Realising a floating city

Abstract

People are already living on water for centuries in some places around the world. However, the concept of building on water has been reintroduced with a new idea in the last two decades. The new idea is to realise a very large floating structure which is as big as a city. Instead of multiple independent floating houses forming a floating community or residential district, this new idea is to realise a complete city state which floats on the water, a so-called ‘floating city’. The main objective of this report is to give a general design of a floating city to determine the structural feasibility of such a concept. The challenge in this concept lies in the environment the floating community is in. The environment of the floating community determines which and what kind of forces are acting on the platforms. Strength and stability are heavily dependent on which forces are working on the platforms and the magnitude of these forces is also of great importance. It is common sense that such a floating city would survive better in a calm bay then in the open sea with huge waves and frequent storms. That is why this thesis will focus on the latter situation: a floating city in the open sea with a rough environment. The main question in this thesis to be answered is defined as ‘Is it possible and realistic to create floating cities from a structural perspective’. To come to an answer for the main research question, several sub questions can be formulated: - What kind of floating platforms are needed? - How can platforms be connected to each other to form a floating city? - How is the floating city to be moored to stay at one location? - What is the behaviour of the platforms, connections and moorings when the floating community is loaded by (large) waves? The answer is that it is theoretically possible to realise floating cities with modular floating platforms rigidly connected to each other. The platforms are inhabitable under severe wave circumstances and they experience very small displacements as long as the connections between the platforms are very rigid constructed. However, to make sure rigid connections in a multiple mass-spring system are indeed experiencing lower connection forces due to smaller displacements, it is best to find this out with a small scale experiment/modelling program. From the results and calculations in this thesis, it is reliable to connect up to 4 platforms in a linear formation for the chosen design of the hexagonal platform with sides of 60 m and a construction height of 14 m. This means that a floating community of 16 platforms (in a configuration of 4 by 4 platforms) can be realised and house approximately 4000 inhabitants.