关键词: 拖曳锚, 安装缆绳, 相互作用力, 拖曳力, 模型试验

Abstract: The research of deepwater mooring systems and foundations has become a frontal and critical topic in the field of the international ocean engineering. Drag anchors are increasingly used, and it plays a key role in deepwater mooring systems because of better performances both in pullout capacity and deepwater installation. During the drag anchor installation, a complicated interaction happens between the anchor and the installation cable at the shackle. In order to analyze the interaction between the drag anchor and the installation cable effectively, it can be equivalently analyzed through investigating the drag force at the shackle. Studying the calculation methods for the interactional force between the anchor and the installation cable is significant for understanding the forces acting on the anchor in seabed soils and selecting the tonnage of anchor handling vessels. Herein, the expressions of the drag force at the shackle are firstly derived based on the mechanical models for the drag anchor and embedded cable both for cohesive and noncohesive soils. Besides, experimental data are employed to examine the drag force predicted by the developed methods. It is concluded that both the theoretical expressions can reasonably predict the drag force at the shackle. However, the prediction results based on the mechanical model of drag anchors are more accurate and stable. The precision and stability of the two calculation methods for the drag force have been compared. Detailed parametric analysis is also performed for exploring the parametric effects on the prediction models of the drag force at the shackle. Comparing with experimental data, reasonable values of the key parameters in the prediction model are suggested, so as to provide important reference value for analyzing the soil-structure interactional problems.

Key words: drag anchor, installation cable, interactional force, drag force, model experiment