The Variable Damping Concept in Pile Capacity Prediction by Wave Equation Analysis

A wave equation method is applied for pre-driving analysis of driveability calculations and capacity prediction of driven piles. For the majority of piles, there are substantial differences between predicting results and pile capacities determined from static or dynamic tests. Correct calculations of the dynamic resistance are important for accurate prediction of the pile capacity. The dynamic resistance depends on the pile velocity and the damping coefficient, but both of them cannot reflect time-dependent changes of the pile-soil system after the end of driving. Variation of the pile-soil system after pile installation can be taken into account with a variable damping coefficient which should be considered as a function of time or other parameters characterizing soil consolidation around a pile. Wave equation analysis with the variable damping coefficients can provide the range of predicted pile capacities at a site. The existing wave equation programs can utilize the variable damping concept for improving of the prediction of pile capacities at construction sites