical wave equation models. The formulation of this model using the one-dimensional finite element technique and the Newmark numerical solution scheme is presented in detail. The capabilities of this model include the estimation of pile sets, driving stress profiles and the prediction of the static pile capacity from set and stress wave matching techniques. These capabilities are verified with numerous case studies.