Monitoring of a Suction Pile Jacket for Offshore Wind Turbine During Installation

Abstract

Full-scale field installation test of an offshore wind power suction pile jacket foundation with pile penetration depth to diameter ratio about 2.0 was carried out, where the structure stress of the suction pile side wall, connection joint stress, pore water pressure and earth pressure distribution were monitored. Measured shaft stress results are affected by the applied pressure difference, and reverse tension and compression stress were identified at the same depth, indicating that the suction pile shaft was under bending. After self-weight penetration the foundation inclination was 5.0°, as a result the measured connection joint stress reached 100∼150 MPa after being leveled at the suction penetration stage. Measured pore pressure results reveal the reason of large foundation inclination at the self-weight penetration stage, and the attenuation law of pressure difference in different soil at the suction penetration stage. Total and effective earth pressure are obtained on both sides of the suction pile, which are also affected by the applied suction. The field test provides valuable monitoring data of suction pile jacket foundation installation, which can be used in further mechanism study.