Effective soil-stiffness validation: Shaker excitation of an in-situ monopile foundation

摘要: In an attempt to decrease the modelling uncertainty associated with soil-structure interaction of large-diameter monopile foundations, a hydraulic shaker was used excite real-sized, in-situ foundation in stiff, sandy soil near-shore wind farm. The response terms natural frequency and damping pile-only system is significantly more influenced by than full offshore turbine structure, therefore ensures higher degree certainty regarding assessment reaction. Steady-state vibration amplitudes frequencies between 1 9 Hz were retrieved from strain gauges vertically spaced along embedded pile, accelerometers attached top pile shaker. measured validate effective 1D stiffness method, which applied as smart initial guess for model-based identification properties stiffness, inertia. performance method compared currently employed p-y design method. While seems overestimate actual low-frequency about 20%, appears underestimate this 140%. assumption linear behaviour most occurring displacements shown be acceptable. A ratio 20% (critical) identified monopile, estimated correspond 0.14% contribution structure. unique measurement setup yielded ‘first-off’ opportunity model rigidly behaving pile. We have that indeed such reacts stiffer predicted curve its can modeled accurately our recently developed