Installation of marine structures by suction - hydro-mechanical coupled numerical modelling

• Applicant: Professor Dr.-Ing. Jürgen Grabe
• Subject Area: Geotechnics, Hydraulic Engineering
• Term: from 2016 to 2019
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 289128395

The objective of the research project is the investigation of the installation process of suction buckets/suction caissons, which penetrate by application of suction into the seabed consisting of saturated sand or layered soil. The load bearing behaviour with respect to the installation process is investigated as well as the process of extraction of the bucket out of the seabed supported by excess pressure. Building on results of existing model tests of the process of installation and extraction as well as the load bearing behaviour, additional model tests in a geotechnical centrifuge are performed to investigate the drainage behaviour of the soil during the installation, load bearing and extraction. The process of installation and extraction and the load bearing behaviour is also investigated through numerical methods. Therefore, the coupled mechanical hydraulically processes in the soil are better understood and the influence of the installation process on the load bearing behaviour is investigated. An approach, which is existing at the institute, is extended and utilised for investigations on the coupled mechanical hydraulically behaviour in saturated sand and layered soil Therefore, the Finite Element Method (FEM) is utilised for simulations of the load bearing behaviour. Furthermore, the Material-Point Method (MPM) is utilised for simulations of the installation process. Since the MPM-source-code is available at our institute, the program modifications and extensions for any specific problem are feasible. The MPM-models for the simulation of the installation and the FEM-models for the simulation of the load bearing behaviour are validated and applied for a parametric study to investigate different influences.

• DFG Programme: Research Grants