Numerical Simulation of Geotechnical Problems by Coupled Finite and Infinite Elements

Abstract

In geotechnical engineering, numerical simulation of problems is of great importance. This work proposes a new formulation of coupled finite-infinite elements which can be used in numerical simulation of geotechnical problems in both static and dynamic conditions. Formulation and various implementation aspects of the proposed coupled finite-infinite elements are carefully discussed. To the authors' knowledge, this approach that considers coupled finite-infinite elements is more efficient in the sense that appropriate and accurate results are obtained by using less elements. The accuracy and efficiency of the proposed approach is considered by comparing the obtained results with analytical and numerical results. In a static case, the problem of circular domain of infinite length is considered. In a dynamic case, one dimensional wave propagation problems arising from the Heaviside step function and impulse functions are considered. In order to get a more complete picture, two dimensional wave propagation in a circular quarter space is considered and the results are presented. Finally, a soil-structure interaction system subjected to seismic excitation is analyzed. In the analysis of soil-structure interaction phenomenon, frames with different number of storeys and soil media with various stiffness characteristics have been taken into consideration. In the analysis, the finite element software ANSYS has been used. For the newly developed infinite element, the programming has been done by the help of the User Programmable Features of the ANSYS software, which enable creating new elements in the ANSYS software.