Small-Scale Testing of Laterally Loaded Bucket Foundations in Dense Sand

Monopod bucket foundations promise to become a reliable and cost-effective option for offshore wind turbine. In this paper, six small-scale tests of a steel bucket foundation subjected to quasi-static lateral load, are When conducting small-scale experiments on soil, scale effects can considerably affect the tests outcome. To overcome this issue, a novel testing system based on the application of suction between the soil surface and a membrane, is employed. By means of the suction the effective stress of the soil is increased. The tests are conducted at stress levels of 0 kPa, 10 kPa, 15 kPa, 20 kPa, and 30 kPa respectively. The test results successfully prove reliability and consistency of the method. The comparison between the tests conducted at stress level of 0 kPa, and the tests with stress level increased, shows remarkable differences. In particular, the moment rotation curves of tests with pressure applied show more similar trend to large-scale tests. The relationship between scaled overturning moment, M/( • d4), and rotation, is well represented by a power law. The exponent of the power law is consistent among all tests carried out with stress level increased. Besides, attention is given to the instantaneous centre of rotation distribution. Further cyclic loading studies may be carried out adopting this testing system to investigate the accumulated rotation of bucket and monopile foundations.