Centrifuge tests for seismic response of single pile foundation supported wind turbines in sand influenced by earthquake history.

This paper reports on two sets of centrifuge model tests of wind turbines in dry sand and saturated sand subjected to earthquake sequences. The wind turbine system is composed of a single pile foundation and a wind turbine. All tests were applied with liquefaction experiments and analysis projects (LEAP) waves to simplify the analysis. The objectives of the tests are to investigate: (1) the influence of earthquake history on the seismic response of wind turbines; (2) the influence of earthquake history on the dynamic pile-soil interaction; and (3) the influence of two different foundation types on the seismic response of wind turbines. The tests indicated that earthquake history has a significant influence on the natural frequency of the pile and the soil around the pile in the saturated sand, but has no obvious influence on the dry sand. The shear modulus of the soil and the acceleration amplification factor of the pile top in both tests increased and the maximum bending moment envelope of the single pile foundation shrunk. The stiffness of the p-y curve in saturated sand was increased by the earthquake history, while that in dry sand was not significantly affected. [ABSTRACT FROM AUTHOR]