The Numerical Solution of Large Scale Dynamic Soil-structure Interaction Problems

In the analysis of the dynamic behaviour of many civil engineering structures, it is essential to account for the interaction between the structure and its environment. Despite the advance of high performance computers, the numerical solution of large scale dynamic soil-structure interaction (SSI) problems remains very challenging and in many cases beyond current computer capabilities.This dissertation addresses the development and application of fast, stable, and accurate numerical techniques for the solution of dynamic SSI problems, focusing on linear problems formulated in the frequency domain. A domain decomposition approach is employed, where finite elements for the structure(s) are coupled to boundary elements for the soil, accounting for the soil's stratification. Innovative methodologies are presented for improving the efficiency and applicability of existing three-dimensional and two-and-a-half-dimensional formulations, allowing for the solution of large scale dynamic SSI problems. The computational performance of the proposed procedures is assessed and their suitability is illustrated through numerical examples.The novel techniques are subsequently employed for the efficient solution of several challenging dynamic SSI problems related to railway induced ground vibrations. The vibration reduction efficiency of mitigation measures on the propagation path in the soil, including an open trench and a stiff wave barrier, is studied in detail, providing fundamental insight in the underlying physical mechanisms; trenches and barriers of infinite and finite length are analyzed. The wave propagation in a dense urban environment characterized by multiple closely-spaced buildings is considered as well, taking the dynamic through-soil coupling of all structures into account.status: publishe