Deformation behavior of saturated sandy soil under offshore wind bucket-shaped foundation ultimate overburden conditions

Liquefaction of saturated sandy soils poses a significant risk in earthquake-prone areas, often resulting in severe deformation and damage to infrastructure. This study through large-scale shaking table tests, investigating the deformation characteristics of saturated sandy soil foundations subjected to varying load levels, ranging from 20% to 50% of the soil’s ultimate bearing capacity (<i>P_ult</i>). The experimental results reveal a distinct “bow-shaped” distribution in both lateral displacement and settlement, with a critical inflection point identified at 30% of Pult. When the applied load is less than or equal to 30% of Pult, lateral displacement decreases with depth. However, when the load exceeds 30% of <i>P_ult</i>, lateral displacement increases with depth. Higher loads appear to reduce the severity of liquefaction due to enhanced soil resistance. Settlement induced by liquefaction exhibits a non-linear pattern, peaking at approximately 20% of <i>P_ult</i>; beyond this point, settlement initially decreases and then increases again at 50% of Pult. These findings offer valuable insights into the interaction between overlying structural loads and liquefaction-induced deformation, providing a theoretical basis for the seismic design of foundations and contributing to the development of more accurate predictive models for foundation stability during earthquakes.