Long-term settlements of a ship lock: Measurements vs. FE-prediction using a high cycle accumulation model

• Published in: Computers and geotechnics Vol. 97; pp. 222 - 232
• Main Authors: Machaček, J., Wichtmann, T., Zachert, H., Triantafyllidis, Th
• Format: Journal Article
• Language: English
• Published: New York Elsevier Ltd 01-05-2018; Elsevier BV
• Subjects: Accumulation; Computer simulation; Cyclic loading; Cyclic loads; Finite element analysis; Finite element method; Finite element simulations; High-cycle accumulation (HCA) model; Iron; Load; Locks; Long-term settlements; Mathematical models; Measurement; Offshore; Offshore engineering; Offshore operations; Offshore structures; Parameter sensitivity; Parameters; Predictions; Procedures; Repeated loading; Settling; Ship lock; Ships; Simulation; Soils; Subsoils; Turbine engines; Turbines; Uelzen I; Water waves; Wind power; Wind turbines; Long-term settlements; High-cycle accumulation (HCA) model; Ship lock; Finite element simulations; Uelzen I
• ISSN: 0266-352X; 1873-7633
• DOI: 10.1016/j.compgeo.2018.01.009

During their lifetime many geotechnical structures are subject to a high number of repetitive loading cycles with small strain amplitudes, a so-called high-cyclic loading. Well-known examples are foundations for offshore wind turbines exposed to a cyclic loading caused by wind and water waves. In the case of ship locks, being the subject of the present paper, the high-cyclic loading results from the repeated filling and emptying of the lock chamber which leads to a cyclic change of the water pressures acting on the walls and the bottom of the chamber. Generally, a high-cyclic loading may lead to progressive settlements and a tilting of foundations. Up to now, the availability of validated and standardized analysis procedures for the proof of the serviceability limit state for foundations subject to high-cyclic loading is still limited. One procedure which proved good results for that purpose in recent years is a numerical approach based on finite element (FE) calculations using a high-cycle accumulation (HCA) model to predict the long-term behavior of the subsoil. Subject of this contribution is the application of the HCA model in FE simulations of the ship lock Uelzen I, aiming on a further validation of the proposed procedure. This ship is a well documented structure with long-term monitoring, significantly differing from foundations for offshore wind turbines, which were studied for the validation of the HCA-model so far. Simplifications of the subsoil and the determination of the input parameters for the FE simulations are presented. The long-term settlements predicted by the HCA model are compared to field measurements over two decades. Furthermore, a sensitivity study regarding the influence of various parameters on the predicted settlements is shown.