Research On Prestress Tensioning And Lifting Technique Of Composite Bucket Foundation For Offshore Wind Turbine

China's wind power market has entered a new stage to accelerate the establishment of a clean,low-carbon,safe and efficient modern energy system.Composite bucket foundation for offshore wind turbine and the one-step installation technology,which are developed by Tianjin University,perform onshore construction instead of offshore construction.Better construction conditions bring about more reliable and stable quality.Therefore,application prospect is broad against the background of massive development of global offshore wind energyPrefabricate-assemble-lift-transport compose the core concept of composite bucket foundation fabrication technology,by which the different components are prefabricated respectively.Integrated production line,specialized construction equipment and sophisticated design-construction system for wind power are built accordingly.This paper mainly focuses on the key processes of composite bucket foundation,including prestress tensioning and lifting technique.A tensioning method of four tendons being strained synchronously is proposed based on structural characteristics of transitional segment,thus reducing tensioning batches significantly.Comparative analyses on structural responses and stress distribution are performed among different tensioning schemes,and the optimal scheme is concluded by multi-evaluation.Meanwhile,assembly scheme for prestressed transitional segment and hive bucket is designed based on structural characteristics and construction requirements of composite bucket foundation,and optimization analysis upon lifting centre layout is conducted,which includes simulations on structural stress responses.The research results can provide guidance for massive and standardized construction in the future.