Overall Design of Multi-module Offshore Floating Bridge and a Method for Random Analysis of Anchor Tension

Abstract

This paper proposes a multi-module floating bridge design for offshore applications and establishes a coupled motion response analysis method for the anchoring system of the floating bridge. Time-domain coupled analysis is performed under the combined effects of wind, wave, and current loads, resulting in the maximum tension of the anchor chain in random waves. Using the typical island and reef sea area of Zhoushan, China as an example, the randomness of waves is considered, and a random sampling method is adopted. The main configuration, connection structure, and mooring system design schemes are presented, and the maximum tension of the anchoring system is numerically calculated and analyzed. The random distribution of the maximum anchor chain tension is obtained, the goodness-of-fit test is conducted for the fitting results, and the main degree-of-freedom motion response is analyzed under different exceedance probabilities. The results show that the multi-module offshore floating bridge meets the design requirements, and the statistical characteristics of the maximum tension of the anchor chain under random waves conform to the Gumbel distribution. The mode of the random distribution of the maximum anchor chain tension increases by 7.65% when fully loaded compared to the unloaded condition. In different exceedance probability scenarios, there are significant differences in the maximum tension of the anchor chain and the motion response of the main degrees of freedom of the floating bridge.