Friction anlysis of large diameter steel cylinder penetration process using 3D-DEM

Abstract

Large open-ended cylinder piles have been widely used for engineering foundation of port. The penetration process of the large-diameter steel cylinder exhibit complex behaviors, which is difficult to be measured by test and reproduced in numerical models. This study presents a friction analysis of large diameter steel penetration process by using the discrete element method (DEM), which can simulate large deformation and nonlinearity well. Centrifugal model and full-scale model were developed to analyze the sliding friction of the cylinder during installation and the contact force chain of soil particles. The validity of the DEM model was examined by comparing with theoretical values and published studies. Parametric studies were carried out to study the effects of contact parameters on side friction. Simulation results showed that, unlike pile penetration, there is no obvious soil-plug effect during the penetration process of large-diameter steel cylinder. Besides, the inside friction is smaller than the outside friction for large-diameter steel cylinder. What’s more, the computational cost of full-scale model based on the upscale theory was less than the centrifugal model. There is a close relationship between the side friction and micro contact parameters, which provides a reference for the follow-up study of cylinder or pile penetration using DEM.