Time‐Domain Analysis of Dynamically Loaded Single Piles

Abstract

The response analysis of single piles under time‐dependent forces and incident wave excitations is developed (method I) using a very efficient but approximate hybrid boundary element technique. The soil displacement equations are obtained using an efficient step‐by‐step time integration scheme. Treating the piles as one‐dimensional structures, its solutions are obtained by discretizing the differential equations of pile motions using finite difference approximations. The two systems are then coupled through the equilibrium and compatibility relations at the pile‐soil interface. An alternate general multiregion boundary element formulation (method II) is used to analyze the same problem, where the transformation of three‐dimensional (3‐D) dynamic BEM formulation into cylindrical coordinates and the integration along the circumferential direction lead to an axisymmetric analysis with only two‐dimensional (2‐D) boundary discretization. Good agreement between these two methods, as well as with a Laplace transform‐based transient scheme (method III), reveals the accuracy of the formulation.