Model tests on the bearing capacity of wide-shallow composite bucket foundations for offshore wind turbines in clay

This paper presents a new type of wide-shallow composite bucket foundation (WSCBF) for offshore wind turbines, which can be adapted to the characteristics and development needs of offshore wind farms due its special structural form. Several field tests on the horizontal bearing capacity of WSCBF were carried out in saturated clay off the coast of Jiangsu. The deformation mechanism, the soil-structure interaction and the ultimate bearing capacity of the WSCBF are determined depending on the tests. Based on the position of the rotation center, analytical expressions of soil pressure and ultimate bearing capacity for the WSCBF are presented. The accuracy of the test results and analytical expressions is validated and supplemented by numerical simulation with a finite element method. Moreover, by means of numerical simulation, the envelope curve of ultimate bearing capacity of the WSCBF is described in H-M load space, clarifying the load-bearing characteristics of the WSCBF under combined loads.