Experimental Modeling and Investigation of Seabed Liquefaction at Large Scale, Part I: Wave-Soil Interaction

The design of resilient offshore structures requires knowledge of the prevailing seabed dynamics under wave-induced loading. In particular, seabed liquefaction as one of the most severe forms of seabed dynamics must be understood to prevent structural failure. Progressing toward such knowledge and insights, the present paper analyzes the results of a unique large-scale experimental test campaign of wave-soil interaction and seabed liquefaction in the large wave-current flume, GWK+, at the Coastal Research Centre, Hannover, Germany. Being embedded in a comprehensive test campaign, this paper presents Part I of this campaign, while a companion paper concerns wave-structure-soil interaction. For the study, a 1 m x 6 m x 5 m (depth x length x width) soil pit was set up in the flume, filled with fine sand with D 50 = 0.066 mm, and exposed to waves of varying wave heights. The results showed that it is possible to trigger liquefaction for specific wave conditions, i.e., wave heights >= 0.86 m, with the experimental setup and that the excess pore pressure follows the previously observed sequence. In addition, a discussion of model effects and uncertainties provides suggestions for future improvements in the experimental setup.