Capacity of double-plate vertically loaded anchor in saturated marine fine sand

Experimental and finite element analyses were conducted to formulate the relationship between drag force and drag length as well as the ultimate loading capacity for the double-plate vertically loaded anchor (DPVLA) model in saturated marine fine sand. Results show that compared to the conventional VLA model, the DPVLA model can significantly enhance the peak drag force value and ultimate loading capacity. In the drag penetration test, the peak drag force value for the DPVLA model increases with the initial orientation and included angle. When the drag force is at its peak, the drag length of the DPVLA model is approximately six times the width of the model's upper fluke; this drag length is smaller than that of the VLA model. In addition, increasing the included angle significantly improves the ultimate loading capacity of the DPVLA model in the ultimate loading test when the included angle is 0-30 degrees. However, the DPVLA model cannot facilely penetrate the soil layer in the drag penetration test when the included angle exceeds 30 degrees; hence, this limit must be observed. Increasing the bottom fluke length of the DPVLA model can also increase the ultimate loading capacity. This increases the anchor model weight, enabling the anchor to rapidly sink to the seabed. Based on numerical simulation results, a yield locus equation for the ultimate loading capacity of the DPVLA model subjected to combined loading in saturated fine sand was proposed. The penetration trajectory for the DPVLA model was also obtained from the yield locus equation of ultimate loading capacity.