On- and Offshore Civil Engineering Structures

(Bauwerke im und am Wasser)

Water has always exercised a magic attraction on mankind. Port facilities, bridges and homes are increasingly taking over river banks and coastal areas. Construction is even going one step further: Wind power is especially easy to farm on the open sea. Innovative research is indispensable to ensure that structures of this kind in and by the water can resist the elements on a lasting basis.

Wind power is enjoying an unbroken upswing all over the world. With an installed capacity of more than 25 gigawatts, Germany is one of the leading wind power generators in Europe. As relatively constant winds blow on the coast and in the open sea and are not braked there by either forests or extensive construction, the trend in recent years has been toward offshore wind farms. Alpha Ventus, Germany’s first offshore wind farm about 45 kilometers off the coast of the North Sea island of Borkum, is to be followed in the yearsahead by a large number of other projects in the German Bight. That is why the On- and Offshore Civil Engineering Structures research center will have ambitious and complex issues to handle from this sector of the future for many years to come.

Which foundations at which sea depth and in which ground conditions make the most sense in geotechnical and constructional terms and how the gigantic power generation plants are best installed in the open sea are technical issues that are still by no means fully resolved. Wind and waves are a constant burden on the foundations and deform them as time goes by. How great this effect is and whether it might in certain circumstances lead to problems in the future remains to be seen. So does the question of how much soil excavation is needed for new kinds of shallow foundations without affecting seabed fauna and flora too adversely.

The constructional side of offshore wind power is but one of many issues with which TUHH institutes participating in the On- and Offshore Civil Engineering Structures research center are actively concerned. Near- and offshore civil engineering structures such as port facilities and dikes, light-houses, bridges or works related to land reclamation in port areas are also focal points of research. Especially in view ofits proximity to the Elbe River and the North and Baltic Seas, Hamburg could hardly be a better location for a research center of this kind.

The external loads to which on- and offshore structures are exposed are extremely varied. Changing water levels, currents, waves, wind, ice, corrosion and collisions with ships, when they occur, can cause damage. Against this backdrop the research center concentrates on interdisciplinary issues such as the development of new building materials and processes, serviceability and ultimate limit state computer simulations for buildings and constructions, the innovative operation of buildings with the aid of automation, studies related to the thermal comfort of people within buildings, the energy efficiency of those buildings and how to deal with the large number of existing buildings.

Research is already under way on, inter alia, the extent to which ultra high performance concrete can be used in the special conditions that prevail near and in the water. This will require extensive series of tests related to the chemistry and physics of building materials to establish the material’s corrosion behavior. In dike construction the TUHH research scientists are looking for alternatives to Klei, an impermeable aged alluvial clay from the marsh region that is widely used to clad the outer surfaces of dikes.

Special attention is paid to the modernization and extension of port facilities. If the Port of Hamburg is to hold its own in competition with large seaport locations such as Antwerp or Rotterdam, it must be upgraded to accommodate future ship sizes. The largest freighters already carry up to 13,000 containers. As larger ships cause significantly higher loads on the existing quay walls, the quay walls will need to be extended or reinforced or redesigned. Construction methods themselves are on the testbed. They must be more economic in the future while staying safe.

Another major role in the constructions considered and investigated by the research center is the aspect of sustainable use of regenerative energy, such as geothermal energy. Intelligent façade renovation concepts for future use in Hamburg’s Hafencity district are also intended to help optimize buildings in energy terms. Last but not least, innovative concepts in building comfort, building supervision and maintenance of existing and new buildings in and by the water are on the research agenda. The aim of all On- and Offshore Civil Engineering Structures research center activities is to ensure that people continue to enjoy living safely by the water.

Homepage: http://www.tu-harburg.de/fspbau/