INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING, zyxwv VOL. 37, 257-278 (1994) A FINITE ELEMENT MODEL FOR THE SIMULATION OF PILE DRIVING MOUNIR E. MABSOUT* zyxwvut Department of Civil Engineering, American University of Beirut, zyxwv P.O. Box 11-0236, Beirut, Lebanon JOHN L. TASSOULAS' Department of Civil Engineering, The University of Texas, Austin, TX, zyxw 78712-1076, U.S.A. SUMMARY The feasibility of conductinga detailed analysis of pile driving using a finite element technique is examined in this paper, taking into account the non-linearbehaviour of undrained clayey soil and tracing the penetration of the pile into the soil. A three-dimensional model is used for this purpose, which is handled by two-dimensional analysis due to the axisymmetric nature of the problem. A non-linear time-domain dynamic analysis is performed in which the hammer blows on the pile are represented by a periodic forcing function, and the pile penetration is treated using a frictional contact slideline algorithm. The model is applied to the driving of a concrete pile in a clayey soil. INTRODUCTION The importance of developing a reliable method for the analysis of pile driving has long been recognized as essential in foundation engineering practice. The high cost of pile installation, particularly for deep-water offshore structures, requires proper simulation of the driving problem. zy A one-dimensional wave equation analysis as applied to the pile-driving problem was first put to practical use by Smith' in 1960. This method takes into account the time-dependent events occurring as a result of a hammer blow. A series of mass-spring elements are used to discretize the hammer-cushion-cappile system, while the soil around the pile and below its tip is represented by discrete non-linear springs and dashpots. While the wave equation method has been widely used for the solution of the driving problem, the accuracy of the results has not always been satisfactory. This is mainly due to the simplistic one-dimensional way in which the soil has been modelled. It is, therefore, conceivable that a full-scale three-dimensional modelling of the pile-driving problem would lead to more accurate results. This modelling can accommodate the stress waves induced by the driving process in the soil surrounding the pile. A more realistic representation can then be obtained. Limited attempts have been made so far to analyse the pile-driving problem using a three- dimensional model. Chow and Smith' performed axisymmetric finite element analyses for solid and pipe piles in undrained clays. They used an elastic-perfectly plastic soil model with a von Mises yield function, dependent on its undrained shear strength. These studies have shown significant differences in behaviour in comparison with the one-dimensional analysis, especially zy * Assistant Professor f Professor 0029-598 1/94/020257-22$16.00 zyxwvu 0 1994 by John Wiley & Sons, Ltd. Received 9 September 1992 Revised 31 March 1993