Shaking table experiments to investigate the seismic response of drag embedded anchors

Abstract

Drag embedded anchors (DEA) are widely used in offshore engineering. The anchor foundations are installed in the seabed through the drag force applied by the mooring line and provide holding capacity to marine structures. Offshore wind farms in Taiwan are located in active earthquake zones, where a considerable amount of sandy soil at the upper layer of seabed results in a high potential for soil liquefaction. Since DEA are a promising option for floating wind turbines, this study conducted a shaking table test on two 1/30-scale anchors in medium dense sand to investigate the dynamic behavior of DEA during earthquakes and after excess pore water pressure dissipation. The test results reveal no significant impact on the orientation of the anchors, which could be due to the uplift force from the excess pore water pressure acting on the fluke. After the excess pore water pressure dissipates, the soil density increases, and the fluke angle becomes favorable, thus increasing the anchor's holding capacity when subjected to additional drag.