Drivability prediction of vibrated steel piles

Within the framework of a European research project ( BBRI, 1994 ) and a subsequent national research project ( BBRI, 1995 -1997), the Belgian Building Research Institute investigated the vibratory driving technique for installing steel (sheet)piles. Drivability and environmental aspects of this installation method were studied, and two analytical models were developed in order to predict drivability and/or vibration nuisance in the surroundings. In this contribution the calculation method to predict the drivability of vibratory driven piles and sheet-piles is presented. The method is based on a simple analytical model integrating the equations of motion and calibrated by the results of a more complex wave equation simulation of the soil behaviour around the pile. The proposed method incorporates degradation of soils under cyclic loading as well as liquefaction of granular materials below the water table. Geotechnical input is derived from the results of cone penetration tests. The paper presents experimental results collected on several sites where geotechnical data and vibratory performance of sheet piles were collected. Correlation between calculated and measured driving times is ascertained.