Research On Wave Load On Composite Bucket Foundations

Realizing the advantages of efficiency and environment protection, manycountries have been paying attention to the exploitation and the utilization ofwind-powered electricity generation in nowadays. Moreover，the offshore windresources is five times as the onshore, so, the rise of offshore wind power has beeninevitable. As the most vital part of offshore wind power design, subtle calculation ofthe wave load on foundation is especially crucial. This article is based on theMacCamy-Fuchs Formula and improves the formula for the calculation of the waveload on composite bucket foundation. We have calculated the wave load of fourregular wave conditions by using the improved formula, and verified the new formulaby using the Flow-3D numerical flume simulation and physical model testing. Themain content of this thesis is shown as follow:(1) Based on the linear diffraction theory, we improved the MacCamy-FuchsFormula. The formulas of the horizontal wave force calculation are derived bychanging the invariable-diameter in the MacCamy-Fuchs formulas to avariable-diameter. Under the condition of the linear wave theory, the resultscalculated by the improved formula are similar to the results calculated by thepredecessors.(2) Based on the Flow3D, a3D numerical model for the wave load onfoundations is built. The numerical model uses linear regular wave-generationboundary and a wave-absorbing device. The device combines effects of porous mediaand outflow boundary. Best wave-absorbing effects appear in a vertical porosityvalued of0.8. Compared with the results came from improved formula, the resultscalculated by numerical model have a difference ranged from3%-9%.(3) Wave model tests set up in a flume at50m long.25pulse pressure sensorswere installed in the composited bucket foundation model. We calculated thecoefficients of conversion of point and area fluctuating pressure. And in the conditionof the flume wave tests, the value of these coefficients ranged from0.75to0.85. Theresults of this physical modelling experiment have a small difference which ranged1%-10%with the results came from improved formula and numerical wave model. The result can be used for optimizing structure design.