Study On Force Transfer Characteristics Of Prestressed Concrete Transition Section For Composite Bucket Foundation

As a new type of offshore wind power foundation,large-scale composite bucket foundation can be constructed on land and installed offshore rapidly which has strong ability against overturning and strong applicability.It can make full use of the rich offshore wind power resources.As the main structure to transfer forces in this new offshore wind power foundation,transition structure plays an significant role in transferring the loads from upper structures to the ground,taking great advantage of the bearing capacity of the ground.In the engineering projects,prestressed concrete transition structure is always at compound stress state and the bearing capacity of composite bucket foundation composed of it depends largely on the transition structure's capability in transferring forces.In this paper,the large-scale 3MW composite bucket foundation was chosen as the original model,on the basis of which finite element software was used to look for the reasonable transition structure model.The detailed contents are as follows:Numerical analysis of two typical transition structure models was conducted using ABAQUS.It was found that by using curved transition structure,huge bending moments on the top of the transition structure caused by transverse or compound loads can be transformed into small stresses at the bottom of the transition structure by curved type as well as prestressed bars,which means that curved transition structure has good load transmission characteristic.Pseudo static tests were done on the curved transition structures without prestressed bars or with six or eight prestressed bars to investigate their failure modes and load transmission characteristic.According to the test results,curved transition structures with eight prestressed bars have better load-transmitting performances.Three-dimensional finite element models established in ABAQUS were verified by test results and were used to further study the mechanical properties of curved transition structures and provide theoretical guidance for engineering design and application.