Effects of reconsolidation time on holding capacity of deepwater dynamically installed anchors

Abstract

A dynamically installed anchor (DIA) is a practical and promising type of anchor for deepwater offshore engineering. Currently, very few research studies have reported the effects of reconsolidation time on the holding capacity of DIAs. Moreover, there is no well-established, simple, and practical method for determining the time-dependent holding capacity of a DIA. To solve this problem, a series of centrifuge model tests was conducted by varying the reconsolidation time. In the intermediate-term reconsolidation scenario, the normalized holding capacity increased with the dimensionless time in an approximately log-linear manner. Based on this finding and a conventional American Petroleum Institute (API) method put forth in 2007 as well as the cylindrical cavity expansion theory, a simple three-term framework was developed to estimate the time-dependent holding capacity of DIAs. In this framework, cavity closure and skin friction were quantitatively correlated with the reconsolidation time. To validate the feasibility of the proposed framework, the predicted results were compared with the experimental results of cases in this study and other researchers’ work. As such, it was verified whether this framework could be used to estimate the time-dependent holding capacity of DIAs rationally.