Influence of Groundwater Depth on Pile–Soil Mechanical Properties and Fractal Characteristics under Cyclic Loading

The analysis of the behavior soil and foundations when piles in offshore areas are subjected to long-term lateral loading (wind) is one major problems associated with smooth operation superstructure. strength pile-soil system influenced by variations water content soil. At present, there no studies carried out analyzing mechanical deformational both material laterally loaded groundwater level as a variable. In this paper, series 1-g model tests were conducted explore monopile under unidirectional cyclic loading, based on foundation an wind turbine near island. influence underground load magnitude performance pile–soil was analyzed. To visualize movements particles during experimental process, particle image velocimetry (PIV) used record displacement field various conditions. relationship curves between pile top steps, well stiffness displayed. Combined fractal theory, dimension each curve calculated evaluate sensitivity interaction system. results showed that conditions depth main factors affecting interaction. increased all test groups progressed; however, increase decreased initial stiffness. dry higher than saturated soil, but less unsaturated ability limit dropped. greater fluctuation displacement, larger curve, variation interval roughly 1.24–1.38. average increment cumulative cycle step following positively correlated dimension. Based PIV results, changes predominantly focused early stages experiment, short-term effects effects. addition, research limited single layer. layered investigated, will be more complex ground future.