Seismic response of large-scale prestressed concrete bucket foundation for offshore wind turbines

2014 ◽  
Vol 6 (1) ◽  
pp. 013127 ◽  
Author(s):  
Puyang Zhang ◽  
Hongyan Ding ◽  
Conghuan Le
Keyword(s):  
Seismic Response ◽  
Wind Turbines ◽  
Prestressed Concrete ◽  
Large Scale ◽  
Offshore Wind ◽  
Bucket Foundation ◽  
Offshore Wind Turbines

Preliminary Analysis on Integrated Transportation Technique for Offshore Wind Turbines

2013 ◽  
Author(s):  
Puyang Zhang ◽  
Hongyan Ding ◽  
Conghuan Le ◽  
Siyu Zhang ◽  
Xu Huang
Keyword(s):  
Wind Turbines ◽  
Large Scale ◽  
Time Windows ◽  
Economic Benefits ◽  
Offshore Wind ◽  
Unit Weight ◽  
Construction Technology ◽  
Bucket Foundation ◽  
Offshore Wind Turbines ◽  
Hoisting System

With current construction technology of offshore wind turbines, there is a need for a major marine spread to install the foundation, tower and turbine. There is a clear benefit that offshore installation can be integrated into one operation. The large-scale composite bucket foundation is a basis for the one-step integrated transportation and installation technique with a special vessel. The proposed transportation and installation technique will minimize offshore spread and maximize the proportion of work carried out onshore with consequent benefits in terms of cost, quality and safety. The composite bucket foundation with self-floating property would be towing into a semicircle groove of the vessel and connected with wireropes of the fixed crane. Afterwards, tower and turbine are attached onto the foundation at shore and the whole unit of foundation, tower and turbine is loaded out from the quayside, transported to site and set down on the seabed. During transportation, half of the unit weight is taken by the hoisting system of the vessel and other weight is supported by air cushions inside the composite bucket foundation. A detailed case is studied to determine the motions of the vessel with two units to confirm the viability and feasibility of such a method of the integrated transportation. The transportation and installation methodology are developed to reduce the time spent on offshore works in order to fit the installation work within the time windows with great economic benefits.

Experimental Study on Installation of Composite Bucket Foundations for Offshore Wind Turbines in Silty Sand

2016 ◽  
Vol 138 (6) ◽  
Author(s):  
Puyang Zhang ◽  
Zhi Zhang ◽  
Yonggang Liu ◽  
Hongyan Ding
Keyword(s):  
Wind Turbines ◽  
Large Scale ◽  
Silty Sand ◽  
Offshore Wind ◽  
Scale Model ◽  
Positive Pressure ◽  
Adjustment Process ◽  
Outer Diameter ◽  
Bucket Foundation ◽  
Offshore Wind Turbines

The composite bucket foundation (CBF) is a cost-competitive foundation for offshore wind turbines, which can be adapted to the loading characteristics and development needs of offshore wind farms due to its special structural form. There are seven sections divided inside the CBF by steel bulkheads, which are arranged in a honeycomb structure. The six peripheral sections with the skirt have the same proportions while the middle orthohexagonal one is a little larger. With the seven-section structure, the CBF has reasonable motion characteristics and towing reliability during the wet-tow construction process. Moreover, the pressure inside the compartments can control the levelness of the CBF during suction installation. Several large-scale model tests on suction installation of CBF have been performed in order to explore the feasibility of the tilt adjusting technique in saturated silty sand off the coast of Jiangsu in China. The composite bucket foundation in the tests has an outer diameter of 3.5 m and a clear wall height of 0.9 m. During the suction-assisted penetration process, the pressures in all the compartments were controlled to level the foundation in a timely operation. A convenient method is to improve the CBF inclination by controlling the inside differential pressure among the compartments. It can be commonly carried out by applying suction/positive pressure with intermittent pumping among the seven compartments. Another adjusting technique for a big tilt with deeper penetration is operated with decreasing the penetration depth achieved by suction-assisted lowering the relatively high compartments and positive pressures raising the relatively low compartments. Test results show that the reciprocating adjustment process can be repeated until the CBF is completely penetrated into a designed depth.

Design of large-scale prestressing bucket foundation for offshore wind turbines

2012 ◽  
Vol 18 (2) ◽  
pp. 79-84 ◽  
Author(s):  
Jijian Lian ◽  
Hongyan Ding ◽  
Puyang Zhang ◽  
Rui Yu
Keyword(s):  
Wind Turbines ◽  
Large Scale ◽  
Offshore Wind ◽  
Bucket Foundation ◽  
Offshore Wind Turbines

Development of a CFD-CSD Coupling Technique for Large Scale Offshore Wind Turbines

2020 ◽  
Author(s):  
Auraluck Pichitkul ◽  
Lakshmi N. Sankar
Keyword(s):  
Fluid Dynamics ◽  
Renewable Energy ◽  
Wind Turbines ◽  
Large Scale ◽  
Time History ◽  
Offshore Wind ◽  
Offshore Wind Turbine ◽  
Renewable Energy Resources ◽  
Aerodynamic Loads ◽  
Offshore Wind Turbines

Abstract Wind engineering technology has been continuously investigated and developed over the past several decades in response to steadily growing demand for renewable energy resources, in order to meet the increased demand for power production, fixed and floating platforms with different mooring configurations have been fielded, accommodating large-scale offshore wind turbines in deep water areas. In this study, the aerodynamic loads on such systems are modeled using a computational structural dynamics solver called OpenFAST developed by National Renewable Energy Laboratory, coupled to an in-house computational fluid dynamics solver called GT-Hybrid. Coupling of the structural/aerodynamic motion time history with the CFD analysis is done using an open File I/O process. At this writing, only a one-way coupling has been attempted, feeding the blade motion and structural deformations from OpenFAST into the fluid dynamics analysis. The sectional aerodynamic loads for a large scale 5 MW offshore wind turbine are presented, and compared against the baseline OpenFAST simulations with classical blade element-momentum theory. Encouraging agreement has been observed.

scholarly journals Floating Performance of a Composite Bucket Foundation with an Offshore Wind Tower during Transportation

Energies ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 882 ◽  
Author(s):  
Hongyan Ding ◽  
Zuntao Feng ◽  
Puyang Zhang ◽  
Conghuan Le ◽  
Yaohua Guo
Keyword(s):  
Wind Turbine ◽  
Wind Turbines ◽  
Wind Farm ◽  
Wind Farms ◽  
Interaction Force ◽  
Offshore Wind ◽  
Construction Technique ◽  
Bucket Foundation ◽  
Offshore Wind Turbines ◽  
One Step

The composite bucket foundation (CBF) for offshore wind turbines is the basis for a one-step integrated transportation and installation technique, which can be adapted to the construction and development needs of offshore wind farms due to its special structural form. To transport and install bucket foundations together with the upper portion of offshore wind turbines, a non-self-propelled integrated transportation and installation vessel was designed. In this paper, as the first stage of applying the proposed one-step integrated construction technique, the floating behavior during the transportation of CBF with a wind turbine tower for the Xiangshui wind farm in the Jiangsu province was monitored. The influences of speed, wave height, and wind on the floating behavior of the structure were studied. The results show that the roll and pitch angles remain close to level during the process of lifting and towing the wind turbine structure. In addition, the safety of the aircushion structure of the CBF was verified by analyzing the measurement results for the interaction force and the depth of the liquid within the bucket. The results of the three-DOF (degree of freedom) acceleration monitoring on the top of the test tower indicate that the wind turbine could meet the specified acceleration value limits during towing.

Lifting Technique of Composite Bucket Foundation for Offshore Wind Turbines

2020 ◽  
Author(s):  
Hongyan Ding ◽  
Zuntao Feng ◽  
Puyang Zhang ◽  
Conghuan Le
Keyword(s):  
Finite Element ◽  
Prestressed Concrete ◽  
Large Scale ◽  
Element Model ◽  
Offshore Wind ◽  
Force Transmission ◽  
Element Analysis ◽  
Bucket Foundation ◽  
Transition Section ◽  
Section Structure

Abstract The onshore pre-fabrication technology for composite bucket foundations takes “prefabrication-assembly-lifting” as the core concept. The practice of pre-fabrication of upper and lower structures is prefabricated respectively. In the research of hoisting engineering technology, combined with the structural form and construction requirements of composite bucket foundation, the assembly scheme of the upper prestressed concrete transition section and the lower steel bucket and the hoisting scheme of integral foundation with compartments were designed. The finite element model in the lifting process of composite bucket foundation was established by the large-scale general finite element analysis software ABAQUS. For the optimization analysis of the lifting point arrangement during hoisting process, the number, position and arrangement form of lifting points are simulated and analyzed. The results show that the maximum value of the principal stress of the concrete transition section structure appears in the assembly stage with the lower steel bucket, and the structure checking calculation should be carried out as the most unfavorable lifting condition in construction; the peak point of structural stress is at the junction of girder and secondary beams and inner ring beams of concrete roof, which belongs to the weak position of force transmission. In construction, it should be paid attention to as the key part of monitoring to ensure composite bucket foundation is under reasonable stress and the stability in the lifting process. The research results can provide guidance and reference for the future batch production and standardization production construction for composite bucket foundations.

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