Analysis of a pullout force acting on vacuum anchors in sea wave energy converters

Introduction. When sea wave energy converters are designed, floating buoys, being part of their structure, must be reliably anchored to the bottom. To date, numerous engineering solutions are developed towards this end. They feature various methods of fixing floating buoys to the bottom (weights, anchors, and sinkers).

Materials and methods. The vacuum anchor is designed to fix floating buoys, or sea wave energy extractors, to the soil of the sea bottom. The goal of the study is to substantiate the engineering solution to use vacuum anchors for sea wave energy converters, designated for temporary coastal construction facilities. Methods of theoretical and experimental research, identification of domestic and foreign sources, analysis and comparison of data were employed to achieve this goal.

Results. The article presents conceptual schemes of vacuum anchors to be embedded in weak soils. The authors offer an engineering solution and analyze the holding capacity of a vacuum anchor. As a result of experimental studies, the value of the static friction coefficient is found on the surface of a polymer vacuum anchor in silty waterlogged soil. This coefficient allows analyzing the immersion of vacuum anchors in weak soils and the pullout of vacuum anchors from weak soils. The authors describe the technology of vacuum anchor immersion in weak bottom soil; analyze conditions for the anchor immersion in the weak soil of the bottom, and conditions for the anchor pullout.

Conclusions. Vacuum anchors, designed for weak bottom soils, have a great holding capacity, relatively small dimensions and cost, including the cost of construction and embedment. Their practical application will reduce the cost of (1) foundations made for floating sea wave energy extractors and (2) energy transformation into useful power in various process flows designed to generate energy for coastal construction facilities.

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