Development of numerical models for the long-term behaviour of monopile foundations under cyclic loading considering the installation effects

Abstract

Abstract In most geotechnical simulations, the initial condition of the soil is assumed to be homogenous in terms of the void ratio and stress distribution. Thus, the influences of the installation process are not considered. In the study presented in this paper, the effects of the installation process by vibratory and impact driving means on the cyclic deformation behaviour of monopile foundations are investigated. The development and validation of different numerical models for the simulation of cyclic horizontal loading are presented. In the first model, the installation effects are taken into account in the form of the initial conditions of soil, which are based on a separate simulation for pile penetration. In the second model, a simplified approach uses some simple modifications of the initial value of soil in a certain zone around the pile shaft. With the results of small-scale model tests, the numerical approaches are validated. It is observed that the piles with impact and vibratory driving have significantly different deformation behaviours under cyclic loading.