Correlation and directionality of extreme load parameters in the German Bight

• Applicant: Privatdozent Dr.-Ing. Michael Hansen
• Subject Area: Structural Engineering, Building Informatics and Construction Operation ; Architecture, Building and Construction History, Construction Research, Sustainable Building Technology
• Term: from 2014 to 2017
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 262668125

There is a lack of knowledge about simultaneously occurring extreme wind speed and sea states. Former investigations show that individual extreme events in the German Bight are expected from different directions. Therefore, the commonly used predefined superposition of several extreme events in the design process is incorrect. It is not well known whether and how an extreme event has to be superimposed with other less extreme environmental events. Actually most investigations are founded on numerical simulated data which are very uncertain. A reliable model to combine existing loads based on measurement time series does not exist. Therefore, such a model to combine simultaneously occurring extreme wind and sea states in the southern North Sea has to be developed.In the last ten years the federal government has initiated the construction of several research platforms in the sea. Using ongoing measurements on these research platforms an extensive pool of data has been built. With this dataset investigations of simultaneous extreme events with the same direction are possible. Starting with "conventional" combination rules used in usual building construction and structural engineering a new approach will be developed to describe the different extreme load parameters of the German Bight. Input data for this calculation are measurement time series of load parameters. This method will be validated based on the example of synchronous measurement time series of the research platform FINO 1. The transferability of the method to other locations will be checked compared to the local measurement time series of locations FINO 3, Nordseeboje II / III. These approaches to combine load parameters are structurally independent. Thus, existing simulation approaches of the offshore-specific stress determination of the total system can still be applied. Such a model to combine extreme load parameters may be the basis for a variety of applications. Primarily, such a model will be used for a safe and economic design of offshore structures. For the determination of weather windows for construction and maintenance work the knowledge of combined wind and sea state events is of great importance, too.

• DFG Programme: Research Grants