Improvement of an accumulation model for high cyclic loading

• Applicants: Professor Dr.-Ing. Theodoros Triantafyllidis; Professor Dr.-Ing. Torsten Wichtmann
• Subject Area: Geotechnics, Hydraulic Engineering
• Term: from 2010 to 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 170048988

The high-cycle accumulation model of the proponents can be used in order to predict the permanent deformations of foundations subjected to a high-cyclic loading. Examples for a practical application are the long-term deformations of offshore wind power plants, which are loaded by wind and waves, or the non-uniform residual settlements of high-speed railway tracks. The research work done so far on this field has demonstrated the need for further research. The first phase of this project was primarily dedicated to the development of a simplified calibration procedure for the material constants of the model, considering the grain size distribution curve including fines content, shell lime content and grain shape. In the second phase, the influence of inherent fabric (specimen preparation method) on the various components of the accumulation model will be studied. Furthermore, a high-cyclic loading is often multi-dimensional, which leads to an acceleration of the accumulation. This is considered by a new theory including such effects for the strain amplitude. However, this theory still has to be experimentally validated. The multiplicativity of the influencing factors as proposed in the high-cycle model has also still to be proven. Furthermore, the recently detected (partial or full) elimination of the memory of the soil due to cyclic preloading history caused by monotonic deformations has to be studied in more detail.

• DFG Programme: Research Grants