Abstract:
The hollow cone-shaped foundation is a novel onshore wind turbine foundation,which has higher cyclic lateral bearing capacity than the traditional circular gravity-based foundation.A series of lateral cyclic loading tests are carried out to investigate the cyclic bearing behaviors of the hollow cone-shaped foundation with different base plate diameters.The constant-amplitude cyclic loading tests show that the accumulated displacement gradually increases along the loading direction as the number of cycles loading increases,and finally reaches a stable state.The accumulated displacement and rotation angle increase with the increasing the base plate diameter when the load amplitude δ
b=0.2 and 0.5,but firstly increases and then decreases when the load amplitude δ
b=0.8.For the cyclic amplitude δ
b=0.2,0.5,and 0.8,the cyclic stiffness of the hollow cone-shaped foundation decreases by 39%,59.7%,and 43.9%with the increasing of the base plate diameter,respectively.The variable-amplitude cyclic loading tests show that the accumulated displacement sharply increases along the loading direction,and the cyclic stiffness first increases and then decreases as the load amplitude increases.On the contrary,there is an opposite variation trend as the load amplitude decreases.The formula of calculating the rotation angle of the hollow cone-shaped foundation under constant amplitude cyclic loads is proposed,and the results by using this formula agree well with the model test.